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Yuri B Saalmann

3 papers in the library · publishing 2022-2026

Papers

Protocol for testing global neuronal workspace and integrated information theories of consciousness in non-human primates and mice.

PloS one January 1, 2026 Matilda Gibbons, Ethan G McBride, Raghuram Holenarasipura Venkatasubbaiah et al.

An adversarial collaboration will test competing predictions from Global Neuronal Workspace Theory and Integrated Information Theory about the neural correlates of consciousness. Non-human primates and mice will perform a go-nogo task with supra-threshold visual and auditory stimuli while neural activity is recorded from multiple cortical areas using Neuropixels electrodes. To causally test timing and location predictions, prefrontal cortex activity will be manipulated via electrical stimulation in primates or optogenetic silencing in mice. The protocol details experimental design, analyses, divergent predictions, and anticipated outcomes.

Evaluation of putative signatures of consciousness using specific definitions of responsiveness, connectedness, and consciousness.

British journal of anaesthesia February 1, 2024 Cameron P Casey, Sean Tanabe, Zahra Z Farahbakhsh et al.

Many EEG-based measures previously thought to indicate unconsciousness actually track sensory connectedness—awareness of the environment—rather than consciousness itself. Analyzing data from the UNderstanding Consciousness Connectedness and Intra-Operative Unresponsiveness Study, researchers tested 10 resting-state EEG markers derived from unresponsive subjects during dexmedetomidine and propofol sedation and natural sleep. While several markers correlated with reported subjective experience (consciousness), none were specific to consciousness alone; each was also linked to connectedness. Loss of normalized-symbolic transfer entropy (front to back) was associated with connectedness across all conditions, and the shift from disconnected consciousness to unconsciousness involved significant decreases in permutation entropy and spectral exponent. The findings caution against equating unresponsiveness with unconsciousness.

Thalamic deep brain stimulation paradigm to reduce consciousness: Cortico-striatal dynamics implicated in mechanisms of consciousness.

PLoS computational biology July 1, 2022 Michelle J Redinbaugh, Mohsen Afrasiabi, Jessica M Phillips et al.

Deep brain stimulation (DBS) of the central lateral thalamus in macaques can produce episodes of vacant staring with low-frequency brain oscillations, termed vacant, perturbed consciousness (VPC). The likelihood of VPC depended on stimulation frequency. During VPC, measures of neural complexity and integration decreased, and communication in cortico-striato-thalamic circuits changed substantially, with increased low-frequency power and coherence, especially in thalamo-parietal and cortico-striatal pathways. These features resembled absence epilepsy. The same DBS method, at different frequencies, can also increase consciousness in anesthetized macaques, offering a flexible tool to study consciousness with fewer confounds and to inform clinical research on consciousness disorders.