*Article* **Correlations of Ion Composition and Power E**ffi**ciency in a Reverse Electrodialysis Heat Engine**

**Fabao Luo 1,2,\*, Yang Wang 3, Maolin Sha 1 and Yanxin Wei 1**

Received: 30 September 2019; Accepted: 18 November 2019; Published: 22 November 2019

**Abstract:** The main objective of this study is to explore the influence of ion composition on the trans-membrane potential across the ion exchange membrane (IEM), and thus offers a reference for the deep insight of "reverse electrodialysis heat engine" running in the composite systems. In comparison to the natural system (river water | seawater), the performance of the reverse electrodialysis (RED) stack was examined using NaHCO3, Na2CO3, and NH4Cl as the supporting electrolyte in the corresponding compartment. The effect of flow rates and the concentration ratio in the high salt concentration compartment (HCC)/low salt concentration compartment (LCC) on energy generation was investigated in terms of the open-circuit voltage (OCV) and power density per membrane area. It was found that the new system (0.49 M NaCl + 0.01 M NaHCO3|0.01 M NaHCO3) output a relatively stable power density (0.174 W·m−2), with the open-circuit voltage 2.95 V under the low flow rate of 0.22 cm/s. Meanwhile, the simulated natural system (0.5 M NaCl|0.01 M NaCl) output the power density 0.168 W·m−2, with the open-circuit voltage 2.86 V under the low flow rate of 0.22 cm/s. The findings in this work further confirm the excellent potential of RED for the recovery of salinity gradient energy (SGP) that is reserved in artificially-induced systems (wastewaters).

**Keywords:** salinity gradient power; reverse electrodialysis; concentration difference; electrolyte composition


*5.2. Limitations of the Study and Future Work*

The main limitation of our study was a restricted sample size, relatively small, but also composed of volunteers. It is also possible that the study itself was overly time-consuming and difficult for our participants. This would explain why part of the participants resigned from the participation in the study.

Moreover, we focused on participants' declarations and not on real behaviors as indicators of energy consumption. We asked participants to report energy consumption, but we observed a large proportion of missing responses for this item.

Future work should focus on larger, more diverse samples and provide easier to use applications for participants. Ideally, some data could be collected directly from SMP and compared to survey data in collaboration with an energy provider.

Despite a few mentioned limitations, the originality of this contribution relies on using the stage model approach, so far not explored thoroughly in the energy related studies (see [35]). Moreover, we tested our hypotheses in a longitudinal field experiment, which allowed us to observe changes in the process.


**1. Introduction**

When compared to non-pregnant women, the risk of urinary tract infection (UTI) with bacteriuria increases considerably during pregnancy. Infection with bacteriuria during pregnancy has been linked to an increased risk of pyelonephritis [1]. Several physiological changes occur during normal pregnancy, including an increase in the volume of vascular and interstitial of the renal system, which results in a rise in kidney dimension of roughly 1 cm and a 30% rise in renal volume. In addition, by mid-pregnancy, around 80% of women will have dilated upper urinary tracts, ureters, pelvis, and calycle area. The right side of the body experiences dilation more frequently than the left [2]. Hydronephrosis and hydroureter, respectively, are dilations of the kidney and ureter that occur most commonly during the second trimester and last until birth. This dilation can be caused by both hormonal and mechanical factors; an increase in progesterone hormone levels causes a decrease in bladder and ureteral tone [3]. Urinary stasis was caused by mechanical causes such as gravid uterine compression paired with smooth muscle relaxation, which slowed ureter peristalsis and increased bladder volume capacity. Pregnancy-induced alterations in urine pH, osmolality, and glycosuria may further amplify bacterial growth [2]. Symptomatic infections (acute cystitis, acute pyelonephritis) occur when bacteria invade urinary tract tissues and trigger an inflammatory reaction, whereas asymptomatic bacteriuria (ASB) occurs when bacteria grow in urine without presenting symptoms of acute UTI [1]. Asymptomatic bacteriuria is more common in pregnant women than in non-pregnant women, and it is frequently underreported since diagnosis is difficult owing to the lack of particular symptoms or signs, whereas symptomatic bacteriuria creates no concerns because diagnosis and treatment are simple [1]. The most prevalent medical complication during pregnancy is urinary tract infection (UTI), which accounts for 20% of pregnancies and 10% of antepartum hospitalizations [4–6]. The most common bacterium that causes UTI in pregnant and nonpregnant women is *Escherichia coli* [7]. Preterm delivery is more common when the bacterium group B-streptococcus is infected, and when antibiotics are used often to treat UTIs caused by other organisms [8]. Other variables that contribute to an increase in UTI during pregnancy include a narrow urethra and closeness to the anus and vagina. Wesley [9] and the inability of women to completely empty their bladder. Lower socioeconomic groups have a higher incidence [9]. The risk is also reported to be increased by sexual activity and some contraceptive techniques [10]. Because of the physical link between the female urethra and the vagina, it is susceptible to damage during sexual intercourse and microorganisms being massaged up the urethra into the bladder during pregnancy/childbirth [11, 12]. Urinary tract abnormalities or stones, diabetes, immunosuppression, and a history of UTI all enhance the risk [13, 14]. It has severe consequences for both the unborn infant and the mother. Acute pyelonephritis, poor neonatal weight, and premature birth are all elevated risks, as is the risk of preeclampsia [1, 15], maternal anemia, hypertension, phlebitis, and thrombosis. Some bacteria can cause uterine contraction and cervix tearing by producing inflammatory mediators (phospholipase A2, arachidonic acid, and prostaglandins) [16]. Early detection and treatment of UTI has been linked to a better pregnancy outcome and a lower incidence of acute pyelonephritis, underscoring the need of screening all pregnant women regardless of symptoms. Although urine culture is regarded as the gold standard test, it takes a long time to complete. Several fast screening assays are now in use, however the data supporting their effectiveness is of poor quality. However, it has been found that combining them is a reliable option with sensitivity and specificity equivalent to urine culture. **Objective**: This study has been carried out to determine prevalence rate of urinary tract infection in pregnancy in compare to non-pregnant woman and to roll out the impact of pregnancy on the frequency of UTI.


**6. Conclusions**

To reduce the electric loss in the connection of battery cells for electric vehicles, the joining process and the resulting transition resistance are essential. By introducing a model representing the joints' partial resistances, the current flow through the connection could be investigated. As a consequence, various joint geometries were investigated using a laser welding process to leverage and examine the observed edge current phenomenon. Naturally the current density along the material edges of the overlap, which are perpendicular to the current flow, was predominantly higher compared to the inner contact area. By measuring a *CQI* for each proposed connection, the influence of different weld seam geometries could be identified. Using double welds close to the edges of the overlapped materials yielded the investigations minimum *CQI* of about 0.52 and should hence be considered for manufactural purposes. The sheer increase of the welded contact area should be critically assessed, as it had a significantly smaller influence to the *CQI* and could even reduce the joint's conductivity.

**Author Contributions:** Idea, study design and laser welding were done by S.H. The development of the measurement system and measurements have been performed by S.K. The electrical modelling and theoretical background was contributed by C.Ü. A.O. contributed to the laser welding process and study design. A.G. and D.U.S. contributed to all parts. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Conflicts of Interest:** The authors declare no conflict of interest.


*Edited by Taner Demirer*

This book documents the increased number of stem cell-related research, clinical applications, and views for the future. The book covers a wide range of issues in cell-based therapy and regenerative medicine, and includes clinical and preclinical chapters from the respected authors involved with stem cell studies and research from around the world. It complements and extends the basics of stem cell physiology, hematopoietic stem cells, issues related to clinical problems, tissue typing, cryopreservation, dendritic cells, mesenchymal cells, neuroscience, endovascular cells and other tissues. In addition, tissue engineering that employs novel methods with stem cells is explored. Clearly, the continued use of biomedical engineering will depend heavily on stem cells, and this book is well positioned to provide comprehensive coverage of these developments.

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New Advances in Stem Cell Transplantation

Photo by Sinhyu / iStock


*3.2.2 Pleiotropic effects of statins in mesenchymal tumors*

Cholesterol is involved in the sarcomagenesis process, with an inverse relationship between increased cholesterol synthesis activity and decreased survival of patients with sarcoma [11, 55].

### **Table 2.**

*Pleiotropic effects of statin on mesenchymal tumors.*

## *<IP_ADDRESS> Effects of statins on cell proliferation and cell cycle*

Statins, essentially lipophilic ones [56], suppress cell proliferation [57], promote cell differentiation *in vitro* [56], mainly in tumor cells [56], and prevent the prenylation of Ras and Rho. These effects are due to the increased phosphorylation of IF2α, JNK and c-Jun, and alteration of the p53, p21Cip1 and CDK1 gene expression [58, 59], which arrest cells in the G0/G1 and the S phases.

## *<IP_ADDRESS> Effect of statins on cell viability and apoptosis*

Statin induces loss of cell viability [56, 60] and anoikis [61, 62], followed by p53 translocation, cytochrome c release [63], decreased expression of bcl-2 [64], caspase 9 and 3 activation [65], apoptosis and cell differentiation [66].

## *<IP_ADDRESS> Enhancement of chemotherapeutic effect*

Statins enhance the antitumor effects of chemotherapy [67]. Thus, lovastatin enhances the effect of doxorubicin on NIH-3 T3 sarcoma cells [65], and in osteosarcomas, stimulates apoptosis and invasive behavior [68]. Sublethal doses of simvastatin potentiate the cytotoxicity of doxorubicin in rhabdomyosarcomas [65], reducing *in vivo* cardiac toxicity in mice [69, 70]. It is believed that these effects are produced by the action of the p53 protein (**Figure 5**); the JNK phosphorylation [67]; the decreased MMP-2 activity [68], the decrease in drug resistance regulated by the p-glycoprotein/ ABCB1 gene [71], whose expression is associated with a poor prognosis in children diagnosed with soft tissue sarcoma [62].


Milking required concordance. An irritated animal or milkmaid reduced milk-yield, reducing human nutrition. Humans had to maintain mutual affection toward animals evident in taboos on swearing/screaming at cattle, widespread across Eurasia (Plotnikova, 1999b). Music ritualized and fortified this union across different cultures (Shevtsov, 1988; Wallin, 1991; Alekseyev, 1995; Ivarsdotter, 1995, 2004; Novik, 1999; Dorina, 2004; Dissanayake, 2005; Kolltveit, 2008; Cheng, 2009; Yoon, 2018), especially evident in surviving traditions of milking songs (Nielsen, 1997; Pegg, 2001; Gioia, 2006b), animal lullabies (Kondratyeva, 1989; Kyrgys, 2002; Tchotchkina, 2003; Kan-ool, 2012), and spells (Kondratyeva, 1996; Kyrgys, 2002; Bordzhanova, 2007; Sodgerel, 2012, 2016; Tiukhteneva, 2017)—which all share the union of musicality and love/care that characterizes human motherese (Trevarthen, 2019).

Principal traits of such music can be extracted from the current practice of Scandinavian herder's music-making. Its chief task is to control the behavior of the grazing livestock during the warm seasons at distant pastures (Ivarsdotter, 2004). The herder aims at influencing the animal's emotional state over a range of distances, up to a few kilometers. Long-distance transmission requires a special vocal technique and musical instruments. The same musical signals convey different information to livestock and humans: commanding animals while informing animalowners at the farmstead of their animal's wellbeing. This dual communication has been faceted through a transhumance system known as shieling in England (Cheape, 1996), and fabod ¨ in Scandinavia (Svensson, 2015)—emerging during the late Bronze Age in response to the scarcity of local winter fodder (Tesch, 1992). In Sweden, the shieling standard was set in Dalarna, and the alternative local traditions are considered its variations (Svensson, 2015). Traces of shieling are spotted across Europe, from the Hebrides to the Carpathians, becoming widespread by the Iron Age (Cheape, 1996). In Norway, the earliest fossil fields of lynchets show signs of cultivation during the late Bronze Age (Skrede, 2005), confirmed by palaeobotanic and archeological dating (Kvamme, 1988).

Shieling is characterized by seasonal migration to a summer station where herders spend their daytime supervising animals, preparing fodder for the coming winter, and produce dairy during evenings (Cabouret, 1984). Since milking, butter- and cheese-making traditionally constituted the women's job, shieling and its music became female prerogatives in Scandinavia. There, milking could dishonor a man, and shieling was managed exclusively by young women (Svensson, 2015). In Ireland, shieling was a family business, whereas in Spain, France, and Switzerland dairy-work and herding were conducted by men.

The gender difference, undoubtfully, played a role in shaping the European pastoral musical traditions. Scandinavian, Icelandic, Alpine, Jurassic, Pyrenean, Apennine, Sardinian, Balkan, Turkish, and Caucasian mountains have sheltered singing styles that originated in the herding culture, and shared a peculiar singing technique based on a forceful high-laryngeal falsetto-like sound production (Wallin, 1991, 510). Wallin (pp. 511–23) summarizes the archeological, anthropometric, and genetic research to support the ethnographic findings of Carl-Allan Moberg (1971). Moberg outlines the core traits of the archaic Fabodv ˚ asendet ¨ music: "head-voice" vocal technique, utilitarian function of long-distance signaling, and ideological roots in pagan magic.

The centerpiece of Fabodv ˚ asendet ¨ tradition is its "maximaldistance" style—"kula"—that I distinguish from "kulning"—an umbrella-term for the entire Fabodv ˚ asendet ¨ 42. Local names for kulning (e.g., lockrop) imply the alluring of animals by magic properties of sound to suggest certain behavior to the herd, avert evil trolls and predator-animals—following shamanic tradition of maiden singing (Mitchell R. W., 2001). In Swedish mythology, forest spirits possessed their own cattle, and herdswomen (kulerska) learned kulning from skogsra˚, "sirens of the woods" (Johnson, 1990). Suggestive power of kulning was deemed so high that women lived in fabods ˚ alone without any weapons. Folk beliefs attributed this power to beauty. Indeed, well-ornamented high "warbling" register of distant female voice made men and women pause their work and enjoy the sounds (Ivarsdotter, 1986). For humans, kula clearly presented an aesthetic object despite bearing utilitarian status of "non-music" (Frodin, 1929 ¨ ) 43 . For animals, kula constituted a "safety call." Both attitudes focus on positive rather than negative emotions—not only to keep the cattle under human control, preventing panic, but also to boost the kulerska's confidence and alertness (Wallin, 1991, 420)44 . SFTO must have emerged as a set of sonic attributes, perception of which was directly "wired" to reward circuits in brains of humans and domestic animals.

Wallin (1991, 420) rightfully stresses that matriarchy influenced early pastoralism: "the maternal instinct and care" instilled the social holding of attachment to stabilize and reinforce the animal-human affiliation. Distinctively female, Fabod ˚ tradition must have prehistoric roots (Johnson, 1990). Motherese undoubtedly prototyped a close-range kulning. Animal-directed vocalizations acoustically and functionally resemble lullabies by commanding calmness/happiness—not just in Sweden (Wallin, 1991, 392) but also on the other side of Eurasia, in Altai (Kondratyeva, 1996). Common traits include

42There is a wealth of terms used in Scandinavian countries to refer to herding vocalizations (Rosenberg, 2003, 8). Although the term "kulning" (kolning) is most commonly used in English in relation to the special technique of the long-distance vocal calling, I follow Wallin (1991, 387) in reserving the term "kula" (he uses the alternative spelling "kola") which in Swedish means "to make a distant call" exclusively for long-distance communication. This is necessary, because longdistance "kula" calls are routinely inserted in mid-distance and close-distance vocalizations, while it is the long-distance "kula" style that distinguishes shieling vocalizations from other forms of traditional Scandinavian music.

43It should be noted that the peculiar status of pastoral music as a form of heterospecific communication is responsible for the emic views on kulning as **nonmusic**. This is yet another confirmation of the need in the etic approach. Across Eurasia, herder-made music is distinguished from "normal" music as a form of "magic." The profession of the herder is traditionally associated with sorcery: herders are believed to sign a contract with the evil forest spirits, receiving magic power for vocal and instrumental music-making in exchange for not using their gifts publicly, under the threat of death (Plotnikova, 1999b). At the eastern end of Eurasia, in Altai, supernatural beliefs are even stronger, reserved not only for professional herders (chabans) but for all livestock-owners who use pastoral spells (Kondratyeva, 1996). All vocalizations of this type are considered non-music—to the extent that informants perceive any request to "sing" a spell as being ridiculous. 44Noteworthy, despite a 16-hour-long workday and insecurity of living alone without any weapons, shieling jobs were always highly sought after, since women remained in charge of their summer life and enjoyed freedom unavailable to them at the farmstead (Rosenberg, 2014).

prolonged singing, formulaic regularity, vocables, smooth contours, motherese-talking, and caressing (Tiukhteneva, 2017). In animistic societies, both infant-lulling (Kondratyeva, 1989; Farber, 1990; Tchotchkina, 2003; Gioia, 2006a; Milne, 2017; Garroway, 2019) and domestication rites for newborn cattle (Aksyonov, 1964; Johnson, 1990; Kondratyeva, 1996; Plotnikova, 1999b; Kan-ool, 2012; Tiukhteneva, 2017) are associated with magic, achievable by female "charms."

Similar to lullabies are milking songs (Nielsen, 1997)—used across Eurasia, from Scotland to Mongolia (Gioia, 2006b, 71). Remarkably, when milking, Mongolian herdsmen switch to motherese-like "musical talk," based on animal onomatopoeia (Yoon, 2018). Known cases of male pastoral calling engage falsetto to imitate the female model (Uttman, 2002). Similarly, in surviving pastoral traditions of Altai, lulling is reserved for women, and require throat-singing if sung by men (Tiukhteneva, 2017). Pastoral spells in Altaic tradition constitute female prerogative, but are occasionally performed by men (Kondratyeva and Kopytov, 2017), engaging throat-singing (Kyrgys, 2002, 64). Like falsetto, throat-singing emphasizes harmonics that make melodies appear registrally higher—closer to the female range—and, like female kula, resembling pure tones.

The same applies to whistling signals, used across Eurasia by herdsmen to stimulate and/or safe-guard animals (Levin and Suzukei, 2006, 134–40). Just like kulning, in pastoral societies whistling is associated with sorcery (Plotnikova, 1999a) and is thoroughly regulated by taboos (Dzenzelevskii, 1984). Acoustically, whistling comes closest to "kula" in distancerange, loudness, and tonal quality (Eklund and Mcallister, 2015). To command their animals, Altaic herdsmen produce whistles audible over 4–5 km, and throat-singing—3 km (Pegg, 2001, 236). Curiously, female "head voice," required by kula, is called "whistle register" (Sundberg, 1987, 50). And xo¨omii ¨ (throat-singing) is considered a form of whistling in Mongolia (Pegg, 1992).

Wallin (1991, 523) sees shieling music as part of the prehistoric expansion of a novel herding culture northwest of Anatolia/Balkan/Caucasus toward Iceland, with its base in Jamtland (**Figure 6**). Jamtland's "forest barrow" marked the end of tundra after the glaciers' retreat, attracting hunters and supporting a mixed pastoral economy that survived at the coldest outskirt of Europe practically unchanged until the late Middle Ages. Geographic and chronological distribution of cattle-herding across Europe, quite well-studied, provides timing references for Wallin's model. The outcome of this geomusicological45 correlation is presented in **Figure 6**.

Domesticated cattle spread East-to-West along the Mediterranean coastline, encapsulating most of "yodeling" territories ≈6000 BC. The South-to-North expansion took much longer—Central Sweden became pastoralized in the 2nd millennium BC. Dissemination of cattle and Indo-European languages went hand by hand. The Indo-European language family covers most of Europe—except for Finno-Ugric languages of Fennoscandia and Russia. Another notable exception is Turkey whose Indo-European languages (Hittite, Luwian, Palaic, Lydian) died out during Antiquity. Formation of each new Indo-European language seems to have followed the adoption of husbandry. The yodeling areas correspond to the earlier stages in expansion of the Indo-European languages, conserved by the mountain systems: Taurus, Pontic, and Armenian Highland in Turkey, the neighboring Caucasus, Balkan, and more remote Carpathian, Alps, Jura, Apennine, Sardinian, Corsican, and Pyrenean. The dissemination routes either curve around the mountains or cross them by riverbeds. The oldest routs ran by the Mediterranean coastline along the 40N latitude, supporting the conclusion of Diamond and Bellwood (2003) that the domesticates and languages spread faster to East-West than to South-North. This explains the divergence of pastoral music tradition into two types: Southern yodeling versus Nordic kulning and kulning-likes46, distinguished by different bovine genomes. Studies of Y-chromosomal variation have identified two primary taurine haplogroups in Europe, split in two homogenous regions alongside cultural, historic, religious, and linguistic boundaries between the pied or red cows of the Nordic and Baltic/Slavic lands, on the one hand, and the spotted yellow or brown breeds of Switzerland and southern territories, on the other hand (Edwards et al., 2011).

Kulning and yodel form respectively Northern and Southern "dialects" of a cattle-directed "language"—a satellite of the proto-Indo-European. The main role in the Indo-European "domestication package" belonged to cattle—the largest meat- and milk-source of all domesticates. The emergence of cattle-related mythology reflects the importance of cattle and explains the sudden proliferation of cattle burials across Northern Europe ≈3000 BC (Sjogren and Price, 2013 ¨ ) 47. Symbolic elevation of cattle could characterize the entire Neolithic "revolution" in Eurasia, more noticeable in Scandinavia, where ox symbolism replaced red-deer symbolism after ox overtook deer as the most important food source (Tilley, 1996, 183–4). If wild deer opposed the human sphere as a utilitarian object of desire, domesticated ox was included into the human sphere as the emotional object of desire. And music is indispensable in supporting emotionality.

Divinization of music (Franklin, 2006) and ox (Campbell, 2017), so prominent in Indo-European tradition, could have a single origin in Indo-Iranian lands—bound to the concept of non-violence (Tull, 1996). Cattle sacrifice is depicted in prehistoric Sujanpura petroglyphs (Brooks and Wakankar, 1976). The ritual use of burnt cow dung is still common in Hinduism,

45The scope and the method of geomusicology were introduced by George Carney (Nash and Carney, 1996). Izaly Zemtsovsky formulated an analogous approach in his proposal to establish a new discipline of ethnogeomusicology (Zemtsovsky, 2005).

46Thus, Finnish "ringing calls" present a form of vocalization that acoustically and culturally resembles Swedish kulning while featuring a few unique traits (Uttman, 2002). Occasionally, ringing calls are performed by men (falsetto), utilize a peculiar lip technique (generating the "phui"-like tonal quality), and engage "darker" vowels.

47Cattle definitely carried special symbolic significance in Neolithic England (Ray and Thomas, 2003). Cattle received the same funeral treatment as humans in Danube winter burials as part of the Sun cult which thrived throughout the 4th millennium BC, probably because of drastic swings in solar activity (Horva`ıth, 2012). The second millennium BC Linear-B tablets from Knossos testify that, unlike sheep/goats, cattle was given names, bestowed with individuality—and was associated with royalty and sacrificial rites (McInerney, 2010, 50–53).

shieling pastoralism, dark green—the "core" Fabod regions, and cr ˚ eme—the area where yodel-like vocalizations survived within pastoral cultures ( ` Moberg, 1955, 1971; Baumann, 1976; Leuthold, 1981; Ivarsdotter, 1986; Wallin, 1991; Mitchell S. A., 2001; Uttman, 2002; Plantenga, 2004). The origin of the latter can be dated by the timeline of the spread of domesticates over Europe, which is well studied. Animal icons show the approximate place and time of origin of domesticated cow, goat, sheep, and pig, based on available archeological data (Zeder, 2008; Driscoll et al., 2009; Peters et al., 2017). Color-filled thick arrows show the timeline and main routs of dissemination of domesticated cattle during the Neolithic and early Bronze Age according to the archeological and genetic data (Caramelli, 2006; Lougas et al., 2007 ˜ ; Zeder, 2008; Rowley-Conwy, 2011, 2013; Tresset and Vigne, 2011; Blauer and Kantanen, 2013 ¨ ; Marciniak, 2013; Sana, 2013 ˜ ; Schulting, 2013; Sjogren and Price, 2013 ¨ ; Berthon, 2014; Cramp et al., 2014; Felius et al., 2014; Sørensen and Karg, 2014). The darker the arrow's color, the older the date. The double-dotted black line approximates the border between the Northern and Southern European bovine genetic funds. Colored ovals and outlined arrows indicate the hypothetical origin and the spread of Indo-European languages according to the computational methods, based on Bayesian logic and phylogenetic analysis algorithms (Diamond and Bellwood, 2003; Gray and Atkinson, 2003; Atkinson et al., 2005; Atkinson and Gray, 2006; Bellwood, 2008; Gray et al., 2011; Anthony and Ringe, 2015; Chang et al., 2015; Heggarty, 2015). The brown oval marks the area of genesis of Proto-Indo-European language according to the "Anatolian hypothesis" (Renfrew, 1987), whereas the orange oval—to the earlier "steppe hypothesis" (Gimbutas, 1993; Anthony, 1995). The dashed outlined arrows show the earliest stages of dissemination of the Indo-European languages from the Yamnaya epicenter. Both hypotheses generally agree in defining the later stages (Gray et al., 2011)—represented by solid outlined arrows.

traceable to the 3000 BC Ashmounds (Boivin, 2004). The Shivabull affiliation is evident in the Bronze Age Harappan "Proto-Shiva" (Hiltebeitel, 2011). Harappan symbolism clearly elevates the cattle over other domesticates, evident in the buffalo figurine amulets and seals that are likely to assimilate the west-bound Indo-Iranian cult of Mother Goddess, eventually forming the "Sacred Cow" concept (Lodrick, 2005). This corresponds to veal and cow-milk becoming primary foods during Rigvedic and

Vedic times—there were people at that time who lived on milk alone (Prakash, 1961, 12). Milk products were used in rituals and offerings to gods, certainly accompanied by music, promoting the transformation of cow into the symbol of femininity and fecundity in Vedic literature (Brown, 1964). Consecration of cow gave it purity: even its urine and dung were used for healing and cleansing (Korom, 2000).

The cultural context of kulning and the tradition of homesharing with cattle strongly resembles the Vedic cultural blend of non-violent femininity, cow-worship, and magic. It is not accidental that kula finds a nearly perfect match in Tibetan traditional pastoral songs with long rhythmically free undulating phrases, extremely tense timbre of high quasi-falsetto voice, generous ornamentation, and an ongoing variation (Stuart, 2008, XXIV). This is the most ancient of the three major forms of Tibetan music, peculiar to a nomadic pastoral culture, and originating from cattle calls (Crossley-Holland, 1967). Like kulning, it incorporates parlando and recitative for close-distance vocalization to animals, and also includes milking songs (Plantenga, 2004, 113).

Introduction of milk revolutionized the Neolithic lifestyle, supporting the psychological revolution in human-animal relations and bi-specific musical communication—especially in Northern Europe, where milk quickly replaced fish as the main food—manifested by the widespread adoption of milk-storing pottery (Cramp et al., 2014). The archeological evidence agrees with the genetic evidence of the time of emergence of lactase persistence48. Lactase persistence reflects the adaptation to diet (Hancock et al., 2010)—without which adults have lactose intolerance and nutritional loss (Campbell et al., 2005). Ill effects of malnutrition coexisted with milkbound diseases during the adoption of the milk-based diet. Mycobacterium tuberculosis existed 40,000 years ago, but became pathological for humans only from 6200–5500 BC onward (Hershkovitz et al., 2015) - by the time when the spread of husbandry reached Central Europe. Seemingly "the same" milk could either kill or nurture life—which must have promoted new supernatural beliefs and rituals to "exorcize" milkproduction in replacement of the earlier hunter/gatherer rituals. Music, so common for religious applications, most certainly supported this reform.

For Europe, geographic distribution of Indo-European languages49 (Heggarty, 2015) goes hand in hand with the distribution of taurine mtDNA that descends from the Fertile Crescent (Caramelli, 2006). And subdivision of the bovine European genetic pool into Northern/Southern genotypes (Edwards et al., 2011) matches the distribution pattern of lactase persistence: 40% of adults in Greece versus 90% in Scandinavia/England (Curry, 2013). Those populations that consumed more dairy have higher occurrence of lactase persistence (Bersaglieri et al., 2004). Evidently, milk dependence was more than twice higher in the North. The Indo-European expansion occurred through the farmers' immigration and interaction with local foragers rather than by technological import alone (Rowley-Conwy, 2011). Greater lactase persistence in the North reflects the dairy's effectiveness in providing nutrients, the convenience of its storage in cold climate, the insurance against bad harvests (Gerbault et al., 2013), and health benefits of increased vitamin D consumption in low-sunlight conditions (Flatz and Rotthauwe, 1973).

Kulning emerged to nourish the symbiotic co-dependence of humans and cattle in harsh Nordic conditions that demanded stronger bonding than those of more diverse pastoral economies of Southern yodel territories, therefore employing a **female pastoral model**.

The biggest contender for the Indo-European language family in Northern Europe—the Uralic family (Diamond and Bellwood, 2003)—relates to another domesticate: the reindeer. Reindeer hunting was essential for colonization of Eurasian Arctic/Subarctic (Gordon, 2003). However, reindeer domestication still remains in its early phase (Reimers and Colman, 2009). The distinction between reindeerhunting and reindeer-herding remains vague—even reindeer owners often do not know if a particular reindeer is "wild" or "domestic" (Ventsel, 2006) 50. Leading fences and corrals have been used for hunting wild reindeers and only recently have they become "domestic" accessories (Aronsson, 1991). Reindeer pastoralism emerged gradually from taming individual reindeers for transportation and decoy-hunting—compensating for the depletion of wild reindeer population (Vorren, 1973) that occurred during the 13–16th centuries (Hansen and Olsen, 2014, 175)51. Reindeer domestication must have started in parallel with cattle domestication in Norway/Sweden but lingered into the Middle Ages—absorbing cultural traits of human-to-cattle communication.

The principal psychological trait of kulning is the "humanization" and child-like patronizing of cattle. Similar attitude characterizes reindeer pastoralism: animal is treated like a family member whose life is valued and its attitudes are respected (Ingold, 1986). Kulning, yodel, and reindeercommunication should all be regarded as various "**languages of domestication**," generated by borrowing "acoustic traps and snares"—i.e., onomatopoeic decoy calls—from hunters

48Lactase persistence was completely absent in early Neolithic population 5500 BC (Burger et al., 2007), making its first appearance in Scandinavia in 3400 BC (Malmstrom et al., 2010 ¨ ), by 3000 BC in Iberia (Plantinga et al., 2012) and taking over Europe thereafter (Marciniak and Perry, 2017). This timeframe agrees with the scenario represented in **Figure 6**.

49The Indo-European family contains 144 languages divided amongst 11 distinct branches—with even more languages most certainly having existed in the past but gone extinct (Diamond and Bellwood, 2003). In Europe, non-Indo-European languages are limited to merely 11 documented languages (only 8% of the total number of languages): Etruscan, Basque, Iberian, Tartessian, Estonian, Finnish, Urartian, Sumerian, Hurrian, Hattic, and Mitannian—plus 3 undocumented languages: Pictish, Lepontic, and Ligurian (Robb, 1993).

50Herders routinely let their reindeers graze unsupervised for a rather extensive length of time. Inevitably, many animals become lost, turn wild, and can then be hunted (Stepanoff et al., 2017 ´ ). Also, the herder's strategy of searching for his lost animals strikingly resembles that of hunting.

51This caused the import of non-native reindeers via the emerging Russo-Finno-Scandinavian markets and transition to pastoralism (Røed et al., 2018). Genetic evidence points to 3 epicenters of reindeer domestication: Fennoscandia, Western and Eastern Russia (Røed et al., 2008). Reindeer domestication took about 6000 years. Its earliest evidence comes from the 4000 BC petroglyphs (Helskog, 2012), a 1510–1130 BC burial (Murashkin et al., 2016), and the paleolinguistic tracking of words for reindeer that date back to 1500–1000 BC (Aikio, 2006).

and syntactically reorganizing them into "animal-directed" words to control the herd, its leader, and the individual animals (Alekseyev, 1995).

Kulning and yodel are Indo-European musical "cowlanguages," later adapted for goats/sheep as they became personalized like cows52, whereas reindeer-vocalizations make a Finno-Ugric "reindeer-language."

Kulning's SFTO was forged by long-distance delivery of the desired subharmonic structure. Kula is characterized by dynamic maximization (80–100 dB SPL at 50 cm)53 while fixing 4 formants at FF, 1700, 3,000 and 4,000 Hz throughout all frequency changes, restraining vibrato, and raising the larynx above the resting position (Johnson et al., 1982). Elevating laryngeal position up to 4 cm increases the sub-glottal pressure tenfold as compared to talking (Ivarsdotter, 1986). Somehow, this causes no distortions, and kula's "harmonic signature" remains virtually unchanged at close- and mid-distances (1–11 m) contrasting the "classic" falsetto (Eklund and Mcallister, 2015). Harmonic conservation is still observable at 22 m in kulning, albeit varying between different performers (Eklund et al., 2019). Evidently, kula is designed to transmit kulerska's harmonic and melodic "signatures" to the herd at distances common in herding (Rosenberg, 2014).

Long-distance spectral optimization is known in intergroup communication of some primates (Waser and Waser, 1977). However, optimization to preserve subharmonic structures is unique to kula.

Kula's sounds are supposed to stand out in the environmental soundstage by featuring unnaturally hyper-periodic noise-free spectrum. Kula's harmonicity aligns with "**pleasantness**" following the cow-bell paradigm. Animal-bells were used in Scandinavia at least from 1–4th centuries (possibly, from the beginning of the Bronze Age) to repel evil spirits, mark a humancontrolled territory, and decorate the herd's leading animal (Kolltveit, 2008). For cattle, the bell signified human control, herd-leader's authority, and a safety signal. Humans associated bells with nature, peacefulness, goodness, and protection, employing bells to "borrow" the land from the forest spirits (Emsheimer, 1991, 43). Therefore, overall harmonicity signifies strongly positive values—in line with kulning's perceived beauty and safety/care. Across the animal world, too, harmonicity (pure-tonedness) and inharmonicity are meaningful along the friendliness/fear opposition (Morton, 1977).

Long-distance transmission requires high intensity and register. For 1 km, the most effective transmission occurs at ≈2 kHz (= C7) (Graf, 1980; Gray and Atkinson, 2003)—the range of a piccolo flute. Perhaps, whistling prototyped kula. Whistles are common in communication with dogs and the herd. And whistles exceed calling and yodeling in long-distance intelligibility: correct identification of whistles at 170 m distance is 95% versus 58% for yodeling and 70% for calling (Titze et al., 2018). Bi-factorial changes of rhythm/pitch-contour in whistling signals would pave the road for tri-factorial changes of rhythm/pitch/phrase-length in kula.

Long-distance communication eliminates mimics and gestures from semiosis, making it rely exclusively on acoustic attributes and demanding long-term memory (Wallin, 1991, 390). Exclusion of visual cues promotes the prolongation of a musical expression to facilitate its recognition and memorization. Therefore, phrase length reflects the distance: longer distances require longer phrases (p. 391). Changes in distance generate musical syntax (**Figure 7**).

Close distance promotes short phrases of multi-registral motherese-like recitative where only the "reciting tones" are pitched, and exaggerated leaps employ legato and portamento (**Figure 7B**). Pitches have tendency to monotony in low register at phrasal ends, which generates tonicity. Vocalizations are mostly stimulating and diverse in their referential/propositional content.

Middle distance makes motherese inaudible, instead requiring a different approach. Vocalizations become euphonized: engaging "parlando" rather than recitative54, "smoothening" the leaps, increasing the share of pitched tones, and stressing rhythmic patterning and ordering. The calming effect of these adjustments, inappropriate for stimulating applications that are mostly common for mid-distance communication, is compensated by intensifying dynamics, structural contrasts, and staccato articulation (**Figure 7A**). Notwithstanding diversification, the highest-register "peak-tones" at motivic beginnings are often monotonous, prototyping the musical "leading-tone" by requiring some sort of continuation (as in a melodic resolution).

Longer distance further increases the share of musicality and pleasantness in herding vocalizations. They prioritize audition over visualization by engaging "call-phrases," made of exclamatory imperatives and summoning, free from referential/propositional context (Wallin, 1991, 417). Verbalized vocalization is replaced by a wordless kula (p. 410). Simple phrase-sentences consist of motif chains akin to incipits, climaxes, and cadences of Gregorian tunes (Helmer,

52Ivarsdotter describes how goat-calling follows the model of cow-calling, adapting it to the livelier nature of goats, notorious for their proneness to naughtiness (Ivarsdotter, 2004). Similarity of cow-calling (Kolock), goat-calling (Getlock), and sheep-calling (Farlock ˚ ) is obvious from listening to their archive recordings published by Swedish radio (Ivarsdotter, 1995). The same similarity is retained in pastoral incantations and spells that survive in Altai region—all three types of calling differ primarily in the prevalence of different phonemes for each of these three animals (Tiukhteneva, 2017). The musical characteristics of all three types of calling closely resemble one another (Kondratyeva and Mazepus, 1999). This suggests that similarity between cow, goat, and sheep pastoral communication is a wide-spread Eurasian phenomenon.

53The highest SPL level is reached at a 30 cm distance from the sound source (125 dB) which exceeds the ear's pain threshold at 120 dB (Rosenberg, 2014). The average SPL of kula at 1000 Hz is 113 dB. This is dynamically comparable to an operatic soprano singing fortissimo, except that the soprano's technique requires maintaining a fixed larynx configuration at a low position. However, the maximal SPL of the soprano does not exceed 90 dB near the lips and does not change much from modulating the pitch (Johnson, 1984).

54The term "parlando" was adopted by Anna Johnson in her report (Johnson, 1979) despite the traditional use of this term to refer to Western operatic singing that imitates speech and engages speaking "voice registers" (Sicoli, 2015) despite the absence of such intention for kulerska. Sung out words of closedistance kulning surprisingly resemble the operatic "parlando" sound. The kulning parlando contrasts the recitative kulning that minimizes voicing and remains much closer to talking than to singing, especially in its dynamics. The opposition of kulning parlando and kulning recitative resembles the opposition of operatic parlando and secco recitative, on the one hand, and the genre of melodrama that became popular in Western classical music in the 19th century, on the other hand.

FIGURE 7 | Patterns of TO in four main types of vocalization in the vocal tradition of kulning. Since kulning is essentially ametric and averbal (except for the closest range recitative), its analytic charts omit lyrics. Unlike the previous figures, the vertical dash lines indicate the onset of motifs. The colored arc-line symbol represents an ornamental melismatic shake. (A) Stimulative medium-distance kulning: parlando (a), exclamation (b), and onomatopoeia (c) motifs (http://chirb.it/ntIxfM). This style is designed to compel the entire herd to move in the desired direction and, most probably, sets a model of interaction with animals for the other three styles. The three motifs achieve stimulation, each in a different way, contrasting one another in register, harmonicity, rhythm, and articulation. Motif "a" alerts by its staccato zigzag leaping between two registers. Motif "b" combines stimulation (staccato leap up to the "shrieking" register) with relaxation (legato leap down to the long tone). The "shrieking" peak-tones maintain the same pitch level (melodic regularity)—reflected by the dotted double-arrows (numbers indicate the frequency discrepancy in cents). Motif "c" teases the cattle by imitating dog's barking. The stimulative specialization of (A) is manifested in its prevalence of staccato, loud dynamics, three registers within a wide ambitus, exuberance of leaps, and briefness of motifs and tones. Noteworthy, the motifs "a2" and "c" resemble the "fetch-command" archetype (Figure 5E). (B) Stimulative close-distance kulning: recitative (a) and motherese (b) motifs (http://chirb.it/8K3Lqg). (B), like (A), is stimulative but dynamically gentler due to closer distance (≈9 dB softer). This allows for diverse motherese-like prosodic exaggerations in motivating individual animals. Motif "a" expresses love/care by greatly prolonging the "recitative tone," sustaining its pitch and harmonicity. Motif "b" stimulates animals by briefly stressing the upper "head-voice" register with a shake-like embellishment, then sliding it all the way down to the low talking voice. Compared to (A), (B) is smoother: fewer registers, less staccato, and longer motifs and tones. (B) tends to support a monotone (a predecessor of tonicity), most noticeable at phrasal ends. (C) Inhibitive longer-distance kulning: simple kula (a), exclamation (b), and parlando (c) motifs (http://chirb.it/n6f0sv). This style functionally opposes (B) by commanding the herd to stop grazing and to go home, implying that it is no longer safe to stay out. The chief function of "a" (kula) is to instill confidence in the herder's control over the animals. "Kula" typically consists of a chain of motifs stitched together to form a characteristic shape of steep ascension to the crest point and thereafter a gradual fall-off. However, motifs might differ according to their phrasal functions: initiation, climax, decay, and cadence. The resulting kula receives a basic modal TO: anchor tones constitute "degrees" of the mode, forming a fifth between the marginal degrees and dividing it in wider upper and narrower lower parts. The Roman numerals indicate degrees (I = stable is marked as T = "tonic"). The "b" motif presents "exclamation": a gradual sliding down (≈4th), softer than in (A), and shaped like the "stop-command" (Figure 5E). Similarly shaped is the parlando "c" motif, much smoother than (B) due to its prevailing legato, freer rhythm, more homogenous registers, and longer motifs and tones. (D) Tropotrophic maximal-distance kulning: exclusive use of complex kula sentences (http://chirb.it/gpyC7t). Delivering signals over a kilometer requires taking multiple short caesuras throughout the span of the kula's descending formula, which distinguishes (D) from (C) by making kula complex. Motifs make up phrases, and phrases—sentences, all of which create modal complexity: anchor-tones form intervallic relations that define degrees within a mode (usually, 5–7 degrees). Upper degrees open kula, forming an antecedent cadence (marked by letter "D"—"dominant" function). Lower degrees end kula with the consequent cadence (marked by "T"—"tonic"), providing resolution. (Continued)

#### FIGURE 7 | Continued

fpsyg-11-01358 July 22, 2020 Time: 21:48 # 30

Compared to (C), sentences in (D) are longer, rhythmically freer, more homogenous (by maintaining legato, a single register, the narrowest of ambitus for all kulning styles, and no leaps). Relaxation, secured by modal resolution, is supported by beautification: exclusive use of legato in smoothly shaped phrases and exquisite ornamentation (shakes, trills). (D) differs from (C) by sacrificing dynamic shaping on a phrasal level and, instead, reproduces the same dynamic contour on a motivic level—the final long tone is almost always the loudest in a motif (i.e., stable). Increased homogeneity and melodic consonance (i.e., absence of leaps) are called to motivate the herd not to depart any further beyond the range of hearing kula.

1975). Each phrase is distinguished by a wavelike melodicdynamic "envelop" with an abrupt quick rise and a gradual prolonged fall. Kula pushes vocalizations higher, squeezing their ambitus, homogenizing timbres and legato articulation, while loosening the rhythm (**Figure 7C**). This triggers the modal genesis: kula's anchor-tones turn into degrees, with more-or-less sustained pitch values. The lowest degree becomes "tonic," in contrast to the unstable upper degrees, thereby forming tetrachord-based modes.

Maximum-range communication complicates kula by introducing hierarchic structuring (motifs-phrasessentences) and by engaging the contrasting phrasal functions (initiation/climax/interruption/termination). The stimulating effect of the increased syntactic contrasts, undesirable for maximum-range communication that focuses on keeping the animals calm, is compensated by greater melodic homogeneity: maximizing legato, sentence-length, and dynamics, while minimizing melodic-intervallic, rhythmic, and registral diversity (**Figure 7D**). Longer span necessitates inter-phrasal caesuras, marking multiple phrases within long sentences, joined by stereotypical declining inter-phrasal melodic and dynamic "envelops." Melody relies on pentachordal skeleton, divided in upper major and lower minor 3rds, often supported with quartal/quintal infrafix (Johnson, 1979). Kula breaks in a series of antecedent-consequent sentences that engage different pentachord/tetrachord(s)—usually conjunct. This produces heptatonic modes (**Figure 8**).

The ongoing unveiling of musical structures makes kulning particulate by stacking up certain phrasal types while avoiding certain other combinations. This establishes syntactic rules and implicit music theory of TO for herders and herds. Herders perceive kulning as improvised "musical work in progress" (akin jazz improvisation) that elaborates a specific "theme" selected by the kulerska (Rosenberg, 2014). Herded animals probably perceive kulning as a series of programmed Pavlovian-conditioned routines. In both cases, compositionality promotes particulate semiosis: the meaning of a streak of phrases consists of the sum of the meanings of each of the constituent phrases. In effect, kulning tells a "continuing story" of the day, going through an elaboration of a musical theme (Rosenberg, 2014).

The herd's daily movement generates SFTO by stitching/ restitching phrases of 5 syntactic-semantic types (**Table 6**):

Genesis of SFTO follows the path of human-to-dog whistling communication. Noteworthy, kulning's exclamations and onomatopoeic calls engage stop- and fetch-whistle features (see **Figures 5E,F**).

The proof for SFTO's pragmatic efficacy is in the herd's fulfilling of the shepherd's commands (Wallin, 1991, 410).

Yet another source of semiosis for kulning was phonemic symbolism. Complete absence of words in kula and minimal wording of motherese suggest the prelingual existence of kulning. Wallin (1991, 410–413) rightfully emphasizes that there is no reason to label kula's sounds as "phonemes"—they are mere homologues to vowels and consonants, shaped by the anatomic-physiological conditions of breathing and acting while uttering. The same applies to traditional Alpine yodel (Fenk-Oczlon and Fenk, 2009a). Yodel and kulning vocables are formed not by phonological oppositions of local languages but by the communication distance and the extent of the desired stimulation/inhibition for a given call. Thus, the highest larynx and intensity at the onset of long-distance inhibitive kula-phrases generate a semantically "negative" [i], whereas a relaxed post-climactic position in the mid-distance tropotrophic kula generates a "positive" [a]. Similarly, glottal stops at phrasal ˚ beginnings and endings range from a gentle [h] to a harsh [tj], depending on the needed attack and tenuto decay (Rosenberg, 2014). The choice of the most common kulning syllables (Ahlback, 2007 ¨ ) can be explained by human/animal's natural selection for effective distant communication (Wallin, 1991, 390).

**Monodization** of kulning was imperative in genesis of SFTO.

Animal communication usually employs male "chorus," male-female "duetting," or "antiphonal" formats (Yoshida and Okanoya, 2005). Musicologically, this corresponds to a special type of texture—"isophony": the ongoing out-of-sync multi-part reproduction of the same thematic material (Nikolsky, 2018). Isophonic jumble precludes SFTO. For multifactorial patterning to emerge, each vocalizer must clearly hear his/her voice in order to track spectral changes without any contamination by a partner. This is how infants learn to make their own songs and how children acquire "musical ear" (Nikolsky, 2020). Even in non-European traditions that are exclusively polyphonic, such as Aka Pygmy, motherese and children-made music remain monophonic (Rouget, 2011). This is because an auditory stimulus must be objectified to become accessible for reproduction: a relation of 2 tones in certain aspect must be realized as an auditory constant to lay the foundation for construction of a musical mode (Nazaikinsky, 1973). For perception, the listener must discover permanence of the foreground "sound-object" against the background of a sound-stage, and memorize it in order to relate to it all of the subsequent changes in the thematic material.

Just as one cannot learn prosody of a language by listening to the crowd, one cannot learn SFTO by listening to isophony. And

#### TABLE 6 | Acoustic traitsof main motif types and their semantic values in kulning.

Ten AEs (in rows) are used in five types of phrases (in columns), each characterized by a unique combination of AE patterns, the most distinctive of which are pitch, rhythm, articulation, dynamics, and register. Each type also is distinguished by its semantic specialization: kula—safety signal for grazing, exclamation calls—social "grooming talk," onomatopoeia—playful teasing, parlando—commanding and convincing, and motherese— endearing and trusting. Except for the long-distance kula (whose sentences can reach up to 15 s), all other types are quite brief (usually, 0.3–2 s) and are intermixed with the same-distance or shorter-distance motif types (i.e., kula phrases can be included in motherese recitative, but motherese cannot be included in kula). The maximal distance squeezes the ambitus into an octave confined to a single highest register. This compresses degrees into steps of a smaller or a longer intervallic size, depending on their phrasal position. Climactic step tends to constitute the interval of major 2nd, whereas cadential step—of minor 2nd, to emphasize and facilitate resolution of tension ("major" for a peak in tension, "minor" for relaxation). The framework of a breath cycle sets the basis for traditional association of major with happiness (climax = inspiration = maximal power) and of minor with sadness (cadence = expiration = collapse). Mid-distance kula transposes heptatonic structures to lower registers, fitting them into a tetrachord (pentachord, if a climactic motif is added). Octave equivalence secures heptatony. Closer distances enable alterations, flattening or sharpening of the unstable degrees, and timbral recoloring. Stacking phrases of contrasting TO and semantic values, learnable by humans and domesticated animals, generates the SFTO. See a fuller version of this table in Appendix 2 "A Comparative Structural Analysis of Musograms," inSupplementary Material.

fpsyg-11-01358 July 22, 2020 Time: 21:48 # 31

herding music promotes monodic application: herding demands hours of solitary interaction with animals, ideal for testing their response to music-making.

## CONCLUSION

Homo heidelbergensis was already anatomically capable of practicing proto-music which was most probably isophonic, lacking the combined coding of pitch/rhythm—without which conventionalization of the semiotically functional melodymaking was hardly possible. Isophony supports only group communication of zero- and first-order intentionality, limited and conditioned by the genetically embedded instinctive responses to isophonic formula. Learning of multi-factorial particulate expression and second-order intentionality requires monophonic production. AE's pattern becomes fully semiotic only when many senders/receivers remember it as the bearer of the same semantic value that connotes a certain affective state—"binding hearer to speaker" through "tying of some social sentiment" (Wallin, 1991, 420).

Emotional contagion is possible in isophonic signals, but it is primed to a single most salient AE—provided all communicators share the necessary neuro-anatomical substrates (Snowdon et al., 2015). Harmony, meter, texture, and form are not supported by non-human brains; neither is a premediated "construction" of an intended message. Animal interpretation of auditory signals is inherently circumstantial—determined by the signaling context (Zuberbuhler, 2017 ¨ ). Therefore, human music is often "misunderstood" by animals, requiring music's "translation" into animal's "sonic templates of recognition" (Snowdon and Teie, 2013).

For ACs to evolve into music, a repertory of patterns of AEs had to be extracted from proto-musicking practice and abstracted into elemental signs to continuously inform someone(s) of the communicator's affective state, intentions, and needs. Such use emerged in communication with domesticated dogs, thereafter, adapted for herding. Hunting/gathering does not demand such communication. Instead, it prioritizes collective collaboration: bringing participants emotionally "in-tune," binding them into a group to increase one's powers. Such use makes sense in situations of using loud complex sounds while hunting large prey and repelling human predators in open savannah space (Jordania, 2011). Large groups of big-game foragers tend to prioritize collective music-making over personal, confining the latter to prepubertal age, like Aka Pygmies (Rouget, 2011). Homo probably exported isophonic proto-music from Africa to Europe.

The last Glacial Maximum greatly reduced the European population by the Gravettian—until the Magdalenian repopulation (Maier, 2017) enabled the rise of symbolic cultures (Kozłowski, 2015) and ethnolinguistic genesis (Zilhao, ˜ 2014). Low-density foraging groups usually form alliances, cemented by linguistic commonalities and intermarriage (Marlowe, 2005). Music surpasses language in its bonding capacities (Nakata and Trehub, 2004). Gravettian proto-music must have adjusted isophony for new cultural applications,

especially religious. Smaller groups generate a smaller sonic "jumble," facilitating the recognition of specific musical elements. Smaller groups also promote honesty in communication (Richerson and Boyd, 2005). Honest musical expression enables and validates the person-to-person musical communication. This opens doors to the cultural development of a motherese communicative model. Small groups are likely to promote motherese-like duetic and babbling-like solitary musicmaking. Thus, collective music-making is exceedingly rare in Northern Siberia (Alekseyev, 1967) which has always remained underpopulated (Sikora et al., 2019)—closely resembling life in glaciated Europe.

Motherese talk, lullabies, onomatopoeia, and instinctive utterances supplied the initial material for the formation of bi-specific SFTO. Changes in distance while continuously communicating with the herd put in place the musical modes. The closest distance promotes low-register monotony, middle distance—high-register monotony, long distance tetrachord-based tonicity, and maximal distance—conjunct pentachord/tetrachord octave-equivalent modes with dominanttonic functionality. Monotony increases the tuning accuracy of anchor-tones, firstly defining principal degrees (tonic, supertonic, dominant), and then additional unstable degrees (Alekseyev, 1976). Characteristic modal intonations of different phrasal styles and varying position within a breathing cycle charge modal degrees with specific functionality, which directs the formation of semantic values for each of the common modal intonations. This triggers the process of modal evolution as outlined by Beliaev (1963) and elaborated by Nikolsky (2015a, 2016).

Nordic kulning is probably a vestige of an archaic cattleoriented "domestication language" which descended from yodel—accompanying the northerly spread of Indo-European languages throughout Europe. Other Eurasian domestication languages accompanied the spread of the Uralic and Turkic language families, and were optimized, respectively, for reindeer and horse. Remy Dor cross-analyzed vocalizations/whistles of ´ herders speaking 20 Turkic languages, from Anatolia to Yakutia, and inferred their syntactic organization (Dor, 2005), identifying their common utterances (Dor, 1993). Like Wallin and Alekseyev, Dor too found continuity between vocalizations of hunters and herders: "somatotropic" vocalizations, designed to make the prey come closer, evolved into "fetch" or "home-return" calls, while "somatofugal" vocalizations evolved into "stop" calls to repel predators. The new class of "somatoneutral" vocalizations emerged in order to keep an animal at a constant distance (like safety-call kula). Strong biological foundation of this distancegoverned communication made it well-conserved—practically indestructible—unlike languages or music systems (Dor, 2008).

Domestication languages could underlie modern languages and musics, as traditional beliefs suggest. Swedish rural informants considered kulning an ancient "language" (Moberg, 1971, 145). And on the opposite end of Eurasia, Mongolian herders believe that their music-making is derivative of the "large language," superior to human language and designed to communicate with animals, nature, and spirits (Pegg, 2001, 235). Altaic xo¨omii ¨ most likely constitutes yet another "domestication language."

Capacity to simultaneously control numerous AEs and second-order intentionality enabled humans to create a heterospecific semiotic system of communicating desirable affective states, which gave humans control over domestic animals, resolved human sustenance needs, and put in place music as we know it. The semiotically functional tonal organization that distinguishes music from speech might have emerged no earlier than during the Neolithic "revolution" as a result of forging new conventions of human-to-animal vocal communication.

## DIRECTIONS FOR FUTURE RESEARCH

Comparative examination of human-to-animal signaling for different domesticate animals across different geographic regions can confirm whether the paradigm of "musical domestication language," divisible in "dialects" and integrable into "language families," is applicable here.

Collecting a database of patterns of human-to-animal communication would be analogous to building a lexicon of a newly discovered natural human language or to establishing a stock of typical idioms in the musical communication within a novel musical culture. Once established, such database can be statistically analyzed and cross-examined in relation to other databases, e.g., of emotional expressions in music. This could substantiate or invalidate my conclusions.

The perception of specific elements and patterns of humanto-animal communication by humans and animals can be experimentally tested. This could identify syntactic and pragmatic rules that cannot be assessed by acoustic analysis alone. Together, both approaches can evaluate semiotic efficacy of TO in pastoral signaling. This, in turn, can establish whether introduction of herding communication during the Neolithic Revolution was capable of generating SFTO in music to make it break away from the basics of animal communication.

Experimental archaeo-ethnomusicology could provide yet another way of verifying this hypothesis. Members of isolated tribes that maintain a hunter/gatherer lifestyle and use no domestic animals can be introduced to domestic animals and "taught" to use music-like signals to command them. Their progress can be analyzed and compared to patterns of conspecific acquisition of music skills by human infants, as well as to the available archaeological, genetic, and paleo-physiological data.

## AUTHOR CONTRIBUTIONS

The author confirms being the sole contributor of this work and has approved it for publication.

## ACKNOWLEDGMENTS

I am grateful to CT and MR for reviewing the manuscript for this paper, and to Sheila Bazleh for copy-editing it. My special thanks to Leonid Perlovsky, Steven Brown, Piotr Podlipniak, Leon Crickmore, Theodor Levin, Margarita Mazo, and Philipp

Tagg for their critical input in relation to matters of semiotics of music, and to Isaly Zemtsovsky, Eduard Alekseyev, and Frank Scherbaum for reviewing my approach to modal analysis.

#### SUPPLEMENTARY MATERIAL

The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fpsyg. 2020.01358/full#supplementary-material

#### REFERENCES

DATA SHEET S1 | Appendix 1 – A new method of modal multifactorial analysis of tonal organization in music and music-like sounds.

This technical paper contains instructions for identifying the tonal organization in a music work, a music-like vocalization (e.g., infant's babbling) or music-like animal signals (e.g., bird's song) – including sounds that are indefinite or modulating in pitch.

DATA SHEET S2 | Appendix 2 – A comparative structural analysis of musograms used in Figures 3, 4, 7 of this article.

This document contains a comprehensive analysis of the characteristic traits of tonal organization in the examples of human musical communication, animal vocal communication, and bi-specific communication between domestic animals and their human guardians.

Sundberg, J. (1987). The Science of the Singing Voice. DeKalb, IL: Northern Illinois University Press.

Devouche, and M. Gratier (Cham: Springer International Publishing), 1–18. doi: 10.1007/978-3-030-04769-6 1

**Conflict of Interest:** The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Copyright © 2020 Nikolsky. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.


**1. Introduction**

#### *1.1. Iconic Representations in the Manual Systems*

The affordances of the body and hands allow iconic representations of linguistic information in manual systems. The non-arbitrary form-meaning mappings of the realworld entities is a ubiquitous property of sign languages that can be observed at many levels of linguistic organization (e.g., Klima and Bellugi 1979; Emmorey 2014; Lepic and Padden 2017; Perniss et al. 2010; Padden et al. 2013; and Taub 2001). For example, iconicity plays a role in the large proportion of a signed lexicon (Pietrandrea 2002); the path, manner and location of a sign are frequently iconic (Senghas et al. 2004); information delivery in the event structure, such as telicity, can be iconic (Wilbur 2003); and the way sign languages use or encode space can have iconic motivations (e.g., Padden 2016; Perniss 2007; and Vermeerbergen 2006).

The non-arbitrary nature of iconic forms may seem to be straightforward for perception and production. However, they are not readily accessible to individuals having no prior experience with communication in the manual modality (e.g., Klima and Bellugi 1979; Ortega et al. 2017; and Pizzuto and Volterra 2000). Taub (2001) proposed that there are a least several sub-processes that are essential in inventing an iconic form, such as recognizing

**Citation:** Ergin, Rabia. 2022. Emerging Lexicon for Objects in Central Taurus Sign Language. *Languages* 7: 118. https://doi.org/ 10.3390/languages7020118

Academic Editors: Wendy Sandler, Mark Aronoff and Carol Padden

Received: 12 November 2021 Accepted: 28 March 2022 Published: 11 May 2022

**Publisher's Note:** MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

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associations between concepts and a variety of sensory (visual, auditory, and kinesthetic) images, selecting a candidate image representative of the target concept and schematizing and encoding the selected image using a phonologically valid linguistic form. From among many possible candidates as a representative image of the target concept, *which iconic forms are recognized as more salient for selection?*

Previous investigations in the lexicons of manual systems (improvised gestural systems and emerging and established sign languages) presented evidence for the systematic variation in the use of *action-based* or *object-based* iconic forms across semantic categories and event structures. These iconic forms have been discussed under a variety of terms so far, focusing on the representational role of the hands, either representing the agentive role of the signer or a salient property of the referent (e.g., Brentari et al. 2012; Ergin and Brentari 2017; Meir et al. 2013; Müller 2013; Müller et al. 2013; Ortega and Özyürek 2020; Padden et al. 2013, 2015; and Supalla 1982). Among the iconic modes of representation defined in the manual modality are, for example, *acting*, depicting how objects are manipulated (Müller 2013), and *object*-depicting entities through the shape, dimensions, or outline of an object with no action representations involved (Padden et al. 2013). Padden et al. (2013) further elaborated on the iconic patterning for lexical signs for handheld man-made artifacts ("tool") by dividing them into two groups—*handling*, representing an agent manipulating the target tool by handling it, and *instrument*, representing the manipulated tool itself—and presenting evidence for distinct iconic patterning across semantic categories in the use of these iconic forms. For example, "hammer" in American Sign Language (ASL) is expressed with a *handling* type handshape showing how a hammer is grasped, along with the typical downward repeating movement depicting the canonical action associated with this object. "Toothbrush" in ASL is expressed with an *instrument* type handshape with the index finger extended while the hand moves sideways back and forth near the mouth, as in the action of brushing one's teeth. Padden et al. (2013) reported that in response to stimuli involving the images of common objects such as clothes, utensils, cosmetic products, and tools, the signers of ASL, Al-Sayyid Bedouin Sign Language (ABSL), and New Zealand Sign Language (NZSL) tend to produce instrument strategies more frequently as opposed to handling strategies, whereas American and Bedouin non-signing gesturers display the opposite pattern. These findings indicate that *first*, despite speaking different languages and living in different regions of the world, non-signing gesturers display similar cognitive tendencies, and the types of iconic strategies they use systematically differ from the ones used by signers. *Second*, instrument forms as iconic strategies may be an important linguistic tool to expand the lexicon of sign languages by adding more handshape distinctions as opposed to the gestural ones produced in an improvised fashion. Similar to the findings of Padden et al. (2013), in a cross-linguistic analysis on a total of eight established and emerging sign languages, including Central Taurus Sign Language (CTSL), Hwang et al. (2017) reported recurring patterns for naming entities, even if they individually varied in imagistic form: *handling* and *instrument* forms (both involve a manipulative action) are used for tools, whereas *object* forms (i.e., static forms with no action involved) are more often used for fruits and vegetables. Hou (2018) reported similar grouping of iconic strategies for tools and foods in San Juan Quiahije Chatino Sign Language. Tools, as a category of stimuli, seem to strongly elicit forms exhibiting human agency, whereas this is less prevalent in semantic categories like fruits and vegetables.

Other studies on emerging sign languages report systematic variation across event structures. For example, Ergin and Brentari (2017) reported that CTSL signers favor *object* strategies depicting the form of an object over *handling* strategies depicting an action associated with the target object in non-agentive contexts, as opposed to agentive ones. When the object is acting on its own or not acting at all in a non-agentive context, such as "The lollipop is on the table", CTSL signers tend to use object-based iconic strategies (i.e., object handshapes) to represent the form of a lollipop. When the object is being acted upon by an agent, as in "The man puts the lollipop on the table", they tend to use action-based iconic strategies (i.e., handling handshapes) more frequently. Moreover, Ergin and Brentari (2017)

reported that the use of these strategies may evolve over time in that CTSL in its first generation1 favored handling strategies over object strategies, but as of the second generation, it evolved into a system favoring object strategies over handling strategies. Using the same stimuli, Goldin-Meadow et al. (2015) also reported systematic opposition between non-agentive and agentive contexts in the use of *object* vs. *handling* strategies by Nicaraguan homesigners, the cohort 1 and cohort 2 signers of Nicaraguan Sign Language (NSL), and a group of American Sign Language (ASL) signers. All four groups, including homesigners, used object-based iconic strategies almost exclusively in non-agentive contexts and used handling strategies more frequently in agentive contexts, suggesting that systematically varying morphological constructs are fundamental properties of language that appear under a variety of environmental conditions. Another important finding of this study is the consistency of these iconic handshape types being wider for ASL and NSL signers in comparison with the homesigners. In other words, individuals using a shared sign system with others are more consistent in the type of iconic strategies they use across agentive vs. non-agentive contexts than those using a non-shared system. In addition, as in the case of CTSL, Goldin-Meadow et al. (2015) reported generational differences in the use of these iconic strategies. NSL cohort 2 and the ASL signers produced more handling handshapes than object handshapes in their predicates in agentive contexts as opposed to NSL cohort 1 and homesigners, which suggests that these iconic strategies may evolve and stabilize over time as a system matures.

An important finding of the previous studies is that sign languages exhibit crosslinguistic differences in terms of iconic patterning. For instance, in a comprehensive study conducted on 11 sign languages, Nyst et al. (2021) reported cross-linguistic differences across languages in the use of handling vs. object strategies in response to the images of 10 common objects. Adamorobe, Nanabin, and Ghanaian Sign Language exhibit a preference for object handshapes. Ivory Coast, Malian, and Portugese Sign Language exhibit a preference for handling handshapes. Kenyan, Ethiopian, Guinea-Bissau, and Boukako Sign Language as well as the Sign Language of the Netherlands, is a middle group without a strong preference for either handshape2. In addition, sign languages may display differences in the developmental paths they take. For example, while CTSL begins with handling strategies and evolves into a system favoring object strategies over time, NSL follows the opposite path (Ergin and Brentari 2017 and Goldin-Meadow et al. 2015, respectively). In summation, despite showing certain tendencies across semantic categories (i.e., foods elicit object-based iconic forms and tools elicit action-based iconic forms), there seem to be language-specific tendencies across languages, leading to variation.

The patterning of iconic forms across semantic categories and event structures is not only a property of emerging and established signed lexicons. Recent evidence from the improvised gestures of hearing adults shows alignments between sign languages and gestural communication in that there are systematic variations in the use of iconic gestural forms, possibly shaped by similar cognitive tendencies. For example, Schembri et al. (2005) detected similar movements and locations for the manual productions of non-signing Australians and signers of Australian Sign Language in response to a task involving classifier predicates of motion, but their choice of handshapes differs significantly. In addition, in a pantomime generation task in which participants were asked to produce gestures for written words they were presented on a computer screen, Ortega et al. (2017) showed that Dutch speakers' gestures share varying degrees of form overlap with the signs from the Sign Language of the Netherlands (full, partial, or no overlap). Moreover, hearing participants guessed the meanings of signs with full and partial overlap more accurately, and they assigned these signs higher iconicity ratings than signs with no overlap. These findings suggest that deaf and hearing adults converge in their iconic depictions for some concepts (e.g., TO-CUT, TO-SAW, or LAPTOP), possibly as an outcome of the shared conceptual knowledge and manual-visual modality. Furthermore, Ortega and Özyürek (2020) found systematicity in the implementation of iconic strategies in the gestural forms of various concepts. They showed that action-based iconic forms (i.e., *acting*) through

reenacting the motion of the action associated with the target object were favored to refer to manipulable objects, whereas object-based forms such as recreation the form of an object (i.e., hand *representing* the object) and tracing its shape with the hands (i.e., *drawing*) were favored to refer to the static state and non-manipulable nature of an object, respectively.

In addition, several previous studies argued that action simulations are the precursors of manual iconic forms (Cook and Tanenhaus 2009 and Hostetter and Alibali 2008), with some recent empirical support for action-based iconic representations to be the building blocks of an emerging lexicon in the manual modality. For example, Ortega and Özyürek (2020) presented evidence for an overwhelming tendency for the use of action-based forms, implying that *acting* might be a building block of an emerging lexicon in the manual modality. Similarly, Ortega et al. (2014) claimed that action-based iconic forms are developmental milestones in the language acquisition process and present evidence for action-based signs to be favored more in children-adult interactions and object-based (perceptual) signs to be favored more in adult-adult interactions.

In summation, these findings provide us with insight into the systematic tendency in the use of certain *action-based* or *object-based* iconic features to refer to a certain type of referents and possible pathways for iconic forms to become linguistic tools over time in the manual modality. Specifically, the findings in favor of the dominance of actionbased iconic forms in the gestural productions are intriguing in that they trigger further questions regarding the perception of real-world referents and the invention of iconic forms representing them. *Are the object-based iconic forms or the action-based iconic forms recognized as more salient for selection for iconic representations? What forms the building blocks of an emerging lexicon in the manual modality?*

#### *1.2. Combination of Signs and ˙Iconic Strategies*

Using multi-sign strings such as compounds in order to distinguish concepts across semantic categories is a common property of sign languages (e.g., BLUE ˆ SPOT for "bruise" in ASL (Klima and Bellugi 1979)). Evidence from emerging sign languages indicates that this mechanism is present in the initial stages of a language, and some combinations of signs used for object descriptions are systematic (e.g., Ergin et al. 2021; Meir et al. 2010; and Tkachman and Sandler 2013). Ergin et al. (2021) reported that CTSL signers frequently use multi-sign strings to refer to entities from various semantic categories (e.g., everyday objects, utensils, and fruits and vegetables). While some of these multi-sign descriptions are relatively conventionalized compounds (e.g., TEA ˆ ONE-ON-ANOTHER for "teapot"), others have the flavor of idiosyncratically longer descriptions (e.g., TEA ˆ POUR-FROM-HANDLE ˆ ONE-ON-ANOTHER, FLAME ˆ PUT-ON ˆ ONE-ON-ANOTHER). When expressing a systematic compound3, CTSL seems to be following a certain pattern in terms of sequencing its constituents. Tea, an action involving an iconic constituent delivering information about the function of the object, frequently precedes the constituent signaling the static form or the size or shape of the target object (ONE-ON-ANOTHER) (Figure 1).

Similar results have been reported in Israeli Sign Language (ISL) and Al-Sayyid Bedouin Sign Language (ABSL): the constituents involving the size or shape (i.e., static form) information of the target object occupied the final positions in the compounds (e.g., CHICKEN ˆ OVAL-OBJECT for "egg" in ABSL or LIPSTICK ˆ SMALL-OBJECT for "lipstick" in ISL). However, in its initial stages, when a language does not have a conventionalized lexical item for a referent, longer descriptions become inevitable (e.g., WRITE ˆ ROW ˆ MONTH ˆ ROW ˆ WRITE for "calendar" in ABSL) (Meir et al. 2010; and Sandler et al. 2011). Similarly, Tkachman and Sandler (2013) reported a high tendency in both ISL and ABSL to produce compounds and longer sign strings in response to picture stimuli of unfamiliar objects which did not have a conventionalized lexical item in ISL or ABSL. Morgan (2015) also found that some compounds in Kenyan Sign Language such as BLACK ˆ PEAR-SHAPE ("avocado") display a systematic order among their components, but other multi-sign strings involve longer sequences with constituents in variable orders and with some items repeated multiple times.

**Figure 1.** (**a**) A Turkish teapot. (**b**) The sign for TEA. (**c**) The sign for ONE-ON-ANOTHER.

The findings from Zinacantec Family Homesign (Z) show that compounding is present even in a first-generation language.  Despite having conventionalized lexical items such as CHICKEN, Haviland (2013) reported that Z signers are not always consistent. For example, for a small SLEDGEHAMMER, a Z signer may produce multi-sign strings starting with a handling handshape showing how a hammer is held, which also indicates the size of the target object, followed by a pounding action and completing with four full vertical strokes. On another occasion, in response to the picture of two ordinary hammers, the same Z signer may produce three distinct vertical pounding movements.

To sum up, using more than one sign or word to refer to real-world referents is a ubiquitous feature of natural languages. Evidence from emerging sign languages and homesign systems suggests that this feature springs up quickly in the initial stages of a language. While rarely used daily objects elicit idiosyncratically longer sequences of constituents (e.g., see Ergin et al. 2021 for "gas tank" variants in CTSL), more frequently used objects (e.g., "teapot" in CTSL) tend to elicit shorter sign strings or systematically ordered compounds. Whether there are generational differences in the combinatorial use of sign strings to refer to everyday objects and whether presenting stimuli in isolation vs. context affects the combinatorial structures remain open questions.

#### *1.3. The Focus of This Study*

Previous studies mentioned in Sections 1.1 and 1.2 mainly focused on either objectbased (i.e., static iconic forms with no action involved) or action-based iconic forms and presented evidence for systematic variation of them across semantic categories or distinct event structures. This study aims to investigate the *action*, *object*, and simultaneous use of *action* and *object* as iconic strategies (see the coding procedure in Section 2.1) and their combinations used for referring to everyday objects across generations in the emerging lexicon of Central Taurus Sign Language. The motivation for this investigation is to understand (1) whether a language in its initial stages favors *action*, *object*, or simultaneous production of *action* and *object* strategies as a more salient property to represent a target object iconically, (2) whether there are generational differences in the use of these strategies and their combinations, and (3) whether signers modulate their use of these strategies and their combinations in response to stimuli presented in isolation vs. context.

Section 1.4 introduces Central Taurus Sign Language (CTSL). Section 2 presents the design and results of study 1, which investigates CTSL responses when the target objects are presented in isolation. Section 3 presents study 2, which compares the CTSL responses when the target objects are presented in isolation vs. context.

#### *1.4. Central Taurus Sign Language*

Central Taurus Sign Language (CTSL) is a village sign language which emerged spontaneously over the past 50 years or so in the absence of a conventionalized linguistic model. It developed in a geographically isolated area with little or no influence from Turkish Sign Language (TiD). It is mainly used in a small village located in the Central Taurus Mountain Range of southern Turkey. The deaf individuals, comprising approximately 4.6% of the village population, are connected to each other by birth or through marriage (see Supplementary S1 for the family tree). The high incidence of deafness in the village (compared with a typical incidence of deafness of approximately 0.5%) is an outcome of recessive deafness in the community and the prevalence of consanguineous marriages in families with deaf individuals. CTSL has about 25 deaf signers today, 17 of whom use CTSL as their sole language, whereas others can use Turkish Sign Language at varying proficiency levels. In addition, there are approximately 80 hearing Turkish speakers who also have some degree of fluency in CTSL.

In order to track the developmental trajectory of the language, we identify three cohorts of signers in the community. CTSL-1 is the first cohort of signers, who were born as the first deaf child in their family and who therefore would have had little or no linguistic input early in life (n = 9; age range = 49–61). CTSL-2 is the second cohort, comprising the deaf and younger siblings of cohort 1 signers. They would have had more linguistic input because they had at least one older sibling who signed (n = 8; age range = 42–54). CTSL-3 is the third cohort of deaf signers from the younger generation: children of CTSL-1 and CTSL-2 signers (n = 4; age range = 24–30) (see Ergin 2017; Ergin and Brentari 2017; Ergin et al. 2018, 2020, 2021). There were also four deaf children who constituted a potential fourth cohort, though their linguistic behavior has not been documented yet.

#### **2. Study 1**

The goal of this study is to investigate object-based and action-based iconic strategies and their combinations across generations when the target objects are presented in isolation.

#### *2.1. Materials and Methods*

**Participants.** Ten deaf signers from 2 successive age cohorts (5 CTSL-1 signers: *M*age = 51.8, age range = 43–55; 5 CTSL-2 signers: *M*age = 41.4, age range = 35–444) were tested. All of the participants used CTSL as their sole language, and the CTSL-2 signers were the younger siblings of the CTSL-1 signers.

**Stimuli and Procedure.** The deaf CTSL signers were tested in a *picture-naming task*. They viewed stimuli involving pictures of 26 everyday objects (Table 1) on a computer screen and labeled them for another deaf addressee or a hearing family member fluent in CTSL. A previous investigation of CTSL revealed systematic opposition across semantic categories such as tools and fruits and vegetables, which frequently elicit *handling* or *instrument* (cf. simultaneous *action* and *object* in the current coding scheme) and *object* strategies in CTSL, respectively (Hwang et al. 2017). In order not to create a bias for certain iconic strategies in the cumulative results, these semantic categories were not used in the current stimuli set. Instead, a variety of everyday objects that were not previously studied in CTSL for iconic representations were included in the stimuli set. All of the stimuli items were presented in isolation (i.e., non-agentive context) in a single randomized block (see Supplementary S2 for the pictures of the stimuli items). The data were collected in August 2013.

**Table 1.** List of objects used in study 1.

**Coding Procedure.** The responses to the stimuli were transcribed using ELAN, a tool developed at the Max Planck Institute for Psycholinguistics in Nijmegen, for analysis of the spoken language, sign language, and gestures (Crasborn and Sloetjes 2008) and coded5 based on the following the criteria defining the iconic representations of the target stimuli items.

Action: In this strategy, the signer's hand represents a hand performing an action (cf. "acting" by Müller 2013). For example, for CAR, the sign that represents holding the steering wheel with both hands and controlling it by moving the hands up and down in opposite directions is coded as an "action".

Object: The hand represents the object itself or represents an aspect of the target object, such as its dimensions, size, or shape (Ergin and Brentari 2017 and Padden et al. 2013). There is no motion representing an action. For instance, COOKING POT, a sign involving two C-static handshapes representing the **shape** of the pot, is coded as an "object" sign. A sign representing the **size** of an object, as well as the simultaneous depiction of shape and size, is also coded as an "object" sign6. Object signs depicting the size or shape of an object can be either one-handed or two-handed (e.g., GLASS, an L-handshape after DRINK to represent the size of the glass, or STICK, with two extended index fingers showing the length of the stick). Finally, signs involving the hand or hands in any configuration **tracing**7 the outline of an object is also coded as an "object" sign (e.g., BREAD BOARD, with two flat hands moving horizontally outward to trace the surface of a bread board, or DRESS, with the flat dominant hand facing upward and tracing the length of the dress or the length of its sleeves on the signer's body).

Note that the goal was to understand whether it was the object-based or the actionbased iconic representations that were more salient to be selected for iconic representations. That is why the object category was not divided into further subcategories (e.g., size, shape, and tracing), but all static forms depicting the physical property of the target object as a whole or an aspect of it (e.g., size) were evaluated under the "object" category.

Action and Object: In this strategy, action and object strategies are used simultaneously. If it is a one-handed sign, the dominant hand is used either as an instrument or an agent handling the object and simultaneously performing the action associated with that instrument (e.g., BROOM, with extended widespread fingers representing the object and simultaneously producing vertical right-to-left movement of the hand representing the sweeping action, or GLASS, where the C-handshape represents handling the object or its shape, and the motion represents bringing the glass to the mouth for drinking) (cf. "instrument" and "handling" by Padden et al. 2013 and "handling" by Ergin and Brentari 2017).

If it is a two-handed sign, both hands are simultaneously used to represent an object with the non-dominant hand and to depict an action performed on that object with the dominant hand (e.g., MATCH, where the dominant hand represents the action of swiping a matchstick, and the non-dominant hand represents the surface of a match box, where the action takes place).

Deictic: Gestures involving showing, pointing, or touching the objects in the immediate physical environment with or without the object present are coded as "deictic" signs (e.g., SCARF, by touching the scarf one is wearing). The pointing can be with an open hand or extended index finger (Kita 2003).

Unrecognizable signs that did not fit any of the categories listed above were coded as "other" (e.g., MATCH, where the signer produces a sign with the index finger and thumb touching each other, but it is not clear whether the signer refers to the size of the match or he or she is holding the match).

Repeated signs in a response were ignored. For example, in a sign string like "action1— deictic1—action1—deictic1", the action sign and the deictic with the same form and function were repeated and therefore ignored. This response was counted as a two-sign string. Likewise, a string involving "object1—action1—action2—object1" was considered a threesign string, as the same object sign was repeated at the end.