Newsome W T, Paré E B
Department of Neurobiology and Behavior, State University of New York, Stony Brook 11794.
J Neurosci. 1988 Jun;8(6):2201-11. doi: 10.1523/JNEUROSCI.08-06-02201.1988.
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.
生理学实验表明，灵长类动物的颞中视觉区（MT）在视觉运动的皮层分析中起着重要作用。我们通过研究MT化学损伤对心理物理学阈值的影响，来探究MT在视觉感知中的作用。我们训练恒河猴完成心理物理学任务，从而能够评估它们对运动和对比度的敏感度。对于运动心理物理学，我们采用了动态随机点显示，使我们能够在掩蔽运动噪声中改变运动信号的强度。我们测量了猴子能够成功完成方向辨别时的阈值强度。在对比度任务中，我们测量了猴子能够成功辨别静止光栅方向时的阈值对比度。向MT注射鹅膏蕈氨酸会导致运动阈值显著升高，但对对比度阈值几乎没有影响。结果表明，MT中的神经活动对运动感知有选择性贡献。
