Dickie Yu

Functional magnetic resonance imaging of facial information processing in children with autistic disorder, attention deficit hyperactivity disorder and typically developing controls

Abstract The present study used functional magnetic resonance imaging (fMRI) to compare the neural activation patterns of children diagnosed with autistic disorder (AD), attention deficit hyperactivity disorder (ADHD), and typically developing controls (TCs) in response to a task involving evaluation of facial expressions. Substantially greater functional activity was noted in TCs compared to both subjects diagnosed with AD and ADHD. Consistent with previous studies, differences in functional activation of the amygdala, fusiform gyrus, cerebellum, mesolimbic, and temporal lobe cortical regions of the brain during a task evaluating facial expressions were noted in AD compared to TCs. Differences in the neural activity in these brain regions were also observed in children diagnosed with AD compared to those diagnosed with ADHD. Overall decreased neural activity was observed during the faces task performance in the AD group compared to the other two groups, a finding consistent with studies using adults. Both TC and ADHD control groups showed increased inferior frontal cortex activity compared to the AD group. Significant activity was present in both TC and ADHD control groups in the insula which was absent in the AD group; this is consistent with other studies showing dysfunction of the mesolimbic system in children with AD. Although frontostriatal and mesolimbic systems appear to be affected in AD, these deficits were not in the same attentional networks which are dysfunctional in children diagnosed with ADHD.

Reactions of young children to the MRI scanner environment.

Seventy children aged 2 to 7 years were exposed to the MRI environment through a series of steps typical of a research study. Their willingness to proceed through the process was used to estimate the prevalence of fear. Thirty‐seven children (53%; 95% confidence interval [41%, 65%]) completed the approach sequence. Although the correlation of child age in months (Mean (M) = 60.1, standard deviation = 16.5, N = 70) and highest successful step (M = 5.8, standard deviation = 2.6, 95% confidence interval [5.2, 6.4]) completed was not statistically significant at the 0.05 level, r (68) = 0.21, P = 0.08, 95% confidence interval [−0.03, 0.42], the proportion of children aged 6‐7 years who successfully completed all steps (14 of 21, 67%, 95% confidence interval [50%, 84%]) was significantly different from the proportion of children aged 2‐3 years who completed all steps (six of 23, 26%, 95% confidence interval [11%, 41%]) (Fishers exact test, two‐tailed P = 0.0148). A failure rate of at least 50% should be included into group size calculations when performing studies with young children (2‐7 years), in addition to motion and other experimental factors. Magn Reson Med, 2010.

Stereotyped Behavior in Developmentally Delayed or Autistic Populations Rhythmic or Nonrhythmic

Stereotypies are high-frequency, highly repetitive, nonfunctional behaviors that are also often characterized as rhythmic. Rhythmicity suggests that the behavior is periodic, occurring at fixed intervals. Few studies, however, have rigorously demonstrated periodicity in stereotypy. This study examined various topographies of stereotypy in 9 participants and used spectral methods to detect existence of periodicities. TWo general patterns emerged in the spectral analysis. Participants who engaged in stereotypic rocking showed peaks in their power spectra; participants who engaged in other topographies of stereotypy did not show peaks. Thus, it appears that although some stereotypies-notably, rocking-have a periodic component, rhythmicity does not appear to be a characteristic of stereotypy in general.

Low-Cost Procedures to Conserve a Public Sport Environment

This study examined the effects of an educational sign prompt and a weekly lottery on golfers repairing of ballmarks on the greens of an 18-hole public golf course. The educational sign prompt contained: (1) an explanation and photographs of ballmarks, (2) three recommended steps to repair ballmarks, and (3) a request for help to repair ballmarks. During the weekly lottery, golfers could receive a raffle ticket to win a free round of golf from a weekly draw if they were spotted repairing a ballmark by golf course staff. Both the educational sign prompt and the weekly lottery seemed to be equally effective in decreasing unrepaired ballmarks on greens and both were favorably received by golfers. Since completion of the study, the educational sign prompt was adopted by the golf course.