Pubmed du 20/09/10

Pubmed du jour

2010-09-20 12:03:50

1. Kuhn G, Kourkoulou A, Leekam SR. {{How Magic Changes Our Expectations About Autism}}. {Psychol Sci} (Sep 21)

In the vanishing-ball illusion, the magician’s social cues misdirect the audience’s expectations and attention so that the audience « sees » a ball vanish in the air. Because individuals with autism spectrum disorder (ASD) are less sensitive to social cues and have superior perception for nonsocial details compared with typically developing individuals, we predicted that they would be less susceptible to the illusion. Surprisingly, the opposite result was found, as individuals with ASD were more susceptible to the illusion than a comparison group. Eye-tracking data indicated that subtle temporal delays in allocating attention might explain their heightened susceptibility. Additionally, although individuals with ASD showed typical patterns of looking to the magician’s face and eyes, they were slower to launch their first saccade to the face and had difficulty in fixating the fast-moving observable ball. Considered together, the results indicate that individuals with ASD have difficulties in rapidly allocating attention toward both people and moving objects.

2. Lind SE, Bowler DM. {{Episodic memory and episodic future thinking in adults with autism}}. {J Abnorm Psychol} (Sep 20)

The ability to remember past experiences (episodic memory) is thought to be related to the ability to imagine possible future experiences (episodic future thinking). Although previous research has established that individuals with autism spectrum disorder (ASD) have diminished episodic memory, episodic future thinking has not previously been investigated within this population. In the present study, high-functioning adults with ASD were compared to closely matched typical adults on a task requiring participants to report a series of events that happened to them in the past and a series of events that might happen to them in the future. For each event described, participants completed two modified Memory Characteristics Questionnaire items to assess self-reported phenomenal qualities associated with remembering and imagining, including self-perspective and degree of autonoetic awareness. Participants also completed letter, category, and ideational fluency tasks. Results indicated that participants with ASD recalled/imagined significantly fewer specific events than did comparison participants and that participants with ASD demonstrated impaired episodic memory and episodic future thinking. In line with this finding, participants with ASD were less likely than comparison participants to report taking a field (first-person) perspective and were more likely to report taking an observer (third-person) perspective during retrieval of past events (but not during simulation of future events), highlighting that they were less likely to mentally reexperience past events from their own point of view. There were no group differences in self-reported levels of autonoetic awareness or fluency task performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

3. Pineles SL, Avery RA, Liu GT. {{Vitamin B12 Optic Neuropathy in Autism}}. {Pediatrics} (Sep 20)

Dietary vitamin B(12) deficiency was identified as a cause of partially reversible optic neuropathy in 3 autistic children. All of the affected children presented with gradual visual loss. Examination revealed optic atrophy, and further questioning regarding diet revealed that all 3 children had severe food selectivity and highly stereotyped diets that resulted in an almost total lack of animal products in their diets. Vitamin B(12) levels were low in all 3 children. Treatment with intramuscular vitamin B(12) and normalization of vitamin B(12) levels resulted in improvement of visual functioning in all 3 children. These cases illustrate that food selectivity, a known complication of autism, can result in vitamin deficiency that can cause visual loss and optic atrophy. Physicians must have a high index of suspicion when evaluating children with autism and visual loss to detect this rare cause of optic atrophy.