Category: Speech

Categories
Auditory Perception Auditory Speech Processing EEG / MEG Evoked Activity Linguistics Papers Place of Articulation Features Publications Speech

New paper out in Jour­nal of Speech, Lan­guage, & Hear­ing Research [Update]

We are hap­py to announce that our paper “Asym­me­tries in the pro­cess­ing of vow­el height” will be appear­ing in the Jour­nal of Speech, Lan­guage, & Hear­ing Research, authored by Philip Mon­a­han, William Idsar­di and Math­ias Scharinger. A short sum­ma­ry is giv­en below:

Pur­pose: Speech per­cep­tion can be described as the trans­for­ma­tion of con­tin­u­ous acoustic infor­ma­tion into dis­crete mem­o­ry rep­re­sen­ta­tions. There­fore, research on neur­al rep­re­sen­ta­tions of speech sounds is par­tic­u­lar­ly impor­tant for a bet­ter under­stand­ing of this trans­for­ma­tion. Speech per­cep­tion mod­els make spe­cif­ic assump­tions regard­ing the rep­re­sen­ta­tion of mid vow­els (e.g., [{varepsilon}]) that are artic­u­lat­ed with a neu­tral posi­tion in regard to height. One hypoth­e­sis is that their rep­re­sen­ta­tion is less spe­cif­ic than the rep­re­sen­ta­tion of vow­els with a more spe­cif­ic posi­tion (e.g., [æ]).

Method: In a mag­ne­toen­cephalog­ra­phy study, we test­ed the under­spec­i­fi­ca­tion of mid vow­el in Amer­i­can Eng­lish. Using a mis­match neg­a­tiv­i­ty (MMN) par­a­digm, mid and low lax vow­els ([{varepsilon}]/[æ]), and high and low lax vow­els ([I]/[æ]), were opposed, and M100/N1 dipole source para­me­ters as well as MMN laten­cy and ampli­tude were examined.

Results: Larg­er MMNs occurred when the mid vow­el [{varepsilon}] was a deviant to the stan­dard [æ], a result con­sis­tent with less spe­cif­ic rep­re­sen­ta­tions for mid vow­els. MMNs of equal mag­ni­tude were elicit­ed in the high–low com­par­i­son, con­sis­tent with more spe­cif­ic rep­re­sen­ta­tions for both high and low vow­els. M100 dipole loca­tions sup­port ear­ly vow­el cat­e­go­riza­tion on the basis of lin­guis­ti­cal­ly rel­e­vant acoustic–phonetic features.

Con­clu­sion: We take our results to reflect an abstract long-term rep­re­sen­ta­tion of vow­els that do not include redun­dant spec­i­fi­ca­tions at very ear­ly stages of pro­cess­ing the speech sig­nal. More­over, the dipole loca­tions indi­cate extrac­tion of dis­tinc­tive fea­tures and their map­ping onto rep­re­sen­ta­tion­al­ly faith­ful cor­ti­cal loca­tions (i.e., a fea­ture map).

[Update]

The paper is avail­able here.

Ref­er­ences

  • Scharinger M, Mon­a­han PJ, Idsar­di WJ. Asym­me­tries in the pro­cess­ing of vow­el height. J Speech Lang Hear Res. 2012 Jun;55(3):903–18. PMID: 22232394. [Open with Read]
Categories
Auditory Speech Processing Degraded Acoustics EEG / MEG Neural Oscillations Noise-Vocoded Speech Papers Publications Speech

New paper accept­ed in Cere­bral Cor­tex [Update]

Obleser, J., Weisz, N. (in press) Sup­pressed alpha oscil­la­tions pre­dict intel­li­gi­bil­i­ty of speech and its acoustic details. Cere­bral Cortex.

[Update]

Paper is avail­able here.

Ref­er­ences

  • Obleser J, Weisz N. Sup­pressed alpha oscil­la­tions pre­dict intel­li­gi­bil­i­ty of speech and its acoustic details. Cereb Cor­tex. 2012 Nov;22(11):2466–77. PMID: 22100354. [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
Auditory Neuroscience Degraded Acoustics Editorial Notes Events fMRI Linguistics Posters Publications

Vis­it us at CNS

UPDATE — The Vol­cano ash that Island is kind­ly sup­ply­ing might pre­vent us from get­ting to Mon­tréal. Let’s see whether we make it until the poster ses­sion starts on Sun­day. But I am slight­ly pes­simistic on that.

 

I am cur­rent­ly quite busy with fin­ish­ing off loads of old data and prepar­ing new adven­tures in audi­to­ry neu­ro­science. Stay tuned for more!

Mean­while, if you have a few-hours stop-over in Mon­tréal, Cana­da next week: Why don’t you come and find us at the Annu­al Meet­ing of the Cog­ni­tive Neu­ro­science Soci­ety.

I will present a col­lab­o­ra­tive effort with old Kon­stanz acquain­tance Dr. Nathan Weisz on brain oscil­la­to­ry mea­sures in degrad­ed speech—a field I feel very strong­ly about cur­rent­ly and which will sure­ly keep me busy for years to come:

Poster D 53 — Spec­tral fea­tures of speech dri­ve the induced EEG brain response: Para­met­ric changes in Alpha- and Theta-band power

Also, our stu­dent Lars Mey­er will present a neat fMRI study we recent­ly ran on real­ly nasty (yet per­fect­ly legal) Ger­man syn­tax and how the brain deals with it under as-nasty (poor, that is) acoustics:

Poster I31 — When Com­plex Gram­mar Must Pass the Bot­tle­neck of Degrad­ed Acoustics: an fMRI Study.

See you in Montréal!