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 Cortex Auditory Neuroscience Editorial Notes Neural Oscillations Papers Psychology

Sto­ry time: Hen­ry & Obleser (2012) revisited

Sto­ry time: Some time in ear­ly 2011, I sat down with an Amer­i­can, fresh PhD grad­u­ate who had just joined my new lab, in a Leipzig bar (Café Can­tona; if you are inter­est­ed you can find this great 247 bar with exquis­ite food also in the acknowl­edg­ments of, e.g., Obleser & Eis­ner, Trends Cogn Sci, 2009).
To the day, I could still point you to the table she and I sat down at, and the wall I faced (which is notable because we actu­al­ly spent an unhealthy amount of time and mon­ey there over the years). Soon there­after, we grabbed a beer mat and start­ed scrib­bling waves and marked where we would place so-called tar­gets (psy­chol­o­gist lin­go) and talked a lot of gib­ber­ish about fre­quen­cy mod­u­la­tion. I remem­ber vidid­ly that I had just read an insane­ly long review paper on neur­al oscil­la­tions by Wolf­gang Klimesch (that, more in pass­ing, cit­ed old-school tales of Schmitt fil­ters by the late great Francesco Varela or pio­neers  sound­ing like record pro­duc­ers, Dust­man & Beck, 1965), while the young Amer­i­can oppo­site me turned out to be an—if adventurous—die-hard expert on audi­to­ry psychophysics.

Who would have thought that this very night would car­ry me towards tenure in three years’ time, and her around the globe as an esteemed young colleague.
When I nowa­days check Google schol­ar, I am amazed to see that already more than 100 oth­er papers have cit­ed what direct­ly grew out of that beer mat one and a half years later—not count­ing the many more papers this said post­doc, Mol­ly Hen­ry, has pro­duced since.

Here is the link to how excit­ed we were when the paper appeared in PNAS in 2012, and a link to the lit­tle movie a ger­man sci­ence pro­gram kind­ly pro­duced on all of this in 2013.

Categories
Ageing Auditory Cortex Auditory Neuroscience Auditory Perception Degraded Acoustics EEG / MEG Evoked Activity Hearing Loss Papers Psychology Publications Speech

New paper in press: Wöst­mann, Schröger, & Obleser in J Cogn Neurosci

Con­grat­u­la­tion to PhD stu­dent Malte Wöst­mann, who – with Erich Schröger and Jonas Obleser – has a new arti­cle in press at the Jour­nal of Cog­ni­tive Neuroscience

Acoustic detail guides atten­tion allo­ca­tion in a selec­tive lis­ten­ing task

forth­com­ing. We will update you accord­ing­ly as the paper comes online. We will share how­ev­er one of Malte’s fig­ures here as a teas­er: The paper utilis­es a very clas­sic com­po­nent of the evoked poten­tial, the con­tin­gent neg­a­tive vari­a­tion (the CNV; or a close rel­a­tive there­of, see the actu­al paper for dis­cus­sion) to study how old­er and younger lis­ten­ers allo­cate their atten­tion­al resources depend­ing on implic­it cues on to-be-expect­ed lis­ten­ing difficulties.

Screen Shot 2014-10-19 at 19.37.43

Ref­er­ences

  • Wöst­mann M1, Schröger E, Obleser J. Acoustic Detail Guides Atten­tion Allo­ca­tion in a Selec­tive Lis­ten­ing Task. J Cogn Neu­rosci. 2014 Nov 12:1–13. PMID: 25390200. [Open with Read]
Categories
Auditory Cortex Auditory Neuroscience Auditory Perception EEG / MEG Neural Oscillations Neural Phase Papers Psychology

New paper in press: Hen­ry, Her­rmann, & Obleser in PNAS

Con­grat­u­la­tions to Audi­to­ry Cognition’s very own Mol­ly Hen­ry who, with Björn Her­rmann and Jonas Obleser, is about to pub­lish yet anoth­er PNAS paper:

Entrained neur­al oscil­la­tions in mul­ti­ple fre­quen­cy bands co-mod­u­late behavior

Hen­ry MJ, Her­rmann B, & Obleser J. PNAS, in press.

We are very excit­ed about this one, as it harks back to Molly’s 2012 PNAS paper yet ups the ante some­what: How do neur­al oscil­la­tions behave towards a more real­is­ti­cal­ly com­plex mix­ture of acoustic reg­u­lar­i­ties, and how does lis­ten­ing behav­iour change as a func­tion of var­i­ous neur­al entrained phases?

read a short sum­ma­ry here…
Our sen­so­ry envi­ron­ment is teem­ing with com­plex rhyth­mic struc­ture, but how do envi­ron­men­tal rhythms (like those present in speech or music) affect our per­cep­tion? In a human elec­troen­cephalog­ra­phy study, we inves­ti­gat­ed how audi­to­ry per­cep­tion is affect­ed when brain rhythms (neur­al oscil­la­tions) syn­chro­nize with the com­plex rhyth­mic struc­ture in syn­thet­ic sounds that pos­sessed rhyth­mic char­ac­ter­is­tics sim­i­lar to speech. We found that neur­al phase in mul­ti­ple fre­quen­cy bands syn­chro­nized to the com­plex stim­u­lus rhythm and inter­act­ed to deter­mine tar­get-detec­tion per­for­mance. Crit­i­cal­ly, the influ­ence of neur­al oscil­la­tions on tar­get-detec­tion per­for­mance was present only for fre­quen­cy bands syn­chro­nized with the rhyth­mic struc­ture of the stim­uli. Our results elu­ci­date how mul­ti­ple fre­quen­cy bands shape the effec­tive neur­al pro­cess­ing of envi­ron­men­tal stimuli.

Stay tuned until after PNAS embar­go has been lifted!

[UPDATE]

PNAS paper is online. Check it out here.

Ref­er­ences

  • Hen­ry MJ1, Her­rmann B2, Obleser J1. Entrained neur­al oscil­la­tions in mul­ti­ple fre­quen­cy bands comod­u­late behav­ior. Proc Natl Acad Sci U S A. 2014 Oct 14;111(41):14935–40. PMID: 25267634. [Open with Read]
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
Auditory Cortex Auditory Neuroscience Auditory Perception Clinical relevance EEG / MEG Evoked Activity Hearing Loss Papers Psychology Publications

New paper in press: Her­rmann et al., Hear­ing Research [Update]

Audi­to­ry fil­ter width affects response mag­ni­tude but not fre­quen­cy speci­fici­ty in audi­to­ry cortex

This is fan­tas­tic news on a fri­day morn­ing: Obleser lab Post­doc Björn Her­rmann teamed up with his fel­low Post­docs Math­ias Scharinger and Mol­ly Hen­ry to study how spec­tral analy­sis in the audi­to­ry periph­ery (termed fre­quen­cy selec­tiv­i­ty) relates to pro­cess­ing in audi­to­ry cor­tex (termed fre­quen­cy speci­fici­ty; see also Björns paper in J Neu­ro­phys­i­ol 2013).

Giv­ing this an age­ing and hear­ing loss per­spec­tive and build­ing on the con­cept of audi­to­ry fil­ters in the cochlea (Moore et al.), Björn found that  the over­all N1 ampli­tude of lis­ten­ers, but not their fre­quen­cy-spe­cif­ic neur­al adap­ta­tion pat­terns, is cor­re­lat­ed with the pass-band of the audi­to­ry filter.

This sug­gests that widened audi­to­ry fil­ters are com­pen­sat­ed for by a response gain in fre­quen­cy-spe­cif­ic areas of audi­to­ry cor­tex; the paper is in press and forth­com­ing in Hear­ing Research.

 

Update:

Paper is avail­able online.

Ref­er­ences

  • Her­rmann B, Hen­ry MJ, Scharinger M, Obleser J. Audi­to­ry fil­ter width affects response mag­ni­tude but not fre­quen­cy speci­fici­ty in audi­to­ry cor­tex. Hear Res. 2013 Oct;304:128–36. PMID: 23876524. [Open with Read]
Categories
Auditory Neuroscience Auditory Speech Processing EEG / MEG Linguistics Papers Psychology Publications Speech

New paper out: Are ear­ly N100 and the late Gam­ma-band response neg­a­tive­ly cor­re­lat­ed in com­pre­hen­sion of degrad­ed speech?

Late 2010 was par­tic­u­lar­ly good to us:

Mul­ti­ple brain sig­na­tures of inte­gra­tion in the com­pre­hen­sion of degrad­ed speech

by Jonas Obleser and Son­ja Kotz, in Neu­roIm­age.

The final pdf will hope­ful­ly be avail­able online very soon. Mean­while the fig­ure below cap­tures our main results:

Ref­er­ences

  • Obleser J, Kotz SA. Mul­ti­ple brain sig­na­tures of inte­gra­tion in the com­pre­hen­sion of degrad­ed speech. Neu­roim­age. 2011 Mar 15;55(2):713–23. PMID: 21172443. [Open with Read]