New mem­bers in the Obleser lab

In the Obleser lab, we wel­come new mem­bers and PhD stu­dents Mar­tin Orf and Tro­by Lui.
Mar­tin did his MSc in Audi­ol­o­gy Tech­nol­o­gy here at the Uni­ver­si­ty of Lübeck. He is now join­ing us for PhD project fund­ed gen­er­ous­ly by our indus­try part­ner Widex Sivan­tos Audi­ol­o­gy,
revolv­ing around hear­ing aids and elec­troen­cephalo­graph­ic sig­na­tures of atten­tion.
Tro­by did her MSc in Psy­chol­o­gy at Hong-Kong Uni­ver­si­ty and has already pub­lished in Neu­roim­age. She will do her PhD under direct super­vi­sion of Malte Wöst­mann in our lab, work­ing on a DFG-fund­ed project on atten­tion­al rhythms.
We also bid farewell to long-time Oble­ser­lab ally and PhD stu­dent Leo Waschke, who fin­ished his PhD on a high, and who is now a post­doc in Doug Garrett’s lab at the Max Planck Insti­tute in Berlin.
Hel­lo and Good­bye!

09. January 2020 by Felix Greuling
Categories: Editorial Notes, Events, Uncategorized |

New paper in press in elife: Waschke et al.

Oble­ser­lab senior PhD stu­dent Leo Waschke, along­side co-authors Sarah Tune and Jonas Obleser, has a new paper in eLife.

The pro­cess­ing of sen­so­ry infor­ma­tion from our envi­ron­ment is not con­stant but rather varies with changes in ongo­ing brain activ­i­ty, or brain states. Thus, also the acu­ity of per­cep­tu­al deci­sions depends on the brain state dur­ing which sen­so­ry infor­ma­tion is processed. Recent work in non-human ani­mals sug­gests two key process­es that shape brain states rel­e­vant for sen­so­ry pro­cess­ing and per­cep­tu­al per­for­mance. On the one hand, the momen­tary lev­el of neur­al desyn­chro­niza­tion in sen­so­ry cor­ti­cal areas has been shown to impact neur­al rep­re­sen­ta­tions of sen­so­ry input and relat­ed per­for­mance. On the oth­er hand, the cur­rent lev­el of arousal and relat­ed nora­dren­er­gic activ­i­ty has been linked to changes in sen­so­ry pro­cess­ing and per­cep­tu­al acu­ity.

How­ev­er, it is unclear at present, whether local neur­al desyn­chro­niza­tion and arousal pose dis­tinct brain states that entail vary­ing con­se­quences for sen­so­ry pro­cess­ing and behav­iour or if they rep­re­sent two inter­re­lat­ed man­i­fes­ta­tions of ongo­ing brain activ­i­ty and joint­ly affect behav­iour. Fur­ther­more, the exact shape of the rela­tion­ship between per­cep­tu­al per­for­mance and each of both brain states mark­ers (e.g. lin­ear vs. qua­drat­ic) is unclear at present.

In order to trans­fer find­ings from ani­mal phys­i­ol­o­gy to human cog­ni­tive neu­ro­science and test the exact shape of unique as well as shared influ­ences of local cor­ti­cal desyn­chro­niza­tion and glob­al arousal on sen­so­ry pro­cess­ing and per­cep­tu­al per­for­mance, we record­ed elec­troen­cephalog­ra­phy and pupil­lom­e­try in 25 human par­tic­i­pants while they per­formed a chal­leng­ing audi­to­ry dis­crim­i­na­tion task.

Impor­tant­ly, audi­to­ry stim­uli were selec­tive­ly pre­sent­ed dur­ing peri­ods of espe­cial­ly high or low audi­to­ry cor­ti­cal desyn­chro­niza­tion as approx­i­mat­ed by an infor­ma­tion the­o­ret­ic mea­sure of time-series com­plex­i­ty (weight­ed per­mu­ta­tion entropy). By means of a closed-loop real time set­up we were not only able to present stim­uli dur­ing dif­fer­ent desyn­chro­niza­tion states but also made sure to sam­ple the whole dis­tri­b­u­tion of such states, a pre­req­ui­site for the accu­rate assess­ment of brain-behav­iour rela­tion­ships. The record­ed pupil­lom­e­try data addi­tion­al­ly enabled us to draw infer­ences regard­ing the cur­rent lev­el of arousal due to the estab­lished link between nora­dren­er­gic activ­i­ty and pupil size.

 

Sin­gle tri­al analy­ses of EEG activ­i­ty, pupil­lom­e­try and behav­iour revealed clear­ly dis­so­cia­ble influ­ences of both brain state mark­ers on ongo­ing brain activ­i­ty, ear­ly sound-relat­ed activ­i­ty and behav­iour. High desyn­chro­niza­tion states were char­ac­ter­ized by a pro­nounced reduc­tion in oscil­la­to­ry pow­er across a wide fre­quen­cy range while high arousal states coin­cid­ed with a decrease in oscil­la­to­ry pow­er that was lim­it­ed to high fre­quen­cies. Sim­i­lar­ly, ear­ly sound-evoked activ­i­ty was dif­fer­en­tial­ly impact­ed by audi­to­ry cor­ti­cal desyn­chro­niza­tion and pupil-linked arousal. Phase-locked respons­es and evoked gam­ma pow­er increased with local desyn­chro­niza­tion with a ten­den­cy to sat­u­rate at inter­me­di­ate lev­els. Post-stim­u­lus low fre­quen­cy pow­er on the oth­er hand, increased with pupil-linked arousal.

Most impor­tant­ly, local desyn­chro­niza­tion and pupil-linked arousal dis­played dif­fer­ent rela­tion­ships with per­cep­tu­al per­for­mance. While par­tic­i­pants per­formed fastest and least biased fol­low­ing inter­me­di­ate lev­els of audi­to­ry cor­ti­cal desyn­chro­niza­tion, inter­me­di­ate lev­els of pupil-linked arousal were asso­ci­at­ed with high­est sen­si­tiv­i­ty. Thus, although both process­es pose behav­ioural­ly rel­e­vant brain states that affect per­cep­tu­al per­for­mance fol­low­ing an invert­ed u, they impact dis­tinct sub­do­mains of behav­iour. Tak­en togeth­er, our results speak to a mod­el in which inde­pen­dent states of local desyn­chro­niza­tion and glob­al arousal joint­ly shape states for opti­mal sen­so­ry pro­cess­ing and per­cep­tu­al per­for­mance. The pub­lished man­u­script includ­ing all sup­ple­men­tal infor­ma­tion can be found here.

09. January 2020 by Felix Greuling
Categories: Auditory Neuroscience, Auditory Perception, EEG / MEG, Papers, Perception, Uncategorized |

Jonas appoint­ed as Review­ing edi­tor to eLife

I am hon­oured to have been asked to join the edi­to­r­i­al board of eLife, a jour­nal I very much hon­our for their fresh approach to excel­lent sci­en­tif­ic pub­lish­ing.

eLife is a pub­lish­ing ini­tia­tive by the Max Planck Soci­ety, the Well­come Trust, and Howard Hugh­es Med­ical Insti­tute.

My tenure as review­ing edi­tor has start­ed Decem­ber 2019.

07. January 2020 by Jonas
Categories: Uncategorized |

Mohsen Alavash and Sarah Tune win sci­ence award

Con­grat­u­la­tions to AC post­docs Mohsen Alavash and Sarah Tune for receiv­ing the sci­ence award of the Uni­ver­si­ty of Lübeck. Each year the uni­ver­si­ty hon­ors an out­stand­ing sci­en­tif­ic pub­li­ca­tion with this award. We are proud that Sarah and Mohsen were award­ed for their joint work on the neur­al net­work (re-)configurations sup­port­ing suc­cess­ful lis­ten­ing behav­ior. The study was pub­lished ear­li­er this year in PNAS.
Read more about the study in PNAS and the award cer­e­mo­ny that took place in ear­ly Novem­ber (Ger­man press release).

Fotos: Gui­do Kollmeier, Rechte: Uni­ver­sität zu Lübeck.

 

07. December 2019 by Felix Greuling
Categories: Uncategorized |

New paper in press in the Jour­nal of Neu­ro­science

Wöst­mann, Alavash and Obleser demon­strate that alpha oscil­la­tions in the human brain imple­ment dis­trac­tor sup­pres­sion inde­pen­dent of tar­get selec­tion.

In the­o­ry, the abil­i­ty to selec­tive­ly focus on rel­e­vant objects in our envi­ron­ment bases on selec­tion of tar­gets and sup­pres­sion of dis­trac­tion. As it is unclear whether tar­get selec­tion and dis­trac­tor sup­pres­sion are inde­pen­dent, we designed an Elec­troen­cephalog­ra­phy (EEG) study to direct­ly con­trast these two process­es.

Par­tic­i­pants per­formed a pitch dis­crim­i­na­tion task on a tone sequence pre­sent­ed at one loud­speak­er loca­tion while a dis­tract­ing tone sequence was pre­sent­ed at anoth­er loca­tion. When the dis­trac­tor was fixed in the front, atten­tion to upcom­ing tar­gets on the left ver­sus right side induced hemi­spher­ic lat­er­al­i­sa­tion of alpha pow­er with rel­a­tive­ly high­er pow­er ipsi- ver­sus con­tralat­er­al to the side of atten­tion.

Crit­i­cal­ly, when the tar­get was fixed in front, sup­pres­sion of upcom­ing dis­trac­tors reversed the pat­tern of alpha lat­er­al­i­sa­tion, that is, alpha pow­er increased con­tralat­er­al to the dis­trac­tor and decreased ipsi­lat­er­al­ly. Since the two lat­er­al­ized alpha respons­es were uncor­re­lat­ed across par­tic­i­pants, they can be con­sid­ered large­ly inde­pen­dent cog­ni­tive mech­a­nisms.

This was fur­ther sup­port­ed by the fact that alpha lat­er­al­i­sa­tion in response to dis­trac­tor sup­pres­sion orig­i­nat­ed in more ante­ri­or, frontal cor­ti­cal regions com­pared with tar­get selec­tion (see fig­ure).

The paper is also avail­able as preprint here.

 

09. November 2019 by Jonas
Categories: Attention, Auditory Neuroscience, Neural Oscillations, Papers, Psychology, Uncategorized |

New lab mem­ber Sebas­t­ian Puschmann

We wel­come Dr. Sebas­t­ian Puschmann as a new post­doc in the Obleser/Auditory Cog­ni­tion lab!

Sebas­t­ian has a back­ground in Physics. He received his train­ing in audi­to­ry cog­ni­tive neu­ro­science at the Uni­ver­si­ty of Old­en­burg and the Mon­tre­al Neu­ro­log­i­cal Insti­tute. In Lübeck, Sebas­t­ian will push for­ward stud­ies on the neur­al mechan­ics and neur­al changes in hear­ing loss.

 

 

 

09. September 2019 by Jonathan Mortensen
Categories: Uncategorized |

New DFG project led by Mohsen Alavash on the Net­work Neu­ro­science of Spa­tial Atten­tion

Con­grat­u­la­tions to our cur­rent­ly ERC-fund­ed lab mem­ber and post­doc Mohsen Alavash who has just secured 3‑year fund­ing (~380,000 €) by the Deutsche Forschungs­ge­mein­schaft (DFG) for an ambi­tious project: Mohsen wants to get clos­er to a net­work/­graph-the­o­ret­i­cal descrip­tion of how spa­tial atten­tion in the lis­ten­ing brain is organ­ised. In a lat­er stage of the project, Mohsen also plans on study­ing how the net­work organ­i­sa­tion of spa­tial atten­tion may be altered in hear­ing-impaired lis­ten­ers.

We are glad that Mohsen plans on run­ning this project with­in the Obleser lab, here at the Uni­ver­si­ty of Lübeck.

Also, make sure to check out Mohsen’s lat­est pub­li­ca­tion on the top­ic.

21. August 2019 by Jonas
Categories: Adaptive Control, Attention, fMRI, Grants, Hearing Loss, Uncategorized |

Jonas pre­sent­ed for the KIND Hörs­tiftung in Berlin (Video)

Im Feb­ru­ar hat­te ich die Ehre, für die Kind Hörs­tiftung auf deren 2019er Sym­po­sium in Berlin unsere Arbeit­en zur Vorher­sage des Hör­erfol­gs exem­plar­isch anhand einiger unser­er Stu­di­en all­ge­mein­ver­ständlich zu beleucht­en. Ein 25-minütiges Video dieses Vor­trags ist jet­zt online.

(In Feb­ru­ary, I had the hon­our of pre­sent­ing some of our recent work on pre­dict­ing indi­vid­u­als’ lis­ten­ing suc­cess at the sym­po­sium of the Kind Hear­ing Foun­da­tion. A video in Ger­man is now avail­able.)

07. August 2019 by Jonas
Categories: Adaptive Control, Auditory Neuroscience, Auditory Speech Processing, Auf deutsch, Events, Executive Functions, Hearing Loss, Media, Speech |

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