Objective: To verify differences in the visual scanning strategies between pervasive developmental disorders (PDD) and controls when they are observing social and non-social pictures.
Method: PDD group (PDDG) comprised by 10 non-retarded subjects (age from 4 to 41) and age-matched control group (CG). Nine social pictures with human beings (including two pictures of cat mask), and 3 nonsocial pictures of objects were presented for 5 seconds. Saccadic movements and fixation were recorded with equipment EyeGaze (LC Technologies Inc.).
Results: PDDG (mean=292.73, SE=67.62) presented longer duration of saccadic movements for social pictures compared to CG (mean=136.06, SE=14.01) (p=0.04). The CG showed a higher number of fixations in the picture 7 (a women using a cat mask, with the eyes erased) (CG: mean=3.40; PDDG: mean=1.80; p=0.007).
Conclusion: The results suggest differences in strategies that PDD explore human picture. Moreover, these strategies seem not to be affected by the lack of expected part of the face (the eyes).