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Author: Jonas

Categories
Auditory Cortex EEG / MEG Evoked Activity Papers Place of Articulation Features Publications

New Paper out: Com­pre­hen­sive map of a language’s vow­el space

We are glad to announce that our paper (Math­ias Scharinger, Saman­tha Poe, & William Idsar­di) on cor­ti­cal rep­re­sen­ta­tions of Turk­ish vow­els is in press in Jour­nal of Cog­ni­tive Neu­ro­science. In this paper, we extend pre­vi­ous meth­ods of obtain­ing cen­ters of cor­ti­cal activ­i­ty evoked by vow­el exem­plars (e.g. Obleser et al., 2003, on Ger­man) and pro­vide an N1m ECD (Equiv­a­lent Cur­rent Dipole) map of the entire vow­el space of Turk­ish. Intrigu­ing­ly, ECD loca­tions mapped near­ly per­fect to loca­tions in F2/F1 space, although our mod­el com­par­i­son sug­gest­ed that inclu­sion of dis­crete fea­ture based pre­dic­tors for both loca­tions as well as col­lo­ca­tions of vow­els in audi­to­ry cor­tex improves the mod­el fits sub­stan­tial­ly. We dis­cuss the find­ings on the back­ground of neur­al cod­ing schemes for speech-relat­ed audi­to­ry categories.

Fig­ure 1: Loca­tions of Turk­ish vow­el stim­uli in acoustic space (F1,F2, top pan­el) and N1m ECD loca­tions in cor­ti­cal space (lat­er­al-medi­al/an­te­ri­or-pos­te­ri­or/in­fe­ri­or-supe­ri­or, bot­tom panel).

UPDATE: Paper is avail­able here.

Ref­er­ences

  • Scharinger M, Idsar­di WJ, Poe S. A com­pre­hen­sive three-dimen­sion­al cor­ti­cal map of vow­el space. J Cogn Neu­rosci. 2011 Dec;23(12):3972–82. PMID: 21568638. [Open with Read]
Categories
Auditory Cortex Auditory Neuroscience Auditory Working Memory Clinical relevance EEG / MEG Neural Oscillations Papers Publications Speech

New paper out: Alpha oscil­la­tions in audition

I am also delight­ed to report the fruits of a very recent col­lab­o­ra­tion with Nathan Weisz and his OBOB lab at the Uni­ver­si­ty of Kon­stanz, Germany.

Alpha Rhythms in Audi­tion: Cog­ni­tive and Clin­i­cal Perspectives

In this review paper, which appears in the new, excit­ing “Fron­tiers in Psy­chol­o­gy” jour­nal, we sum the recent evi­dence that alpha oscil­la­tions (here broad­ly defined from 6 to 13 Hz) are play­ing a very inter­est­ing role in the audi­to­ry sys­tem, just as they do in the visu­al and the somatosen­so­ry system.

In essence, we back Ole Jensen’s and oth­ers’ quite pari­mo­nious idea of alpha as a func­tion­al inhi­bi­tion / gat­ing sys­tem across cor­ti­cal areas.

From our own lab, pre­lim­i­nary data from two recent exper­i­ments is includ­ed: On the role of alpha osil­la­tions as a poten­tial mark­er for speech intel­li­gi­bil­i­ty and its acoustic deter­mi­nants, as well as on speech degra­da­tion and work­ing mem­o­ry load and their com­bined reflec­tion in alpha pow­er increases.

 

NB — the final pdf is still lack­ing, and Front Psy­chol is still not list­ed in PubMed. This should not stop you from sub­mit­ting to their excit­ing new jour­nals, as the review process is very fair and effi­cient and the out­reach via free avail­abil­i­ty promis­es to be considerable.

Ref­er­ences

  • Weisz N, Hart­mann T, Müller N, Lorenz I, Obleser J. Alpha rhythms in audi­tion: cog­ni­tive and clin­i­cal per­spec­tives. Front Psy­chol. 2011 Apr 26;2:73. PMID: 21687444. [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 Cortex Auditory Speech Processing EEG / MEG Evoked Activity Linguistics Papers Place of Articulation Features Publications

Paper in press: Are labi­als special?

This went online just a day before Christmas:

Neu­ro­mag­net­ic evi­dence for a fea­t­ur­al dis­tinc­tion of Eng­lish con­so­nants: Sen­sor- and source-space data

by Math­ias Scharinger, Jen­nifer Mer­ick­el, Joshua Riley, and William Idsardi
http://dx.doi.org/10.1016/j.bandl.2010.11.002

We want­ed to look at fea­t­ur­al (cat­e­gor­i­cal) place of artic­u­la­tion dis­tinc­tions in Eng­lish con­so­nants, and select­ed labi­al and coro­nal frica­tives and glides for an MMN study. In this study, we looked at sen­sor- and source-space effects of labi­al deviants pre­ced­ed by coro­nal stan­dards and coro­nal deviants pre­ced­ed by labi­al stan­dards, across the two man­ners of artic­u­la­tion, i.e. frica­tives and glides. Note that there are rather dra­mat­ic acoustic dif­fer­ences between these man­ners of artic­u­la­tion: uncor­re­lat­ed noise through nar­row con­stric­tion vs. vow­el-like sound with typ­i­cal res­o­nance fre­quen­cies. We found con­sis­tent place-of-artic­u­la­tion effects, inde­pen­dent of man­ner of artic­u­la­tion: labi­al deviants pro­duced larg­er MMN, con­tra a direc­tion­al hypoth­e­sis of under­spec­i­fi­ca­tion, and dipole source loca­tions fol­lowed the Obleser-gra­di­ent in that labi­als elicit­ed N1m dipoles ante­ri­or to dipoles of coro­nals in audi­to­ry cortex.

Ref­er­ences

  • Scharinger M, Mer­ick­el J, Riley J, Idsar­di WJ. Neu­ro­mag­net­ic evi­dence for a fea­t­ur­al dis­tinc­tion of Eng­lish con­so­nants: sen­sor- and source-space data. Brain Lang. 2011 Feb;116(2):71–82. PMID: 21185073. [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]
Categories
Auditory Cortex Auditory Neuroscience fMRI Linguistics Papers Publications Speech

New paper out: Pat­terns of vow­el and con­so­nant sensitivity

Dear fol­low­ers of the slow­ly emerg­ing Obleser lab,
I am glad to present to you a new paper that was pub­lished last week:

“Seg­re­ga­tion of vow­els and con­so­nants in human audi­to­ry cor­tex: Evi­dence for dis­trib­uted hier­ar­chi­cal orga­ni­za­tion”

by Jonas Obleser, Amber Leaver, John Van­Meter, and Josef P. Rauscheck­er, in Fron­tiers in Psy­chol­o­gy. It was sub­mit­ted to the new sec­tion of Audi­to­ry Cog­ni­tive Neu­ro­science and wil be one of the first papers to appear in this section.

The paper present evi­dence from a small-vox­el 3T study we scanned in George­town a few years ago that

  • nat­u­ral­ly coar­tic­u­lat­ed syl­la­bles like /de:/ or /gu:/ con­tain enough infor­ma­tion for a machine learn­ing algo­rithm to tell vow­el cat­e­gories (front vs back) from each oth­er, and also stop con­so­nant cat­e­gories (/d/ vs /g/) – across participants!
  • with a sur­pris­ing­ly sparse over­lap across sub­ar­eas of the supe­ri­or tem­po­ral cor­tex, how­ev­er and
  • data from the left ante­ri­or region of inter­est (defined as left and ante­ri­or of a prob­a­bilis­tic pri­ma­ry audi­to­ry cor­tex def­i­n­i­tion sen­su Rademach­er et al., 2001) appears par­tic­u­lar­ly “geared” towards these speech–from-speech classifications.

The paper was edit­ed by Mic­ah Mur­ray and received very con­struc­tive reviews from Elia Formisano and Lee Miller (a fea­ture of Fron­tiers jour­nals is to dis­close the peer review­ers after accep­tance; nice fea­ture, I think.)

The final pdf is avail­able online now, and it seems that the Pubmed list­ings for the Fron­tiers in psy­chol­o­gy jour­nal are about to hap­pen very soon.

Ref­er­ences

  • Obleser J, Leaver AM, Van­meter J, Rauscheck­er JP. Seg­re­ga­tion of vow­els and con­so­nants in human audi­to­ry cor­tex: evi­dence for dis­trib­uted hier­ar­chi­cal orga­ni­za­tion. Front Psy­chol. 2010 Dec 24;1:232. PMID: 21738513. [Open with Read]
Categories
Editorial Notes Events

Autumn trav­els

Before our lit­tle lab gets into full throt­tle in late 2010/early 2011 with a great selec­tion of new stu­dents and post­docs join­ing, I will be tour­ing a bit with my most recent data. 

For late Octo­ber, my for­mer co-super­vi­sor Adi­ti Lahiri has kind­ly invit­ed me to give a talk in Oxford.

In Novem­ber, I will be attend­ing the Neu­ro­bi­ol­o­gy of Lan­guage Con­fer­ence in San Diego and present our α‑band in spec­tral­ly vs. tem­po­ral­ly degrad­ed word com­pre­hen­sion data.

Direct­ly fol­low­ing is the Soci­ety for Neu­ro­science con­fer­ence, in San Diego as well. Come and find us in a Nano-sym­po­sium Jonathan Peelle has kind­ly put together.

It will take place on Wednes­day after­noon (last day), Novem­ber 17, and will fea­ture a great selec­tion of speak­ers from our field.

Categories
Editorial Notes Job Offers

The Obleser lab is mate­ri­al­is­ing: We’re hiring!

Spread the news: We are hir­ing for 2011.

The Max-Planck-Insti­tute for Human Cog­ni­tive and Brain Sci­ences (MPI–CBS) in Leipzig and its new­ly estab­lished Max Planck Research Group on “Audi­to­ry Cog­ni­tion”, led by Jonas Obleser, are now offering

Post­doc and PhD positions

for up to 3 years, prefer­ably start­ing by Jan­u­ary 2011.

Post­doc appli­cants: Suc­cess­ful can­di­dates will have a PhD in cog­ni­tive neu­ro­science, psy­chol­o­gy, or nat­ur­al sci­ences. Pri­or expe­ri­ence with either fMRI or EEG/MEG meth­ods is expect­ed, and an inter­est in fur­ther apply­ing and com­bin­ing both domains in their research is high­ly desir­able. The suc­cess­ful can­di­date will share our enthu­si­asm in prob­lems of hear­ing and lis­ten­ing com­pre­hen­sion, and ide­al­ly has already demon­strat­ed this by con­tribut­ing to the field, although researchers with a back­ground in visu­al or oth­er neu­ro­science are of course also encour­aged to apply. He or she should have a sol­id meth­ods back­ground; hands-on expe­ri­ence in prob­lems of data and sta­tis­ti­cal analy­sis, and should be will­ing to co-super­vise the PhD and Mas­ter stu­dents in the group. The posi­tion offered does not include any teach­ing obligations.

PhD appli­cants: The can­di­dates must have a mas­ter degree (or equiv­a­lent) in psy­chol­o­gy, cog­ni­tive sci­ences, neu­ro­science, med­i­cine, or a relat­ed field. Pro­fi­cien­cy in oral and writ­ten Eng­lish is nec­es­sary. PhD stu­dents will have the oppor­tu­ni­ty to par­tic­i­pate in the cur­ricu­lum of the Inter­na­tion­al Max-Planck Research School.

Start­ing date for all posi­tions is flex­i­ble. Salary is depen­dent on expe­ri­ence and based on MPI stipends or equiv­a­lent salary accord­ing to Ger­man Pub­lic ser­vice regulations.

The research will be con­duct­ed at the MPI–CBS in Leipzig, Ger­many, an inter­na­tion­al­ly lead­ing cen­tre for cog­ni­tive and imag­ing neu­ro­science equipped with a 7.0 T MRI scan­ner, three 3.0 T MRI scan­ners, a 306 chan­nels MEG sys­tem, a TMS sys­tem and sev­er­al EEG suites. All facil­i­ties are sup­port­ed by expe­ri­enced IT and physics staff. Our insti­tute (just 190 km, or 70 min­utes by train, south of Berlin) offers a very inter­na­tion­al envi­ron­ment, with Eng­lish being the lan­guage spo­ken in the lab­o­ra­to­ry. It offers a friend­ly and gen­er­ous envi­ron­ment of researchers with diverse back­grounds and with an excel­lent infrastructure.

In order to increase the pro­por­tion of female staff mem­bers, appli­ca­tions from female sci­en­tists are par­tic­u­lar­ly encour­aged. Pref­er­ence will be giv­en to dis­abled per­sons with the same qualification.

Appli­ca­tions should be kind­ly sent to per­son­al [at] cbs.mpg.de using the code “PD 2÷2010” for Post­doc or ”D5/2010” for PhD appli­ca­tions in the sub­ject. Please send your email below as a sin­gle, appro­pri­ate­ly named pdf attach­ment and should enclose a cov­er let­ter (max. 2 pages) that also spec­i­fies your future research inter­ests; a CV; up to three rep­re­sen­ta­tive reprints; and con­tact details of 2 per­son­al ref­er­ences. This call remains open until the posi­tions are filled.

For fur­ther details please con­tact Dr Jonas Obleser, Max Planck Insti­tute for Human Cog­ni­tive and Brain Sci­ences, Leipzig, Ger­many, obleser [at] cbs [·] mpg [·] de