Expectancy · Unveiling expectancy neuronal coding in the cerebral cortex induced by naturalistic tactile stimuli

Unveiling expectancy neuronal coding in the cerebral cortex induced by naturalistic tactile stimuli

We address the problem of how does the brain encode predictable sensory information coming from the environment. The way we suddenly notice the cease of a repetitive noise or how magicians surprise us with the unexpected disappearance of an object reveals our preparedness for incoming stimulus. If we want to understand how we encode and use sensory information, it is of most importance to study sensory representations in combination with our internal representation of the world. This research lies in the domain of sensory processing and encoding. It aims at understanding the basic coding rules and features of the somatosensory cortical area in order to use it as a model of how we more generally encode and use information. This allows to comprehend better and inform on the general healthy state of the brain in the sensory areas, in order to look for differences or malfunctions in the case of disease. This study is also of great importance in the field of brain machine interfaces as it helps on the understanding of general encoding for the use of proper sensory embodiment of prostheses. The objective of our project is to find neuronal signatures of expectancy signals in a spatiotemporal predictive manner in a somatosensory cortex. We take advantage of the precisely arranged tactile system of the rodents, the whisker system, and provide a carefully controlled multi-whisker stimulation in a highly predictable manner. The arrangement of whiskers in arcs and rows in the snout of the rat allows us to design a converging pattern of whisker deflections towards a single whisker. We simultaneously look into the associated primary sensory cortex, which is the first cortical area to receive the signal from the stimulation. In this area, called ´barrel cortex´, there is an arrangement of neuronal structures in the form of barrels that match the geometry of the whiskers and receive their corresponding sensory input. We looked for neuronal activity arising during truncated spatiotemporal patterns. These stimulations have an absent deflection in the last part of the stimulus that corresponds to the target whisker associated with the barrel being measured. Our results show that the neuronal activity in the somatosensory cortex carries information about the expected spatiotemporal patterns of stimulation.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз