a fundamental question that is currently hotly debated is to what extent music processing shares perceptual mechanisms with language .
one way to examine this question is to study transfer effects between musical and language abilities , as such a transfer may be mediated by shared mechanisms .
for example , slevc and miyake ( 2006 ) showed that native japanese speakers with high musical aptitude spoke english with better pronunciation than did their peers with less musical aptitude .
similarly , speakers of tone languages are better able to reproduce musical pitch patterns in singing than english speakers ( pfordresher and brown , 2009 ) .
the latter domain - transfer effect from language to music suggests that tone language acquisition , that makes use of small pitch contrasts to convey meaning , fine - tunes pitch perception which in turn can be carried over to musical tasks .
the objective of the present study was to re - examine this issue . in the present study
, we tested whether early exposure to a tone language may confer a sensory advantage in discriminating subtle pitch deviations in non - speech tone sequences .
to this aim , we asked both speakers of a tone language , mostly mandarin , and speakers of non - tone languages ( mostly french ) , to detect pitch changes that were at or just above threshold . to assess the specificity of the transfer
, we used a control condition in which the task was to detect equally subtle time changes . in both conditions , participants heard standard sequences of five piano tones presented monotonically ( constant pitch ) and isochronously [ constant intertone interval ( iti ) ] , as well as comparison sequences in which the fourth tone was displaced in pitch or time .
musicians were excluded so as to control for possible transfer effects due to musical training rather than language experience .
indeed , it has been shown that musicians outperformed non - musicians in the processing of lexical tones ( wong et al .
in such cases , the positive transfer effects observed between music and language abilities could be the consequence of other factors than shared sensory processing .
one likely mediating factor is that musicians have enhanced attentional or executive control capacities as compared to non - musicians ( bialystok and depape , 2009 ) . yet
, non - musicians might differ in musical capacity . in order to measure individual differences in musical abilities ,
all participants were tested with a standardized battery  the montreal battery of evaluation of amusia ( mbea ; peretz et al .
, 2003 )  that was developed for westerners but that showed similar sensitivity in speakers of a tone language ( nan et al . , 2010 ) .
twenty - four speakers of a tone language ( referred to as tone speakers ) and 25 speakers of a non - tone language ( referred to as non - tone speakers ) were tested in montreal ( see table 1 ) . the native language of tone speakers was mandarin ( n  =  18 ) , vietnamese ( n  =  4 ) , or cantonese ( n  =  2 ) ; all had immigrated to canada in adulthood and had spoken french and/or english as a second language for 6  years on average ( sd  =  5 ) . otherwise , tone and non - tone speakers
none of the participants reported any hearing disorder and all were paid for their participation .
f , female ; r , right - handed . based on a scale of musical training with 1 = less than a year ; 2 = 13 years ; 3 = 46 years ; 4 = 710 years ; 5 = more than 10 years . to screen
for any musical deficit and to assess individual differences in musical abilities , all participants were tested on the mbea , a validated and standardized collection of six tests developed to assess normal music perception and memory ( peretz et al . , 2003 ) .
different classification trials in which a standard melody was followed by a comparison melody . for trials where the comparison melody differed from the standard ,
one note was altered in one of the following ways : it was out of the scale of the melody while preserving the contour ( scale test ) , it changed the contour of the melody while preserving the scale ( contour test ) , or it changed the intervallic distance between two successive notes while maintaining the contour and the scale ( interval test ) .
in half the trials , the duration of two adjacent notes was changed so that the rhythmic grouping of the melody was altered . for the metric test , half the 30 trials were written in duple meter and half in triple meter and the participant was asked to classify each trial as either a march or a waltz .
finally , recognition of melodies ( memory test ) was evaluated . in this last test , participants had to discriminate 
old  melodies that they heard in the previous five tests from  new  melodies similar in structure to the old melodies but never heard before .
the melodies were novel , written in the western tonal musical system and presented on a piano timbre ; they contained 10 notes on average .
the scores obtained on the mbea revealed that one tone speaker performed 2 sd below the tone speakers average performance ( m  =  84% ; sd  =  7 ) .
the data of this amusic participant were excluded . as can be seen in table 2 , the two groups obtained similar scores on the mbea tests , except for the scale test on which tone speakers obtained lower scores than non - tone speakers .
nevertheless , there was no significant group effect [ f(1 , 47 )  =  1.66 , p  =  0.20 ] nor interaction between group and the mbea tests [ f(4 , 184 )  =  1.38 , p  =  0.23 ] .
percentage of correct responses ( sd ) obtained on the montreal battery of evaluation of amusia ( mbea ) by speakers of a tone and non - tone language .
stimuli consisted of 21 different sequences , each containing five successive tones . in the standard sequence , all tones were 120  ms long , played at the pitch level of c6 ( 1047  hz ) , and synthesized with a piano timbre ; the iti ( onset to onset ) was 350  ms . in the comparison sequences ,
the fourth tone was displaced by one of five pitch distances upward or downward from c6 ; the five pitch distances used ranged from 1  hz ( 1.56 cents ) to 15  hz ( 25 cents ; 100 cents corresponds to 1 semitone ; figure 1 ) .
the 1  hz distance was chosen so as to be at threshold at a reference frequency above 1000  hz ( e.g. , moore , 1973 ) . in the 10 time - altered sequences ,
the fourth tone was displaced by one of five temporal increments earlier or later than its isochronous position ; the five temporal increments ranged from 6 to 14% of the iti .
participants were tested individually , with separate sessions for the pitch and time tasks , presented in a counterbalanced order across subjects . in both tasks ,
button when they detected a change and a  no  button when they were unable to detect a change .
trials were randomized , and half contained no change ( i.e. , the standard monotonic , isochronous sequence ) .
participants did not receive feedback but were informed about the nature of the possible change and the location where it could occur .
each test session comprised 360 sequences ( 180 standard sequences , 18 of each of 10 altered sequences ) .
the stimuli were presented bilaterally through sennheiser hd450 headphones in a quiet room , at an intensity level of 70  db spl(a ) .
twenty - four speakers of a tone language ( referred to as tone speakers ) and 25 speakers of a non - tone language ( referred to as non - tone speakers ) were tested in montreal ( see table 1 ) . the native language of tone speakers was mandarin ( n  =  18 ) , vietnamese ( n  =  4 ) , or cantonese ( n  =  2 ) ; all had immigrated to canada in adulthood and had spoken french and/or english as a second language for 6  years on average ( sd  =  5 ) . otherwise , tone and non - tone speakers
none of the participants reported any hearing disorder and all were paid for their participation .
f , female ; r , right - handed . based on a scale of musical training with 1 = less than a year ; 2 = 13 years ; 3 = 46 years ; 4 = 710 years ; 5 = more than 10 years . to screen
for any musical deficit and to assess individual differences in musical abilities , all participants were tested on the mbea , a validated and standardized collection of six tests developed to assess normal music perception and memory ( peretz et al . , 2003 ) .
different classification trials in which a standard melody was followed by a comparison melody . for trials where the comparison melody differed from the standard ,
one note was altered in one of the following ways : it was out of the scale of the melody while preserving the contour ( scale test ) , it changed the contour of the melody while preserving the scale ( contour test ) , or it changed the intervallic distance between two successive notes while maintaining the contour and the scale ( interval test ) .
in half the trials , the duration of two adjacent notes was changed so that the rhythmic grouping of the melody was altered . for the metric test , half the 30 trials were written in duple meter and half in triple meter and the participant was asked to classify each trial as either a march or a waltz .
finally , recognition of melodies ( memory test ) was evaluated . in this last test , participants had to discriminate 
old  melodies that they heard in the previous five tests from  new  melodies similar in structure to the old melodies but never heard before .
the melodies were novel , written in the western tonal musical system and presented on a piano timbre ; they contained 10 notes on average .
the scores obtained on the mbea revealed that one tone speaker performed 2 sd below the tone speakers average performance ( m  =  84% ; sd  =  7 ) .
the data of this amusic participant were excluded . as can be seen in table 2 , the two groups obtained similar scores on the mbea tests , except for the scale test on which tone speakers obtained lower scores than non - tone speakers .
nevertheless , there was no significant group effect [ f(1 , 47 )  =  1.66 , p  =  0.20 ] nor interaction between group and the mbea tests [ f(4 , 184 )  =  1.38 , p  =  0.23 ] .
percentage of correct responses ( sd ) obtained on the montreal battery of evaluation of amusia ( mbea ) by speakers of a tone and non - tone language .
stimuli consisted of 21 different sequences , each containing five successive tones . in the standard sequence , all tones were 120  ms long , played at the pitch level of c6 ( 1047  hz ) , and synthesized with a piano timbre ; the iti ( onset to onset ) was 350  ms . in the comparison sequences ,
the fourth tone was displaced by one of five pitch distances upward or downward from c6 ; the five pitch distances used ranged from 1  hz ( 1.56 cents ) to 15  hz ( 25 cents ; 100 cents corresponds to 1 semitone ; figure 1 ) .
the 1  hz distance was chosen so as to be at threshold at a reference frequency above 1000  hz ( e.g. , moore , 1973 ) . in the 10 time - altered sequences ,
the fourth tone was displaced by one of five temporal increments earlier or later than its isochronous position ; the five temporal increments ranged from 6 to 14% of the iti .
participants were tested individually , with separate sessions for the pitch and time tasks , presented in a counterbalanced order across subjects . in both tasks ,
button when they detected a change and a  no  button when they were unable to detect a change .
trials were randomized , and half contained no change ( i.e. , the standard monotonic , isochronous sequence ) .
participants did not receive feedback but were informed about the nature of the possible change and the location where it could occur .
each test session comprised 360 sequences ( 180 standard sequences , 18 of each of 10 altered sequences ) .
the stimuli were presented bilaterally through sennheiser hd450 headphones in a quiet room , at an intensity level of 70  db spl(a ) .
response when there was a change ) minus false alarms ( f.a . , corresponding to a  yes 
response when there was no change ) was computed for each participant as a function of the type , direction , and size of change .
it is worth noting that the groups did not differ in correct rejections ( a  no  response to a trial containing no pitch change ) with 68 and 73% for the tone and non - tone speakers , respectively , t(47 )  =  1.28 , p  =  0.21 .
a 2 ( group )    2 ( direction )    5 ( distance ) mixed - design analysis of variance ( anova ) was computed on the percentage of hits - f.a .
was obtained , f(4,188 )  =  4.65 , p  <  0.01 , separate anovas for each direction were conducted , with group as the between - subjects factor and distance as the within - subjects factor .
a significant two - way interaction emerged for downward pitch changes , f(4,188 )  =  5.09 , p  <  0.01 .
as can be seen in figure 2a , tone speakers consistently performed below non - tone speakers in the detection of downward pitches , except at 1  hz where groups did not differ , t(47 )  =  1.32 , p  =  0.19 . at this smallest interval change distance , 17 tone speakers and 19 non - tone speakers performed at chance level .
statistically significant group differences emerged at 2  hz , t(47 )  =  2.05 , p  <  0.05 , and remained present at the largest pitch falls of 25 cents .
in contrast , no interaction [ f(4,188 )  =  1.06 , p  =  0.38 ] or main effect involving group appeared for upward pitch changes [ f(1,48 )  =  1.67 , p  =  0.20 ; figure 2b ] .
performance of the tone and non - tone language speakers in the pitch change detection task : ( a ) downward changes ; ( b ) upward changes .
the anova revealed no main effect or interaction involving group ( f  <  1.15 ; p 's  >  0.10 ) , but a main effect of time distance , with f(4,188 )  =  213.29 , p  <  0.001 ( figure 3 ) .
performance of the tone and non - tone language speakers in the time change detection task .
bars represent 2 se . in order to assess whether the observed difference between the groups could be attributed to different experience of a tone language rather than to differences in musical aptitude
, we assessed whether performance on each mbea test could predict performance in the pitch change detection task ( all conditions pooled together ) . as can be seen in table 3 , we found significant correlations between all pitch - related musical ( scale , contour , and interval ) tests and performance in the pitch change detection task .
it is worth pointing out that this correlation between fine - grained pitch perception and musical pitch discrimination is a general trend .
thus , group differences in musical aptitude are unlikely to account for the impairment observed for falling pitches in speakers of a tone language . to assess this statistically , the scores on the pitch - based musical tests were averaged and included as a covariate in a 2 ( group )    2 ( direction )    5 ( distance ) mixed - design ancova .
essentially the same results as reported above were obtained , with a three - way interaction between all three factors , f(4,184 )  =  5.94 , p  <  0.005 , and a significant two - way interaction for the falling pitch changes only , f(4 , 184 )  =  4.24 , p  <  0.005 .
bivariate correlations between performance on the pitch detection task ( pooled across all conditions ) and performance on each test of the mbea .
* p  <  0.05 ; * * p  <  0.01 ( two - tailed ) . individual performance pooled across conditions in the pitch detection task as a function of melodic scores averaged across scale , contour and interval tests of the mbea , obtained by tone and non - tone language speakers .
contrary to expectations , we find no evidence for enhanced perception of pitch in tone language speakers . on the contrary , we find an impairment that is limited to downward pitch changes .
this impairment appears specific as tone language speakers do not differ from non - tone language speakers in their perception of upward pitch changes or in their perception of subtle time changes .
moreover , this impairment can not be attributed to low musical aptitude since the impairment remains when individual differences in musical pitch - based processing are taken into account .
thus , fluency in a tone language interferes with the perception of falling pitches in a non - speech context .
bent et al . ( 2006 ) found a similar pattern in the identification of pitch contours as rising , falling or flat .
in contrast , the tone language speakers misidentified the falling pitch contours more often than did the non - tone language speakers , which is consistent with the direction - specific impairment reported here .
this response pattern can be attributed to long - term exposure to mandarin tones in which larger pitch ranges are typically used for falling tones than for rising tones ( e.g. , xu , 1994 ) .
although the pitch rises and falls are larger in naturally produced tones than the rises and falls of the stimuli used here and in bent et al .
s ( 2006 ) study , the differences between rising and falling that characterizes lexical tones may have influenced the criteria used for non - speech stimuli presented at near - threshold levels . in sum , the statistical pitch regularities of tone languages may lead to the use of a language - specific perceptual strategy in a non - speech context .
recourse to a language strategy in pitch discrimination is probably optional and promoted by the use of pitch deviations near threshold . as we have observed in two other studies ( tillmann et al . , 2011 ; tillmann et al . ,
submitted ) , the more severe is a pitch perception deficit , the more beneficial is the speech context as compared to a non - speech context .
more specifically , we found that fine - grained pitch discrimination was better in spoken syllables than in acoustically matched tones in amusic individuals while normal controls showed the reverse pattern ( tillmann et al . ,
similarly , in another study using lexical tones , we found that amusics with a severe pitch disorder performed better on syllables than on musical analogs ( tillmann et al .
thus , speech - specific processes can influence pitch perception when differences are difficult to hear .
when pitch differences are large , there would be no need to use speech processes as a compensatory strategy .
this may account for the fact we do not replicate the perception results obtained by pfordresher and brown 's ( 2009 ) . while we test pitch changes that are less than 25 cents apart , pfordresher and brown ( 2009 ) use distances from 25 to 800 cents and find both a tone language advantage and no pitch contour effect .
while we find no support for the notion that tone language experience fine - tunes pitch perception , we find evidence that individual differences in pitch perception carry over to music perception . in both tone and non - tone language speakers , performance in the pitch detection task
thus , individual differences in fine - grained pitch perception are linked to musical abilities independently of native language . in sum
, fine - tune pitch perception might be a prerequisite for achieving high levels of melodic abilities . in the advent of pitch discrimination difficulties , as in near - threshold discrimination or in the case of amusia
, speech - specific processes may contribute to the pitch discrimination task albeit in a less effective manner than by a musical or acoustic mechanism .
the authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest .
 here we present evidence that native speakers of a tone language , in which pitch contributes to word meaning , are impaired in the discrimination of falling pitches in tone sequences , as compared to speakers of a non - tone language . 
 both groups were presented with monotonic and isochronous sequences of five tones ( i.e. , constant pitch and intertone interval ) . 
 they were required to detect when the fourth tone was displaced in pitch or time . while speakers of a tone language performed more poorly in the detection of downward pitch changes 
 , they did not differ from non - tone language speakers in their perception of upward pitch changes or in their perception of subtle time changes . 
 moreover , this impairment can not be attributed to poor musical abilities since the impairment remains unchanged when individual differences in musical pitch - based processing is taken into account . 
 thus , the impairment appears highly specific and may reflect the influence of statistical regularities of tone languages . 
Introduction
Materials and Methods
Participants
Material and procedure
Results
Discussion
Conflict of Interest Statement