Stimulus-specific adaptation of responses to small-field motion in CL-, TB- and CPU neurons.

A. Responses to small-field motion are marked by rapid adaptation between the first and second presentation of a single moving small-field square. Box- and bubble plots show differences in spike count between stimulus time-windows and background activity in a period of 450 ms preceding stimulation, based on N responses obtained from n neurons. Notches in box plots indicate 95% confidence interval of the median and circular plot markers in bubble plots are scaled to the frequency of observations (see scale, bottom right). Some outliers were truncated for the sake of better visualization. m, median; asterisks: level of statistical significance (Bonferroni-corrected) of difference in median as calculated by Wilcoxon rank-sum tests (* pcorrpcorrpcorrFig 3D). Data include many cases where first and second stimulus differed in direction of motion (see Table 1). Nevertheless, pronounced adaptation occurs between the first and second stimulus. B. In many cases, adaptation could be reversed by switching the elevation of a horizontal trajectory, as illustrated here for population data of CL1 neurons sufficient in sample size for statistical testing.