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Auditory Cortex Auditory Perception Cross-Modal Integration EEG / MEG Neural Oscillations Perception

New paper out: Plöchl, Gas­ton, Mer­ma­gen, König & Hair­ston, Sci­en­tif­ic Reports

An arti­cle by our new AC group mem­ber Michael Plöchl from his PhD project in Osnabrück has been accept­ed for pub­li­ca­tion in Sci­en­tif­ic Reports. In their study, Plöchl, Gas­ton, Mer­ma­gen, König and Hair­ston demon­strate that “Oscil­la­to­ry activ­i­ty in audi­to­ry cor­tex reflects the per­cep­tu­al lev­el of audio-tac­tile integration”.


Cross-modal inter­ac­tions between sen­so­ry chan­nels have been shown to depend on both the spa­tial dis­par­i­ty and the per­cep­tu­al sim­i­lar­i­ty between the pre­sent­ed stim­uli. Here we inves­ti­gate the behav­ioral and neur­al inte­gra­tion of audi­to­ry and tac­tile stim­u­lus pairs at dif­fer­ent lev­els of spa­tial dis­par­i­ty. Addi­tion­al­ly, we mod­u­lat­ed the ampli­tudes of both stim­uli in either a coher­ent or non-coher­ent man­ner. We found that both audi­to­ry and tac­tile local­iza­tion per­for­mance was biased towards the stim­u­lus in the respec­tive oth­er modal­i­ty. This bias lin­ear­ly increas­es with stim­u­lus dis­par­i­ty and is more pro­nounced for coher­ent­ly mod­u­lat­ed stim­u­lus pairs. Analy­ses of elec­troen­cephalo­graph­ic (EEG) activ­i­ty at temporal–cortical sources revealed enhanced event-relat­ed poten­tials (ERPs) as well as decreased alpha and beta pow­er dur­ing bimodal as com­pared to uni­modal stim­u­la­tion. How­ev­er, while the observed ERP dif­fer­ences are sim­i­lar for all stim­u­lus com­bi­na­tions, the extent of oscil­la­to­ry desyn­chro­niza­tion varies with stim­u­lus dis­par­i­ty. More­over, when both stim­uli were sub­jec­tive­ly per­ceived as orig­i­nat­ing from the same direc­tion, the reduc­tion in alpha and beta pow­er was sig­nif­i­cant­ly stronger. These obser­va­tions sug­gest that in the EEG the lev­el of per­cep­tu­al inte­gra­tion is main­ly reflect­ed by changes in ongo­ing oscil­la­to­ry activity.