Is MT a Multi-Modal Information Processing Region? 9.4T Monkey and 3T Human Studies
Single Paper Presentation

Christopher Moore
MIT

Aimee Nelson
University of Toronto

     Abstract ID Number: 202
     Full text: Not available
     Last modified: March 22, 2006
     Presentation date: 06/20/2006 8:30 AM in Hamilton Building, McNeil Theatre
     (View Schedule)

Abstract
Recent reports describe activation of MT+ correlated with moving tactile stimulation in sighted humans. These findings suggest that the formerly ‘unimodal’ area MT is multi-modal, and that its information-processing role supercedes its visual designation.

Several alternative explanations exist for these results. These studies used only moving stimuli in awake humans: As such, 'cognitive' factors may be central to MT+ activation, and MT+ may not be selective for motion. Further, MT+ in the human is an amalgam of areas, likely including established multi-modal areas.

In humans scanned at 3T during vibrotactile stimulation (100Hz for 1s), we observed consistent MT+ activation (N=5/7 Ss). Using identical stimuli in anesthetized monkeys scanned at high field (9.4T) and high resolution (.6x.6x1mm voxels), we observed MT+ activation, replicated within and across animals. Preliminary visual fMRI, anatomical MR and histological studies suggest that MT proper was activated by this tactile input.

These studies demonstrate that tactile input to MT+ is robust: It is not dependent on motion content or conscious awareness, and is not species specific. Further, they suggest that MT+ activation is localized to area MT proper. In total, they support the hypothesis that MT is multisensory, and plays a significantly broader information-processing role than previously appreciated.