Sense, memory, and decision-making in the somatosensory cortical network

The brain constructs representations of objects and concepts based in sensory information combined with experience. This mental process, that we call perception, is the result of a chain of events consisting of phenomena such as detection, memory, discrimination, categorization and decision-making. Although the phenomenon of perception is not necessarily dependent on a given sensory modality (e.g. visual perception, auditory, tactile), single sensory models are indispensable for studying the neural mechanisms that generate it. The somatosensory system is a suitable model for studying the manner in which presentation of a single physical variable (e.g. vibration) triggers a perceptual process. Here, we discuss some recent studies in the somatosensory system that in our view, constitute a breakthrough to understanding decision making.

► Sensory activity increasingly predicts behavior across the processing hierarchy. ► Decisions are made by comparing past and current sensory information. ► Comparison is observed in early sensory areas such as S2. ► A subtraction of oppositely tuned populations underlies frequency discrimination. ► Decision related activity emerges in parietal and frontal cortical circuits.