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Author: Jonas

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New paper in Schiz­o­phre­nia Bul­letin Open: Erb et al., Aber­rant per­cep­tu­al judge­ments on speech-rel­e­vant acoustic fea­tures in hal­lu­ci­na­tion-prone individuals

Hal­lu­ci­na­tions – per­cepts in the absence of an exter­nal stim­u­lus – con­sti­tute an intrigu­ing mod­el of how per­cepts are gen­er­at­ed and how per­cep­tion can fail. They can occur in psy­chot­ic dis­or­ders, but also in the gen­er­al population.
Healthy adults vary­ing in their pre­dis­po­si­tion to hal­lu­ci­na­tions were asked to iden­ti­fy “speech” in ambigu­ous sounds. Lis­ten­ers qual­i­fy­ing as more hal­lu­ci­na­tion-prone in two estab­lished ques­tion­naires per­cep­tu­al­ly down-weight­ed the speech-typ­i­cal low fre­quen­cies (pur­ple sub­group in the fig­ure for illus­tra­tion). Instead, the hal­lu­ci­na­tion-prone indi­vid­u­als pri­ori­tised high fre­quen­cies in their “speech­i­ness” judge­ments of ambigu­ous sounds.
At the same time, the high­er one scored on hal­lu­ci­na­tion-prone­ness, the more con­fi­dent on a giv­en (always ambigu­ous!) tri­al they were. Hal­lu­ci­na­tion-prone­ness and actu­al sen­so­ry evi­dence had a com­pa­ra­ble impact on con­fi­dence, con­sis­tent with the idea that the emer­gence of hal­lu­ci­na­tions is root­ed in an altered per­cep­tion of sounds.
This research may con­tribute to improv­ing ear­ly diag­no­sis and pre­ven­tion strate­gies in
indi­vid­u­als at risk for psychosis.

From the abstract:
“Hal­lu­ci­na­tions con­sti­tute an intrigu­ing mod­el of how per­cepts are gen­er­at­ed and how per­cep­tion can fail. Here, we inves­ti­gate the hypoth­e­sis that an altered per­cep­tu­al weight­ing of the spec­tro-tem­po­ral mod­u­la­tions that char­ac­ter­ize speech con­tributes to the emer­gence of audi­to­ry ver­bal hal­lu­ci­na­tions. Healthy adults (N=168) vary­ing in their pre­dis­po­si­tion for hal­lu­ci­na­tions had to choose the ‘more speech-like’ of two pre­sent­ed ambigu­ous sound tex­tures and give a con­fi­dence judge­ment. Using psy­chophys­i­cal reverse cor­re­la­tion, we quan­ti­fied the con­tri­bu­tion of dif­fer­ent acoustic fea­tures to a listener’s per­cep­tu­al deci­sions. High­er hal­lu­ci­na­tion prone­ness covar­ied with per­cep­tu­al down-weight­ing of speech-typ­i­cal, low-fre­quen­cy acoustic ener­gy while pri­ori­tis­ing high fre­quen­cies. Remark­ably, high­er con­fi­dence judge­ments in sin­gle tri­als depend­ed not only on acoustic evi­dence but also on an individual’s hal­lu­ci­na­tion prone­ness and schizo­typy score. In line with an account of altered per­cep­tu­al pri­ors and dif­fer­en­tial weight­ing of sen­so­ry evi­dence, these results show that hal­lu­ci­na­tion-prone indi­vid­u­als exhib­it qual­i­ta­tive and quan­ti­ta­tive changes in their per­cep­tion of the mod­u­la­tions typ­i­cal for speech.”
The paper is avail­able here.

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Ageing Degraded Acoustics Editorial Notes Executive Functions Job Offers Uncategorized

We’re hir­ing (again): DFG-fund­ed 3‑year PhD posi­tion, apply by July 12 2020

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Ageing Auditory Cortex Auditory Neuroscience Auditory Perception fMRI Hearing Loss Papers Perception Psychology Publications

New paper in eLife: Erb et al., Tem­po­ral selec­tiv­i­ty declines in the aging human audi­to­ry cortex

Con­grat­u­la­tions to Oble­ser­lab post­doc Julia Erb for her new paper to appear in eLife, “Tem­po­ral selec­tiv­i­ty declines in the aging human audi­to­ry cor­tex”.

It’s a trope that old­er lis­ten­ers strug­gle more in com­pre­hend­ing speech (think of Pro­fes­sor Tour­nesol in the famous Tintin comics!). The neu­ro­bi­ol­o­gy of why and how age­ing and speech com­pre­hen­sion dif­fi­cul­ties are linked at all has proven much more elu­sive, however.

Part of this lack of knowl­edge is direct­ly root­ed in our lim­it­ed under­stand­ing of how the cen­tral parts of the hear­ing brain – audi­to­ry cor­tex, broad­ly speak­ing – are organized.

Does audi­to­ry cor­tex of old­er adults have dif­fer­ent tun­ing prop­er­ties? That is, do young and old­er adults dif­fer in the way their audi­to­ry sub­fields rep­re­sent cer­tain fea­tures of sound?

A spe­cif­ic hypoth­e­sis fol­low­ing from this, derived from what is known about age-relat­ed change in neu­ro­bi­o­log­i­cal and psy­cho­log­i­cal process­es in gen­er­al (the idea of so-called “ded­if­fer­en­ti­a­tion”), was that the tun­ing to cer­tain fea­tures would “broad­en” and thus lose selec­tiv­i­ty in old­er com­pared to younger listeners.

More mech­a­nis­ti­cal­ly, we aimed to not only observe so-called “cross-sec­tion­al” (i.e., age-group) dif­fer­ences, but to link a listener’s chrono­log­i­cal age as close­ly as pos­si­ble to changes in cor­ti­cal tuning.

Amongst old­er lis­ten­ers, we observe that tem­po­ral-rate selec­tiv­i­ty declines with high­er age. In line with senes­cent neur­al ded­if­fer­en­ti­a­tion more gen­er­al­ly, our results high­light decreased selec­tiv­i­ty to tem­po­ral infor­ma­tion as a hall­mark of the aging audi­to­ry cortex.

This research is gen­er­ous­ly sup­port­ed by the ERC Con­sol­ida­tor project AUDADAPT, and data for this study were acquired at the CBBM at Uni­ver­si­ty of Lübeck.

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New paper in press in Neuropsychologia

Wöst­mann, Lui, Friese, Kre­it­e­wolf, Nau­jokat and Obleser demon­strate that the vul­ner­a­bil­i­ty of work­ing mem­o­ry to audi­to­ry dis­trac­tion is rhythmic.

Pre­vi­ous research has shown that the atten­tion­al sam­pling of tar­get stim­uli is rhyth­mic at ~3–8 Hz (e.g. Fiebelko­rn et al. 2013; Lan­dau & Fries, 2012). In the present study, Malte Wöst­mann and col­leagues test­ed to what extent the sup­pres­sion of dis­trac­tor stim­uli would be rhyth­mic, as well. Indeed, two mea­sures of dis­trac­tion – mem­o­ry recall accu­ra­cy and the dis­trac­tor-evoked N1 ERP com­po­nent – were peri­od­i­cal­ly mod­u­lat­ed at slow fre­quen­cies (~2–4 Hz) by the tem­po­ral onset of a dis­tract­ing speech stimulus.

In a fol­low-up exper­i­ment, the rhyth­mic dis­tractibil­i­ty could be repli­cat­ed: In a visu­al match-to-sam­ple task, mem­o­ry recall accu­ra­cy was peri­od­i­cal­ly mod­u­lat­ed at ~2.75 Hz by the onset of a dis­tract­ing noise stim­u­lus dur­ing mem­o­ry retention.

The paper is avail­able here.

For a preprint of the paper, see.   

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We are hir­ing! 4‑y post­doc­tor­al position

There is now an open­ing for an up-to-4-year (!) post­doc posi­tion in my lab for late summer/fall. Join us in Lübeck, Ger­many, and do cool behav­iour­al and neu­ro­science on neur­al dynam­ics, age­ing, sen­so­ry decline with us!

The appli­ca­tion dead­line (as sin­gle PDF to the email address named in the add!) is June 7 2020, see Ger­man and Eng­lish PDFs for all details.

Feel free to ring me up any time if you are inter­est­ed in chat­ting before­hand. Look­ing for­ward to many inter­est­ing applications!

— J.O.

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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!
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Auditory Neuroscience Auditory Perception EEG / MEG Papers Perception 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.

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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.