It is widely accepted [Morrone et al. Nature Neuroscience, 2000] that particular cortical areas like MT/V5 respond to optic flow stimuli. In order to test the hypothesis that the MT+ complex might also share a supramodal organization, we measured the neural response evoked during visual and tactile perception of coherently moving dot patterns (optic and tactile flows) in sighted and blind subjects by using functional magnetic resonance imaging. In particular a group of volunteers were asked to see and touch, during distinct trials, random distribution of dot patterns while moving in circular and translational direction. An ad hoc designed device made of nonmagnetic material was used. Both tactile and visual motion perception consistently activated MT+. In order to exclude the hypothesis that activation in visual cortical areas during tactile discrimination tasks might be attributed merely to visual imagery, tactile stimuli were presented to blind adults, confirming the activation of MT+ complex as well. Moreover, in order to assess the conjecture of supramodality of flow a magneto-compatible haptic display based on the contact area spread rate paradigm (specific aspect of tactile flow) was realized and used in fMRI experiment for investigating the neural activity elicited by tactile flow, providing satisfactory results.
|Titolo:||Optic and tactile flow: does a supramodal response exist?|
|Anno del prodotto:||2005|
|Appare nelle tipologie:||4.1 Contributo in Atti di convegno|