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Author: Jonas

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Papers Publications

Sen­si­tiv­i­ty of rat infe­ri­or col­licu­lus neu­rons to fre­quen­cy dis­tri­b­u­tions by Her­rmann et al.

New paper in press by AC Alum­ni Björn Her­rman in col­lab­o­ra­tion with Ed Bartlett and col­leagues from Pur­due Uni­ver­si­ty on stim­u­lus-sta­tis­ti­cal and stim­u­lus-spe­cif­ic adap­ta­tion in the rat infe­ri­or col­licu­lus that will appear soon in the Jour­nal of Neurophysiology.

Sen­si­tiv­i­ty of rat infe­ri­or col­licu­lus neu­rons to fre­quen­cy distributions

Abstract
Stim­u­lus-spe­cif­ic adap­ta­tion refers to a neur­al response reduc­tion to a repeat­ed stim­u­lus that does not gen­er­al­ize to oth­er stim­uli. How­ev­er, stim­u­lus-spe­cif­ic adap­ta­tion appears be influ­enced by addi­tion­al fac­tors. For exam­ple, the sta­tis­ti­cal dis­tri­b­u­tion of tone fre­quen­cies has recent­ly been shown to dynam­i­cal­ly alter stim­u­lus-spe­cif­ic adap­ta­tion in human audi­to­ry cor­tex. The cur­rent study inves­ti­gat­ed whether sta­tis­ti­cal stim­u­lus dis­tri­b­u­tions also affect stim­u­lus-spe­cif­ic adap­ta­tion at an ear­li­er stage of the audi­to­ry hier­ar­chy. Neur­al spik­ing activ­i­ty and local field poten­tials were record­ed from infe­ri­or col­licu­lus neu­rons of rats while tones were pre­sent­ed in odd­ball sequences that formed two dif­fer­ent sta­tis­ti­cal con­texts. Each sequence con­sist­ed of a repeat­ed­ly pre­sent­ed tone (stan­dard) and three rare deviants of dif­fer­ent mag­ni­tudes (small, mod­er­ate, large spec­tral change). The crit­i­cal manip­u­la­tion was the rel­a­tive prob­a­bil­i­ty with which large spec­tral changes occurred. In one con­text, the prob­a­bil­i­ty was high (rel­a­tive to all deviants) while it was low in the oth­er con­text. We observed larg­er respons­es for deviants com­pared to stan­dards, con­firm­ing pre­vi­ous reports of increased response adap­ta­tion for fre­quent­ly pre­sent­ed tones. Impor­tant­ly, the sta­tis­ti­cal con­text in which tones were pre­sent­ed strong­ly mod­u­lat­ed stim­u­lus-spe­cif­ic adap­ta­tion. Phys­i­cal­ly and prob­a­bilis­ti­cal­ly iden­ti­cal stim­uli (mod­er­ate deviants) in the two sta­tis­ti­cal con­texts elicit­ed dif­fer­ent respons­es mag­ni­tudes con­sis­tent with neur­al gain changes and thus neur­al sen­si­tiv­i­ty adjust­ments induced by the spec­tral range of a stim­u­lus dis­tri­b­u­tion. The data show that already at the lev­el of the infe­ri­or col­licu­lus stim­u­lus-spe­cif­ic adap­ta­tion is dynam­i­cal­ly altered by the sta­tis­ti­cal con­text in which stim­uli occur.

Ref­er­ences

  • Her­rmann B1, Parthasarathy A2, Han EX, Obleser J3, Bartlett EL2. Sen­si­tiv­i­ty of rat infe­ri­or col­licu­lus neu­rons to fre­quen­cy dis­tri­b­u­tions. J Neu­ro­phys­i­ol. 2015 Sep 9:jn. PMID: 26354316. [Open with Read]
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
Ageing Auditory Speech Processing Degraded Acoustics Hearing Loss Media Publications Speech

Quick inter­view for detektor.fm

Based on Malte’s recent J Neu­rosci study, Jonas did a brief inter­view for Ger­man radio detektor.fm today and talked lis­ten­ing effort, dig­i­tal phone lines, noise reduc­tion, and next-gen­er­a­tion hear­ing aids with host Tere­sa Nehm. (In Ger­man only.)

Categories
Auditory Speech Processing EEG / MEG Linguistics Papers Publications Speech

New edi­to­r­i­al in “Brain & Lan­guage”: Re-vis­it­ing the elec­tro­phys­i­ol­o­gy of language

I had the hon­our of guest-edit­ing a spe­cial issue for the clas­sic jour­nal “Brain and Lan­guage” and have thus con­tributed a brief edi­to­r­i­al (now online) to this issue. The spe­cial issue re-vis­its old themes and new leads in the elec­tro­phys­i­ol­o­gy of speech, lan­guage, and its precursors.

UPDATE: The full spe­cial issue appeared in Sep­tem­ber 2015 and all arti­cles are now acces­si­ble and citable. Thanks for your kind attention!

Categories
Editorial Notes Job Offers

New job post

Please spread the word:

We are offer­ing a PhD post (alter­na­tive­ly, a half-time Post­doc­tor­al post) in our new Audi­to­ry Cog­ni­tion Uni­ver­si­ty of Lübeck branch! (Eng­lish ver­sion here.)

Categories
Ageing Auditory Cortex Editorial Notes Events Grants

ERC Con­sol­ida­tor Grant award­ed to Jonas Obleser

It is with great plea­sure that we can report on a new major grant for the Audi­to­ry Cog­ni­tion group / Obleser lab: In the 2014 call by the Euro­pean Research Coun­cil (ERC), Jonas Obleser has very recent­ly been award­ed an ERC Con­sol­ida­tor grant (for researchers 7–12 years post their PhD), worth 1.97 mil­lion €. The grant has been award­ed to fund a project enti­tled “The lis­ten­ing chal­lenge: How age­ing brains adapt”. The project will last for five years.

Read the offi­cial ERC press release here.

 

NEW-Logo-ERC-OUTLINEadapt-logo-2

Categories
EEG / MEG Neural Oscillations Neural Phase Papers Publications

Strauß again — in Jour­nal of Neuroscience

Alum­na Dr. Antje Strauß just got anoth­er paper on:

Alpha Phase Deter­mines Suc­cess­ful Lex­i­cal Deci­sion in Noise

by Antje Strauß, Mol­ly Hen­ry, Math­ias Scharinger, and Jonas Obleser

appeared in Jour­nal of Neu­ro­science. Check the abstract below;

Abstract
Psy­chophys­i­cal tar­get detec­tion has been shown to be mod­u­lat­ed by slow oscil­la­to­ry brain phase. How­ev­er, thus far, only low-lev­el sen­so­ry stim­uli have been used as tar­gets. The cur­rent human elec­troen­cephalog­ra­phy (EEG) study exam­ined the influ­ence of neur­al oscil­la­to­ry phase on a lex­i­cal-deci­sion task per­formed for stim­uli embed­ded in noise. Neur­al phase angles were com­pared for cor­rect ver­sus incor­rect lex­i­cal deci­sions using a phase bifur­ca­tion index (BI), which quan­ti­fies dif­fer­ences in mean phase angles and phase con­cen­tra­tions between cor­rect and incor­rect tri­als. Neur­al phase angles in the alpha fre­quen­cy range (8–12 Hz) over right ante­ri­or sen­sors were approx­i­mate­ly antiphase in a pres­tim­u­lus time win­dow, and thus suc­cess­ful­ly dis­tin­guished between cor­rect and incor­rect lex­i­cal deci­sions. More­over, alpha-band oscil­la­tions were again approx­i­mate­ly antiphase across par­tic­i­pants for cor­rect ver­sus incor­rect tri­als dur­ing a lat­er peri­s­tim­u­lus time win­dow (∼500 ms) at left-cen­tral elec­trodes. Strik­ing­ly, lex­i­cal deci­sion accu­ra­cy was not pre­dict­ed by either event-relat­ed poten­tials (ERPs) or oscil­la­to­ry pow­er mea­sures. We sug­gest that cor­rect lex­i­cal deci­sions depend both on suc­cess­ful sen­so­ry pro­cess­ing, which is made pos­si­ble by the align­ment of stim­u­lus onset with an opti­mal alpha phase, as well as inte­gra­tion and weight­ing of deci­sion­al infor­ma­tion, which is cou­pled to alpha phase imme­di­ate­ly fol­low­ing the crit­i­cal manip­u­la­tion that dif­fer­en­ti­at­ed words from pseu­do­words. The cur­rent study con­sti­tutes a first step toward char­ac­ter­iz­ing the role of dynam­ic oscil­la­to­ry brain states for high­er cog­ni­tive func­tions, such as spo­ken word recognition.
Categories
EEG / MEG Neural Oscillations Neural Phase Papers Publications

New Paper out in Psy­chophys­i­ol­o­gy — Wilsch et al.

A new paper on

Slow-delta phase con­cen­tra­tion marks improved tem­po­ral expec­ta­tions based on the pas­sage of time

by AC PhD Anna Wilsch, alum­ni post­docs Mol­ly Hen­ry & Björn Her­rmann, AC head Jonas Obleser along with Burkhard Maess appeared in Psychophysiology.

Check the online source, or take a quick look on the abstract below.

Abstract
Tem­po­ral expec­ta­tions enhance neur­al encod­ing pre­ci­sion, reflect­ed in opti­mized align­ment of slow neur­al oscil­la­to­ry phase, and facil­i­tate sub­se­quent stim­u­lus pro­cess­ing. If an even­t’s exact occur­rence time is unknown, tem­po­ral expec­ta­tions arise sole­ly from the pas­sage of time. Here, we show that this spe­cif­ic type of tem­po­ral expec­ta­tion is also reflect­ed in neur­al phase orga­ni­za­tion. While under­go­ing mag­ne­toen­cephalog­ra­phy, par­tic­i­pants per­formed an audi­to­ry-delayed match­ing-to-sam­ple task with two syl­la­bles (S1, S2). Crit­i­cal­ly, S1-onset time var­ied in the 0.6–1.8‑s (i.e., 0.6−1.7 Hz) range. Increas­ing S1-onset times led to increased slow-delta (0.6−0.9 Hz) phase coher­ence over right fron­totem­po­ral sen­sors dur­ing S1 encod­ing. More­over, indi­vid­u­als with high­er slow-delta coher­ence showed decreased alpha pow­er (8−13 Hz) dur­ing sub­se­quent mem­o­ry reten­tion. In sum, tem­po­ral expec­ta­tions based on the pas­sage of time opti­mize the pre­cise align­ment of neur­al oscil­la­to­ry phase with an expect­ed stimulus.

Ref­er­ences

  • Wilsch A1, Hen­ry MJ, Her­rmann B, Maess B, Obleser J. Slow-delta phase con­cen­tra­tion marks improved tem­po­ral expec­ta­tions based on the pas­sage of time. Psy­chophys­i­ol­o­gy. 2015 Feb 16. PMID: 25684032. [Open with Read]