Born R T, Groh J M, Zhao R, Lukasewycz S J
Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Neuron. 2000 Jun;26(3):725-34. doi: 10.1016/s0896-6273(00)81208-8.
To track a moving object, its motion must first be distinguished from that of the background. The center-surround properties of neurons in the middle temporal visual area (MT) may be important for signaling the relative motion between object and background. To test this, we microstimulated within MT and measured the effects on monkeys' eye movements to moving targets. We found that stimulation at "local motion" sites, where receptive fields possessed antagonistic surrounds, shifted pursuit in the preferred direction of the neurons, whereas stimulation at "wide-field motion" sites shifted pursuit in the opposite, or null, direction. We propose that activating wide-field sites simulated background motion, thus inducing a target motion signal in the opposite direction. Our results support the hypothesis that neuronal center-surround mechanisms contribute to the behavioral segregation of objects from the background.
为了追踪一个移动的物体，必须首先将其运动与背景的运动区分开来。颞中区（MT）神经元的中心-外周特性可能对于发出物体与背景之间的相对运动信号很重要。为了验证这一点，我们在MT内进行微刺激，并测量其对猴子追踪移动目标的眼动的影响。我们发现，在“局部运动”部位进行刺激时，感受野具有拮抗外周，追踪会朝着神经元的偏好方向移动，而在“广域运动”部位进行刺激时，追踪会朝着相反方向或零方向移动。我们提出，激活广域部位模拟了背景运动，从而在相反方向上诱导出目标运动信号。我们的结果支持了这样一种假说，即神经元的中心-外周机制有助于从背景中对物体进行行为上的分离。
