Episode 4 of the Language Neuroscience Podcast. Ever wondered about the role of neural oscillations & neural entrainment in speech & language? Well I have… so I invited the great @jonasobleser to come talk about it. I really enjoyed this conversation! https://t.co/vflcfxbLS5 pic.twitter.com/BPkruYV26E
— Stephen Wilson (@smwilsonau) March 9, 2021
Thanks to colleague Stephen Wilson from Vanderbilt University for inviting me to this conversation!
The episode with Jonas is also available on Spotify.
— Ein deutsches automatisch erstelltes Transkript ist hier erhältlich (alle Übersetzungen ohne Gewähr).
We are excited to share that former Obleserlab PhD student Leo Waschke, together with his new (Doug Garrett, Niels Kloosterman) and old (Jonas Obleser) lab has published an in-depth perspective piece in Neuron, with the provocative title “Behavior need neural variability”.
Our article is essentially a long and extensive tribute to the “second moment” of neural activity, in statistical terms, essentially: Variability — be it quantified as variance, entropy, or spectral slope — is the long-neglected twin of averages, and it holds great promise in understanding neural states (how does neural activity differ from one moment to the next?) and traits (how do individuals differ from each other?).
We would like to extend a warm welcome to our new lab members:
Dr. Hong-Viet (“Hongi”) Ngo, who is a Uni Lübeck PhD alumnus himself, but joins us from the Donders Institute and who is an avid expert on sleep, memory, and auditory stimulation to entrain slow-wave sleep activity.
Markus Kemper just graduated from University of Lübeck and is a trained acoustics engineer and audiologist, ready to embark on a PhD dissecting the psychological and physiological reality of that elusive construct “listening effort”. Notably, Markus is funded by a joint effort of the Department of Psychology, University of Lübeck, and our Campus neighbour and industry partner, the Deutsche Hörgeräte Institut, DHI (German Institute of Hearing Aids).
What a time to make such career moves during a pandemic — good luck, and a productive and enjoyable time to both of you!
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.
New PhD opportunity: @bjoherrmann (Rotman Research) and @ObleserLab at @UniLuebeck, Germany, have a @dfg_public-funded 3‑year PhD position! (neural dynamics, temporal expectation, ageing). Apply now until July 12! Please RT widely/alert your MSc/RAs. https://t.co/gphGf8Xx4c pic.twitter.com/GneEmTGvaP
— Jonas Obleser (@jonasobleser) June 26, 2020
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.
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.
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!
Feel free to ring me up any time if you are interested in chatting beforehand. Looking forward to many interesting applications!