Figure 8.

hIT activity-pattern dissimilarities and judged dissimilarities are significantly correlated within all images and within category subsets of images. (A) Scatter plot of hIT activity-pattern dissimilarities and judged dissimilarities taken from the subject-average RDMs shown in Figure 3A. A dot is placed for each stimulus pair based on its hIT activity-pattern dissimilarity and judged dissimilarity (three example stimulus pairs are shown). The large gray dots represent all possible stimulus pairs (r = 0.39, p < 0.0001; r is Spearman correlation coefficient). The smaller colored dots placed on top of the gray dots code for subsets of images: green dots represent animate object pairs (r = 0.34, p < 0.0001), cyan dots represent inanimate object pairs (r = 0.19, p < 0.0001), and red dots represent object pairs consisting of an animate and an inanimate object (r = −0.16, p < 0.9975). Consistent with the results in Figure 3, the marginal histograms show that both hIT and judged dissimilarities are larger for object pairs that cross the animate-inanimate category boundary (red) than for object pairs that do not cross this boundary (green and cyan). (B) To test whether the continuous match between hIT and judged dissimilarities would generalize to the population of similarity judgment subjects, we computed the correlation of each single-subject judgment RDM with the subject-average hIT RDM and tested whether the average of those correlations was significantly larger than zero, using a one-sample t test. Bars show the average correlation between hIT and judged dissimilarities across subjects. Error bars show SEM. Asterisks indicate significance (p < 0.001).