Identification of response patches in V1.

The first column from the left shows a part of the activation maps associated with different stimulus colors. The three vertical dots stand for six more maps that are not shown due to space limitation. A threshold derived from the control map was used to identify the individual response regions in each activation map. These response regions are shown as the white patches in the second column from the left. The individual response regions elicited by various stimuli were combined to form the composite response patches, as shown in the third column from the left. The rightmost column shows the kind of composite response patches that were analyzed in the current study. Each of these patches meets both of the following criteria: 1) it encompasses individual response regions that are associated with five or more stimulus colors; 2) it doesn't extend to the map borders.