Relationship between contrast sensitivity (half-saturation contrast, C₅₀) and the spatial properties of the receptive fields in area DM.

<p>Separate analyses are presented for the length (left column) and width (right column) dimensions of the receptive field. Top row shows the relationship between the optimal length (A) and width (D) of the stimulus, and contrast sensitivity (C₅₀). Data from cells that showed significant spatial inhibition upon presentation of stimuli up to 30° in length or width are indicated by filled circles (end inhibition in panel A, side inhibition in panel D). The middle row summarizes the data shown in the top row, by grouping neurons according to the preferred length (B) and width (E) in three groups, according to optimal size (&lt;10°, 10–20° and &gt;20°). The data points are medians for these groups, and error bars represent the inter quartile ranges. Bottom row illustrates the mean C₅₀ for DM cells. Black bars represent means for EI and SI cells (in C and F, respectively), and white bars represent the means for NEI₁₅ and NSI₁₅ cells.