Touch

Abstract

The modality of touch encompasses distinct cutaneous, kinesthetic, and haptic systems that are distinguished on the basis of the underlying neural inputs. The cutaneous receptors are embedded in the skin; the kinesthetic receptors lie in muscles, tendons, and joints; and the haptic system uses combined inputs from both. Topics in this chapter range from sensory phenomena, such as threshold‐level responses, to cognitive and memory processes associated with the haptic system. Haptic perception extracts properties of objects and surfaces that lead to recognition of objects. Material properties are highly accessible, relative to geometric properties, providing a contrast between haptics and vision. The haptic system provides a map of space within reach of the body that provides the basis for recognition of two‐dimensional patterns and outline drawings. The spatial map is subject to systematic distortion, particularly as a result of the movements used in exploration. Interactions between haptic and visual perception are described with respect to attention, representation, and memory. As do other modalities, the sense of touch gives rise to implicit and explicit forms of memory. The chapter concludes with applications of research on touch, including aids for the blind and deaf and virtual environments that provide haptic feedback.

Imagining material versus geometric properties of objects: an fMRI study

“…Within the perceptual system, material properties differ in the nature of the peripheral receptors that mediate the perceptual outcome, the pattern of exploratory movements used to seek the properties, and the nature and time-course of computations that are done on the basis of peripheral signals (see Ref. [20], for a review). Considering memorybased processing, including imagery, haptically accessible properties differ in the visual cues with which they are associated.…”

Aging and Curvature Discrimination From Static and Dynamic Touch

“…It is very important to note, however, that cutaneous activity resulting from simple contact is not the only source of information available to support the tactile perception of object shape. When we actively manipulate objects using a variety of exploratory procedures [16,17], this leads to activation of not only cutaneous receptors within the skin, but also results in the stimulation of muscle and joint receptors. The additional sensory and proprioceptive information made possible by active touch has been shown to enhance shape perception [18][19][20][21][22].…”

Bimanual curvature discrimination of hand-sized surfaces placed at different positions

“…In other words, how large can the width of a trough gap be before the participant perceives its presence or before it starts changing the perceived overall shape? Because little haptic research has been devoted to psychophysical measurements of 3-D object properties (for a review, see Klatzky & Lederman, 2003), we consider these important first steps to take when studying haptic shape perception, with the main challenge, of course, of physically quantifying the cues.…”