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fMRI evidence for sensorimotor transformations in human cortex during smooth pursuit eye movements
- Source :
- Neuropsychologia. 46:2203-2213
- Publication Year :
- 2008
- Publisher :
- Elsevier BV, 2008.
-
Abstract
- Smooth pursuit eye movements (SP) are driven by moving objects. The pursuit system processes the visual input signals and transforms this information into an oculomotor output signal. Despite the object's movement on the retina and the eyes' movement in the head, we are able to locate the object in space implying coordinate transformations from retinal to head and space coordinates. To test for the visual and oculomotor components of SP and the possible transformation sites, we investigated three experimental conditions: (I) fixation of a stationary target with a second target moving across the retina (visual), (II) pursuit of the moving target with the second target moving in phase (oculomotor), (III) pursuit of the moving target with the second target remaining stationary (visuo-oculomotor). Precise eye movement data were simultaneously measured with the fMRI data. Visual components of activation during SP were located in the motion-sensitive, temporo-parieto-occipital region MT+ and the right posterior parietal cortex (PPC). Motor components comprised more widespread activation in these regions and additional activations in the frontal and supplementary eye fields (FEF, SEF), the cingulate gyrus and precuneus. The combined visuo-oculomotor stimulus revealed additional activation in the putamen. Possible transformation sites were found in MT+ and PPC. The MT+ activation evoked by the motion of a single visual dot was very localized, while the activation of the same single dot motion driving the eye was rather extended across MT+. The eye movement information appeared to be dispersed across the visual map of MT+. This could be interpreted as a transfer of the one-dimensional eye movement information into the two-dimensional visual map. Potentially, the dispersed information could be used to remap MT+ to space coordinates rather than retinal coordinates and to provide the basis for a motor output control. A similar interpretation holds for our results in the PPC region.
- Subjects :
- Adult
Male
genetic structures
Cognitive Neuroscience
Motion Perception
Precuneus
Posterior parietal cortex
Experimental and Cognitive Psychology
Stimulus (physiology)
Smooth pursuit
Behavioral Neuroscience
Mental Processes
Image Processing, Computer-Assisted
Reaction Time
medicine
Humans
Visual Pathways
Prefrontal cortex
Cerebral Cortex
Brain Mapping
Parietal lobe
Eye movement
Magnetic Resonance Imaging
Pursuit, Smooth
eye diseases
Oxygen
medicine.anatomical_structure
Pattern Recognition, Visual
Fixation (visual)
Evoked Potentials, Visual
Female
Visual Fields
Psychology
Neuroscience
Photic Stimulation
Subjects
Details
- ISSN :
- 00283932
- Volume :
- 46
- Database :
- OpenAIRE
- Journal :
- Neuropsychologia
- Accession number :
- edsair.doi.dedup.....9f0be413e8d57f5838753a13fd89b919