To perceive external environment more efficiently, the sensory information derived from the modality of touch, or tactile information, is processed in terms of its physical features and affective responses to these features. This review summarizes the current understanding about how haptic information is processed in skin, spinal cord, and cerebral cortex of animals and humans. Typically, different non-noxious somatosensory information is coded by various cutaneous sensory neurons called low-threshold mechanoreceptors (LTMRs). Next, haptic processing starts at the dorsal horn of the spinal cord, and then it partially segregates into different pathways, transmitting information to the somatosensory cortex, the first crucial brain area for haptic information processing. Moreover, several relatively independent brain networks are responsible for the processing of different properties of haptic information. Finally, by discussing the interactions between touch and other sensory modalities, we argue that such interactions are plastic, which is warranted in the future work to generate extensive value in applications.

sensory perception  /  haptic information  /  cross-modality  /  neural mechanisms  /  applications