Superior non-specific motor learning in the blind

Implicit sequence learning using auditory cues leads to modality-specific representations

The implicit acquisition of statistical information from the environment is considered a fundamental type of human learning. Paradigms using visually cued sequences have been frequently used to study implicit learning. However, learning sequences of auditory cues is likely to be important in domains such as language or music. In three experiments, we established a novel auditorily cued implicit perceptual-motor sequence learning paradigm to compare to traditional visually cued sequence learning and identify whether this type of learning generalizes across cue modality. Participants exhibited reliable sequence-specific learning to auditory cues in all three experiments (Experiments 1-3), which was generally not influenced by explicit knowledge (Experiment 2). In Experiment 3, a large drop in knowledge expression in the novel cue modality was observed, suggesting that the acquired implicit sequence knowledge depended largely on sensory-specific representations. Overall, auditorily cued learning was similar to, though proceeded faster than, learning in comparable visually cued sequence learning paradigms. Similarity between learning from cues in different sensory modalities suggests that there may be a common process for the automatic extraction of sequential statistical structure. However, the lack of robust transfer sequence knowledge across modalities argues against a purely domain-general learning mechanism for all kinds of sequences. By expanding quantitative methodologies to characterize sequence learning in the auditory domain, these findings illustrate the possibility of bridging research in sequence and statistical learning domains to identify common mechanisms of complex cognitive skill and language learning.

Cerebellar Transcranial Direct Current Stimulation in Children with Developmental Coordination Disorder: A Randomized, Double-Blind, Sham-Controlled Pilot Study

Evidence-based therapeutic options for children with developmental coordination disorder (DCD) are scarce. This work explored the effects of cerebellar anodal transcranial direct current stimulation (atDCS) on three 48 h-apart motor sequence learning and upper limb coordination sessions in children with DCD. The results revealed that, as compared to a Sham intervention (n = 10), cerebellar atDCS (n = 10) did not meaningfully improve execution speed but tended to reduce the number of execution errors during motor sequence learning. However, cerebellar atDCS did neither meaningfully influence offline learning nor upper limb coordination, suggesting that atDCS’ effects are circumscribed to its application duration. These results suggest that cerebellar atDCS could have beneficial effects as a complementary therapeutic tool for children with DCD.

Static magnetic stimulation of the primary motor cortex impairs online but not offline motor sequence learning

Static magnetic fields (SMFs) are known to alter neural activity, but evidence of their ability to modify learning-related neuroplasticity is lacking. The present study tested the hypothesis that application of static magnetic stimulation (SMS), an SMF applied transcranially via a neodymium magnet, over the primary motor cortex (M1) would alter learning of a serial reaction time task (SRTT). Thirty-nine participants took part in two experimental sessions separated by 24 h where they had to learn the SRTT with their right hand. During the first session, two groups received SMS either over contralateral (i.e., left) or ipsilateral (i.e., right) M1 while a third group received sham stimulation. SMS was not applied during the second session. Results of the first session showed that application of SMS over contralateral M1 impaired online learning as compared to both ipsilateral and sham groups, which did not differ. Results further revealed that application of SMS did not impair offline learning or relearning. Overall, these results are in line with those obtained using other neuromodulatory techniques believed to reduce cortical excitability in the context of motor learning and suggest that the ability of SMS to alter learning-related neuroplasticity is temporally circumscribed to the duration of its application.