A selective impairment of motion perception following lesions of the middle temporal visual area (MT)
William T. Newsome,EB Pare +1 more
TLDR
The results indicate that neural activity in MT contributes selectively to the perception of motion.Abstract:
Physiological experiments indicate that the middle temporal visual area (MT) of primates plays a prominent role in the cortical analysis of visual motion. We investigated the role of MT in visual perception by examining the effect of chemical lesions of MT on psychophysical thresholds. We trained rhesus monkeys on psychophysical tasks that enabled us to assess their sensitivity to motion and to contrast. For motion psychophysics, we employed a dynamic random dot display that permitted us to vary the intensity of a motion signal in the midst of masking motion noise. We measured the threshold intensity for which the monkey could successfully complete a direction discrimination. In the contrast task, we measured the threshold contrast for which the monkeys could successfully discriminate the orientation of stationary gratings. Injections of ibotenic acid into MT caused striking elevations in motion thresholds, but had little or no effect on contrast thresholds. The results indicate that neural activity in MT contributes selectively to the perception of motion.read more
Citations
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The highly irregular firing of cortical cells is inconsistent with temporal integration of random EPSPs
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Neural Basis of a Perceptual Decision in the Parietal Cortex (Area LIP) of the Rhesus Monkey
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References
More filters
Journal ArticleDOI
Transformed Up‐Down Methods in Psychoacoustics
TL;DR: A broad class of up‐down methods used in psychoacoustics with due emphasis on the related problems of parameter estimation and the efficient placing of observations is described, including examples where conventional techniques are inapplicable.
A method of measuring eye movements using a scleral search coil in a magnetic field
TL;DR: With the subject exposed to an alternating magnetic field, eye position may be accurately recorded from the voltage generated in a coil of wire embedded in a scleral contact lens worn by the subject.
Journal ArticleDOI
Implantation of magnetic search coils for measurement of eye position: an improved method.
Journal ArticleDOI
A Method of Measuring Eye Movemnent Using a Scieral Search Coil in a Magnetic Field
TL;DR: In this article, the voltage generated in a coil of wire embedded in a scleral contact lens worn by the subject was measured using two magnetic fields in quadrature phase and two coils on the lens, one may measure horizontal, vertical and torsional eye movements simultaneously.
Journal ArticleDOI
Anatomy and physiology of a color system in the primate visual cortex.
TL;DR: The results suggest that a system involved in the processing of color information, especially color-spatial interactions, runs parallel to and separate from the orientation-specific system.