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Neural basis of self

The neural basis of self is the idea of using modern concepts of neuroscience to describe and understand the biological processes that underlie humans' perception of self-understanding. The neural basis of self is closely related to the psychology of self with a deeper foundation in neurobiology. Experimental techniques In order to understand how the human mind makes the human perception of self, there are different experimental techniques. One of the more common methods of determining brain areas that pertain to different mental processes is by using Functional Magnetic Resonance Imaging. fMRI data is often used to determine activation levels in portions of the brain. fMRI measures blood flow in the brain. Areas with higher blood flow as shown on fMRI scans are said to be activated. This is due to the assumption that portions of the brain receiving increased blood flow are being used more heavily during the moment of scanning. Positron emission tomography is another method u

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Publications associées (16)

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Students will acquire an integrative view on biological and artificial algorithms for controlling autonomous behaviors in animals and robots. Students will synthesize and apply this knowledge in oral presentations and exercises.

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Evidence accumulation relates to perceptual consciousness and monitoring

Fosco Bernasconi, Olaf Blanke, Wenwen Chang, Nathan Quentin Faivre, Michael Eric Anthony Pereira, Mi Xue Tan

A fundamental scientific question concerns the neural basis of perceptual consciousness and perceptual monitoring resulting from the processing of sensory events. Although recent studies identified neurons reflecting stimulus visibility, their functional role remains unknown. Here, we show that perceptual consciousness and monitoring involve evidence accumulation. We recorded single-neuron activity in a participant with a microelectrode in the posterior parietal cortex, while they detected vibrotactile stimuli around detection threshold and provided confidence estimates. We find that detected stimuli elicited neuronal responses resembling evidence accumulation during decision-making, irrespective of motor confounds or task demands. We generalize these findings in healthy volunteers using electroencephalography. Behavioral and neural responses are reproduced with a computational model considering a stimulus as detected if accumulated evidence reaches a bound, and confidence as the distance between maximal evidence and that bound. We conclude that gradual changes in neuronal dynamics during evidence accumulation relates to perceptual consciousness and perceptual monitoring in humans.

2021

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Recovery of supraspinal control of stepping via indirect propriospinal relay connections after spinal cord injury

Grégoire Courtine, Michael V. Sofroniew

Spinal cord injuries (SCIs) in humans and experimental animals are often associated with varying degrees of spontaneous functional recovery during the first months after injury. Such recovery is widely attributed to axons spared from injury that descend from the brain and bypass incomplete lesions, but its mechanisms are uncertain. To investigate the neural basis of spontaneous recovery, we used kinematic, physiological and anatomical analyses to evaluate mice with various combinations of spatially and temporally separated lateral hemisections with or without the excitotoxic ablation of intrinsic spinal cord neurons. We show that propriospinal relay connections that bypass one or more injury sites are able to mediate spontaneous functional recovery and supraspinal control of stepping, even when there has been essentially total and irreversible interruption of long descending supraspinal pathways in mice. Our findings show that pronounced functional recovery can occur after severe SCI without the maintenance or regeneration of direct projections from the brain past the lesion and can be mediated by the reorganization of descending and propriospinal connections. Targeting interventions toward augmenting the remodeling of relay connections may provide new therapeutic strategies to bypass lesions and restore function after SCI and in other conditions such as stroke and multiple sclerosis.

2008

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Selective attention involves a feature-specific sequential release from inhibitory gating

David Pascucci, Gijs Plomp

Selective attention is a fundamental cognitive mechanism that allows our brain to preferentially process relevant sensory information, while filtering out distracting information. Attention is thought to flexibly gate the communication of irrelevant information through top-down alpha-rhythmic (8-12 Hz) functional connections, which influence early visual processing. However, the dynamic effects of top-down influence on downstream visual processing remain unknown. Here, we used electroencephalography to investigate local and network effects of selective attention while subjects attended to distinct features of identical stimuli. We found that attention-related changes in the functional brain network organization emerge shortly after stimulus onset, accompanied by an overall decrease of functional connectivity. Signatures of attentional selection were evident from a sequential release from alpha-band parietal gating in feature-selective areas. The directed connectivity paths and temporal evolution of this release from gating were consistent with the sensory effect of each feature, providing a neural basis for how visual processing quickly prioritizes relevant information in functionally specialized areas.

ACADEMIC PRESS INC ELSEVIER SCIENCE2022

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