One has to be cautious in determining the overall proportions of area 19 cells receiving excitatory input vs. those receiving inhibitory input from PTV as they are not necessarily mutually exclusive. Thus, a number of area 19 cells appeared to receive an excitatory feedback input from PTV when their responses to optimally oriented stimuli were examined but appeared to receive suppressive feedback from PTV when the responses to sub-optimally oriented stimuli were examined (e.g., Figure 3Aii). Furthermore, the strength of suppressive feedback effects was substantially greater when the stimuli were moving faster (e.g., Figure 4; see also Figure 5 for area 17 cells).