Search results for "Sensory input"
showing 6 items of 6 documents
Deimatism: a neglected component of antipredator defence
2017
Deimatic or ‘startle’ displays cause a receiver to recoil reflexively in response to a sudden change in sensory input. Deimatism is sometimes implicitly treated as a form of aposematism (unprofitability associated with a signal). However, the fundamental difference is, in order to provide protection, deimatism does not require a predator to have any learned or innate aversion. Instead, deimatism can confer a survival advantage by exploiting existing neural mechanisms in a way that releases a reflexive response in the predator. We discuss the differences among deimatism, aposematism, and forms of mimicry, and their ecological and evolutionary implications. We highlight outstanding questions …
Contralateral hand anesthesia transiently improves poststroke sensory deficits.
2005
Objective To test a possible strategy to alleviate somatosensory deficits after stroke. Methods Here, we applied ischemic nerve block to the intact hand of patients with chronic stroke, which in healthy subjects elicits improvements in sensibility of the other hand. Results We found that sensibility in the affected hand improved with intact hand anesthesia, but not with intact foot anesthesia or no anesthesia. Interpretation We conclude that reduction of sensory input from the intact hand leads to site-specific improvements in tactile discriminative skills in the affected hand after the period of anesthesia, a potentially relevant finding in designing neurorehabilitative interventions. Ann …
Distinctive Representation of Mispredicted and Unpredicted Prediction Errors in Human Electroencephalography
2015
The predictive coding model of perception proposes that neuronal responses are modulated by the amount of sensory input that the internal prediction cannot account for (i.e., prediction error). However, there is little consensus on what constitutes nonpredicted stimuli. Conceptually, whereas mispredicted stimuli may induce both prediction error generated by prediction that is not perceived and prediction error generated by sensory input that is not anticipated, unpredicted stimuli involves no top-down, only bottom-up, propagation of information in the system. Here, we examined the possibility that the processing of mispredicted and unpredicted stimuli are dissociable at the neurophysiologic…
The role of hedonics in the Human Affectome.
2019
International audience; Experiencing pleasure and displeasure is a fundamental part of life. Hedonics guide behavior, affect decision-making, induce learning, and much more. As the positive and negative valence of feelings, hedonics are core processes that accompany emotion, motivation, and bodily states. Here, the affective neuroscience of pleasure and displeasure that has largely focused on the investigation of reward and pain processing, is reviewed. We describe the neurobiological systems of hedonics and factors that modulate hedonic experiences (e.g., cognition, learning, sensory input). Further, we review maladaptive and adaptive pleasure and displeasure functions in mental disorders …
Prior precision modulates the minimisation of prediction error in human auditory cortex
2018
AbstractThe predictive coding model of perception proposes that successful representation of the perceptual world depends upon cancelling out the discrepancy between prediction and sensory input (i.e., prediction error). Recent studies further suggest a distinction between prediction error associated with non-predicted stimuli of different prior precision (i.e., inverse variance). However, it is not fully understood how prediction error from different precision levels is minimised in the predictive process. The current research used magnetoencephalography (MEG) to examine whether prior precision modulates the cortical dynamics of the making of perceptual inferences. We presented participant…
Chapter 24 Bihemispheric plasticity after acute hand deafferentation
2003
Publisher Summary This chapter summarizes experiments showing that deprivation of somatosensory input could also elicit organizational changes in the hemisphere contralateral to the deafferented one. The existence of interactions among homotopic sites within cortical representations in both hemispheres provides a substrate for such an effect. It has been proposed that chronic deafferentation, in association with long-term practice as in blind, deaf, or individuals with amputation results in compensatory gains in the same and in other sensory modalities. However, the long-term changes described are mild and the question whether blind or deaf people develop enhanced capacities of their remain…