Figure 2.

Categorization and visual search times in Experiment 1. (A) Average categorization times in the animal, dog, and Labrador tasks. (B) Within-category search times: times taken to search for animals among animals, dogs among dogs, and Labradors among Labradors. Error bars represent standard errors of the mean. (C) Between-category search times: times taken to search for animals among nonanimals, dogs among nondogs, and Labradors among non-Labradors. (D) Plot of categorization reaction time (averaged across subjects) for each item against the prediction based on average within- and between-category search times. Triangles represent Labradors, plus symbols represent non-Labrador dogs, circles represent other animals, and squares indicate inanimate objects. The color of each symbol indicates the task: red represents the animal task, green represents the dog task, and blue represents the Labrador task. All trends reached a high level of statistical significance (**** represents p < 0.00005). (E) Categorization times plotted against predicted times for atypical animals (two birds, two snakes, one monkey, and one kangaroo). Circles indicate average predicted and observed times obtained for each atypical animal. The gray and black crosses represent the means obtained from typical and atypical animals respectively. Error bars represent standard errors of the mean. (F) Approximate representation of animals and things in visual search space, constructed using multidimensional scaling on visual search data. In this plot, distances between images are (approximately) inversely proportional to the average time taken by subjects to find one image among another in visual search. The correlation coefficient above the plot represents the degree to which distances in the two-dimensional plot capture the observed distances from visual search data. Some images are scaled down to accommodate them in the plot, and three others have been deleted to avoid clutter.