Visually induced feelings of touch

Recent studies have reported that vision can enhance tactile perception, even in patients with somatosensory deficits. However, it is unclear in these previous studies whether visual input truly enhances detection of tactile stimuli or induces a higher propensity for reporting touch by changing response criteria. In this study, we demonstrate in neurologically normal subjects that in addition to small increases in tactile sensitivity when a non-informative, suprathreshold visual stimulus is presented, there are highly consistent changes in response criteria for reporting touch with vision, even when no tactile stimulus is delivered. These results suggest that some of the previously reported enhancements of touch from vision may rather be a consequence of strategic sensory encoding processes that rely upon the typical correlations between multisensory events.