Open AccessNeural adaptation to silence in the human auditory cortex: a magnetoencephalographic study
Author(s) -
Okamoto Hidehiko,
Kakigi Ryusuke
Publication year - 2014
Publication title -
brain and behavior
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.915
H-Index - 41
ISSN - 2162-3279
DOI - 10.1002/brb3.290
Subject(s) - auditory cortex , magnetoencephalography , silence , adaptation (eye) , psychology , neuroscience , neural adaptation , communication , cognitive science , audiology , cognitive psychology , medicine , electroencephalography , art , aesthetics
Previous studies demonstrated that a decrement in the N1m response, a major deflection in the auditory evoked response, with sound repetition was mainly caused by bottom‐up driven neural refractory periods following brain activation due to sound stimulations. However, it currently remains unknown whether this decrement occurs with a repetition of silences, which do not induce refractoriness. Methods In the present study, we investigated decrements in N1m responses elicited by five repetitive silences in a continuous pure tone and by five repetitive pure tones in silence using magnetoencephalography. Results Repetitive sound stimulation differentially affected the N1m decrement in a sound type‐dependent manner; while the N1m amplitude decreased from the 1st to the 2nd pure tone and remained constant from the 2nd to the 5th pure tone in silence, a gradual decrement was observed in the N1m amplitude from the 1st to the 5th silence embedded in a continuous pure tone. Conclusions Our results suggest that neural refractoriness may mainly cause decrements in N1m responses elicited by trains of pure tones in silence, while habituation, which is a form of the implicit learning process, may play an important role in the N1m source strength decrements elicited by successive silences in a continuous pure tone.