Categories
Attention Auditory Cortex Auditory Neuroscience Auditory Speech Processing EEG / MEG Papers Psychology Publications

New paper in press in Jour­nal of Neur­al Engi­neer­ing: Fiedler et al. on in-ear-EEG and the focus of audi­to­ry attention

Towards a brain-con­trolled hear­ing aid: PhD stu­dent Lorenz Fiedler shows how attend­ed and ignored audi­to­ry streams are dif­fer­ent­ly rep­re­sent­ed in the neur­al respons­es and how the focus of audi­to­ry atten­tion can be extract­ed from EEG sig­nals record­ed at elec­trodes placed inside the ear-canal and around the ear.

Abstract
Objec­tive. Con­ven­tion­al, mul­ti-chan­nel scalp elec­troen­cephalog­ra­phy (EEG) allows the iden­ti­fi­ca­tion of the attend­ed speak­er in con­cur­rent-lis­ten­ing (‘cock­tail par­ty’) sce­nar­ios. This implies that EEG might pro­vide valu­able infor­ma­tion to com­ple­ment hear­ing aids with some form of EEG and to install a lev­el of neu­ro-feed­back. Approach. To inves­ti­gate whether a listener’s atten­tion­al focus can be detect­ed from sin­gle-chan­nel hear­ing-aid-com­pat­i­ble EEG con­fig­u­ra­tions, we record­ed EEG from three elec­trodes inside the ear canal (‘in-Ear-EEG’) and addi­tion­al­ly from 64 elec­trodes on the scalp. In two dif­fer­ent, con­cur­rent lis­ten­ing tasks, par­tic­i­pants ( n  =  7) were fit­ted with indi­vid­u­al­ized in-Ear-EEG pieces and were either asked to attend to one of two dichot­i­cal­ly-pre­sent­ed, con­cur­rent tone streams or to one of two diot­i­cal­ly-pre­sent­ed, con­cur­rent audio­books. A for­ward encod­ing mod­el was trained to pre­dict the EEG response at sin­gle EEG chan­nels. Main results. Each indi­vid­ual par­tic­i­pants’ atten­tion­al focus could be detect­ed from sin­gle-chan­nel EEG response record­ed from short-dis­tance con­fig­u­ra­tions con­sist­ing only of a sin­gle in-Ear-EEG elec­trode and an adja­cent scalp-EEG elec­trode. The dif­fer­ences in neur­al respons­es to attend­ed and ignored stim­uli were con­sis­tent in mor­phol­o­gy (i.e. polar­i­ty and laten­cy of com­po­nents) across sub­jects. Sig­nif­i­cance. In sum, our find­ings show that the EEG response from a sin­gle-chan­nel, hear­ing-aid-com­pat­i­ble con­fig­u­ra­tion pro­vides valu­able infor­ma­tion to iden­ti­fy a listener’s focus of attention.
Categories
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
Auditory Speech Processing EEG / MEG Papers Speech

New Review Paper out: Wöst­mann, Fiedler & Obleser in Lan­guage, Cog­ni­tion and Neuroscience

A review arti­cle for those inter­est­ed in how to use mag­ne­to-/elec­troen­cephalog­ra­phy (M/EEG) to study speech com­pre­hen­sion. We pro­vide a his­tor­i­cal­ly informed overview over depen­dent mea­sures in the time and fre­quen­cy domain, high­light recent advances result­ing from these mea­sures and review the noto­ri­ous chal­lenges and solu­tions speech and lan­guage researchers are faced with when study­ing elec­tro­phys­i­o­log­i­cal brain responses.

Now avail­able online:

http://www.tandfonline.com/doi/full/10.1080/23273798.2016.1262051

Abstract

Mag­ne­to- and elec­troen­cephalo­graph­ic (M/EEG) sig­nals record­ed from the human scalp have allowed for sub­stan­tial advances for neur­al mod­els of speech com­pre­hen­sion over the past decades. These meth­ods are cur­rent­ly advanc­ing rapid­ly and con­tin­ue to offer unpar­al­leled insight in the near-to-real-time neur­al dynam­ics of speech pro­cess­ing. We pro­vide a his­tor­i­cal­ly informed overview over depen­dent mea­sures in the time and fre­quen­cy domain and high­light recent advances result­ing from these mea­sures. We dis­cuss the noto­ri­ous chal­lenges (and solu­tions) speech and lan­guage researchers are faced with when study­ing audi­to­ry brain respons­es in M/EEG. We argue that a key to under­stand­ing the neur­al basis of speech com­pre­hen­sion will lie in study­ing inter­ac­tions between the neur­al track­ing of speech and the func­tion­al neur­al net­work dynam­ics. This arti­cle is intend­ed for both, non-experts who want to learn how to use M/EEG to study speech com­pre­hen­sion and schol­ars aim­ing for an overview of state-of-the-art M/EEG analy­sis methods.

Categories
Auditory Cortex Auditory Neuroscience Auditory Perception Auditory Speech Processing Editorial Notes EEG / MEG Executive Functions Neural Oscillations Neural Phase Papers Publications Speech Uncategorized

[UPDATE] New paper in PNAS: Spa­tiotem­po­ral dynam­ics of audi­to­ry atten­tion syn­chro­nize with speech, Woest­mann et al.

Wöst­mann, Her­rmann, Maess and Obleser demon­strate that the hemi­spher­ic lat­er­al­iza­tion of neur­al alpha oscil­la­tions mea­sured in the mag­ne­toen­cephalo­gram (MEG) syn­chro­nizes with the speech sig­nal and pre­dicts lis­ten­ers’ speech comprehension.

Now avail­able online:

http://www.pnas.org/content/early/2016/03/18/1523357113

Press release:

https://www.uni-luebeck.de/forschung/aktuelles-zur-forschung/aktuelles-zur-forschung/artikel/aufmerksamkeit-in-wellen-erfolgreich-zuhoeren-im-rhythmus-der-sprache.html

spatiotemporal_dynamics

Abstract
Atten­tion plays a fun­da­men­tal role in selec­tive­ly pro­cess­ing stim­uli in our envi­ron­ment despite dis­trac­tion. Spa­tial atten­tion induces increas­ing and decreas­ing pow­er of neur­al alpha oscil­la­tions (8–12 Hz) in brain regions ipsi­lat­er­al and con­tralat­er­al to the locus of atten­tion, respec­tive­ly. This study test­ed whether the hemi­spher­ic lat­er­al­iza­tion of alpha pow­er codes not just the spa­tial loca­tion but also the tem­po­ral struc­ture of the stim­u­lus. Par­tic­i­pants attend­ed to spo­ken dig­its pre­sent­ed to one ear and ignored tight­ly syn­chro­nized dis­tract­ing dig­its pre­sent­ed to the oth­er ear. In the mag­ne­toen­cephalo­gram, spa­tial atten­tion induced lat­er­al­iza­tion of alpha pow­er in pari­etal, but notably also in audi­to­ry cor­ti­cal regions. This alpha pow­er lat­er­al­iza­tion was not main­tained steadi­ly but fluc­tu­at­ed in syn­chrony with the speech rate and lagged the time course of low-fre­quen­cy (1–5 Hz) sen­so­ry syn­chro­niza­tion. High­er ampli­tude of alpha pow­er mod­u­la­tion at the speech rate was pre­dic­tive of a listener’s enhanced per­for­mance of stream-spe­cif­ic speech com­pre­hen­sion. Our find­ings demon­strate that alpha pow­er lat­er­al­iza­tion is mod­u­lat­ed in tune with the sen­so­ry input and acts as a spa­tiotem­po­ral fil­ter con­trol­ling the read-out of sen­so­ry content.
Categories
Ageing Auditory Speech Processing Degraded Acoustics Hearing Loss Media Publications Speech

Quick inter­view for detektor.fm

Based on Malte’s recent J Neu­rosci study, Jonas did a brief inter­view for Ger­man radio detektor.fm today and talked lis­ten­ing effort, dig­i­tal phone lines, noise reduc­tion, and next-gen­er­a­tion hear­ing aids with host Tere­sa Nehm. (In Ger­man only.)

Categories
Auditory Speech Processing EEG / MEG Linguistics Papers Publications Speech

New edi­to­r­i­al in “Brain & Lan­guage”: Re-vis­it­ing the elec­tro­phys­i­ol­o­gy of language

I had the hon­our of guest-edit­ing a spe­cial issue for the clas­sic jour­nal “Brain and Lan­guage” and have thus con­tributed a brief edi­to­r­i­al (now online) to this issue. The spe­cial issue re-vis­its old themes and new leads in the elec­tro­phys­i­ol­o­gy of speech, lan­guage, and its precursors.

UPDATE: The full spe­cial issue appeared in Sep­tem­ber 2015 and all arti­cles are now acces­si­ble and citable. Thanks for your kind attention!

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
Ageing Auditory Neuroscience Auditory Speech Processing Clinical relevance Degraded Acoustics Executive Functions fMRI Hearing Loss Noise-Vocoded Speech Papers Publications Speech

New paper in press: Erb & Obleser, Fron­tiers in Sys­tems Neuroscience

Julia Erb just got accept­ed the third study of her PhD project,

Upreg­u­la­tion of cog­ni­tive con­trol net­works in old­er adults’ speech comprehension

It will appear in Fron­tiers in Sys­tems Neu­ro­science soon.

The data are an exten­sion (in old­er adults) of Julia’s Jour­nal of Neu­ro­science paper ear­li­er this year.

Ref­er­ences

  • Erb J, Obleser J. Upreg­u­la­tion of cog­ni­tive con­trol net­works in old­er adults’ speech com­pre­hen­sion. Front Syst Neu­rosci. 2013 Dec 24;7:116. PMID: 24399939. [Open with Read]