Relationship between postural control and restricted, repetitive behaviors in autism spectrum disorders.

Restricted, repetitive behaviors (RRBs) are one of the core diagnostic criteria of autism spectrum disorders (ASD), and include simple repetitive motor behaviors and more complex cognitive behaviors, such as compulsions and restricted interests. In addition to the core symptoms, impaired movement is often observed in ASD. Research suggests that the postural system in individuals with ASD is immature and may never reach adult levels. RRBs have been related to postural sway in individuals with mental retardation. Our goals were to determine whether subjects with ASD had greater postural sway and whether RBS-R scores were related to the magnitude of postural sway. We compared the center of pressure (COP) sway area during quiet stance with scores on the Repetitive Behavior Scale-Revised (RBS-R) in children with ASD and typically developing (TD) controls ages 3-16. All subjects had Non-verbal IQ > 70. Subjects performed four quiet stance trials at a self-selected stance width for 20 s. Subjects with ASD had greater postural sway area compared to controls. Not surprisingly, subjects with ASD exhibited greater frequencies and intensities of RRBs overall and on all six subscales. Further, there was a positive correlation between postural sway area and presence of RRBs. Interestingly, results of the postural sway area for the ASD group suggests that roughly half of the ASD subjects scored comparable to TD controls, whereas the other half scored >2 SD worse. Motor impaired children did not have significantly worse IQ scores, but were younger and had more RRBs. Results support previous findings of relationships between RRBs and postural control. It appears that motor control impairments may characterize a subset of individuals with ASD. Better delineation of motor control abilities in individuals with ASD will be important to help explain variations of abilities in ASD, inform treatment, and guide examination of underlying neural involvement in this very diverse disorder.

Adding voucher-based incentives to coping skills and motivational enhancement improves outcomes during treatment for marijuana dependence.

Sixty individuals seeking outpatient treatment for marijuana dependence were randomly assigned to 1 of 3 treatments: motivational enhancement (M), M plus behavioral coping skills therapy (MBT), or MBT plus voucher-based incentives (MBTV). In the voucher-based incentive program, participants earned vouchers exchangeable for retail items contingent on them submitting cannabinoid-negative urine specimens. MBTV engendered significantly greater durations of documented marijuana abstinence during treatment compared with MBT and M, and a greater percentage of participants in the MBTV group compared with the MBT or M groups were abstinent at the end of treatment. No significant differences in marijuana abstinence were observed between the MBT and M groups. The positive effects of the voucher program in this study support the utility of incentive-based interventions for the treatment of substance dependence disorders including marijuana dependence.

Adults seeking treatment for marijuana dependence: a comparison with cocaine-dependent treatment seekers.

Sixty-two individuals seeking treatment for marijuana dependence completed a comprehensive assessment. Sociodemographics, substance use, psychosocial functioning, psychiatric symptoms, and medical status were compared with similar data collected from 70 treatment-seeking, cocaine-dependent individuals. Substantial psychosocial and psychiatric problems were observed in both groups. In general, the marijuana group reported substance-use histories and a range of impairment comparable with the cocaine group; however, they showed less severe dependence. The marijuana group was more ambivalent and less confident about stopping their marijuana use than the cocaine group was about stopping their cocaine use. These findings indicate that treatment-seeking, marijuana-dependent individuals exhibit substantial problems and that further efforts to develop effective treatments for this population are warranted.

The effects of gender, menstrual phase and practice on the perceived location of the midsagittal plane.

Women show menstrual phase-related cognitive changes that suggest altered hemispheric activation for a particular task, such that they demonstrate the greatest lateral performance differences on prototypical left hemisphere tasks during the luteal phase and on prototypical right hemisphere tasks during menstruation. Additionally, menstrual phase may alter total cerebral responsiveness, such that response times and performance accuracy for many tasks are best during the luteal phase and most impaired during the menstrual phase. We evaluated the effect of menstrual phase on spatial bisection (a perceptuospatial task) to help further understand hormonally-mediated changes in interhemispheric dynamics. Healthy young adult women and men blindly pointed to their midsagittal plane with either hand. Women were repeatedly tested according to menstrual phase, and men were tested at similar intervals. The mean pointing error in the luteal phase differed significantly from that of all other phases and did not differ significantly from those of men, who pointed significantly to the left across test sessions. These findings suggest that, in space bisection tasks, women are more likely to have asymmetric hemispheric activation during the luteal phase than during the menstrual phase. Thus, space bisection did not resemble other prototypical right hemisphere behaviors. The luteal phase may have nonspecifically activated both hemispheres on this task instead of suppressing right hemisphere function, and a slight functional asymmetry favoring the right hemisphere may have been promoted. In addition, intermanual pointing discrepancies in both subject groups decreased over repeated sessions. This suggests that, while practice alters an internal kinesthetic reference, it does not influence an imaginal extrapersonal spatial reference.