Neural synergy between kinetic vision and touch.

Ambiguous visual information often produces unstable visual perception. In four psychophysical experiments, we found that unambiguous tactile information about the direction of rotation of a globe whose three-dimensional structure is ambiguous significantly influences visual perception of the globe. This disambiguation of vision by touch occurs only when the two modalities are stimulated concurrently, however. Using functional magnetic resonance imaging, we discovered that touching the rotating globe, even when not looking at it, reliably activates the middle temporal visual area (MT+), a brain region commonly thought to be crucially involved in registering structure from motion. Considered together, our results show that the brain draws on somatosensory information to resolve visual conflict.