Table 1.

Comparison of the incidence of response modulation observed with different texture configurations for V1 neurons with RF sizes 1° or smaller

ABCD
Figure diameterNumber of neuronsOrientation-defined figureFigure aloneSurround aloneContextual modulation and response to surround (A, C)
8848 (54.5%)57 (64.8%)82 (93.2%)48 (54.5%)
9726 (26.8%)32 (33%)81 (83.5%)22 (22.7%)
9719 (19.6%)21 (21.6%)54 (55.6%)15 (15.5%)
886 (6.8%)3 (3.4%)38 (43.2%)3 (3.4%)
713 (4.2%)4 (5.6%)32 (45.1%)2 (2.8%)
23008 (34.8%)0
12°23007 (30.4%)0
  • Columns A and B show the number of neurons that had modulation index values significantly >1.0 (p < 0.05, 1-tailedt test) for the orientation-defined figure and the figure-alone configurations, respectively. Column C shows the number of neurons that gave a significant response to the surround texture alone, relative to the spontaneous firing rate of the neuron (determined by the statistical criteria used for calculating the response latency; see Materials and Methods). Column D contains the number of neurons that exhibited both contextual modulation to the orientation-defined figure and a significant response to the surround texture when presented alone.