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Category: Papers

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Auditory Cortex EEG / MEG Papers Perception Publications

New paper in press in the Euro­pean Jour­nal of Neu­ro­science: Wöst­mann et al demon­strate that the pow­er of pres­tim­u­lus alpha oscil­la­tions direct­ly relates to con­fi­dence in pitch-discrimination

What is the mech­a­nis­tic rel­e­vance of neur­al alpha oscil­la­tions (~10 Hz) for per­cep­tion? To answer this ques­tion, we analysed EEG data from a task that required par­tic­i­pants to com­pare the pitch of two tones that were, unbe­knownst to par­tic­i­pants, iden­ti­cal. Impor­tant­ly, this task entire­ly removed poten­tial con­founds of vary­ing evi­dence in the stim­u­lus or vary­ing accu­ra­cy. We found that high­er pres­tim­u­lus alpha pow­er cor­re­lat­ed with low­er con­fi­dence in pitch dis­crim­i­na­tion. These results demon­strate that the rela­tion­ship of pres­tim­u­lus alpha pow­er and deci­sion con­fi­dence is direct in nature and, that it shows up in the audi­to­ry modal­i­ty sim­i­lar to what has been shown before in vision and somatosen­sa­tion. Our find­ings sup­port the view that low­er pres­tim­u­lus alpha pow­er enhances neur­al base­line excitability.

The paper is avail­able as preprint 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
Adaptive Control Auditory Cortex Auditory Neuroscience Auditory Working Memory Neural Oscillations Papers Perception Psychology Uncategorized

New paper in The Jour­nal of Neu­ro­science: Wilsch et al.., Tem­po­ral expec­ta­tion mod­u­lates the cor­ti­cal dynam­ics of short-term memory

Con­grat­u­la­tions to Oble­ser­lab alum­na Anna Wilsch, who is – for now – leav­ing acad­e­mia on a true high with her lat­est offer­ing on how tem­po­ral expec­ta­tions (“fore­knowl­edge” about when some­thing is to hap­pen) shape the neur­al make-up of memory!

Record­ed while the Oble­ser­lab was still in Leipzig at the Max Planck, and analysed with great input from our co-authors Mol­ly Hen­ry, Björn Her­rmann as well as Christoph Her­rmann (Old­en­burg), Anna used Mag­ne­toen­cephalog­ra­phy in an intri­cate but ulti­mate­ly very sim­ple sen­so­ry-mem­o­ry paradigm.

 

While sen­so­ry mem­o­ries of the phys­i­cal world fade quick­ly, Anna here shows that this decay of short-term mem­o­ry can be coun­ter­act­ed by tem­po­ral expectation.

Notably, spa­tial­ly dis­trib­uted cor­ti­cal pat­terns of alpha (8−−13 Hz) pow­er showed oppos­ing effects in audi­to­ry vs. visu­al sen­so­ry cor­tices. More­over, alpha-tuned con­nec­tiv­i­ty changes with­in supramodal atten­tion net­works reflect the allo­ca­tion of neur­al resources as short-term mem­o­ry rep­re­sen­ta­tions fade.

— to be updat­ed as the paper will become avail­able online –

Categories
Auditory Cortex Auditory Perception Auditory Speech Processing Hearing Loss Papers Perception Publications Speech

New paper in Ear and Hear­ing: Erb, Lud­wig, Kunke, Fuchs & Obleser on speech com­pre­hen­sion with a cochlear implant

We are excit­ed to share the results from our col­lab­o­ra­tion with the Cochlea Implant Cen­ter Leipzig: AC post­doc Julia Erb’s new paper on how 4‑Hz mod­u­la­tion sen­si­tiv­i­ty can inform us on 6‑month speech com­pre­hen­sion out­come in cochlear implants.

Erb J, Lud­wig AA, Kunke D, Fuchs M, & Obleser J (2018). Tem­po­ral sen­si­tiv­i­ty mea­sured short­ly after cochlear implan­ta­tion pre­dicts six-month speech recog­ni­tion outcome

Now avail­able online:

https://insights.ovid.com/crossref?an=00003446–900000000-98942

Abstract:

Objec­tives:

Psy­choa­coustic tests assessed short­ly after cochlear implan­ta­tion are use­ful pre­dic­tors of the reha­bil­i­ta­tive speech out­come. While large­ly inde­pen­dent, both spec­tral and tem­po­ral res­o­lu­tion tests are impor­tant to pro­vide an accu­rate pre­dic­tion of speech recog­ni­tion. How­ev­er, rapid tests of tem­po­ral sen­si­tiv­i­ty are cur­rent­ly lack­ing. Here, we pro­pose a sim­ple ampli­tude mod­u­la­tion rate dis­crim­i­na­tion (AMRD) par­a­digm that is val­i­dat­ed by pre­dict­ing future speech recog­ni­tion in adult cochlear implant (CI) patients.

Design:

In 34 new­ly implant­ed patients, we used an adap­tive AMRD par­a­digm, where broad­band noise was mod­u­lat­ed at the speech-rel­e­vant rate of ~4 Hz. In a lon­gi­tu­di­nal study, speech recog­ni­tion in qui­et was assessed using the closed-set Freiburg­er num­ber test short­ly after cochlear implan­ta­tion (t0) as well as the open-set Freiburg­er mono­syl­lab­ic word test 6 months lat­er (t6).

Results:

Both AMRD thresh­olds at t0 (r = –0.51) and speech recog­ni­tion scores at t0 (r = 0.56) pre­dict­ed speech recog­ni­tion scores at t6. How­ev­er, AMRD and speech recog­ni­tion at t0 were uncor­re­lat­ed, sug­gest­ing that those mea­sures cap­ture par­tial­ly dis­tinct per­cep­tu­al abil­i­ties. A mul­ti­ple regres­sion mod­el pre­dict­ing 6‑month speech recog­ni­tion out­come with deaf­ness dura­tion and speech recog­ni­tion at t0 improved from adjust­ed R2 = 0.30 to adjust­ed R2 = 0.44 when AMRD thresh­old was added as a predictor.

Con­clu­sions:

These find­ings iden­ti­fy AMRD thresh­olds as a reli­able, nonre­dun­dant pre­dic­tor above and beyond estab­lished speech tests for CI out­come. This AMRD test could poten­tial­ly be devel­oped into a rapid clin­i­cal tem­po­ral-res­o­lu­tion test to be inte­grat­ed into the post­op­er­a­tive test bat­tery to improve the reli­a­bil­i­ty of speech out­come prognosis.

 

Categories
Auditory Cortex Brain stimulation Papers Psychology Publications

New paper in press at eNeu­ro: Herb­st, Fiedler and Obleser on track­ing tem­po­ral haz­ard in the human EEG

Here, we show that human par­tic­i­pants use implic­it mod­u­la­tions of  tem­po­ral haz­ard, the prob­a­bil­i­ty of an item to occur at a cer­tain moment in time giv­en it has not yet occurred, when per­form­ing a pitch dis­crim­i­na­tion task. Using an encod­ing mod­el approach allows us to iso­late the track­ing of  tem­po­ral haz­ard by the time domain EEG sig­nal, notably by the sup­ple­men­tary motor area, a region known for its impli­ca­tion in timing.

The paper is avail­able as preprint:

https://www.biorxiv.org/content/early/2017/12/14/233551

Herb­st SK, Fiedler L & Obleser J (2018), Track­ing tem­po­ral haz­ard in the human elec­troen­cephalo­gram using a for­ward encod­ing mod­el. eNeu­ro (in press). 

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:

Back­ground: Spa­tial 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
Auditory Perception Clinical relevance Papers Perception Psychology Publications

New paper out in the ‘Euro­pean Jour­nal of Neu­ro­science’: Tune, Wöst­mann & Obleser

AC post­docs Sarah Tune and Malte Wöst­mann have a new paper out online in the spe­cial issue on Neur­al Oscil­la­tions in the Euro­pean Jour­nal of Neu­ro­science! We are excit­ed to share the results from our first study of the ERC-fund­ed project on lis­ten­ing behav­ior and adap­tive con­trol in mid­dle-aged adults. In this study, we asked whether the fideli­ty of alpha pow­er lat­er­al­iza­tion would serve as a neur­al mark­er of selec­tive audi­to­ry atten­tion in the age­ing lis­ten­er. The results of our mul­ti­vari­ate approach demon­strate that under­stand­ing inter-indi­vid­ual dif­fer­ences is para­mount to under­stand­ing of the role of alpha oscil­la­tions in audi­to­ry atten­tion across age.

Tune, S., Wöst­mann, W., & Obleser, J. (2018) Prob­ing the lim­its of alpha pow­er lat­er­al­i­sa­tion as a neur­al mark­er of selec­tive atten­tion in mid­dle-aged and old­er listeners.

Now avail­able online:

http://onlinelibrary.wiley.com/doi/10.1111/ejn.13862/full/

 

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!