Effects Of Auditory Perceptual Training On The Motor System In Auditory Processing In Spectrum Discrimination Task

Perceptual training refers to the enhancement of a specific perception through training task.At present,studies have demonstrated the utility of auditory perceptual training for repairing the impaired nervous system in the context of various neuropsychiatric disorders.However,the perceived gains obtained with this training method are not stable.Understanding the neural mechanisms of perceptual training will provide insights into the design of more stable training programs for neural injury.Recent studies have shown that the motor system is also activated during auditory responses,suggesting that auditory perceptual training may also enhance perceptual performance by affecting connections between motor related brain regions in auditory processing with the primary auditory cortex and Broca’s area.Probing into this influence will contribute to further understanding of auditory mechanisms and the longitudinal effects of perceptual learning on the brain.The magnetoencephalogram recording data of young and old subjects during the tone discrimination task were selected for analysis in this study.First,the behavioral data of the subjects were analyzed to investigate whether auditory perceptual training can improve their auditory perceptual abilities and the effects in different age groups.Source localization was then completed.The regions of interest,time windows of interest versus bands of interest were determined based on source localization results and time-frequency analysis.Ultimately,phase-locked value analysis,coherence analysis,and phase transfer entropy analysis in each time window of interest for each day’s data in the experiment were done in the overall group,the younger group,and the older group to estimate the functional connectivity of motor and auditory brain regions in auditory processing.The obtained analysis results will be statistically examined by different day contrasts to analyze the longitudinal effects of auditory perceptual training on the functional connectivity of motor and auditory brain compartments in auditory processing.The findings suggested that perceptual training could enhance the tone discrimination task performance,and the level of the subjects’ tone discrimination ability increased gradually with the progress of training,reaching the optimal level on the 9th day.Perceptual training had different enhancing effects for older and younger adults.The enhancement of task performance in young adults was only demonstrated at the optimal level of tone discrimination,whereas the enhancement of task performance in older adults was demonstrated at both the optimal level of tone discrimination and the overall level of tone discrimination.The principle of the role of auditory perceptual training on the improvement of tone discrimination ability may be that perceptual training promotes the encoding efficiency of the inferior frontal gyrus together with the superior limbic gyrus and the central sulcus in co-regulating auditory attention before the auditory task and in the auditory response,leading to the higher efficiency in discriminating tones.In the “task preparation phase”,phase synchronization between the central sulcus and parts of the inferior frontal gyrus decreased after 5 days of training and persisted until the end of the whole training;In the auditory response phase,the coherence between the supramarginal gyrus with the inferior frontal gyrus and the coherence between the postcentral gyrus with the inferior frontal gyrus were significantly reduced after 9 days of training and returned to a level of the first day on day 12.The difference of the effect of perceptual training on the group of different ages was also observed.The functional connectivity changes of the younger group subjects were similar to those of the overall group,whereas the older group showed no significant changes after 12 days of training.