The availability of vision and tactile gating in a reaching and grasping task


A multitude of events bombard our sensory systems at every moment of our lives. Thus, it is important for the sensory cortex to gate unimportant events. Tactile suppression is a well-known phenomenon defined as a reduced ability to detect tactile events on the skin before and during movement. Previous experiments (Buckingham et al., 2010; Colino et al., 2014) found detection rates decrease just prior to and during finger abduction, and decrease according to the proximity of the moving effector.  However, what effect does vision have on tactile gating? There is ample evidence (see Serino & Haggard, 2010) observing increased tactile acuity when participants see their limbs.  The present study examined how tactile detection changes in response to visual condition (vision/no-vision).  Ten human participants used their right hand to reach and grasp a cylinder. Tactors were attached to the index finger and the forearm of both the right and left arm and vibrated at various epochs relative to a “go” tone. Results replicate previous findings from our laboratory (Colino et al., 2014).  Also, tactile acuity decreased when participants did not have vision.  These results indicate that the vision affects the somatosensation via inputs from parietal areas (Konen & Haggard, 2014) but does so in a reach-to-grasp context.

Acknowledgments: NSERC, CFI