UC Santa Barbara

This thesis employed systems modeling and engineering design methods in order to study the `thermal grill illusion' (TGI), a perceptual illusion in which a spatial configuration of warm and cool elements produce a paradoxical pseudo-burning sensation.

The motivation for this study was derived from the possibility to develop new methods for assessing peripheral sensory deficits affecting the sense of touch, associated with peripheral neuropathy. Thermal grill stimuli, consisting of spatial configurations of alternating warm and cool elements, are non-injurious and can elicit rapid and unambiguous perceptual responses, whose absence might provide a reliable indicator of sensory loss, although this has not been previously investigated, and is only indirectly addressed in this thesis.

An integrated custom electrothermal display was optimized for delivering thermal grill stimuli to the body. In order to validate the display technique, a thermodynamic model accounting for heat exchange (diffusion) through the skin was developed and the model predictions were compared with thermal perception. I calibrated and assessed the approach in perceptual experiments with healthy human subjects.