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Tag: NeuroImage

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Auditory Cortex Auditory Neuroscience Auditory Perception EEG / MEG Neural Oscillations Papers Publications Speech

New paper: Her­rmann, Hen­ry, Hae­gens & Obleser in Neuroimage

And again, AC-Alum­ni Björn Her­rmann got a new paper in press / online at Neu­roIm­age on

Tem­po­ral expec­ta­tions and neur­al ampli­tude fluc­tu­a­tions in audi­to­ry cor­tex inter­ac­tive­ly influ­ence perception

Abstract
Align­ment of neur­al oscil­la­tions with tem­po­ral­ly reg­u­lar input allows lis­ten­ers to gen­er­ate tem­po­ral expec­ta­tions. How­ev­er, it remains unclear how behav­ior is gov­erned in the con­text of tem­po­ral vari­abil­i­ty: What role do tem­po­ral expec­ta­tions play, and how do they inter­act with the strength of neur­al oscil­la­to­ry activ­i­ty? Here, human par­tic­i­pants detect­ed near-thresh­old tar­gets in tem­po­ral­ly vari­able acoustic sequences. Tem­po­ral expec­ta­tion strength was esti­mat­ed using an oscil­la­tor mod­el and pre-tar­get neur­al ampli­tudes in audi­to­ry cor­tex were extract­ed from mag­ne­toen­cephalog­ra­phy sig­nals. Tem­po­ral expec­ta­tions mod­u­lat­ed tar­get-detec­tion per­for­mance, how­ev­er, only when neur­al delta-band ampli­tudes were large. Thus, slow neur­al oscil­la­tions act to gate influ­ences of tem­po­ral expec­ta­tion on per­cep­tion. Fur­ther­more, slow ampli­tude fluc­tu­a­tions gov­erned lin­ear and qua­drat­ic influ­ences of audi­to­ry alpha-band activ­i­ty on per­for­mance. By fus­ing a mod­el of tem­po­ral expec­ta­tion with neur­al oscil­la­to­ry dynam­ics, the cur­rent find­ings show that human per­cep­tion in tem­po­ral­ly vari­able con­texts relies on com­plex inter­ac­tions between mul­ti­ple neur­al fre­quen­cy bands.

Cheers.

Ref­er­ences

  • Her­rmann B1, Hen­ry MJ2, Hae­gens S3, Obleser J4. Tem­po­ral expec­ta­tions and neur­al ampli­tude fluc­tu­a­tions in audi­to­ry cor­tex inter­ac­tive­ly influ­ence per­cep­tion. Neu­roim­age. 2015 Sep 18;124(Pt A):487–497. PMID: 26386347. [Open with Read]
Categories
fMRI Linguistics Papers Publications Speech

New paper in Neu­roIm­age by Scharinger, Hen­ry, & Obleser [UPDATED]

A new paper is about to appear in Neu­roim­age on

Acoustic cue selec­tion and dis­crim­i­na­tion under degra­da­tion: Dif­fer­en­tial con­tri­bu­tions of the infe­ri­or pari­etal and pos­te­ri­or tem­po­ral cortices

by Math­ias Scharinger, Mol­ly J. Hen­ry, Jonas Obleser

Abstract
Cat­e­go­riz­ing sounds is vital for adap­tive human behav­ior. Accord­ing­ly, chang­ing lis­ten­ing sit­u­a­tions (exter­nal noise or periph­er­al hear­ing loss in aging) that may be accom­pa­nied by changes in dis­crim­inabil­i­ty, require lis­ten­ers to flex­i­bly adjust their cat­e­go­riza­tion strate­gies, some­times by changes in uti­liz­ing avail­able acoustic cues.
In this func­tion­al Mag­net­ic Res­o­nance Imag­ing (fMRI) study, we inves­ti­gate the cat­e­go­riza­tion of nov­el, non-speech audi­to­ry stim­uli that var­ied in over­all dis­crim­inabil­i­ty. More­over, we manip­u­late the rel­a­tive infor­ma­tive­ness of a dura­tion ver­sus a spec­tral-peak cue by adding spec­tral degra­da­tion in the mid­dle of the exper­i­ment. The results demon­strate dif­fer­ent roles of tem­po­ral and pari­etal brain areas for audi­to­ry cat­e­go­riza­tion: Tem­po­ral cor­tex acti­va­tion, in par­tic­u­lar in pos­te­ri­or parts of the right supe­ri­or tem­po­ral gyrus, scaled with dis­crim­inabil­i­ty, while left pari­etal cor­tex acti­va­tion was asso­ci­at­ed with changes in cue uti­liza­tion after the appli­ca­tion of spec­tral degradation.
This work extends pre­vi­ous research on audi­to­ry cat­e­go­riza­tion. Impor­tant­ly, the involve­ment of the left infe­ri­or pari­etal lob­ule in changes of cue uti­liza­tion sup­ports its role in domain-gen­er­al process­es that sup­port cat­e­go­riza­tion. Fur­ther, the sen­si­tiv­i­ty of the right pos­te­ri­or supe­ri­or tem­po­ral gyrus to stim­u­lus dis­crim­inabil­i­ty adds to pre­vi­ous find­ings regard­ing its role in audi­to­ry processing. 
[UPDATE] Link added.

Ref­er­ences

  • Scharinger M1, Hen­ry MJ2, Obleser J2. Acoustic cue selec­tion and dis­crim­i­na­tion under degra­da­tion: Dif­fer­en­tial con­tri­bu­tions of the infe­ri­or pari­etal and pos­te­ri­or tem­po­ral cor­tices. Neu­roim­age. 2015 Feb 1;106:373–81. PMID: 25481793. [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
EEG / MEG Linguistics Neural Oscillations Papers Publications

New paper out: Dis­so­ci­a­tion of alpha and theta oscil­la­tions Strauß, Kotz, Scharinger, Obleser

We are very hap­py to announce that PhD stu­dent Antje Strauß got her paper

Alpha and theta brain oscil­la­tions index dis­so­cia­ble process­es in spo­ken word recognition

accept­ed at Neu­roIm­age. Con­grat­u­la­tions! Find her paper here.

See the Abstract
Slow neur­al oscil­la­tions (∼ 1–15 Hz) are thought to orches­trate the neur­al process­es of spo­ken lan­guage com­pre­hen­sion. How­ev­er, func­tion­al sub­di­vi­sions with­in this broad range of fre­quen­cies are dis­put­ed, with most stud­ies hypoth­e­siz­ing only about sin­gle fre­quen­cy bands. The present study uti­lizes an estab­lished par­a­digm of spo­ken word recog­ni­tion (lex­i­cal deci­sion) to test the hypoth­e­sis that with­in the slow neur­al oscil­la­to­ry fre­quen­cy range, dis­tinct func­tion­al sig­na­tures and cor­ti­cal net­works can be iden­ti­fied at least for theta- (∼ 3–7 Hz) and alpha-fre­quen­cies (∼ 8–12 Hz). Lis­ten­ers per­formed an audi­to­ry lex­i­cal deci­sion task on a set of items that formed a word–pseudoword con­tin­u­um: rang­ing from (1) real words over (2) ambigu­ous pseu­do­words (devi­at­ing from real words only in one vow­el; com­pa­ra­ble to nat­ur­al mis­pro­nun­ci­a­tions in speech) to (3) pseu­do­words (clear­ly devi­at­ing from real words by ran­dom­ized syl­la­bles). By means of time–frequency analy­sis and spa­tial fil­ter­ing, we observed a dis­so­ci­a­tion into dis­tinct but simul­ta­ne­ous pat­terns of alpha pow­er sup­pres­sion and theta pow­er enhance­ment. Alpha exhib­it­ed a para­met­ric sup­pres­sion as items increas­ing­ly matched real words,in line with low­ered func­tion­al inhi­bi­tion in a left-dom­i­nant lex­i­cal pro­cess­ing net­work for more word-like input. Simul­ta­ne­ous­ly, theta pow­er in a bilat­er­al fron­to-tem­po­ral net­work was selec­tive­ly enhanced for ambigu­ous pseu­do­words only. Thus, enhanced alpha pow­er can neu­ral­ly “gate” lex­i­cal inte­gra­tion, while enhanced theta pow­er might index func­tion­al­ly more spe­cif­ic ambi­gu­i­ty-res­o­lu­tion process­es. To this end, a joint analy­sis of both fre­quen­cy bands pro­vides neur­al evi­dence for par­al­lel process­es in achiev­ing spo­ken word recognition.

Ref­er­ences

  • Strauβ A1, Kotz SA2, Scharinger M3, Obleser J3. Alpha and theta brain oscil­la­tions index dis­so­cia­ble process­es in spo­ken word recog­ni­tion. Neu­roim­age. 2014 Apr 18. PMID: 24747736. [Open with Read]
Categories
Auditory Cortex EEG / MEG Evoked Activity Linguistics Papers Publications

New Paper out: HELLO? in press (Neu­roIm­age)

Pho­net­ic cues instan­ta­neous­ly mapped onto dialec­tal cat­e­gories appear to be extract­ed at ear­ly moments in audi­to­ry speech per­cep­tion, as we try to show in our paper

You had me at “Hel­lo”: Rapid extrac­tion of dialect infor­ma­tion from spo­ken words

to appear in Neu­roIm­age (Math­ias Scharinger, Philip Mon­a­han, William Idsardi).

In a mod­i­fied pas­sive odd­ball design, we com­pare the Mis­match Neg­a­tiv­i­ty (MMN) to deviants in one Amer­i­can Eng­lish dialect (Stan­dard Amer­i­can Eng­lish or African-Amer­i­can Ver­nac­u­lar Eng­lish) to the stan­dards of the respec­tive oth­er dialect. In a con­trol con­di­tion, deviants with­in the same dialects have the same aver­aged acoustic dis­tance to their stan­dards than the cross-dialec­tal aver­aged acoustic dis­tance. Stan­dards and deviants were always spo­ken exem­plars of ‘Hel­lo’ in both dialects (ca. 500 ms). MMN effects are sig­nif­i­cant in the cross-dialec­tal con­di­tion only, imply­ing that a pure acoustic stan­dard-deviant dis­tance is not suf­fi­cient to elic­it sub­stan­tial mis­match effects. We inter­pret these find­ings, togeth­er with N1m source local­iza­tion data, as evi­dence for a rapid extrac­tion of dialect infor­ma­tion via salient acoustic-pho­net­ic cues. From the loca­tion and ori­en­ta­tion of the N1m source activ­i­ty, we can infer that dialect switch­es from stan­dards to deviants engage areas in supe­ri­or tem­po­ral sulcus/gyrus.

Ref­er­ences

  • Scharinger M, Mon­a­han PJ, Idsar­di WJ. You had me at “Hel­lo”: Rapid extrac­tion of dialect infor­ma­tion from spo­ken words. Neu­roim­age. 2011 Jun 15;56(4):2329–38. PMID: 21511041. [Open with Read]
Categories
Auditory Neuroscience Auditory Perception fMRI Linguistics Papers Publications Speech

New paper out: “Upstream del­e­ga­tion” for pro­cess­ing of com­plex syn­tax under degrad­ed acoustics

A new paper is about to appear in Neu­roim­age on the inter­ac­tion of syn­tac­tic com­plex­i­ty and acoustic degradation.

It is writ­ten by myself, PhD stu­dent Lars Mey­er, and Angela Friederi­ci. In a way, the paper brings togeth­er one of Angela’s main research ques­tions (which brain cir­cuits medi­ate the pro­cess­ing of syn­tax?) with a long-stand­ing inter­est of mine, that is, how do adverse lis­ten­ing sit­u­a­tions affect the com­pre­hen­sion of speech.

The paper is entitled

Dynam­ic assign­ment of neur­al resources in audi­to­ry com­pre­hen­sion of com­plex sentences

The paper first estab­lish­es that acoustic vari­ants of increas­ing­ly com­plex sen­tences essen­tial­ly behave like writ­ten ver­sions of these sentences.
The data then neat­ly show that pro­cess­ing chal­leng­ing (but legal) syn­tax under var­i­ous lev­els of degra­da­tion has a very dif­fer­ent effect on the neur­al cir­cuits involved than prof­it­ing from seman­tics: While the lat­ter has been shown pre­vi­ous­ly to involve more wide­spread, het­ero­modal brain areas, the dou­ble demand of increas­ing­ly com­plex syn­tax and an increas­ing­ly degrad­ed speech sig­nal (from which the com­plex syn­tax has to be parsed) elic­it an “upstream” shift of acti­va­tion back to less abstract pro­cess­ing areas in the supe­ri­or tem­po­ral and prefrontal/frontal cortex.

We ten­ta­tive­ly have termed this process “upstream del­e­ga­tion”. We have also tried and estab­lished a slight­ly unusu­al method to do jus­tice to the fMRI acti­va­tion data: We have includ­ed all z‑scores gath­ered along cer­tain spa­tial dimen­sions, irre­spec­tive of whether they were sub- or suprathresh­old, and have treat­ed them as dis­tri­b­u­tions. Check it out and let us know what you think.

Ref­er­ences

  • Obleser J, Mey­er L, Friederi­ci AD. Dynam­ic assign­ment of neur­al resources in audi­to­ry com­pre­hen­sion of com­plex sen­tences. Neu­roim­age. 2011 Jun 15;56(4):2310–20. PMID: 21421059. [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]