Analogous neural models for tactual and visual learning

Recent evidence concerning the neural basis of visual perception and learning has led to the development of a sequential neural model in which the striate, prestriate, inferior temporal, and ventromedial frontotemporal areas are viewed as successive links in a neocortical-limbic pathway mediating visual-affective associations [17, 20, 21]. In this paper an analogous model is proposed for touch, with the primary and secondary sensory areas (SI and SII) serving as the successive somatosensory links to the ventromedial limbic region. The model helps to account for some otherwise puzzling data reviewed here pertaining to (a) hierarchical organization in tactual perception, (b) localization of the tactual memory trace, and (c) sensory-limbic interaction in tactual learning. The pivotal link in this model is the secondary sensory area (SII), which is assigned a role in somesthesis similar to that attributed to the inferior temporal area in vision. Evidence from a variety of sources is introduced to support the parallel.