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Category: Perception

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Adaptive Control Attention Auditory Cortex Auditory Neuroscience Auditory Perception Auditory Speech Processing Degraded Acoustics EEG / MEG Evoked Activity Executive Functions Neural Oscillations Noise-Vocoded Speech Papers Perception Psychology Publications Speech

New paper in press in Cere­bral Cor­tex: Wöst­mann et al. on ignor­ing degrad­ed speech

Audi­to­ry Cognition’s own Malte Wöst­mann is in press in Cere­bral Cor­tex with his lat­est offer­ing on how atten­tion­al con­trol man­i­fests in alpha pow­er changes: Ignor­ing speech can be ben­e­fi­cial (if com­pre­hend­ing speech poten­tial­ly detracts from anoth­er task), and we here show how this change in lis­ten­ing goals turns around the pat­tern of alpha-pow­er changes with chang­ing speech degra­da­tion. (We will update as the paper becomes avail­able online.)

Wöst­mann, M., Lim, S.J., & Obleser, J. (2017). The human neur­al alpha response to speech is a proxy of atten­tion­al con­trol. Cere­bral Cor­tex. In press.

 

Abstract
Human alpha (~10 Hz) oscil­la­to­ry pow­er is a promi­nent neur­al mark­er of cog­ni­tive effort. When lis­ten­ers attempt to process and retain acousti­cal­ly degrad­ed speech, alpha pow­er enhances. It is unclear whether these alpha mod­u­la­tions reflect the degree of acoustic degra­da­tion per se or the degra­da­tion-dri­ven demand to a listener’s atten­tion­al con­trol. Using an irrel­e­vant-speech par­a­digm in elec­troen­cephalog­ra­phy (EEG), the cur­rent exper­i­ment demon­strates that the neur­al alpha response to speech is a sur­pris­ing­ly clear proxy of top-down con­trol, entire­ly dri­ven by the lis­ten­ing goals of attend­ing ver­sus ignor­ing degrad­ed speech. While (n=23) lis­ten­ers retained the ser­i­al order of 9 to-be-recalled dig­its, one to-be-ignored sen­tence was pre­sent­ed. Dis­tractibil­i­ty of the to-be-ignored sen­tence para­met­ri­cal­ly var­ied in acoustic detail (noise-vocod­ing), with more acoustic detail of dis­tract­ing speech increas­ing­ly dis­rupt­ing lis­ten­ers’ ser­i­al mem­o­ry recall. Where pre­vi­ous stud­ies had observed decreas­es in pari­etal and audi­to­ry alpha pow­er with more acoustic detail (of tar­get speech), alpha pow­er here showed the oppo­site pat­tern and increased with more acoustic detail in the speech dis­trac­tor. In sum, the neur­al alpha response reflects almost exclu­sive­ly a listener’s exer­tion of atten­tion­al con­trol, which is deci­sive for whether more acoustic detail facil­i­tates com­pre­hen­sion (of attend­ed speech) or enhances dis­trac­tion (of ignored speech).
Categories
EEG / MEG Neural Oscillations Papers Perception Publications

New paper in press: Alavash et al. in Net­work Neuroscience

We are proud to pub­lish our recent study on how net­work dynam­ics of beta-band oscil­la­tions in the human brain medi­ate response speed in audi­to­ry per­cep­tu­al deci­sion-mak­ing. This work will appear soon in the first vol­ume of the promis­ing jour­nal Net­work Neu­ro­science.

Pre-print link http://biorxiv.org/content/early/2016/12/19/095356

Abstract
Per­cep­tu­al deci­sions vary in the speed at which we make them. Evi­dence sug­gests that trans­lat­ing sen­so­ry infor­ma­tion into behav­ioral deci­sions relies on dis­trib­uted inter­act­ing neur­al pop­u­la­tions, with deci­sion speed hing­ing on pow­er mod­u­la­tions of neur­al oscil­la­tions. Yet, the depen­dence of per­cep­tu­al deci­sions on the large-scale net­work orga­ni­za­tion of cou­pled neur­al oscil­la­tions has remained elu­sive. We mea­sured mag­ne­toen­cephalog­ra­phy sig­nals in human lis­ten­ers who judged acoustic stim­uli made of care­ful­ly titrat­ed clouds of tone sweeps. These stim­uli were used under two task con­texts where the par­tic­i­pants judged the over­all pitch or direc­tion of the tone sweeps. We traced the large-scale net­work dynam­ics of source-pro­ject­ed neur­al oscil­la­tions on a tri­al-by-tri­al basis using pow­er enve­lope cor­re­la­tions and graph-the­o­ret­i­cal net­work dis­cov­ery. Under both tasks, faster deci­sions were pre­dict­ed by high­er seg­re­ga­tion and low­er inte­gra­tion of cou­pled beta-band (~16–28 Hz) oscil­la­tions. We also uncov­ered brain net­work states that pro­mot­ed faster deci­sions and emerged from low­er-order audi­to­ry and high­er-order con­trol brain areas. Specif­i­cal­ly, deci­sion speed in judg­ing tone-sweep direc­tion crit­i­cal­ly relied on nodal net­work con­fig­u­ra­tions of ante­ri­or tem­po­ral, cin­gu­late and mid­dle frontal cor­tices. Our find­ings sug­gest that glob­al net­work com­mu­ni­ca­tion dur­ing per­cep­tu­al deci­sion-mak­ing is imple­ment­ed in the human brain by large-scale cou­plings between beta-band neur­al oscillations.
Categories
Adaptive Control Auditory Neuroscience EEG / MEG Evoked Activity Hearing Loss Neural Phase Perception Preprints (not peer-reviewed yet) Publications Speech Uncategorized

New preprint paper: Fiedler et al. on pre­dict­ing focus of atten­tion from in-ear EEG

Very proud: PhD stu­dent Lorenz Fiedler goes live (pre-peer-review) with his work of pre­dict­ing the focus of atten­tion in sin­gle-chan­nel/­for­ward mod­els in in-ear EEG!
Here is the preprint of the paper, which now will under­go peer-review. Thanks for check­ing it out!

In-Ear results Fiedler

Categories
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”.

oscillatory_activity

Abstract
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.
Categories
Degraded Acoustics EEG / MEG Linguistics Neural Oscillations Neural Phase Papers Perception Publications Speech

New paper in press in the Jour­nal of Neu­ro­science: Strauß, Hen­ry, Scharinger, & Obleser

Con­grat­u­la­tions to just-grad­u­at­ed for­mer AC PhD stu­dent and fresh GIPSA/Grenoble Post­doc Antje Strauß, who today had the last data set from her PhD the­sis accept­ed as a paper in The Jour­nal of Neu­ro­science. We are all very happy!

The paper is enti­tled “Alpha phase deter­mines suc­cess­ful lex­i­cal deci­sion in noise” and con­tains arguably the first data set to extend prin­ci­ples of (alpha, 8–12 Hz) pre-stim­u­lus phase depen­dence from low-lev­el psy­chophysics to more com­plex lan­guage or cog­ni­tive process­es, here: lex­i­cal decision.

A big hel­lo to AC friend and col­league Niko Busch, by the way, whose bifur­ca­tion index mea­sure served our pur­pos­es very well here!

We will update accord­ing­ly, but mean­while, here is the abstract and my favourite fig­ure from the paper.

Abstract
Psy­chophys­i­cal tar­get detec­tion has been shown to be mod­u­lat­ed by slow oscil­la­to­ry brain phase. How­ev­er, thus far, only low-lev­el sen­so­ry stim­uli have been used as tar­gets. The cur­rent human elec­troen­cephalog­ra­phy study exam­ined the influ­ence of neur­al oscil­la­to­ry phase on a lex­i­cal-deci­sion task per­formed for stim­uli embed­ded in noise. Neur­al phase angles were com­pared for cor­rect ver­sus incor­rect lex­i­cal deci­sions using a phase bifur­ca­tion index, which quan­ti­fies dif­fer­ences in mean phase angles and phase con­cen­tra­tions between cor­rect and incor­rect tri­als. Neur­al phase angles in the alpha fre­quen­cy range (8–12 Hz) over right ante­ri­or sen­sors were approx­i­mate­ly anti-phase in a pre-stim­u­lus time win­dow, and thus suc­cess­ful­ly dis­tin­guished between cor­rect and incor­rect lex­i­cal deci­sions. More­over, alpha-band oscil­la­tions were again approx­i­mate­ly anti-phase across par­tic­i­pants for cor­rect ver­sus incor­rect tri­als dur­ing a lat­er peri-stim­u­lus time-win­dow (around 500 ms) at left-cen­tral elec­trodes. Strik­ing­ly, lex­i­cal deci­sion accu­ra­cy was not pre­dict­ed by either ERPs or oscil­la­to­ry pow­er mea­sures. We sug­gest that cor­rect lex­i­cal deci­sions depend both on suc­cess­ful sen­so­ry pro­cess­ing, which is made pos­si­ble by the align­ment of stim­u­lus onset with an opti­mal alpha phase, as well as inte­gra­tion and weight­ing of deci­sion­al infor­ma­tion, which is cou­pled to alpha phase imme­di­ate­ly fol­low­ing the crit­i­cal manip­u­la­tion that dif­fer­en­ti­at­ed words from pseu­do­words. The cur­rent study con­sti­tutes a first step towards char­ac­ter­iz­ing the role of dynam­ic oscil­la­to­ry brain states for high­er cog­ni­tive func­tions such as spo­ken word recognition.

Untitled copy

Categories
Auditory Neuroscience Auditory Perception Auditory Speech Processing Clinical relevance Degraded Acoustics Gyrus Angularis Linguistics Noise-Vocoded Speech Papers Perception Psychology Speech

New paper in press: Hartwigsen, Golombek, & Obleser in Cor­tex [UPDATED]

In a col­lab­o­ra­tion with the Uni­ver­si­ty Clin­ic of Leipzig and Prof Dr Gesa Hartwigsen (now Uni­ver­si­ty of Kiel), a new paper is to appear in “Cor­tex”, in the forth­com­ing spe­cial issue on Pre­dic­tion in Speech and Lan­guage, edit­ed by Alessan­dro Tavano and AC alum­nus Math­ias Scharinger.

Repet­i­tive tran­scra­nial mag­net­ic stim­u­la­tion over left angu­lar gyrus mod­u­lates the pre­dictabil­i­ty gain in degrad­ed speech comprehension

Hartwigsen G, Golombek T, & Obleser J.

See abstract
Increased neur­al activ­i­ty in left angu­lar gyrus (AG) accom­pa­nies suc­cess­ful com­pre­hen­sion of acousti­cal­ly degrad­ed but high­ly pre­dictable sen­tences, as pre­vi­ous func­tion­al imag­ing stud­ies have shown. How­ev­er, it remains unclear whether the left AG is causal­ly rel­e­vant for the com­pre­hen­sion of degrad­ed speech. Here, we applied tran­sient vir­tu­al lesions to either the left AG or supe­ri­or pari­etal lobe (SPL, as a con­trol area) with repet­i­tive tran­scra­nial mag­net­ic stim­u­la­tion (rTMS) while healthy vol­un­teers lis­tened to and repeat­ed sen­tences with high- vs. low-pre­dictable end­ings and dif­fer­ent noise vocod­ing lev­els. We expect­ed that rTMS of AG should selec­tive­ly mod­u­late the pre­dictabil­i­ty gain (i.e., the com­pre­hen­sion ben­e­fit from sen­tences with high-pre­dictable end­ings) at a medi­um degra­da­tion lev­el. We found that rTMS of AG indeed reduced the pre­dictabil­i­ty gain at a medi­um degra­da­tion lev­el of 4‑band noise vocod­ing (rel­a­tive to con­trol rTMS of SPL). In con­trast, the behav­ioral per­tur­ba­tion induced by rTMS reversed with increased sig­nal qual­i­ty. Hence, at 8‑band noise vocod­ing, rTMS over AG vs. SPL increased the over­all pre­dictabil­i­ty gain. Togeth­er, these results show that the degree of the rTMS inter­fer­ence depend­ed joint­ly on sig­nal qual­i­ty and pre­dictabil­i­ty. Our results pro­vide the first causal evi­dence that the left AG is a crit­i­cal node for facil­i­tat­ing speech com­pre­hen­sion in chal­leng­ing lis­ten­ing conditions.

Screen Shot 2014-09-11 at 21.19.17

Check it out soon!

Ref­er­ences

  • Hartwigsen G1, Golombek T2, Obleser J3. Repet­i­tive tran­scra­nial mag­net­ic stim­u­la­tion over left angu­lar gyrus mod­u­lates the pre­dictabil­i­ty gain in degrad­ed speech com­pre­hen­sion. Cor­tex. 2014 Sep 18. PMID: 25444577. [Open with Read]
Categories
fMRI Papers Perception Publications

New paper in press: Her­rmann et al in NeuroImage

Dr Björn Her­rmann did it again, and is in press at Neu­roIm­age with Her­rmann, Hen­ry, Scharinger, & Obleser on

Sup­ple­men­tary motor area acti­va­tions pre­dict indi­vid­ual dif­fer­ences in tem­po­ral-change sen­si­tiv­i­ty and its illu­so­ry distortions

See abstract
Per­cep­tion of time and tem­po­ral change are crit­i­cal for human cog­ni­tion. Yet, per­cep­tion of tem­po­ral change is sus­cep­ti­ble to con­tex­tu­al influ­ences such as changes of a sound’s pitch. Using func­tion­al mag­net­ic res­o­nance imag­ing (fMRI), the cur­rent study aimed to inves­ti­gate per­cep­tion of tem­po­ral rate change and pitch-induced illu­so­ry dis­tor­tions. In a 6 × 6 design, human par­tic­i­pants (N=19) lis­tened to fre­quen­cy-mod­u­lat­ed sounds (~4 Hz) that var­ied over time in both mod­u­la­tion rate and pitch. Par­tic­i­pants judged the direc­tion of rate change (‘speed­ing up’ vs. ‘slow­ing down’), while ignor­ing changes in pitch. Behav­ioral­ly, rate judg­ments were strong­ly biased by pitch changes: Par­tic­i­pants per­ceived rate to slow down when pitch decreased and to speed up when pitch increased (‘rate-change illu­sion’). The fMRI data revealed acti­va­tion increas­es with increas­ing task dif­fi­cul­ty in pre-SMA, left puta­men, and right IFG/insula. Impor­tant­ly, acti­va­tion in pre-SMA was linked to the per­cep­tu­al sen­si­tiv­i­ty to dis­crim­i­nate rate changes and, togeth­er with the left puta­men, to rel­a­tive reduc­tions in sus­cep­ti­bil­i­ty to pitch-induced illu­so­ry dis­tor­tions. Right IFG/insula acti­va­tions, how­ev­er, only scaled with task dif­fi­cul­ty. These data offer a dis­tinc­tion between regions whose acti­va­tions scale with per­cep­tu­al sen­si­tiv­i­ty to fea­tures of time (pre-SMA) and those that more gen­er­al­ly sup­port behav­ing in dif­fi­cult lis­ten­ing con­di­tions (IFG/insula). Hence, the data under­score that indi­vid­ual dif­fer­ences in time per­cep­tion can be relat­ed to dif­fer­ent pat­terns of neu­ro­func­tion­al activation.

Ref­er­ences

  • Her­rmann B1, Hen­ry MJ2, Scharinger M2, Obleser J2. Sup­ple­men­tary motor area acti­va­tions pre­dict indi­vid­ual dif­fer­ences in tem­po­ral-change sen­si­tiv­i­ty and its illu­so­ry dis­tor­tions. Neu­roim­age. 2014 Jul 23;101C:370–379. PMID: 25064666. [Open with Read]
Categories
Ageing Auditory Perception Degraded Acoustics EEG / MEG Hearing Loss Neural Oscillations Papers Perception Publications Speech

Strauß strikes again — fron­tiers in Human Neuroscience

It’s only a week ago that we updat­ed you about Antje’s lat­est pub­li­ca­tion at Neu­roIm­age. Today, there is a anoth­er one com­ing in; Antje’s, Mal­te’s & Jonas’ per­spec­tive arti­cle on cor­ti­cal alpha oscil­la­tions is in press at fron­tiers in HUMAN NEUROSCIENCE.

Cor­ti­cal alpha oscil­la­tions as a tool for audi­to­ry selec­tive inhibition

— Strauß, Wöst­mann & Obleser

See abstract
Lis­ten­ing to speech is often demand­ing because of sig­nal degra­da­tions and the pres­ence of dis­tract­ing sounds (i.e., “noise”). The ques­tion how the brain achieves the task of extract­ing only rel­e­vant infor­ma­tion from the mix­ture of sounds reach­ing the ear (i.e., “cock­tail par­ty prob­lem”) is still open. In anal­o­gy to recent find­ings in vision, we pro­pose cor­ti­cal alpha (~10 Hz) oscil­la­tions mea­sur­able using M/EEG as a piv­otal mech­a­nism to selec­tive­ly inhib­it the pro­cess­ing of noise to improve audi­to­ry selec­tive atten­tion to task-rel­e­vant sig­nals. We review ini­tial evi­dence of enhanced alpha activ­i­ty in selec­tive lis­ten­ing tasks, sug­gest­ing a sig­nif­i­cant role of alpha-mod­u­lat­ed noise sup­pres­sion in speech. We dis­cuss the impor­tance of dis­so­ci­at­ing between noise inter­fer­ence in the audi­to­ry periph­ery (i.e., ener­getic mask­ing) and noise inter­fer­ence with more cen­tral cog­ni­tive aspects of speech pro­cess­ing (i.e., infor­ma­tion­al mask­ing). Final­ly, we point out the adverse effects of age-relat­ed hear­ing loss and/or cog­ni­tive decline on audi­to­ry selec­tive inhi­bi­tion. With this per­spec­tive arti­cle, we set the stage for future stud­ies on the inhibito­ry role of alpha oscil­la­tions for speech pro­cess­ing in chal­leng­ing lis­ten­ing situations.

Ref­er­ences

  • Strauß A1, Wöst­mann M2, Obleser J1. Cor­ti­cal alpha oscil­la­tions as a tool for audi­to­ry selec­tive inhi­bi­tion. Front Hum Neu­rosci. 2014 May 28;8:350. PMID: 24904385. [Open with Read]