Capture of kinesthesis by a competing cutaneous input.

In four experiments, blindfolded participants were presented with pairs of stimuli simultaneously, one to each index finger. Participants moved one index finger, which was presented with cutaneous and/or kinesthetic stimuli, and this movement caused a raised line to move underneath the other, stationary index finger in a yoked manner. The stimuli were 180º rotations of each other (e.g., < and >), and thus when a < was traced with the moving finger, it caused a > to be felt at the stationary finger. When asked to report the experience, participants predominantly reported the cutaneous stimulus, seemingly being ignorant of the kinesthetic stimulus. This appears to be an intrahaptic capture phenomenon, which is of interest because it suggests that conflict between intrahaptic sensory stimuli can go unnoticed; sometimes we are unaware of how we moved, and sometimes we do not know what we touched. The results are interpreted in light of optimal integration, perceptual suppression, reafference suppression, and inattentional blindness.