Perceived location of touch

• Type of Material: Article
• Authors: Jack Brooks, NeuRa; Jared Medina, Emory University
• Language: English
• Date: 2017
• Publisher: Brain Corporation
• Publication Version: Final Published Version
• Copyright Statement: Jack Brooks and Jared Medina
• License: Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported
• Final Published Version (URL): http://dx.doi.org/10.4249/scholarpedia.42285
• Title of Journal or Parent Work: Scholarpedia
• Volume: 12
• Issue: 4
• Start Page: 42285
• Grant/Funding Information: This material is based upon work supported by the National Science Foundation under grant no. 1632849.
• Keywords: primary somatosensory cortex; touch; cutaneous receptors; thalamus; perception; afferent neurons
• Research Categories: Biology, Neuroscience; Biology, Anatomy

Abstract

Perceiving the location of touch on our skin is a surprisingly complex process. Signals from cutaneous receptors within the skin are transmitted to the brain by afferent neurons to primary somatosensory cortex (S1) via the thalamus. Given noise, both at the level of skin receptors and neurally, the brain needs to decide both whether a stimulus was presented and where that stimulus is located. S1 is organized as a topographic map in which adjacent locations on the skin are represented next to one another. Information in these primary representations have been shown to be plastic – such that a neuron in S1 may represent touch at one location of the skin surface at one point in time, but then represent touch at a different location after cortical and peripheral changes. Therefore, further processing is required to relate activity in these primary representations to a sensation on a specific position on the skin surface. This is achieved by integration with higher order body representations. Finally, touch needs to be localized – not only to a position on the skin surface – but in reference frames relative to the body and the external environment. Therefore, the location of touch can be represented in a number of different representations, each with their own reference frame. We will present evidence on the different stages of processing and representation that are involved in localizing touch.