Alterations in the functional neural circuitry supporting flexible choice behavior in autism spectrum disorders.

Restricted and repetitive behaviors, and a pronounced preference for behavioral and environmental consistency, are distinctive characteristics of autism spectrum disorder (ASD). Alterations in frontostriatal circuitry that supports flexible behavior might underlie this behavioral impairment. In an functional magnetic resonance imaging study of 17 individuals with ASD, and 23 age-, gender- and IQ-matched typically developing control participants, reversal learning tasks were used to assess behavioral flexibility as participants switched from one learned response choice to a different response choice when task contingencies changed. When choice outcome after reversal was uncertain, the ASD group demonstrated reduced activation in both frontal cortex and ventral striatum, in the absence of task performance differences. When the outcomes of novel responses were certain, there was no difference in brain activation between groups. Reduced activation in frontal cortex and ventral striatum suggest problems in decision-making and response planning, and in processing reinforcement cues, respectively. These processes, and their integration, are essential for flexible behavior. Alterations in these systems may therefore contribute to a rigid adherence to preferred behavioral patterns in individuals with an ASD. These findings provide an additional impetus for the use of reversal learning paradigms as a translational model for treatment development targeting the domain of restricted and repetitive behaviors in ASD.

Impact of oral health education on oral hygiene knowledge, practices, plaque control and gingival health of 13- to 15-year-old school children in Bangalore city.

OBJECTIVES: To assess effectiveness of an oral health education (OHE) programme on oral hygiene knowledge, practices, plaque control and gingival health of 13- to 15-year-old school children in Bangalore city. METHODS: Three schools were randomly selected and assigned to experimental I, experimental II and control groups. At baseline, a 20-item questionnaire was used to assess the oral hygiene knowledge and practices. Clinical examinations (Turesky-Gilmore-Glickman modification of Quigley Hein plaque index; Loe-Silness gingival index) were performed by 2 examiners. OHE was provided by the investigator for experimental groups I (lecture using a PowerPoint presentation) and II (lecture using a PowerPoint presentation with toothbrushing demonstration). Control group did not receive any intervention. Reinforcement was provided for experimental groups at 3 and 6 months. At end of 9 months, questionnaire was administered and clinical examinations were performed. Data were analysed using chi-square, anova and post hoc Tukey's tests. RESULTS: Nine months post-intervention, there was significant improvement in oral hygiene knowledge and practices in experimental groups. There were significant reductions in mean plaque index and gingival index scores in the experimental groups. The control group did not show any significant improvement. CONCLUSION: Active involvement of school children with reinforcement of OHE can improve oral hygiene knowledge, practices and gingival health and decrease plaque levels.

Impaired inhibitory control is associated with higher-order repetitive behaviors in autism spectrum disorders.

BACKGROUND: Impairments in executive cognitive control, including a reduced ability to inhibit prepotent responses, have been reported in autism spectrum disorders (ASD). These deficits may underlie patterns of repetitive behaviors associated with the disorder. METHOD: Eighteen individuals with ASD and 15 age- and IQ-matched healthy individuals performed an antisaccade task and a visually guided saccade control task, each with gap and overlap conditions. Measures of repetitive behaviors were obtained using the Autism Diagnostic Inventory-Revised (ADI-R) and examined in relation to neurocognitive task performance. RESULTS: Individuals with an ASD showed increased rates of prosaccade errors (failures to inhibit prepotent responses) on the antisaccade task regardless of task condition (gap/overlap). Prosaccade error rates were associated with the level of higher-order (e.g. compulsions, preoccupations) but not sensorimotor repetitive behaviors in ASD. CONCLUSIONS: Neurocognitive disturbances in voluntary behavioral control suggest that alterations in frontostriatal systems contribute to higher-order repetitive behaviors in ASD.