No abstract

Changes to a scene often go unnoticed if the objects of the change are unattended, making change detection an index of where attention is focused during scene perception. We measured change detection in school-age children and young adults by repeatedly alternating two versions of an image. To provide an age-fair assessment we used a bimanual choice rather than open-ended verbal responses. The difference in detection speed and accuracy between 50-ms versus 250-ms blank screens between views indexed change detection in short-term visual memory independent of sensory and response processes. Younger children were significantly less efficient than older participants, especially when an object changed color or had a part deleted. Changes in object orientation were detected more readily. These results point to important differences in the perceptual reality of younger and older children.

Persons with autism often show strong reactions to changes in the environment, suggesting that they may detect changes more efficiently than typically developing (TD) persons. However, Fletcher-Watson et al. (Br J Psychol 97:537-554, 2006) reported no differences between adults with autism and TD adults with a change-detection task. In this study, we also found no initial differences in change-detection between children with autism and NVMA-matched TD children, although differences emerged when detection failures were related to the developmental level of the participants. Whereas detection failures decreased with increasing developmental level for TD children, detection failures remained constant over the same developmental range for children with autism, pointing to an atypical developmental trajectory for change-detection among children with autism.

The present experiment investigated the effects of subliminal psychodynamic stimuli on anxiety as measured by heart rate. Following an anxiety-inducing task, male and female subjects were tachistoscopically shown, at their subjective thresholds, one of five subliminal stimuli, MOMMY AND I ARE ONE, DADDY AND I ARE ONE (symbiotic messages). MOMMY HAS LEFT ME (abandonment message), I AM HAPPY AND CALM (positively toned but nonsymbiotic phrase), or MYMMO NAD I REA ENO (control stimulus). It was hypothesized that men would exhibit a greater decrease in heart rate after exposure to the MOMMY stimulus than the control message. No definitive predictions were made for women. The abandonment phrase was expected to increase heart rate. A positively toned message was included to assess whether its effects would be comparable to those hypothesized for the MOMMY message. The results yielded no significant effects for stimulus or gender and so provided no support for the hypotheses.