Local precision of visuotopic organization in the middle temporal area (MT) of the macaque.
Local precision of visuotopic organization in the middle temporal area (MT) of the macaque.
复制标题
猕猴中颞区（MT）视觉组织的局部精度。
DOI：
10.1007/bf00235981
复制
发表时间：
1987
影响因子：
2
通讯作者：
Desimone,R
中科院分区：
文献类型：
--
作者：
Albright,TD;Desimone,R
通过对麻醉、固定的猕猴单个神经元的记录，研究了视野在中颞区（MT）的表征。在中心25°范围内测量感受野大小、感受野位置的变异性（散射）和放大系数。至少在短距离内（小于3毫米），MT的视野表现令人惊讶地有序。接受野的大小随着偏心率的线性增加，在所有偏心率下都比V1大十倍。在视野中任何一点的感受野位置的散点表示等于该位置感受野大小的三分之一，在V1中也发现了相同的关系。MT的放大系数仅为中央5°内V1的五分之一左右，但随着离心率的增加，其下降幅度似乎比V1小。由于MT相对于V1的放大倍率较小，同时有较大的感受野大小和散射，因此两个区域的点图像大小（由视野中单个点激活的皮层区域的直径）大致相当。基于这些结果，以及我们之前的发现，即MT中180°的刺激运动轴与V1中180°的刺激方向在组织中的表现量大致相同，我们认为，在视野的一个点上的刺激激活了MT中至少与V1中一样多的功能“模块”。
The representation of the visual field in the middle temporal area (MT) was examined by recording from single neurons in anesthetized, immobilized macaques. Measurements of receptive field size, variability of receptive field position (scatter) and magnification factor were obtained within the representation of the central 25°. Over at least short distances (less than 3 mm), the visual field representation in MT is surprisingly orderly. Receptive field size increases as a linear function of eccentricity and is about ten times larger than in V1 at all eccentricities. Scatter in receptive field position at any point in the visual field representation is equal to about one-third of the receptive field size at that location, the same relationship that has been found in V1. Magnification factor in MT is only about onefifth that reported in V1 within the central 5° but appears to decline somewhat less steeply than in V1 with increasing eccentricity. Because the smaller magnification factor in MT relative to V1 is complemented by larger receptive field size and scatter, the point-image size (the diameter of the region of cortex activated by a single point in the visual field) is roughly comparable in the two areas. On the basis of these results, as well as on our previous finding that 180° of axis of stimulus motion in MT are represented in about the same amount of tissue as 180° of stimulus orientation in V1, we suggest that a stimulus at one point in the visual field activates at least as many functional “modules” in MT as in V1.