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Author: Jonas

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
Editorial Notes

New lab mem­bers joining

As of Decem­ber 1, we will have two new mem­bers join­ing the Lab.

Björn Her­rmann very recent­ly received his Dr. rer. nat. from the Uni­ver­si­ty of Leipzig, after doing method­olog­i­cal­ly advanced worked on MEG and fMRI cor­re­lates of ear­ly auditory–syntactic inter­ac­tions in lan­guage comprehension. 

Dun­ja Kunke is a trained audi­ol­o­gist and will help us gear up the audi­to­ry test­ing rou­tines in our lab; also, she will be of great help when we begin work­ing with hear­ing-impaired listeners.

A warm wel­come to both of you!

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
Editorial Notes

The group is approach­ing cruis­ing altitude

Pic: Ker­stin Flake

I am glad to report that the lab is in full flight. (From left to right: ) Anna Wilsch, Julia Erb, Dr. Math­ias Scharinger, Dr. Mol­ly Hen­ry, and Antje Strauß have joined forces with me. We are hav­ing a splen­did time find­ing out more about speech, degra­da­tion of it, and the neur­al pro­cess­ing of it all. Stay tuned for great project work com­ing from these bright minds in the years to come.

NB – I hope you don’t mind that we chose the charm­ing back sides of Leipzig rather than our post­mod­ern Insti­tute build­ing as a back­ground. We actu­al­ly do work just 100 meters from this spot. Maybe we should make it our new hang-out spot and bring neu­ro­science to the streets?

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 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]