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Category: Executive Functions

Categories
Executive Functions Gyrus Angularis Publications Semantics TMS Uncategorized

New paper out: Tune & Asari­dou, Jour­nal of Neuroscience

Our newest mem­ber of the lab, post-­doc Sarah Tune, just pub­lished a review arti­cle in the Jour­nal of Neu­ro­science. The arti­cle appeared in the “Jour­nal Club” sec­tion, where grad­u­ate stu­dents or post-docs are giv­en the chance to write short review pieces.

Now avail­able online:
Stim­u­lat­ing the Seman­tic Net­work: What Can TMS Tell Us about the Roles of the Pos­te­ri­or Mid­dle Tem­po­ral Gyrus and Angu­lar Gyrus?

Sarah and for­mer UCI Brain Cir­cuits col­league Salo­mi Asari­dou com­ment on a recent TMS study by Dav­ey et al. (2015) who inves­ti­gat­ed the role(s) of the mid­dle tem­po­ral gyrus and angu­lar gyrus in the encod­ing and retrieval of seman­tic infor­ma­tion. Sarah and Salo­mi review and dis­cuss some of the fac­tors that lim­it the inter­pre­ta­tion of rTMS-induced behav­ioral changes in seman­tic judge­ment tasks. Con­clud­ing, they argue that a focus on neur­al net­works and mech­a­nis­tic prin­ci­ples is key to under­stand­ing the neur­al imple­men­ta­tion of seman­tic cognition.

Categories
Auditory Cortex Auditory Neuroscience Auditory Perception Auditory Speech Processing Editorial Notes EEG / MEG Executive Functions Neural Oscillations Neural Phase Papers Publications Speech Uncategorized

[UPDATE] New paper in PNAS: Spa­tiotem­po­ral dynam­ics of audi­to­ry atten­tion syn­chro­nize with speech, Woest­mann et al.

Wöst­mann, Her­rmann, Maess and Obleser demon­strate that the hemi­spher­ic lat­er­al­iza­tion of neur­al alpha oscil­la­tions mea­sured in the mag­ne­toen­cephalo­gram (MEG) syn­chro­nizes with the speech sig­nal and pre­dicts lis­ten­ers’ speech comprehension.

Now avail­able online:

http://www.pnas.org/content/early/2016/03/18/1523357113

Press release:

https://www.uni-luebeck.de/forschung/aktuelles-zur-forschung/aktuelles-zur-forschung/artikel/aufmerksamkeit-in-wellen-erfolgreich-zuhoeren-im-rhythmus-der-sprache.html

spatiotemporal_dynamics

Abstract
Atten­tion plays a fun­da­men­tal role in selec­tive­ly pro­cess­ing stim­uli in our envi­ron­ment despite dis­trac­tion. Spa­tial atten­tion induces increas­ing and decreas­ing pow­er of neur­al alpha oscil­la­tions (8–12 Hz) in brain regions ipsi­lat­er­al and con­tralat­er­al to the locus of atten­tion, respec­tive­ly. This study test­ed whether the hemi­spher­ic lat­er­al­iza­tion of alpha pow­er codes not just the spa­tial loca­tion but also the tem­po­ral struc­ture of the stim­u­lus. Par­tic­i­pants attend­ed to spo­ken dig­its pre­sent­ed to one ear and ignored tight­ly syn­chro­nized dis­tract­ing dig­its pre­sent­ed to the oth­er ear. In the mag­ne­toen­cephalo­gram, spa­tial atten­tion induced lat­er­al­iza­tion of alpha pow­er in pari­etal, but notably also in audi­to­ry cor­ti­cal regions. This alpha pow­er lat­er­al­iza­tion was not main­tained steadi­ly but fluc­tu­at­ed in syn­chrony with the speech rate and lagged the time course of low-fre­quen­cy (1–5 Hz) sen­so­ry syn­chro­niza­tion. High­er ampli­tude of alpha pow­er mod­u­la­tion at the speech rate was pre­dic­tive of a listener’s enhanced per­for­mance of stream-spe­cif­ic speech com­pre­hen­sion. Our find­ings demon­strate that alpha pow­er lat­er­al­iza­tion is mod­u­lat­ed in tune with the sen­so­ry input and acts as a spa­tiotem­po­ral fil­ter con­trol­ling the read-out of sen­so­ry content.
Categories
Auditory Working Memory EEG / MEG Executive Functions Neural Oscillations Papers Publications

New Paper by Lim, Wöst­mann, & Obleser in Jour­nal of Neuroscience

Can you atten­tive­ly “high­light” audi­to­ry traces in mem­o­ry? If so, what are poten­tial neur­al mech­a­nisms of it?

Sung-Joo Lim’s paper in J Neurosci;

Selec­tive Atten­tion to Audi­to­ry Mem­o­ry Neu­ral­ly Enhances Per­cep­tu­al Precision

is now avail­able online (full text).

Abstract
Selec­tive atten­tion to a task-rel­e­vant stim­u­lus facil­i­tates encod­ing of that stim­u­lus into a work­ing mem­o­ry rep­re­sen­ta­tion. It is less clear whether selec­tive atten­tion also improves the pre­ci­sion of a stim­u­lus already rep­re­sent­ed in mem­o­ry. Here, we inves­ti­gate the behav­ioral and neur­al dynam­ics of selec­tive atten­tion to rep­re­sen­ta­tions in audi­to­ry work­ing mem­o­ry (i.e., audi­to­ry objects) using psy­chophys­i­cal mod­el­ing and mod­el-based analy­sis of elec­troen­cephalo­graph­ic sig­nals. Human lis­ten­ers per­formed a syl­la­ble pitch dis­crim­i­na­tion task where two syl­la­bles served as to-be-encod­ed audi­to­ry objects. Valid (vs neu­tral) retroac­tive cues were pre­sent­ed dur­ing reten­tion to allow lis­ten­ers to selec­tive­ly attend to the to-be-probed audi­to­ry object in mem­o­ry. Behav­ioral­ly, lis­ten­ers rep­re­sent­ed audi­to­ry objects in mem­o­ry more pre­cise­ly (expressed by steep­er slopes of a psy­cho­me­t­ric curve) and made faster per­cep­tu­al deci­sions when valid com­pared to neu­tral retrocues were pre­sent­ed. Neu­ral­ly, valid com­pared to neu­tral retrocues elicit­ed a larg­er fron­to­cen­tral sus­tained neg­a­tiv­i­ty in the evoked poten­tial as well as enhanced pari­etal alpha/low-beta oscil­la­to­ry pow­er (9–18 Hz) dur­ing mem­o­ry reten­tion. Crit­i­cal­ly, indi­vid­ual mag­ni­tudes of alpha oscil­la­to­ry pow­er (7–11 Hz) mod­u­la­tion pre­dict­ed the degree to which valid retrocues ben­e­fit­ted indi­vid­u­als’ behav­ior. Our results indi­cate that selec­tive atten­tion to a spe­cif­ic object in audi­to­ry mem­o­ry does ben­e­fit human per­for­mance not by sim­ply reduc­ing mem­o­ry load, but by active­ly engag­ing com­ple­men­tary neur­al resources to sharp­en the pre­ci­sion of the task-rel­e­vant object in memory.

Con­grats!

Categories
Auditory Working Memory Degraded Acoustics EEG / MEG Executive Functions Neural Oscillations Papers Publications

[UPDATE] New review paper by Wilsch & Obleser in press: What works in audi­to­ry work­ing memory?

AC alum­na Anna Wilsch (now Uni­ver­si­ty of Old­en­burg) has a new review paper in press in a spe­cial issue on audi­to­ry work­ing mem­o­ry, curat­ed by Jochen Kaiser (Frank­furt) and Michael Brosch (Magde­burg) in “Brain Research”. We pro­vide a review on neur­al oscil­la­to­ry sig­na­tures of (var­i­ous forms of) audi­to­ry short-term memory.

Wilsch, A., Obleser, J. (in press). What works in audi­to­ry work­ing mem­o­ry? A neur­al oscil­la­tions per­spec­tive. Brain Research

Watch out for that spe­cial issue, as it will have an excel­lent ros­ter of col­leagues con­tribut­ing, and we are proud to be part of it.

The abstract is giv­en below.

Abstract
Work­ing mem­o­ry is a lim­it­ed resource: Brains can only main­tain small amounts of sen­so­ry input (mem­o­ry load) over a brief peri­od of time (mem­o­ry decay). The dynam­ics of slow neur­al oscil­la­tions as record­ed using mag­ne­to- and elec­troen­cephalog­ra­phy (M/EEG) pro­vide a win­dow into the neur­al mechan­ics of these lim­i­ta­tions. Espe­cial­ly oscil­la­tions in the alpha range (8–13 Hz) are a sen­si­tive mark­er for mem­o­ry load. More­over, accord­ing to cur­rent mod­els, the resul­tant work­ing mem­o­ry load is deter­mined by the rel­a­tive noise in the neur­al rep­re­sen­ta­tion of main­tained infor­ma­tion. The audi­to­ry domain allows mem­o­ry researchers to apply and test the con­cept of noise quite lit­er­al­ly: Employ­ing degrad­ed stim­u­lus acoustics increas­es mem­o­ry load and, at the same time, al- lows assess­ing the cog­ni­tive resources required to process speech in noise in an eco­log­i­cal­ly valid and clin­i­cal­ly rel­e­vant way. The present review first sum­ma­rizes recent find­ings on neur­al oscil­la­tions, espe­cial­ly alpha pow­er, and how they reflect mem­o­ry load and mem­o­ry decay in audi­to­ry work­ing mem­o­ry. The focus is specif­i­cal­ly on mem­o­ry load result­ing from acoustic degra­da­tion. These find­ings are then con­trast­ed with con­tex­tu­al fac­tors that ben­e­fit neur­al as well as behav­ioral mark­ers of mem­o­ry per­for­mance, by reduc­ing rep­re­sen­ta­tion­al noise. We end on dis­cussing the func­tion­al role of alpha pow­er in audi­to­ry work­ing mem­o­ry and sug­gest exten­sions of the cur­rent method­olog­i­cal toolkit. 
[Update]

Check out the arti­cle online.

Categories
Adaptive Control Ageing EEG / MEG Executive Functions fMRI Job Offers

We’ll be hir­ing soon: Post­docs wanted

The research group “Audi­to­ry Cog­ni­tion” (head­ed by Prof. Dr. Jonas Obleser; auditorycognition.com) in the recent­ly estab­lished Depart­ment of Psy­chol­o­gy, Uni­ver­si­ty of Lübeck, is seek­ing to hire several

Post­doc­tor­al Researchers

start­ing by Jan­u­ary 2016, ini­tial­ly for 3 years, with the option of a 2‑year exten­sion. These posi­tions will fall into the larg­er frame­work of an ERC Con­sol­ida­tor grant “The lis­ten­ing chal­lenge: How age­ing brains adapt” recent­ly award­ed to Jonas Obleser, and will allow the joint devel­op­ment of cog­ni­tive neu­ro­science and psy­cho­log­i­cal research projects tar­get­ing adap­tive con­trol in the audi­to­ry modal­i­ty of mid­dle-aged adults.

[About the ERC project: The audi­to­ry sen­so­ry modal­i­ty pos­es an excel­lent, although under-utilised, research mod­el to under­stand the cog­ni­tive adjust­ments to sen­so­ry change (here termed “adap­tive con­trol”), their neur­al basis, and their large vari­a­tion amongst indi­vid­u­als. Hear­ing abil­i­ties begin to decline already in the fourth life decade, and our guid­ing hypoth­e­sis is that indi­vid­u­als dif­fer in the extent to which they are neu­ral­ly, cog­ni­tive­ly, and psy­cho­log­i­cal­ly equipped to adapt to this sen­so­ry decline.]

We are look­ing for cre­ative minds with a PhD degree and a promis­ing track record in cog­ni­tive neu­ro­science, psy­chol­o­gy, physics, or engi­neer­ing. A strong back­ground and inter­est in research meth­ods is desir­able. Pri­or expe­ri­ence with either human neu­ro­science meth­ods (espe­cial­ly advanced EEG and/or fMRI analy­ses) or mod­el­ing of rich data sets (e.g., latent growth mod­el­ing, struc­tur­al equa­tion mod­el­ing) is expected.

The Uni­ver­si­ty of Lübeck is a mod­ern uni­ver­si­ty spe­cial­iz­ing in Med­i­cine, Com­put­er Sci­ence, Mol­e­c­u­lar Biol­o­gy, Bio­math­e­mat­ics and Med­ical Engi­neer­ing. Inter­na­tion­al­ly renowned research and high stan­dards of aca­d­e­m­ic tutor­ing char­ac­ter­ize the pro­file of the uni­ver­si­ty. A new ded­i­cat­ed research build­ing (Cen­tre for Brain, Behav­iour, and Metab­o­lism; CBBM) hous­ing also the Obleser lab will open in late 2015.

Pay­ment will fol­low salary group E13 TV‑L (full time), if con­di­tions based on Ger­man Pub­lic ser­vice reg­u­la­tions are satisfied.

 

These posi­tions will be announced offi­cial­ly lat­er in autumn 2015, but inter­est­ed can­di­dates should be in touch now with Jonas Obleser, jonas.obleser@uni-luebeck.de

Categories
Auditory Cortex Auditory Neuroscience Clinical relevance Degraded Acoustics EEG / MEG Executive Functions Hearing Loss Media Neural Oscillations Papers Publications Speech

Max Planck Soci­ety reports on Wöst­mann et al.’s Neur­al alpha dynamics

Some days ago the Max Planck Soci­ety put out a news fea­ture on our most recent Jour­nal of Neu­ro­science paper (see our post):

Aufmerk­sam zuhören — Hirn-Wellen zeigen Mühen des Hörens im Alter an

Sum­ma­ry
Ältere Men­schen kla­gen oft über Hörschwierigkeit­en, beson­ders wenn mehrere Per­so­n­en durcheinan­der sprechen. Forsch­er am Max-Planck-Insti­tut für Kog­ni­tions- und Neu­rowis­senschaften in Leipzig haben her­aus­ge­fun­den, dass der Grund hier­für nicht nur im Ohr, son­dern eben­so in verän­derten Aufmerk­samkeit­sprozessen im Gehirn älter­er Men­schen zu find­en ist. Eine beson­dere Bedeu­tung kommt dabei den Alpha-Wellen zu, deren Anpas­sung an verän­derte Hör­si­t­u­a­tio­nen das Sprachver­ständ­nis in All­t­agssi­t­u­a­tio­nen verbessert.

It nice­ly wraps up Malte’s exper­i­ment on alpha dynam­ics in younger and old­er lis­ten­ers. Check the link above for the full arti­cle (Ger­man).

 

Ref­er­ences

  • Wöst­mann M1, Her­rmann B2, Wilsch A2, Obleser J3. Neur­al alpha dynam­ics in younger and old­er lis­ten­ers reflect acoustic chal­lenges and pre­dic­tive ben­e­fits. J Neu­rosci. 2015 Jan 28;35(4):1458–67. PMID: 25632123. [Open with Read]
Categories
Ageing Auditory Cortex Auditory Neuroscience Clinical relevance Degraded Acoustics EEG / MEG Executive Functions Hearing Loss Neural Oscillations Papers Publications Speech

New paper in press in the Jour­nal of Neu­ro­science: Wöst­mann, Her­rmann, Wilsch, & Obleser [UPDATED #2]

Con­grat­u­la­tions to AC PhD stu­dent Malte Wöst­mann for his new­ly accept­ed paper in the Jour­nal of Neu­ro­science!

Wöst­mann M, Her­rmann B, Wilsch A, & Obleser J.

Neur­al alpha dynam­ics in younger and old­er lis­ten­ers reflect acoustic chal­lenges and pre­dic­tive benefits

J Neu­rosci, in press.

Here is the abstract and my favourite fig­ure from Malte’s paper.

Abstract
Speech com­pre­hen­sion in mul­ti-talk­er sit­u­a­tions is a noto­ri­ous real-life chal­lenge, par­tic­u­lar­ly for old­er lis­ten­ers. Younger lis­ten­ers exploit stim­u­lus-inher­ent acoustic detail, but are they also active­ly pre­dict­ing upcom­ing infor­ma­tion? And fur­ther, how do old­er lis­ten­ers deal with acoustic and pre­dic­tive infor­ma­tion? To under­stand the neur­al dynam­ics of lis­ten­ing dif­fi­cul­ties and accord­ing lis­ten­ing strate­gies, we con­trast­ed neur­al respons­es in the alpha-band (~10 Hz) in younger (20−30 years, n = 18) and healthy old­er (60−70 years, n = 20) par­tic­i­pants under chang­ing task demands in a two-talk­er par­a­digm. Elec­troen­cephalo­grams were record­ed while humans lis­tened to two spo­ken dig­its against a dis­tract­ing talk­er and decid­ed whether the sec­ond dig­it was small­er or larg­er. Acoustic detail (tem­po­ral fine struc­ture) and pre­dic­tive­ness (the degree to which the first dig­it pre­dict­ed the sec­ond) var­ied orthog­o­nal­ly. Alpha pow­er at wide­spread scalp sites decreased with increas­ing acoustic detail (dur­ing tar­get dig­it pre­sen­ta­tion) but also with increas­ing pre­dic­tive­ness (in-between tar­get dig­its). For old­er com­pared to younger lis­ten­ers, acoustic detail had a stronger impact on task per­for­mance and alpha pow­er mod­u­la­tion. This sug­gests that alpha dynam­ics plays an impor­tant role in the changes in lis­ten­ing behav­ior that occur with age. Last­ly, alpha pow­er vari­a­tions result­ing from stim­u­lus manip­u­la­tions (of acoustic detail and pre­dic­tive­ness) as well as task-inde­pen­dent over­all alpha pow­er were relat­ed to sub­jec­tive lis­ten­ing effort. The present data show that alpha dynam­ics is a promis­ing neur­al mark­er of indi­vid­ual dif­fi­cul­ties as well as age-relat­ed changes in sen­sa­tion, per­cep­tion, and com­pre­hen­sion in com­plex com­mu­ni­ca­tion situations. 

Screen Shot 2014-12-03 at 13.07.13

Update #2

Ger­man radio broad­cast­er MDR Info did an inter­view & fea­ture on Mal­te’s Exper­i­ment. Check out the stream below:

Ref­er­ences

  • Wöst­mann M1, Her­rmann B2, Wilsch A2, Obleser J3. Neur­al alpha dynam­ics in younger and old­er lis­ten­ers reflect acoustic chal­lenges and pre­dic­tive ben­e­fits. J Neu­rosci. 2015 Jan 28;35(4):1458–67. PMID: 25632123. [Open with Read]
Categories
Auditory Perception Auditory Working Memory Events fMRI Neural Oscillations Neural Phase Posters

Come and find us at CNS 2014 in Boston this weekend

The Obleser lab will be pre­sent­ing four posters at this year’s Annu­al Meet­ing of the Cog­ni­tive Neu­ro­science Soci­ety in Boston.

If you hap­pen to be there, come check us out!

A125 — Hemo­dy­nam­ic sig­na­tures of (mis-)perceiving tem­po­ral change
Her­rmann, Bjoern

C63 — Tem­po­ral pre­dictabil­i­ty atten­u­ates decay in sen­so­ry memory
Wilsch, Anna

D54 — Stim­u­lus dis­crim­inabil­i­ty and pre­dic­tive­ness mod­u­late alpha oscil­la­tions in a per­cep­tu­al­ly demand­ing mem­o­ry task
Wöst­mann, Malte

D130 — Slow acoustic fluc­tu­a­tions entrain low-fre­quen­cy neur­al oscil­la­tions and deter­mine psy­choa­coustic performance
Hen­ry, Molly