Tutis Vilis
Professor
 |
PH.D. McGill University |
My laboratory is part of the CIHR Group on Perception and Action. As the group's name implies our goal is to explore the function of two important cortical areas, the ventral stream which specializes in the perception of visual objects and the dorsal stream which specializes in directing motor actions. Currently my laboratory is involved in three projects that use functional imaging of the human cortex to address the following issues.
The Contribution of the Dorsal Stream To Object Perception. It is also self evident that the dorsal stream contributes to the action of the ventral stream. For example the cortical visual motion system often facilitates object recognition such as when we spot an animal in the woods only when it moves.
The Function of the Cortical Motion Complex in Humans. One of the key components of the dorsal action stream is the motion complex, an area in the medial temporal cortex that is specialized for motion. We are using fMRI to map the functions of its various compartments in humans.
The Coding of Target Location in the Intra-Parietal Sulcus. The posterior parietal cortex plays a key role in the selection of targets for action and in the coding if their location. The initial coding of target location by the eye is in retinal coordinates. However a limb movement to the same target must be coded on egocentric coordinates. The posterior parietal cortex appears to be crucial for this transformation.
Niemeier M, Goltz HC, Kuchinad A, Tweed DB, Vilis T A contralateral preference in the lateral occipital area: sensory and attentional mechanisms. Cerebral Cortex, 15(3):325-31 2005 Medendorp WP, Goltz HC, Crawford JD, Vilis T Integration of target and effector information in human posterior parietal cortex for the planning of action. J. of Neurophysiol. Feb;93(2):954-62 2005 Large ME, Aldcroft A, Vilis T. Perceptual continuity and the emergence of perceptual persistence in the ventral visual pathway. J. Neurophysiol. 93(6):3453-62. 2005 Medendorp WP, Goltz HC, Vilis T. Directional selectivity of BOLD activity in human posterior parietal cortex for memory-guided double-step saccades J. Neurophysiol. 2006 Mar;95(3):1645-55. H.H.L.M. Goossens, S.P. Dukelow, R.S. Menon, T. Vilis, A.V. van den Berg. Representation of head-centric flow in the human motion complex. J Neurosci. May 24;26(21):5616-27. 2006 Mary-Ellen Large, Adrian Aldcroft, Tutis Vilis. Task related laterality effects in the lateral occipital complex. Brain Res 2007 Jan 12;1128(1):130-8. Epub 2006 Dec 4 Fernandez-Ruiz J, Goltz HC, Desouza JF, Vilis T, Crawford JD. Human Parietal "Reach Region" Primarily Encodes Intrinsic Visual Direction, Not Extrinsic Movement Direction, in a Visual-Motor Dissociation Task. Cereb Cortex. 2007 Jan 10; [Epub ahead of print]
