Mark Hollins, Ph.D.
Professor and Director of Graduate Studies


Department of Psychology
Davie Hall
Chapel Hill, NC 27599-3270

Phone: 919-962-2441
Fax: 919-962-2537

Daniel Harper, MA

I am an advanced graduate student in the Behavioral Neuroscience program and am currently working towards obtaining my PhD in Psychology. My dissertation research focuses on the processing of noxious, thermal, and mechanical signals and several interactions that can occur between different somatosensory submodalities. The somatosensory system utilizes different receptors in the skin to transduce warm, cool, hot, cold, and mechanical stimuli and these signals are transmitted to the central nervous system in separate pathways. However, once the signals reach the spinal cord there is a high degree of integration and cross-talk between modalities. For example, interlaced warm and cool (but not painful) bars cause a perception of burning pain when applied to the skin simultaneously, a phenomenon known as the thermal grill illusion. Recent research in our lab has shown that this interaction between warm and cool produces a pain-like signal at the level of the spinal cord. In addition, I am also studying pain-pain and pain-touch interactions. Even though there is substantial integration of signals in the spinal cord and the brain (like in the thermal grill illusion), my current research indicates that some somatosensory pathways remain separate and distinguishable from one another.


Harper, D.E. & Hollins, M. (2012). Is touch gating due to sensory or cognitive interference? Pain, 153, 1082-1090.

Hollins, M., Harper, D., Maixner, W. (2011). Changes in pain from a repetitive thermal stimulus: The roles of adaptation and sensitization. Pain, 152, 1583-1590.

Hollins, M., Harper, D., Gallagher, S., Owings, E. W., Lim, P. F., Miller, V., Siddiqi, M. Q., Maixner, W. (2009). Perceived intensity and unpleasantness of cutaneous and auditory stimuli: An evaluation of the generalized hypervigilance hypothesis. Pain, 141, 215-221.

Hollins, M., Lorenz, F., Harper, D. (2006). Somatosensory coding of roughness: The effect of texture adaptation in direct and indirect touch. Journal of Neuroscience, 26, 5582-5588.