Abstract
Purpose: Although humans engage the environment constantly with all five senses, we still know relatively little about some aspects of sensory interaction, particularly the relationships between the primary senses (vision and hearing) and the secondary senses (taste, touch/pain, and smell). This is of interest both for our understanding of the links between the neural mechanisms which underlie the different senses, as well as for the diagnosis and treatment of sensory related disorders. The present study reports on the first study designed to explore the basic question of whether fundamental aspects of human vision are related to the somatosensory systems of touch and pain. Methods: Two essential measures of spatial vision (visual acuity, contrast sensitivity) and a measure of temporal vision (flicker fusion threshold) were assessed in 45 healthy young adults (M = 23 y). Within the same session, contact heat and pressure algometer pain threshold/tolerance, as well as touch thresholds (von Frey fibres) were obtained from several locations on each subject’s left hand and arm. Individual subject data was also collected from 12 adults who were evaluated repeatedly over 10 additional sessions. Results: Correlational analyses within the group data revealed very little relationship between any aspects of vision (spatial or temporal) and any of the touch or pain measures. However, data from individuals tested repeatedly revealed that contrast sensitivity was related to pain tolerance obtained with both contact heat and with pressure algometry (both p <0.05). Conclusions: The present results provide evidence that human adults may show a relationship between pain sensitivity and some aspects of spatial vision. Given that dopamine is heavily involved in both the processing of pain as well as spatial information in the cortex, this raises the interesting possibility that the observed co-variation in sensitivity may be explained by dopaminergic involvement.
Meeting abstract presented at VSS 2013