Categories
Adaptive Control Ageing Attention Auditory Cortex Auditory Neuroscience Auditory Speech Processing Executive Functions fMRI Papers Psychology Uncategorized

New paper in PNAS by Alavash, Tune, Obleser

How brain areas com­mu­ni­cate shapes human com­mu­ni­ca­tion: The hear­ing regions in your brain form new alliances as you try to lis­ten at the cock­tail party

Oble­ser­lab Post­docs Mohsen Alavash and Sarah Tune rock out an intri­cate graph-the­o­ret­i­cal account of mod­u­lar recon­fig­u­ra­tions in chal­leng­ing lis­ten­ing sit­u­a­tions, and how these pre­dict indi­vid­u­als’ lis­ten­ing success.

Avail­able online now in PNAS! (Also, our uni is cur­rent­ly fea­tur­ing a Ger­man-lan­guage press release on it, as well as an Eng­lish-lan­guage ver­sion)

Categories
Attention Auditory Cortex Auditory Neuroscience EEG / MEG Papers Perception Psychology Publications

New paper in Neu­roim­age by Fiedler et al.: Track­ing ignored speech matters

Lis­ten­ing requires selec­tive neur­al pro­cess­ing of the incom­ing sound mix­ture, which in humans is borne out by a sur­pris­ing­ly clean rep­re­sen­ta­tion of attend­ed-only speech in audi­to­ry cor­tex. How this neur­al selec­tiv­i­ty is achieved even at neg­a­tive sig­nal-to-noise ratios (SNR) remains unclear. We show that, under such con­di­tions, a late cor­ti­cal rep­re­sen­ta­tion (i.e., neur­al track­ing) of the ignored acoustic sig­nal is key to suc­cess­ful sep­a­ra­tion of attend­ed and dis­tract­ing talk­ers (i.e., neur­al selec­tiv­i­ty). We record­ed and mod­eled the elec­troen­cephalo­graph­ic response of 18 par­tic­i­pants who attend­ed to one of two simul­ta­ne­ous­ly pre­sent­ed sto­ries, while the SNR between the two talk­ers var­ied dynam­i­cal­ly between +6 and −6 dB. The neur­al track­ing showed an increas­ing ear­ly-to-late atten­tion-biased selec­tiv­i­ty. Impor­tant­ly, acousti­cal­ly dom­i­nant (i.e., loud­er) ignored talk­ers were tracked neu­ral­ly by late involve­ment of fron­to-pari­etal regions, which con­tributed to enhanced neur­al selec­tiv­i­ty. This neur­al selec­tiv­i­ty, by way of rep­re­sent­ing the ignored talk­er, pos­es a mech­a­nis­tic neur­al account of atten­tion under real-life acoustic conditions.

The paper is avail­able here.

Categories
Attention Auditory Cortex Brain stimulation Papers Perception Publications

New paper in press in JASA: Kre­it­e­wolf et al. on the role of voice-fea­ture con­ti­nu­ity for cock­tail-par­ty listening

Oble­ser­lab post­doc Jens Kre­it­e­wolf is in press in The Jour­nal of the Acousti­cal Soci­ety of America!

Togeth­er with our col­leagues, Marc Schön­wies­ner (Montreal/Leipzig), Samuel Math­ias (Yale), and Régis Tra­peau (Montreal/Marseille), we inves­ti­gat­ed the roles of two of the most salient voice fea­tures, glot­tal-pulse rate (GPR) and vocal-tract length (VTL), for per­cep­tu­al group­ing in the cock­tail par­ty. Using care­ful­ly con­trolled stim­uli, we show that lis­ten­ers exploit con­ti­nu­ity in both voice fea­tures to solve the cock­tail-par­ty prob­lem, but that VTL con­ti­nu­ity plays a stronger role for per­cep­tu­al group­ing than GPR con­ti­nu­ity. Our find­ings are in line with the dif­fer­en­tial impor­tance of VTL and GPR for the iden­ti­fi­ca­tion of nat­ur­al talk­ers and have clin­i­cal­ly rel­e­vant impli­ca­tions for cock­tail-par­ty lis­ten­ing in cochlear-implant users.

Data were record­ed using the Dome at BRAMS dur­ing Jens’ ACN Eras­mus Mundus exchange in Montreal.

The paper is avail­able as preprint:

https://www.biorxiv.org/content/early/2018/07/30/379545

 

Categories
Attention Auditory Cortex Auditory Perception Brain stimulation Papers Psychology Publications Speech

New paper in press in Brain Stim­u­la­tion: Wöst­mann, Vosskuhl, Obleser, and Her­rmann demon­strate that exter­nal­ly ampli­fied oscil­la­tions affect audi­to­ry spa­tial attention

In a fine col­lab­o­ra­tion we com­bine exper­tise on audi­to­ry cog­ni­tion (Malte Wöst­mann & Jonas Obleser, Uni­ver­si­ty of Lübeck) and brain stim­u­la­tion (Johannes Vosskuhl and Christoph S Her­rmann, Uni­ver­si­ty of Old­en­burg) to show that exter­nal­ly stim­u­lat­ed alpha and gam­ma oscil­la­tions dif­fer­en­tial­ly affect spa­tial atten­tion to speech. Our par­tic­i­pants per­formed a dichot­ic lis­ten­ing task while being stim­u­lat­ed using tran­scra­nial alter­nat­ing cur­rent stim­u­la­tion (tACS) at alpha or gam­ma fre­quen­cy (vs sham) on the left hemi­sphere. Alpha-tACS rel­a­tive­ly decreased recall of tar­gets con­tralat­er­al to stim­u­la­tion, while gam­ma-tACS reversed this effect. These results sug­gest that exter­nal­ly ampli­fied oscil­la­tions are func­tion­al­ly rel­e­vant to spa­tial attention.

Wöst­mann, M., Vosskuhl, J., Obleser, J., & Her­rmann, C.S. (2018). Oppo­site effects of lat­er­alised tran­scra­nial alpha ver­sus gam­ma stim­u­la­tion on audi­to­ry spa­tial attention.

Now avail­able online:

https://www.sciencedirect.com/science/article/pii/S1935861X18301074

Abstract:

Back­groundSpa­tial atten­tion rel­a­tive­ly increas­es the pow­er of neur­al 10-Hz alpha oscil­la­tions in the hemi­sphere ipsi­lat­er­al to atten­tion, and decreas­es alpha pow­er in the con­tralat­er­al hemi­sphere. For gam­ma oscil­la­tions (>40 Hz), the oppo­site effect has been observed. The func­tion­al roles of lat­er­alised oscil­la­tions for atten­tion are cur­rent­ly unclear.

Hypoth­e­sis: If lat­er­alised oscil­la­tions are func­tion­al­ly rel­e­vant for atten­tion, tran­scra­nial stim­u­la­tion of alpha ver­sus gam­ma oscil­la­tions in one hemi­sphere should dif­fer­en­tial­ly mod­u­late the accu­ra­cy of spa­tial atten­tion to the ipsi-ver­sus con­tralat­er­al side.

Meth­ods: 20 human par­tic­i­pants per­formed a dichot­ic lis­ten­ing task under con­tin­u­ous tran­scra­nial alter­nat­ing cur­rent stim­u­la­tion (tACS, vs sham) at alpha (10 Hz) or gam­ma (47 Hz) fre­quen­cy. On each tri­al, par­tic­i­pants attend­ed to four spo­ken num­bers on the left or right ear, while ignor­ing num­bers on the oth­er ear. In order to stim­u­late a left tem­poro-pari­etal cor­tex region, which is known to show marked mod­u­la­tions of alpha pow­er dur­ing audi­to­ry spa­tial atten­tion, tACS (1 mA peak-to-peak ampli­tude) was applied at elec­trode posi­tions TP7 and FC5 over the left hemisphere.

Results: As pre­dict­ed, uni­hemi­spher­ic alpha-tACS rel­a­tive­ly decreased the recall of tar­gets con­tralat­er­al to stim­u­la­tion, but increased recall of ipsi­lat­er­al tar­gets. Impor­tant­ly, this spa­tial pat­tern of results was reversed for gamma-tACS.

Con­clu­sions: Results pro­vide a proof of con­cept that tran­scra­nial­ly stim­u­lat­ed oscil­la­tions can enhance spa­tial atten­tion and facil­i­tate atten­tion­al selec­tion of speech. Fur­ther­more, oppo­site effects of alpha ver­sus gam­ma stim­u­la­tion sup­port the view that states of high alpha are incom­men­su­rate with active neur­al pro­cess­ing as reflect­ed by states of high gamma.

Categories
Adaptive Control Attention Auditory Working Memory Clinical relevance Executive Functions fMRI Papers Psychology Publications Uncategorized

New paper in press in ‘Neu­roim­age’: Alavash, Lim, et al

Oble­ser­lab post­doc Mohsen Alavash and Oble­ser­lab Alum­na Sung-Joo Lim are in press at Neu­roim­age!

They argue with data from a place­bo-con­trolled dopamin­er­gic inter­ven­tion study that BOLD sig­nal vari­abil­i­ty and the func­tion­al con­nec­tome are sur­pris­ing­ly clear­ly affect­ed by L‑Dopa, and (ii) that the degree of change in these met­rics can explain the degree to which indi­vid­u­als will prof­it from L‑DOPA in per­form­ing the chal­leng­ing lis­ten­ing task (while oth­ers dont; Preprint here ).

Alavash, M., Lim, S.J., Thiel, C., Sehm, B., Deser­no, L., & Obleser, J. (2018) Dopamin­er­gic mod­u­la­tion of hemo­dy­nam­ic sig­nal vari­abil­i­ty and the func­tion­al con­nec­tome dur­ing cog­ni­tive per­for­mance. Neu­roim­age. In press.

— Thanks also and in par­tic­u­lar to our col­leagues Chris­tiane Thiel of Old­en­burg, and Bern­hard Sehm and Lorenz Deser­no of Leipzig, who helped us made this large-scale L‑DOPA project happen!

 

 

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 UU42UU46):

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
Attention Auditory Cortex Auditory Neuroscience Auditory Speech Processing EEG / MEG Papers Psychology Publications

New paper in press in Jour­nal of Neur­al Engi­neer­ing: Fiedler et al. on in-ear-EEG and the focus of audi­to­ry attention

Towards a brain-con­trolled hear­ing aid: PhD stu­dent Lorenz Fiedler shows how attend­ed and ignored audi­to­ry streams are dif­fer­ent­ly rep­re­sent­ed in the neur­al respons­es and how the focus of audi­to­ry atten­tion can be extract­ed from EEG sig­nals record­ed at elec­trodes placed inside the ear-canal and around the ear.

Abstract
Objec­tive. Con­ven­tion­al, mul­ti-chan­nel scalp elec­troen­cephalog­ra­phy (EEG) allows the iden­ti­fi­ca­tion of the attend­ed speak­er in con­cur­rent-lis­ten­ing (‘cock­tail par­ty’) sce­nar­ios. This implies that EEG might pro­vide valu­able infor­ma­tion to com­ple­ment hear­ing aids with some form of EEG and to install a lev­el of neu­ro-feed­back. Approach. To inves­ti­gate whether a listener’s atten­tion­al focus can be detect­ed from sin­gle-chan­nel hear­ing-aid-com­pat­i­ble EEG con­fig­u­ra­tions, we record­ed EEG from three elec­trodes inside the ear canal (‘in-Ear-EEG’) and addi­tion­al­ly from 64 elec­trodes on the scalp. In two dif­fer­ent, con­cur­rent lis­ten­ing tasks, par­tic­i­pants ( n  =  7) were fit­ted with indi­vid­u­al­ized in-Ear-EEG pieces and were either asked to attend to one of two dichot­i­cal­ly-pre­sent­ed, con­cur­rent tone streams or to one of two diot­i­cal­ly-pre­sent­ed, con­cur­rent audio­books. A for­ward encod­ing mod­el was trained to pre­dict the EEG response at sin­gle EEG chan­nels. Main results. Each indi­vid­ual par­tic­i­pants’ atten­tion­al focus could be detect­ed from sin­gle-chan­nel EEG response record­ed from short-dis­tance con­fig­u­ra­tions con­sist­ing only of a sin­gle in-Ear-EEG elec­trode and an adja­cent scalp-EEG elec­trode. The dif­fer­ences in neur­al respons­es to attend­ed and ignored stim­uli were con­sis­tent in mor­phol­o­gy (i.e. polar­i­ty and laten­cy of com­po­nents) across sub­jects. Sig­nif­i­cance. In sum, our find­ings show that the EEG response from a sin­gle-chan­nel, hear­ing-aid-com­pat­i­ble con­fig­u­ra­tion pro­vides valu­able infor­ma­tion to iden­ti­fy a listener’s focus of attention.