Categories
Ageing Auditory Cortex Auditory Neuroscience EEG / MEG Hearing Loss Neural Filters Papers Publications

New paper in Nature Com­mu­ni­ca­tions by Tune et al.

We are very excit­ed to share that Oble­ser­lab post­doc Sarah Tune has a new paper in Nature Com­mu­ni­ca­tions. „Neur­al atten­tion­al-fil­ter mech­a­nisms of lis­ten­ing suc­cess in mid­dle-aged and old­er par­tic­i­pants“ is our lat­est and to-date most exten­sive out­put of the lon­gi­tu­di­nal ERC Con­sol­ida­tor project on adap­tive lis­ten­ing in age­ing indi­vid­ual (AUDADAPT — include link to https://auditorycognition.com/erc-audadapt/).

This co-pro­duc­tion with cur­rent (Mohsen Alavash and Jonas Obleser) and for­mer (Lorenz Fiedler) Oble­ser­lab mem­bers, takes an in-depth and inte­gra­tive look at how two of the most exten­sive­ly stud­ied neu­ro­bi­o­log­i­cal atten­tion­al-fil­ter imple­men­ta­tions, alpha pow­er lat­er­al­iza­tion and selec­tive neur­al speech track­ing, relate to one anoth­er and to lis­ten­ing sucess.

Lever­ag­ing our large, rep­re­sen­ta­tive sam­ple of aging lis­ten­ers (N=155, 39–80 years), we show that both neur­al fil­ter imple­men­tatins are robust­ly mod­u­lat­ed by atten­tion but oper­ate sur­prins­ing­ly inde­pen­dent of one another.

In a series of sophis­ti­cat­ed sin­gle-tri­al lin­ear mod­els that include vari­a­tion in neur­al fil­ter strength with­in and between indi­vid­u­als, we demon­strate how the pref­er­en­tial neur­al track­ing of attend­ed ver­sus ignored speech but not alpha lat­er­al­iza­tion boosts lis­ten­ing success.

To learn more, the paper is avail­able here.

Categories
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.

Categories
Attention Auditory Cortex Auditory Speech Processing EEG / MEG Psychology Speech

AC post­doc Malte Wöst­mann scores DFG grant to study the tem­po­ral dynam­ics of the audi­to­ry atten­tion­al filter

In this three-year project, we will use the audi­to­ry modal­i­ty as a test case to inves­ti­gate how the sup­pres­sion of dis­tract­ing infor­ma­tion (i.e., “fil­ter­ing”) is neu­ral­ly imple­ment­ed. While it is known that the atten­tion­al sam­pling of tar­gets (a) is rhyth­mic, (b) can be entrained, and © is mod­u­lat­ed by top-down pre­dic­tions, the exis­tence and neur­al imple­men­ta­tion of these mech­a­nisms for the sup­pres­sion of dis­trac­tors is at present unclear. To test this, we will use adap­ta­tions of estab­lished behav­iour­al par­a­digms of dis­trac­tor sup­pres­sion and record­ings of human elec­tro­phys­i­o­log­i­cal sig­nals in the Magen­to-/ Elec­troen­cephalo­gram (M/EEG).

Abstract of research project:

Back­ground: Goal-direct­ed behav­iour in tem­po­ral­ly dynam­ic envi­ron­ments requires to focus on rel­e­vant infor­ma­tion and to not get dis­tract­ed by irrel­e­vant infor­ma­tion. To achieve this, two cog­ni­tive process­es are nec­es­sary: On the one hand, atten­tion­al sam­pling of tar­get stim­uli has been focus of exten­sive research. On the oth­er hand, it is less well known how the human neur­al sys­tem exploits tem­po­ral infor­ma­tion in the stim­u­lus to fil­ter out dis­trac­tion. In the present project, we use the audi­to­ry modal­i­ty as a test case to study the tem­po­ral dynam­ics of atten­tion­al fil­ter­ing and its neur­al implementation.

Approach and gen­er­al hypoth­e­sis: In three vari­ants of the “Irrel­e­vant-Sound Task” we will manip­u­late tem­po­ral aspects of audi­to­ry dis­trac­tors. Behav­iour­al recall of tar­get stim­uli despite dis­trac­tion and respons­es in the elec­troen­cephalo­gram (EEG) will reflect the integri­ty and neur­al imple­men­ta­tion of the atten­tion­al fil­ter. In line with pre­lim­i­nary research, our gen­er­al hypoth­e­sis is that atten­tion­al fil­ter­ing bases on sim­i­lar but sign-reversed mech­a­nisms as atten­tion­al sam­pling: For instance, while atten­tion to rhyth­mic stim­uli increas­es neur­al sen­si­tiv­i­ty at time points of expect­ed tar­get occur­rence, fil­ter­ing of dis­trac­tors should instead decrease neur­al sen­si­tiv­i­ty at the time of expect­ed distraction.

Work pro­gramme: In each one of three Work Pack­ages (WPs), we will take as a mod­el an estab­lished neur­al mech­a­nism of atten­tion­al sam­pling and test the exis­tence and neur­al imple­men­ta­tion of a sim­i­lar mech­a­nism for atten­tion­al fil­ter­ing. This way, we will inves­ti­gate whether atten­tion­al fil­ter­ing fol­lows an intrin­sic rhythm (WP1), whether rhyth­mic dis­trac­tors can entrain atten­tion­al fil­ter­ing (WP2), and whether fore­knowl­edge about the time of dis­trac­tion induces top-down tun­ing of the atten­tion­al fil­ter in frontal cor­tex regions (WP3).

Objec­tives and rel­e­vance: The pri­ma­ry objec­tive of this research is to con­tribute to the foun­da­tion­al sci­ence on human selec­tive atten­tion, which requires a com­pre­hen­sive under­stand­ing of how the neur­al sys­tem achieves the task of fil­ter­ing out dis­trac­tion. Fur­ther­more, hear­ing dif­fi­cul­ties often base on dis­trac­tion by salient but irrel­e­vant sound. Results of this research will trans­late to the devel­op­ment of hear­ing aids that take into account neu­ro-cog­ni­tive mech­a­nisms to fil­ter out dis­trac­tion more efficiently.

Categories
Attention Auditory Cortex Auditory Speech Processing Papers Psychology Publications Speech

New paper in press in the Jour­nal of Cog­ni­tive Neuroscience

Wöst­mann, Schmitt and Obleser demon­strate that clos­ing the eyes enhances the atten­tion­al mod­u­la­tion of neur­al alpha pow­er but does not affect behav­iour­al per­for­mance in two lis­ten­ing tasks

Does clos­ing the eyes enhance our abil­i­ty to lis­ten atten­tive­ly? In fact, many of us tend to close their eyes when lis­ten­ing con­di­tions become chal­leng­ing, for exam­ple on the phone. It is thus sur­pris­ing that there is no pub­lished work on the behav­iour­al or neur­al con­se­quences of clos­ing the eyes dur­ing atten­tive lis­ten­ing. In the present study, we demon­strate that eye clo­sure does not only increase the over­all lev­el of absolute alpha pow­er but also the degree to which audi­to­ry atten­tion mod­u­lates alpha pow­er over time in syn­chrony with attend­ing to ver­sus ignor­ing speech. How­ev­er, our behav­iour­al results pro­vide evi­dence for the absence of any dif­fer­ence in lis­ten­ing per­for­mance with closed ver­sus open eyes. The like­ly rea­son for this is that the impact of eye clo­sure on neur­al oscil­la­to­ry dynam­ics does not match alpha pow­er mod­u­la­tions asso­ci­at­ed with lis­ten­ing per­for­mance pre­cise­ly enough (see figure).

The paper is avail­able as preprint here.

 

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
Auditory Cortex Auditory Neuroscience fMRI Papers Publications

New paper by Erb et al. in Cere­bral Cor­tex: Human but not mon­key audi­to­ry cor­tex is tuned to slow tem­po­ral rates

In a new com­par­a­tive fMRI study just pub­lished in Cere­bral Cor­tex, AC post­doc Julia Erb and her col­lab­o­ra­tors in the Formisano (Maas­tricht Uni­ver­si­ty) and Van­duf­fel labs (KU Leu­ven) pro­vide us with nov­el insights into speech evo­lu­tion. These data by Erb et al. reveal homolo­gies and dif­fer­ences in nat­ur­al sound-encod­ing in human and non-human pri­mate cortex.

From the Abstract: “Under­stand­ing homolo­gies and dif­fer­ences in audi­to­ry cor­ti­cal pro­cess­ing in human and non­hu­man pri­mates is an essen­tial step in elu­ci­dat­ing the neu­ro­bi­ol­o­gy of speech and lan­guage. Using fMRI respons­es to nat­ur­al sounds, we inves­ti­gat­ed the rep­re­sen­ta­tion of mul­ti­ple acoustic fea­tures in audi­to­ry cor­tex of awake macaques and humans. Com­par­a­tive analy­ses revealed homol­o­gous large-scale topogra­phies not only for fre­quen­cy but also for tem­po­ral and spec­tral mod­u­la­tions. Con­verse­ly, we observed a strik­ing inter­species dif­fer­ence in cor­ti­cal sen­si­tiv­i­ty to tem­po­ral mod­u­la­tions: While decod­ing from macaque audi­to­ry cor­tex was most accu­rate at fast rates (> 30 Hz), humans had high­est sen­si­tiv­i­ty to ~3 Hz, a rel­e­vant rate for speech analy­sis. These find­ings sug­gest that char­ac­ter­is­tic tun­ing of human audi­to­ry cor­tex to slow tem­po­ral mod­u­la­tions is unique and may have emerged as a crit­i­cal step in the evo­lu­tion of speech and language.”

The paper is avail­able here. Con­grat­u­la­tions, Julia!

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
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.