【摘要】 1.用玻璃绝缘的钨丝电极作细胞外记录,研究不了麻醉猫视皮层17区单个细胞对栅形刺激反应的某些特点。先用光学投影仪在屏幕上投影各种图形以确定细胞感受野位置,并对该细胞感受野性质作一般观察。随后用以电视监示器改装的方波——正弦波栅形发生器提供刺激,研究此细胞的空间频率-反应特性及对比度-反应特性。 2.所有对正弦波栅形有反应和空间频率选择性的细胞同样对方波栅形也有反应和空间频率选择性。它们的最优频率一致。简单细胞的通频带比复杂细胞的略窄。 3.绝大多数细胞对方波栅形的反应都比对同样条件下的正弦栅形反应大(1.33∶1),对比阈值低。 4.记录到少数细胞(7/54,6个为复杂型,1个类型不明),其方波栅形的频率-反应曲线与正弦波栅形的比较,两种反应在低频端有更大的差别,当把栅形对比度降低为接近阈值水平时,这个差别显著变小.更多还原

【Abstract】 1. Extracellular single unit recordings were made with tungsten-in-glass elec trodes in area 17 of the unanaesthetised cat’s cortex. Visual stimuli were presented in two ways: An over head projector produced various light patterns on the screen for determining the position of the receptive field and the type of that cell. And a sine-wave and square-wave grating generator constructed from a television set was used for the investigation of spacial frequency characteristics and the contrast-response characteristics of the cell.2. All cells that responded to and had spacial frequency selectivity for sinewave gratings were responsive to and spacial frequency selective for square-wave gratings. The optimal frequency for both grating patterns were identical for each cell. The frequency tuning curves of the complex cells for square-wave grating were broader than that of simple cells.3. The great majority of the recorded cells, both simple and complex types, were more responsive to square-wave gratings than to sine-wave gratings. And the contrast thresholds for square-wave gratings were also lower.4. The responses of some few cells (6 complex and I unidentified cells out of 54) to square-wave grating were much higher than that to sine-wave grating in the lower spacial frequency region. And the differences became smaller when the contrast of the gratings were decreased to a level near the threshold for the optimal frequency. This is taken as an indication of the presence or absence of the contributions made by the higher harmonic components within the square-wave gratings.更多还原