Evelin Wacker

Tactile Feature Processing and Selective Attention: Two Experimental Investigations in the Human Somatosensory System Evelin Wacker

The somatosensory system is highly diverse in its functionality. Among others, it is responsible for tactile perception and involved in motor control. Considerable effort has been directed towards elucidating how somatosensory processing is organized to subserve these functions. Based on this, Dijkerman and de Haan recently proposed a model to describe the cortical processing of somatosensory information (Dijkerman and de Haan 2007). The aim of the present thesis was to extend this model of somatosensory processing for perception and action, focussing on feature processing and attentional modulation during tactile perception. To this end, two functional magnetic resonance imaging experiments were performed, in which Braille-like tactile stimulation was presented to human volunteers. Based on the experimental results, functions for feature processing and attentional modulation were added to the model by Dijkerman and de Haan. The extended model contributes to the understanding of how the somatosensory system processes tactile input and allows formulating testable hypotheses to motivate future research questions.