Figure 2.

Rapid Serial Visual Presentation BE Task

(A) Timeline of an example trial. The initial picture (i.e., a close-up photograph of a scene) comprised a single, nonoccluded, centrally positioned object and was presented on the computer screen for 250 ms, followed by a briefly presented (250 ms) dynamically changing mask [23]. The second picture (which was always identical to the original picture) immediately followed the mask. The task was to rate the second picture relative to the first. There were five options, i.e., “much closer up,” “a little closer up,” “the same” (the correct answer), “a little farther away,” or “much farther away,” and participants completed 24 trials.

(B) The proportion of trials classified as either “closer up,” “the same” (correct answer), or “farther away” was calculated and represented as a percentage response distribution score (percentage of responses made in each category relative to the total number of responses made). BE is revealed by disproportionally large number of incorrect “closer-up” responses. Overall, control participants made significantly more erroneous BE (i.e., “closer-up”) responses, whereas the patients made significantly more accurate (i.e., “the same”) responses.

(C) Participants also reported how confident they were about their decision using a three-point scale (1 = “not sure,” 2 = “fairly sure,” 3 = “very sure”) and mean confidence ratings were calculated for each of the three response types. Control participants were significantly more confident when making erroneous “closer-up” responses, and patients were significantly more confident about their correct “the same” response. An “I don't remember seeing that at all” option was also included but never selected. Data are presented as means ± 1 SEM; ^∗p < 0.05. See also Figure S3.