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 fMRI Linguistics Papers Publications Speech

New arti­cles

May I humbly point you to three new arti­cles I had the hon­our to be involved in recently.

First­ly, Chris Petkov, Nikos Logo­thetis and I have put togeth­er a very broad overview over what we think is the cur­rent take on pro­cess­ing streams of voice, speech and, more gen­er­al­ly, vocal­i­sa­tion input in pri­mates. It appears in THE NEUROSCIENTIST and is aimed at (sic) neu­ro­sci­en­tists who are not in the lan­guage and audi­tion field on an every­day basis. It goes back all the way to Wer­nicke and also owes a lot to the hard work on func­tion­al and anatom­i­cal path­ways in the pri­mate brain by peo­ple like Jon Kaas, Troy Hack­ett, Josef Rauscheck­er, or Jef­frey Schmahmann.

Sec­ond­ly, Angela Friederi­ci, Son­ja A. Kotz, Sophie Scott and myself have a new arti­cle in press in HUMAN BRAIN MAPPING where we have tried and dis­en­tan­gled the gram­mat­i­cal vio­la­tion effects in speech that Angela had observed ear­li­er in the ante­ri­or supe­ri­or tem­po­ral gyrus and the effects of speech intel­li­gi­bil­i­ty Sophie had clear­ly pin­point­ed in the sul­cus just below. When com­bin­ing these two manip­u­la­tions into one exper­i­men­tal frame­work, the results turned out sur­pris­ing­ly clear-cut! Also, an impor­tant find­ing on the side: While the acti­va­tions we observed are of course bilat­er­al, any kind of true inter­ac­tion of gram­mar and intel­li­gi­bil­i­ty were locat­ed in the left hemi­sphere (both in infe­ri­or frontal and in supe­ri­or tem­po­ral areas). Watch out here for the upcom­ing pre-print.

Final­ly, recent data by Son­ja Kotz and I have some­what scru­ti­nised the way I see the the inter­play of the ante­ri­or and pos­te­ri­or STS, as well as the IFG and, impor­tant­ly, the left angu­lar gyrus (see the fig­ure below show­ing the response behav­iour of the left angu­lar gyrus over var­i­ous lev­els of degra­da­tion as well as seman­tic expectan­cy, with pooled data from the cur­rent as well as a pre­vi­ous study in J Neu­rosci by Obleser et al., 2007). These data, on a fine-tuned cloze-prob­a­bil­i­ty manip­u­la­tion to sen­tences of vary­ing degra­da­tion are avail­able now in CEREBRAL CORTEX. Thanks for you inter­est, and let me know what you think.

 

Ref­er­ences

  • Petkov CI, Logo­thetis NK, Obleser J. Where are the human speech and voice regions, and do oth­er ani­mals have any­thing like them? Neu­ro­sci­en­tist. 2009 Oct;15(5):419–29. PMID: 19516047. [Open with Read]
  • Friederi­ci AD, Kotz SA, Scott SK, Obleser J. Dis­en­tan­gling syn­tax and intel­li­gi­bil­i­ty in audi­to­ry lan­guage com­pre­hen­sion. Hum Brain Mapp. 2010 Mar;31(3):448–57. PMID: 19718654. [Open with Read]
  • Obleser J, Kotz SA. Expectan­cy con­straints in degrad­ed speech mod­u­late the lan­guage com­pre­hen­sion net­work. Cereb Cor­tex. 2010 Mar;20(3):633–40. PMID: 19561061. [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]
Categories
Auditory Neuroscience Auditory Speech Processing Degraded Acoustics Events fMRI Noise-Vocoded Speech Papers Publications

Talk at the Soci­ety for Neu­ro­science Meet­ing, Wash­ing­ton, DC on Wednesday

If you hap­pen to be at SfN this week, you might want to check out my short pre­sen­ta­tion on a recent study [1] we did: What do spec­tral (fre­quen­cy-domain) and tem­po­ral (time-domain) fea­tures real­ly con­tribute to speech com­pre­hen­sion process­es in the tem­po­ral lobes?

It is in the Audi­to­ry Cor­tex Ses­sion (710), tak­ing place in Room 145B. My talk is sched­uled for 0945 am.

[1] Obleser, J., Eis­ner, F., Kotz, S.A. (2008) Bilat­er­al speech com­pre­hen­sion reflects dif­fer­en­tial sen­si­tiv­i­ty to spec­tral and tem­po­ral fea­tures. Jour­nal of Neu­ro­science, 28(32):8116–8124.

Ref­er­ences

  • Obleser J, Eis­ner F, Kotz SA. Bilat­er­al speech com­pre­hen­sion reflects dif­fer­en­tial sen­si­tiv­i­ty to spec­tral and tem­po­ral fea­tures. J Neu­rosci. 2008 Aug 6;28(32):8116–23. PMID: 18685036. [Open with Read]