Our new paper on neur­al entrain­ment with spec­tral fluc­tu­a­tions, and its effects on near-thresh­old audi­to­ry per­cep­tion is now online in the “ear­ly edi­tion” of PNAS:

Hen­ry, MJ & Obleser, J (in press):

Fre­quen­cy mod­u­la­tion entrains slow neur­al oscil­la­tions and opti­mizes human lis­ten­ing behavior

Pro­ceed­ings of the Nation­al Acad­e­my of Sci­ences of the Unit­ed States of Amer­i­ca (PNAS)

The human abil­i­ty to con­tin­u­ous­ly track dynam­ic envi­ron­men­tal stim­uli, in par­tic­u­lar speech, is pro­posed to prof­it from “entrain­ment” of endoge­nous neur­al oscil­la­tions, which involves phase reor­ga­ni­za­tion such that “opti­mal” phase comes into line with tem­po­ral­ly expect­ed crit­i­cal events, result­ing in improved pro­cess­ing. The cur­rent exper­i­ment goes beyond pre­vi­ous work in this domain by address­ing two thus far unan­swered ques­tions. First, how gen­er­al is neur­al entrain­ment to envi­ron­men­tal rhythms: Can neur­al oscil­la­tions be entrained by tem­po­ral dynam­ics of ongo­ing rhyth­mic stim­uli with­out abrupt onsets? Sec­ond, does neur­al entrain­ment opti­mize per­for­mance of the per­cep­tu­al sys­tem: Does human audi­to­ry per­cep­tion ben­e­fit from neur­al phase reor­ga­ni­za­tion? In a human elec­troen­cephalog­ra­phy study, lis­ten­ers detect­ed short gaps dis­trib­uted uni­form­ly with respect to the phase angle of a 3‑Hz fre­quen­cy-mod­u­lat­ed stim­u­lus. Lis­ten­ers’ abil­i­ty to detect gaps in the fre­quen­cy-mod­u­lat­ed sound was not uni­form­ly dis­trib­uted in time, but clus­tered in cer­tain pre­ferred phas­es of the mod­u­la­tion. More­over, the opti­mal stim­u­lus phase was indi­vid­u­al­ly deter­mined by the neur­al delta oscil­la­tion entrained by the stim­u­lus. Final­ly, delta phase pre­dict­ed behav­ior bet­ter than stim­u­lus phase or the event-relat­ed poten­tial after the gap. This study demon­strates behav­ioral ben­e­fits of phase realign­ment in response to fre­quen­cy-mod­u­lat­ed audi­to­ry stim­uli, over­all sug­gest­ing that fre­quen­cy fluc­tu­a­tions in nat­ur­al envi­ron­men­tal input pro­vide a pac­ing sig­nal for endoge­nous neur­al oscil­la­tions, there­by influ­enc­ing per­cep­tu­al processing.

NB: There is also a press release by the Max Planck Soci­ety on the topic.