Neuroscience 2000 Abstract
| Presentation Number: | 250.4 |
|---|---|
| Abstract Title: | Functional magnetic resonance imaging of neural activity in the human visual system related to a luminance contrast illusion: the scintillating grid. |
| Authors: |
Kleiser, R.*1
; Schrauf, M.1
; Stoerig, P.1
1Institute of Physiological Psychology II, University of Duesseldorf, D-40225 Duesseldorf, Germany |
| Primary Theme and Topics |
F. Sensory Systems - 80. Visual cortex: extrastriate |
| Secondary Theme and Topics | I. Neural Basis of Behavior<br />- 105. Cognition: higher functions |
| Session: |
250. Visual cortex: extrastriate--motion perception Poster |
| Presentation Time: | Monday, November 6, 2000 11:00 AM-12:00 PM |
| Location: | Hall G-J |
| Keywords: |
The scintillating grid illusion consists of dark illusory spots flashing on small white disks superimposed on the intersections of a grey-on-black Hermann grid. Numerous such spots are seen transiently within the white disks during saccadic eye movements or brief exposures. To see whether the pronounced flashing illusion activates brain regions known to process flickering or flashing stimuli (e.g. hMT+) we used fMRI (Siemens Magnetom Vision, 1.5 T, EPI, 16 slices, voxel size 3x3x3 mm) on 7 normal subjects. We compared the pattern of activation from presenting the scintillating grid with that from presenting an identical control grid with the disks shifted horizontally from the intersections which abolishes the scintillation. For identification of hMT+ a flowfield stimulus was included in the stimulation protocol. Results show that hMT+ was activated only during the perception of the illusion. In addition, activation was enhanced in a parietal sulcus bilaterally, a region presumed to be involved when subjects attend to motion and location, and within the occipito temporal gyrus (V4+). In addition to the evidence for hMT+ mediation of a purely subjective flashing sensation, our results show that a tiny change in the spatial arrangement of the stimulus produces not only a marked perceptual effect but also activation of a different visuoneuronal cortical network.
Supported by Supported by DFG (SFB 194, A15)
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2000 Neuroscience Meeting Planner. New Orleans, LA: Society for Neuroscience, 2000. Online.
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