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Category: Auditory Cortex

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 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 Cortex Papers Publications

Obleser & Eis­ner in Trends Cogn Sci (in press) available

My year in sci­ence 2008 finds a sat­is­fy­ing end­ing by see­ing the fruits of my col­league Dr. Frank Eisner’s (cur­rent­ly ICN / UCL) and my own year­long efforts online.

Our opin­ion piece on how the prob­lem of pre-lex­i­cal abstrac­tion of speech in struc­tures of the audi­to­ry cor­tex should be best approached is final­ly avail­able as a beau­ti­ful and handy pre-print from Trends in Cog­ni­tive Sci­ences.

As a goody, I quote from the con­clu­sions rather than the open­ly avail­able abstract:

‘Behav­iour­al inves­ti­ga­tions in speech sci­ences and com­pu­ta­tion­al mod­el­ling have led to a detailed under­stand­ing of how the speech per­cep­tion sys­tem can be con­cep­tu­alised. While this type of research can­not by itself pro­duce a neu­roanatom­i­cal mod­el of speech pro­cess­ing, it should guide neu­ro­sci­en­tif­ic inves­ti­ga­tions by pro­vid­ing a the­o­ret­i­cal framework.

Using the cog­ni­tive sub­trac­tion method, func­tion­al neu­roimag­ing stud­ies have broad­ly defined the neu­roanato­my of pre-lex­i­cal pro­cess­ing. Mul­ti­vari­ate neu­roimag­ing tech­niques have the poten­tial to study spec­tro-tem­po­ral encod­ing and abstrac­tion of speech in more detail, and cru­cial­ly, in a man­ner that can be relat­ed to results from oth­er fields. […] We sug­gest that the out­put of these mul­ti­vari­ate meth­ods can serve as input to cog­ni­tive mod­els of speech per­cep­tion, in par­al­lel to behav­iour-based like­li­hoods that have been used in speech sci­ence, wave­form-based like­li­hoods that can be extract­ed with auto­mat­ic speech recog­ni­tion tech­niques, or spike-tim­ing pat­terns that have been observed in ani­mal studies.

The inte­gra­tion of find­ings from all of these areas, and the lat­est tech­no­log­i­cal devel­op­ments with­in each of them, can lead to a testable, neu­roanatom­i­cal mod­el of pre-lex­i­cal abstraction.’

Feel free to mail me for reprints.

Ref­er­ences

  • Obleser J, Eis­ner F. Pre-lex­i­cal abstrac­tion of speech in the audi­to­ry cor­tex. Trends Cogn Sci. 2009 Jan;13(1):14–9. PMID: 19070534. [Open with Read]