Figure 4.

Measuring the accuracy and speed of material categorization with RTs. (a) On each trial, observers indicated the presence or absence of a target category (e.g., stone) with a key press. Auditory feedback was provided, and RTs greater than 1 s were discarded. (b) Errors made by the observers are plotted against their median RTs for the baseline categorization tasks (red and orange; Material RT experiment), material categorization task (green; Material RT experiment), and real versus fake task (blue; Real-Fake RT experiment); there is no evidence of a speed-accuracy trade-off. Chance performance corresponds to 50% error. (c) RT distributions for correct trials, averaged across eight observers, are shown here for each type of task. Compared to baseline tasks, material categorization is slower by approximately 100 ms.