Tehovnik Edward J, Slocum Warren M
Dept. of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Bldg. 46-6041, Cambridge, MA 02139, USA.
J Neurophysiol. 2007 Aug;98(2):559-76. doi: 10.1152/jn.00285.2007. Epub 2007 Jun 13.
It is well known that electrical activation of striate cortex (area V1) can disrupt visual behavior. Based on this knowledge, we discovered that electrical microstimulation of V1 in macaque monkeys delays saccadic eye movements when made to visual targets located in the receptive field of the stimulated neurons. This review discusses the following issues. First, the parameters that affect the delay of saccades by microstimulation of V1 are reviewed. Second, the excitability properties of the V1 elements mediating the delay are discussed. Third, the properties that determine the size and shape of the region of visual space affected by stimulation of V1 are described. This region is called a delay field. Fourth, whether the delay effect is mainly due to a disruption of the visual signal transmitted through V1 or whether it is a disturbance of the motor signal transmitted between V1 and the brain stem saccade generator is investigated. Fifth, the properties of delay fields are used to estimate the number of elements activated directly by electrical microstimulation of macaque V1. Sixth, these properties are used to make inferences about the characteristics of visual percepts induced by such stimulation. Seventh, the disruptive effects of V1 stimulation in monkeys and humans are compared. Eighth, a cortical mechanism to account for the disruptive effects of V1 stimulation is proposed. Finally, these effects are related to normal vision.
众所周知，纹状皮层（V1区）的电激活会干扰视觉行为。基于这一认识，我们发现，对猕猴的V1区进行微电刺激时，当针对位于受刺激神经元感受野内的视觉目标做出扫视眼动时，会延迟扫视眼动。本综述讨论以下问题。首先，回顾影响V1区微刺激导致扫视延迟的参数。其次，讨论介导延迟的V1区元件的兴奋性特性。第三，描述决定受V1区刺激影响的视觉空间区域的大小和形状的特性。该区域称为延迟场。第四，研究延迟效应主要是由于通过V1区传输的视觉信号中断，还是由于V1区与脑干扫视发生器之间传输的运动信号受到干扰。第五，利用延迟场的特性来估计猕猴V1区微电刺激直接激活的元件数量。第六，利用这些特性推断这种刺激诱发的视觉感知的特征。第七，比较V1区刺激对猴子和人类的干扰效应。第八，提出一种解释V1区刺激干扰效应的皮层机制。最后，将这些效应与正常视觉联系起来。
