Perceptual Grouping of Random Dot Patterns in the Presence of a Tilting Frame.

The objective of this study was to investigate the effect of tilting a frame on the perceptual organization in random dot patterns. Ten random patterns of nine dots were generated. For each pattern, a square frame was tilted at seven angles around the dots. Ten observers were asked to indicate the groups of dots in each stimulus. Each stimulus was seen 4 times by each observer which enabled us to study within-subject consistencies provided grouping reports. Within- and between-subject consistencies were computed to study if the responses provided by participants were consistent and thus reliable. The dominant group was defined as the most repeated group in all 40 reports (10 participants, 4 repetitions) obtained for each stimulus. We studied how tilting a frame affected the dominant group in each dot pattern. Perceptual grouping was not affected by tilting the frame. Based on a qualitative inspection, we remark that fundamental principles, for example, proximity, good continuation, and closure, respectively, in the order of strength, may remain the main drivers of the grouping behavior, irrespective of differences in the number of dots in each group, and the frame orientation. The numerosity condition did not affect our results. Similar trends were observed in patterns of 9 and 18 dots patterns.

Priming Global Processing Strategy Improves the Perceptual Performance of Children with Autism Spectrum Disorders.

We investigated (1) if the perceptual integration performance is different in children with ASD in comparison with their typically developed (TD) counterparts; and (2) if activating- priming- the global processing strategy, could benefit the integration performance of children with ASD in the subsequent task. We observed that in comparison with the TD group, children with ASD had lower performance in an information integration task that required identification of illusory shapes. Additionally, we observed that priming the global processing strategy increased the correct identification of the illusory shapes in the subsequent task. We suggested that studies on priming effect shed light on the different aspects of perceptual properties of ASD, and could also be used in developing new rehabilitation plans.

The effect of observers' mood on the local processing of emotional faces: evidence from short-lived and prolonged mood States.

We examined the effect of induced mood, varying in valence and longevity, on local processing of emotional faces. It was found that negative facial expression conveyed by the global level of the face interferes with efficient processing of the local features. The results also showed that the duration of involvement with a mood influenced the local processing. We observed that attending to the local level of faces is not different in short-lived happy and sad mood states. However, as the mood state is experienced for a longer period, local processing was impaired in happy mood compared to sad mood. Taken together, we concluded that both facial expressions and affective states influence processing of the local parts of faces. Moreover, we suggest that mediating factors like the duration of involvement with the mood play a role in the interrelation between mood, attention, and perception.