Discussion
NOTV
SECONDARY, CORTEX
Motor learning performance in our study—i.e., the acquisition of the motor skills necessary for touch-typing—was distinctly higher in TV compared to NOTV (see Fig. Until now, watching television is not yet known to influence adult motor learning performance or VSTM capacity. However, it is recognized that it can alter functional brain network connectivity and brain volume on principleWe therefore suggest that the intervention (i.e., intense visual stimulation through television) induced a specific state of cerebral information exchange, in which resources were focused on the imminent motor learning task, which required to transform visual input (i.e., the letters) into associated motor output (i.e., typing the correct characters on the keyboard). We assume that this state induced improved visuomotor integration and caused superior performance compared to the control group. We consider it possible that the intervention led to an earlier completion of the skill acquisition stage of motor learning and therefore to a faster entry into the consolidation stage accompanied by a better learning performance.The results of our experiment support those conclusions: RSN FC between VAN1 and DMN1 represents exchange between the precentral area and the mPFC (medial prefrontal cortex). Fingers are represented in this precentral area (Brodmann area 4p)Additionally, grey matter volume pre/post comparison through VBM revealed a volume increase in the left entorhinal cortex in TV. This area is known for its role in episodic memory consolidationTask-related FC change revealed a lowering of exchange between right DAN1 (right superior parietal lobule/IPS) and right DAN2 (temporal occipital pole) in TV while it increased in NOTV. Our other results would let expect inverted findings regarding right DAN1 and right DAN2. The superior parietal lobule is part of the secondary sensorimotor cortex. The IPS region is involved in the learning of finger motor sequence learning and visual attentionAdditionally, somatosensory perception investigated by MDT and GOT remained unaffected in our trial in both groups in comparison and within. The top-down processing of somatosensory information input (measured in GOT) seems not to be altered by visual stimulation through television and/or touch-typing training. MDT and its simple bottom-up mechanism is presumably too fastWe suggest that the intervention group TV entered a specific state of cerebral information processing because of intense visual stimulation and the continuous activation of visual information processing areas supported the interaction between handling of visual information and execution of the corresponding motor actions thus enabling better motor learning performance. A relevant aspect however is the fact, that the experimental procedure of our trial included not only an increased amount of visual stimulation through television for TV (from 180 min per day on average to 480 min per day, + 62.5%) but also a non-avoidable reduced amount of visual stimulation through television for NOTV (− 100%): Participants in NOTV usually and on average included 167 min per day of watching television in their daily routine. While planning the procedure of the study, the elimination of television for NOTV was the only feasible control group setting available. A group watching accustomed amounts of television was not practicable as control due to spatial and organisational constraints. This could be an influencing variable since it might function as an interventional alteration of daily routine. Anticorrelated changes in our FC results like the connectivity between right VAN-1 and right DMN-1 support this assumption. However, the main FC results which involve the change of left VIS-A interconnectivity is not anticorrelated. Additionally, the induced alteration of daily routine through increasing television viewing time by ~ 62.5% can be viewed as a much more impactful experimental intervention because it is rarely encountered outside of the experiment: Spending no time watching television is much more common in the participants age group than spending 480 min watching television. The average television viewing time for adults between 20 and 30 years of age is 75 min per dayConcerning other limitations of our study, our trial did not enable us to identify explicit causal interactions between motor learning performance and visual stimulation due to the necessary temporal segregation of these aspects. Additional groups with different intensities of visual stimulation or application of visual stimulation while performing fMRI would enable subsequent experiments to address these limitations. Cranial magnetic resonance spectroscopy in combination with visual stimulation might also provide insight into relevant causal neural mechanisms. Furthermore, visual stimulation based on television does additionally contain auditory information. This might influence FC in the analysed networks. Subsequent experiments could be designed to rely on visual media accompanied by minimal auditory information. Including participants of other age groups (e.g., seniors or teenagers) might also help to contextualise our findings.