Figure 6.
Example of bimodal enhancement in a single E site. A, Raster plots showing responses to an auditory stimulus with an ITD of 50 μs contralateral ear leading (Ac, 30 repetitions, bottom raster), to an auditory stimulus with an ITD of 50 μs ipsilateral ear leading (Ai, 30 repetitions, second plot from bottom), to a visual stimulus 20° in the contralateral side (V, 30 repetitions, middle plot), to the visual together with the contralateral auditory stimulus (AcV, 30 repetitions, second plot from top), and to the visual stimulus with the ipsilateral auditory stimulus (AiV, 30 repetitions, top plot). The shaded bar shows the duration of stimuli. B, The PSTH of responses to the congruent bimodal stimulus (AcV, cyan) is compared with the PSTHs of responses to the visual stimulus (red) and with the contralateral auditory stimulus (blue). The vertical dashed line designates the onset of visual responses. Note that bimodal enhancement (deviation of cyan curve) begins with the visual response. C, Average spike count of stimuli presented in A. The error bars represent the SEM. The bimodal congruent response (AcV) significantly exceeded the sum of its unimodal components (dashed horizontal line; t test, p < 0.01).