Biology subjects

Uhlhaas, P.

Publications and source records attributed to Uhlhaas, P..

3 recordsLinked to original sources

bioRxiv2025

OPM quantum sensors enhance non-invasive neuroimaging performance

Much of our understanding of how neural circuit activity relates to human behaviour as well as mental health stems from non-invasive assessments of the central nervous system. Further progress in key questions, however, requires a higher differentiation of circuit-level activity, which remains constrained by the sensitivity and resolution of existing instruments. Here we show that neural quantum sensing with optically pumped magnetometers (OPMs) addresses this issue by significantly outperforming EEG and conventional MEG in both signal-to-noise ratio (SNR) and signal coherence across trials. SNR for OPMs was increased by up to 205% compared to EEG and by up to 40% compared to conventional MEG. Likewise, the signal coherence across trials of OPMs was increased by up to 61% compared to EEG and by up to 23% compared to conventional MEG. Our data emphasize the important role of OPMs for non-invasive neuroimaging, paving the way for significant advances in basic research as well as translational applications.

neuroscience↗

bioRxiv2022

Neural integration and segregation revealed by a joint time-vertex connectome spectral analysis

Brain oscillations are produced by the coordinated activity of large groups of neurons and different rhythms are thought to reflect different modes of information processing. These modes, in turn, are known to occur at different spatial scales. Nevertheless, how these rhythms support different modes of information processing at the brain scale is not yet fully understood. Here we present "Joint Time-Vertex Connectome Spectral Analysis", a framework for characterizing the spectral content of brain activity both in time (temporal frequencies) and in space (spatial connectome harmonics). This method allows us to estimate the contribution of integration (global communication) and segregation (functional specialization) mechanisms at different temporal frequency bands in source-reconstructed M/EEG signals, thus providing a better understanding of the complex interplay between different information processing modes. We validated our method on two different datasets, an auditory steady-state response (ASSR) and a visual grating task. Our results suggest that different information processing mechanisms are carried out at different frequency channels: while integration seems to be a specific mechanism occurring at low temporal frequencies (alpha and theta), segregation is only observed at higher temporal frequencies (high and low gamma). Crucially, the estimated contribution of the integration and segregation mechanisms predicts performance in a behavioral task, demonstrating the neurophysiological relevance of this new framework.

neuroscience↗

bioRxiv2018

Perceptual phenotypes: Perceptual gains and losses in synesthesia and schizophrenia

Individual differences in perception are widespread. Considering inter-individual variability, synesthetes experience stable additional sensations; schizophrenia patients suffer perceptual deficits in e.g. perceptual organization (alongside hallucinations and delusions). Is there a unifying principle explaining inter-individual variability in perception? There is good reason to believe perceptual experience results from inferential processes whereby sensory evidence is weighted by prior knowledge about the world. Different perceptual phenotypes may result from different precision weighting of sensory evidence and prior knowledge. We tested this hypothesis by comparing visibility thresholds in a perceptual hysteresis task across medicated schizophrenia patients, synesthetes, and controls. Participants rated the subjective visibility of stimuli embedded in noise while we parametrically manipulated the availability of sensory evidence. Additionally, precise long-term priors in synesthetes were leveraged by presenting either synesthesia-inducing or neutral stimuli. Schizophrenia patients showed increased visibility thresholds, consistent with overreliance on sensory evidence. In contrast, synesthetes exhibited lowered thresholds exclusively for synesthesia-inducing stimuli suggesting high-precision long-term priors. Additionally, in both synesthetes and schizophrenia patients explicit, short-term priors - introduced during the hysteresis experiment - lowered thresholds but did not normalize perception. Our results imply that distinct perceptual phenotypes might result from differences in the precision afforded to prior beliefs and sensory evidence, respectively.

neuroscience↗