Search bioRxiv⌕ Search

bioRxiv · 10.1101/2023.06.02.543456

Tactile Imagery Affects Cortical Responses to Vibrotactile Stimulation of the Fingertip

Abstract

Although imagery of tactile sensations is not so well studied compared to other types of mental imagery, it is potentially very useful for brain computer interfaces (BCIs) where it could produce neural modulations needed for BCI operations. Here we assessed neural modulations associated with tactile imagery (TI) by comparing its effects on cortical responses to the effects of actual vibrotactile stimulation of the fingertip. We found that both TI and vibrostimulation evoked event-related frequency changes of the electroencephalographic (EEG) activity. Moreover, TI affected somatosensory evoked potentials (SEPs) evoked by short pulses of vibration. EEG data were collected in 29 participants trained to perform tactile imagery task. Responses to vibratory pulses were measured with and without TI. These SEPs consisted of three prominent components: a P100 response in the centro-parietal regions, a P200 response in the frontal region, and a P300 response in the central regions. The TI consistently resulted in an increase in ipsilateral P100, ipsi- and contralateral P300 and frontal P200. Moreover, TI strengthened the {theta}-band ERS in the frontal region that occurred in response to vibration. These findings suggest that TI not only modulates EEG patterns by itself but also affects cortical processing of physical somatosensory stimuli. Such conjoint processing of both real and imagined somatic sensations could be utilized in BCIs, particularly in clinically relevant BCI that strive to restore somatosensory processing by combining centrally-induced and peripheral activities. Significance StatementWhile it is known that tactile imagery (TI) engages the same cortical areas that are active during the processing of real tactile inputs, neural mechanisms of such shared representation are not well understood. This study employed EEG recordings to examine the interaction between real and imagined somatic sensations. It was found that TI both changes EEG oscillatory activity and facilitates cortical responses to real tactile stimuli. Therefore combining TI with tactile stimulation could be useful for tactile-based brain-computer interfaces (BCIs), particularly the ones of clinical utility for neurorehabilitation and sensory substitution.

Source connections

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Morozova, M., Yakovlev, L., Syrov, N., Perevoznyuk, G., Lebedev, M., Kaplan, A.. 2023-06-06. Tactile Imagery Affects Cortical Responses to Vibrotactile Stimulation of the Fingertip. https://doi.org/10.1101/2023.06.02.543456

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

The Unreasonable Effectiveness of Cell Types in Describing Neuronal Physiological Features

Single-cell RNA sequencing (scRNA-seq) captures detailed gene expression profiles at scale, while patch-clamp recordings measure intrinsic neuronal electrophysiological properties. Modeling the relations between these two modalities remains a challenge. Here, we compare how well electrophysiological features can be predicted by traditional transcriptomic cell type classification, representations derived from a foundational model (scGPT) pretrained on large-scale scRNA-seq datasets, ion channel-coding genes, and highly variable genes. Using paired transcriptomic and electrophysiological patch-sequencing data from 495 human neurons from neurosurgical tissue, we find that cluster-level cell type representations consistently outperform highly variable gene selection, ion channel gene selection, and context-enriched scGPT embeddings. Notably, performance varies across model architectures and initializations, and the best results are obtained by combining the outputs of separate cell type and scGPT-based models. Together, these findings suggest that traditional discrete cellular classification is highly effective in predicting physiological features. For maximum performance it can be complemented by pretrained transformer models.

neuroscience↗

A nonlinear inhibition pathway underlying cortical responses to tuned holographic optogenetic perturbations

Optogenetics enables causal manipulation of cortical activity. Perturbation responses can be counterintuitive due to network interactions, making theory essential for predicting them. Existing approaches often rely on linear approximations, which fail for many biologically relevant perturbations. Here we develop a nonlinear theory of responses to holographic perturbations in cell-type-specific recurrent networks with structured connectivity. We fit a nonlinear model to mouse V1 data, which shows cotuned-ensemble suppression: perturbing spatially clustered neurons with similar preferred orientations yields markedly stronger short-range suppression than perturbing untuned ensembles. We show that cotuned-ensemble suppression arises from a feature-tuned, nonlinear inhibition pathway implicating somatostatin-positive (SST) interneurons. The theory predicts that cotuned ensembles suppress parvalbumin-positive (PV) neurons but facilitate SST neurons, and links the degree of cotuned-ensemble suppression or facilitation to the variance of the SST response. This framework identifies mechanisms by which nonlinear inhibition sculpts cortical dynamics and establishes a predictive basis for targeted optogenetic interventions.

neuroscience↗

Proteomic signatures of APOE ε4 across human tissues and cell types in Alzheimers disease

The apolipoprotein E {varepsilon}4 (APOE {varepsilon}4) allele is the strongest genetic risk factor for late-onset Alzheimers disease (AD). However, the underlying molecular mechanisms remain unclear. This study included 1691 participants from the Religious Orders Study and Rush Memory and Aging Project (ROSMAP), 1226 participants from the Accelerating Medicines Partnership - Alzheimers Disease (AMP-AD) Diverse Cohorts Study, and 735 participants from the Alzheimers Disease Neuroimaging Initiative (ADNI). To characterise APOE {varepsilon}4 molecular effects, we analysed proteomic data from plasma, cerebrospinal fluid (CSF), and induced pluripotent stem cell (iPSC)-derived astrocytes and neurons, as well as transcriptomic and proteomic data from multiple brain regions. The association of APOE {varepsilon}4 with AD neuropathology was also examined. APOE {varepsilon}4 carriers shared a plasma proteomic signature enriched for immune processes, irrespective of AD diagnosis. A machine learning classifier trained on this signature discriminated APOE {varepsilon}4 carriers from non-carriers in an independent cohort using CSF proteomics. APOE {varepsilon}4 carriage was associated with higher Braak stages and Consortium to Establish a Registry for Alzheimers Disease (CERAD) score. However, only limited APOE {varepsilon}4-associated transcriptomic and proteomic changes were observed in bulk brain tissue, with poor cross-layer concordance. Proteomic analyses of iPSC-derived astrocytes and neurons further revealed cell-type-specific APOE {varepsilon}4-associated changes. APOE {varepsilon}4 is associated with a consistent proteomic signature across plasma and CSF. Its molecular effects in the brain differ across cell types, brain regions and molecular layers. These findings support the need for cell-type-resolved multi-omic studies to elucidate how APOE {varepsilon}4 confers AD risk.

neuroscience↗