Tactile rivalry demonstrated with an ambiguous apparent-motion quartet
Keywords:Tactile, Perceptual Rivalry, Ambiguous motion
Deposited by:Olivia Carter
Date of Issue:2008
Journal/Publication Title:Current Biology
Abstract:When observers view ambiguous visual stimuli, their perception will often alternate between the possible interpretations, a phenomenon termed “perceptual rivalry” . To induce perceptual rivalry in the tactile domain, we developed a new tactile illusion, based on the visual apparent motion “quartet” . Pairs of 200 ms vibrotactile stimuli were applied to the finger pad at intervals separated by 300 ms. The location of each successive stimulus pair alternated between the opposing diagonal corners of the ~1 cm2 stimulation array. This stimulation sequence led all participants to report switches between the perception of motion traveling either up/down or left/right across their fingertip. Adaptation to tactile stimulation biased towards one direction caused subsequent ambiguous stimulation to be experienced in the opposing direction. In contrast, when consecutive trials of ambiguous stimulation were presented, motion was generally perceived in the direction consistent with the motion reported in the previous trial. Voluntary eye movements induced shifts in the tactile perception towards a motion axis aligned along a world-centered coordinate frame. Because the tactile quartet results in switching perceptual states despite unvaried sensory input, it is ideally suited to future studies of the neural processes associated with conscious tactile perception.