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Author: Jonas

Categories
Auditory Cortex Auditory Neuroscience Brain stimulation Clinical relevance Degraded Acoustics Hearing Loss Neural Oscillations Neural Phase Papers Psychology Speech

New paper in press with the Old­en­burg brain-stim­u­la­tion crew!

AC alum­na Anna Wilsch has a new paper in press in Neu­roim­age, with Toralf Neul­ing, Jonas Obleser, and Christoph Her­rmann: “Tran­scra­nial alter­nat­ing cur­rent stim­u­la­tion with speech envelopes mod­u­lates speech com­pre­hen­sion”. In this proof-of-concept–like paper, we demon­strate that using the speech enve­lope as a “pilot sig­nal” for elec­tri­cal­ly stim­u­lat­ing the human brain, while a lis­ten­er tries to com­pre­hend that speech sig­nal buried in noise, does mod­u­late the listener’s speech–in–noise com­pre­hen­sion abilities.

The Preprint is here, … 

… while the abstract goes like this:
Cor­ti­cal entrain­ment of the audi­to­ry cor­tex to the broad­band tem­po­ral enve­lope of a speech sig­nal is cru­cial for speech com­pre­hen­sion. Entrain­ment results in phas­es of high and low neur­al excitabil­i­ty, which struc­ture and decode the incom­ing speech sig­nal. Entrain­ment to speech is strongest in the theta fre­quen­cy range (4−8 Hz), the aver­age fre­quen­cy of the speech enve­lope. If a speech sig­nal is degrad­ed, entrain­ment to the speech enve­lope is weak­er and speech intel­li­gi­bil­i­ty declines. Besides per­cep­tu­al­ly evoked cor­ti­cal entrain­ment, tran­scra­nial alter­nat­ing cur­rent stim­u­la­tion (tACS) entrains neur­al oscil­la­tions by apply­ing an elec­tric sig­nal to the brain. Accord­ing­ly, tACS-induced entrain­ment in audi­to­ry cor­tex has been shown to improve audi­to­ry per­cep­tion. The aim of the cur­rent study was to mod­u­late speech intel­li­gi­bil­i­ty exter­nal­ly by means of tACS such that the elec­tric cur­rent cor­re­sponds to the enve­lope of the pre­sent­ed speech stream (i.e., enve­lope-tACS). Par­tic­i­pants per­formed the Old­en­burg sen­tence test with sen­tences pre­sent­ed in noise in com­bi­na­tion with enve­lope-tACS. Crit­i­cal­ly, tACS was induced at time lags of 0 to 250 ms in 50-ms steps rel­a­tive to sen­tence onset (audi­to­ry stim­uli were simul­ta­ne­ous to or pre­ced­ed tACS). We per­formed sin­gle- sub­ject sinu­soidal, lin­ear, and qua­drat­ic fits to the sen­tence com­pre­hen­sion per­for­mance across the time lags. We could show that the sinu­soidal fit described the mod­u­la­tion of sen­tence com­pre­hen­sion best. Impor­tant­ly, the aver­age fre­quen­cy of the sinu­soidal fit was 5.12 Hz, cor­re­spond­ing to the peaks of the ampli­tude spec­trum of the stim­u­lat­ed envelopes. This find­ing was sup­port­ed by a sig­nif­i­cant 5‑Hz peak in the aver­age pow­er spec­trum of indi­vid­ual per­for­mance time series. Alto­geth­er, enve­lope tACS mod­u­lates intel­li­gi­bil­i­ty of speech in noise, pre­sum­ably by enhanc­ing and dis­rupt­ing (time lag with in- or out-of-phase stim­u­la­tion, respec­tive­ly) cor­ti­cal entrain­ment to the speech enve­lope in audi­to­ry cortex.
Categories
Auditory Neuroscience Auditory Speech Processing Psychology

SNAP 2017 was a vast success

SNAP 2017 took place on Decem­ber 8 and 9 in Lübeck, Germany.

Nine inter­na­tion­al­ly esteemed speak­ers and in total more than six­ty researchers from all over Europe, Cana­da and the US made the sec­ond Sig­nal and Noise Along the Audi­to­ry Path­way work­shop a mem­o­rable occa­sion in audi­to­ry neuroscience.

Thanks to every­body for com­ing out!, and see you all again for SNAP 2019, at a loca­tion to be announced.

Categories
Ageing Auditory Neuroscience EEG / MEG Papers Publications

New paper online by Waschke, Wöst­mann & Obleser

Read all about neur­al irreg­u­lar­i­ty in aging brains and how it relates to per­cep­tu­al deci­sions: New paper by PhD stu­dent Leo Waschke. 

Now avail­able online:
https://goo.gl/F4dFfe

Abstract

Sen­so­ry rep­re­sen­ta­tions, and thus human per­cepts, of the phys­i­cal world are sus­cep­ti­ble to fluc­tu­a­tions in brain state or “neur­al irreg­u­lar­i­ty”. Fur­ther­more, aging brains dis­play altered lev­els of neur­al irreg­u­lar­i­ty. We here show that a sin­gle, with­in-tri­al, infor­ma­tion-the­o­ret­ic mea­sure (weight­ed per­mu­ta­tion entropy) cap­tures neur­al irreg­u­lar­i­ty in the human elec­troen­cephalo­gram as a proxy for both, trait-like dif­fer­ences between indi­vid­u­als of vary­ing age, and state-like fluc­tu­a­tions that bias per­cep­tu­al deci­sions. First, the over­all lev­el of neur­al irreg­u­lar­i­ty increased with par­tic­i­pants’ age, par­al­leled by a decrease in vari­abil­i­ty over time, like­ly index­ing age-relat­ed changes at struc­tur­al and func­tion­al lev­els of brain activ­i­ty. Sec­ond, states of high­er neur­al irreg­u­lar­i­ty were asso­ci­at­ed with opti­mized sen­so­ry encod­ing and a sub­se­quent­ly increased prob­a­bil­i­ty of choos­ing the first of two phys­i­cal­ly iden­ti­cal stim­uli to be high­er in pitch. In sum, neur­al irreg­u­lar­i­ty not only char­ac­ter­izes behav­ioural­ly rel­e­vant brain states, but also can iden­ti­fy trait-like changes that come with age. 

 

 

Categories
Adaptive Control Ageing Job Offers Speech Uncategorized

Want to come work with us?

Post­doc posi­tion in the Obleser lab, in the ERC-fund­ed project “Audadapt” — dead­line for appli­ca­tions very soon! (Nov 30 2017). Check out all appli­ca­tions details here!

Categories
Uncategorized

SNAP 2017 — Timetable now online!

SNAP 2017 is draw­ing clos­er. Get ready and take a look at the program:

Day 1: 08.12.2017
Time
08:00 — 09:10 Reg­is­tra­tion / Open­ing remarks
(9:00–9:10)
09:10 — 10:00 Edmund Lalor
10:00 — 10:50 Sarah Ver­hulst
10:50 — 11:10 Cof­fee break
11:10 — 12:00 Christoph Kayser
12:00 — 12:30 Dis­cus­sion (Impuls­es by Son­ja Kotz)
12:30 — 14:00 Lunch
14:00 — 14:50 Tom Fran­cart
14:50 — 15:40 Nima Mes­garani
15:40 — 16:00 Cof­fee break
16:00 — 18:00 Posters and beers
19:00 Speak­ers Din­ner at Bud­dha Bowl
21:00 SNAP Par­ty at Gang 56
Day 2: 09.12.2017
Time
09:30 — 10:20 Jen­nifer Bizley
10:20 — 11:10 Sami­ra Anderson
11:10 — 11:30 Cof­fee break
11:30 — 12:20 Maria Chait
12:20 — 12:50 Dis­cus­sion (Impuls­es by Thomas Münte)
13:00 — 14:00 Lunch
14:00 — 14:50 Josh McDer­mott
14:50 — 15:30 Round-table / Wrap-up
Categories
Ageing Attention Auditory Cortex Auditory Neuroscience Editorial Notes EEG / MEG Executive Functions Neural Phase Posters

Come see us @ Neu­ro­science 2017 in DC

Will be at the Soci­ety for Neu­ro­science Meet­ing next week in DC? Come find us in the Wednes­day after­noon ses­sion with a bunch of (we think) very cool atten­tion-relat­ed posters (Poster boards UU42–UU46):

804.06. Audi­to­ry atten­tion and pre­dic­tive pro­cess­ing co-mod­u­late speech com­pre­hen­sion in mid­dle-aged adults
*S. TUNE, M. WÖSTMANN, J. OBLESER;

804.05. Implic­it tem­po­ral pre­dictabil­i­ty enhances audi­to­ry pitch-dis­crim­i­na­tion sensitivity
*S. K. HERBST, M. PLÖCHL, A. HERRMANN, J. OBLESER;

804.09. Are visu­al and audi­to­ry detec­tion per­for­mance dri­ven by a supramodal atten­tion­al rhythm?
*M. PLOECHL, S. KASTNER, I. C. FIEBELKORN, J. OBLESER;

804.08. Spa­tio-tem­po­ral expec­ta­tions exert dif­fer­en­tial effects on visu­al and audi­to­ry discrimination
*A. WILSCH, J. OBLESER, C. E. SCHROEDER, C. S. HERRMANN, S. HAEGENS

804.07. Tran­scra­nial 10-Hz stim­u­la­tion but also eye clo­sure mod­u­late audi­to­ry attention
*M. WÖSTMANN, L.-M. SCHMITT, J. VOSSKUHL, C. S. HERRMANN, J. OBLESER

Categories
Attention Auditory Neuroscience EEG / MEG Evoked Activity Neural Oscillations Neural Phase Papers Perception Psychology Uncategorized

New paper in Plos Biol­o­gy: Com­ment by Obleser, Hen­ry, & Lakatos

My col­leagues and col­lab­o­ra­tor Peter Lakatos and Mol­ly Hen­ry and I took to our desks and Mat­lab con­soles, when Assaf Bres­ka and Leon Deouell came out ear­li­er this year with their paper in Plos Biology.

We had a few things to say about what we then per­ceived as a rather pes­simistic assess­ment of neur­al entrain­ment. How­ev­er, since then a great and quite fru­ti­ful dis­cus­sion has emerged, now pub­lished in Plos Biology:

Obleser J, Hen­ry, MJ, & Lakatos, P. What do we talk about when we talk about rhythm?, Plos Biol­o­gy 2017

Mean­while, Bres­ka and Deouell added some more behav­iour­al data and replied to us (now also pub­lished).

— Enjoy!

 

Categories
Events Probandensuche Publications

Audi­to­ry cog­ni­tion newsletter

Come and see our very first audi­to­ry cog­ni­tion newslet­ter. From now on we want to present impres­sions of our lat­est work and results twice a year. In the inter­view sec­tion you also have the chance to learn more about our members. 

Please note: As the newslet­ter also reach­es our par­tic­i­pants it is writ­ten in german.