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1.  Normal Rates of Neuroradiological Findings in Children with High Functioning Autism 
Magnetic resonance imaging (MRI) has been used to analyze highly specific volumetric and morphological features of the brains of individuals with autism spectrum disorder (ASD). To date, there are few comprehensive studies examining the prevalence of neuroradiologic findings seen on routine MRI scans in children with ASD. This study examined the prevalence of neuroradiologic findings in children with high functioning ASD, and compared these rates to those in children with Attention-Deficit/Hyperactivity Disorder (ADHD) and children who are typically developing (TD). Results showed that approximately 90% of children had normal MRI scans. There was no significant effect of diagnosis on the total number of neuroradiological findings or the number of specific brain findings. Implications and future research directions are discussed.
doi:10.1007/s10803-011-1407-6
PMCID: PMC3999957  PMID: 22105143
Autism; Magnetic resonance imaging; Neuroradiological findings
2.  Different Neural Patterns Are Associated With Trials Preceding Inhibitory Errors in Children With and Without Attention-Deficit/Hyperactivity Disorder 
Objective
Attention-deficit/hyperactivity disorder (ADHD) is associated with difficulty inhibiting impulsive, hyperactive, and off-task behavior. However, no studies have examined whether a distinct pattern of brain activity precedes inhibitory errors in typically developing (TD) children and children with ADHD. In healthy adults, increased activity in the default mode network, a set of brain regions more active during resting or internally focused states, predicts commission errors, suggesting that momentary lapses of attention are related to inhibitory failures.
Method
Event-related functional magnetic resonance imaging and a go/no-go paradigm were used to explore brain activity preceding errors in 13 children with ADHD and 17 TD controls.
Results
Comparing pre-error with pre-correct trials, TD children showed activation in the precuneus/posterior cingulate cortex and parahippocampal and middle frontal gyri. In contrast, children with ADHD demonstrated activation in the cerebellum, dorsolateral prefrontal cortex (DLPFC), and basal ganglia. Between-group comparison for the pre-error versus pre-correct contrast showed that children with ADHD showed greater activity in the cerebellum, DLPFC, and ventrolateral PFC compared with TD controls. Results of region-of-interest analysis confirmed that the precuneus/posterior cingulate cortex are more active in TD children compared with children with ADHD.
Conclusions
These preliminary data suggest that brain activation patterns immediately preceding errors differ between children with ADHD and TD children. In TD children, momentary lapses of attention precede errors, whereas pre-error activity in children with ADHD may be mediated by different circuits, such as those involved in response selection and control.
doi:10.1016/j.jaac.2011.03.014
PMCID: PMC3971481  PMID: 21703498
ADHD; children; functional magnetic resonance imaging; commission error; go/no-go task
3.  Mood Disorders in Mothers of Children on the Autism Spectrum Are Associated with Higher Functioning Autism 
Autism Research and Treatment  2012;2012:435646.
Mood disorders occur more frequently in family members of individuals with autism spectrum disorders (ASD) than in the general population. There may be associations between maternal mood disorder history patterns and specific ASD phenotypes. We therefore examined the relationship between maternal mood disorders and child autism spectrum disorders in 998 mother-child dyads enrolled in a national online autism registry and database. Mothers of children with ASD completed online questionnaires addressing their child's ASD as well as their own mood disorder history. In multivariate logistic regression models of ASD diagnoses, the odds of an Asperger disorder versus autistic disorder diagnosis were higher among those children whose mothers had a lifetime history of bipolar disorder (OR 2.11, CI 1.20, 3.69) or depression (OR 1.62, CI 1.19, 2.19). Further, maternal mood disorder onset before first pregnancy was associated with higher odds (OR 2.35, CI 1.48, 3.73) of an Asperger versus autism diagnosis among this sample of children with ASD. These data suggest that differences in maternal mood disorder history may be associated with ASD phenotype in offspring.
doi:10.1155/2012/435646
PMCID: PMC3426171  PMID: 22934172
4.  Variability in Post-Error Behavioral Adjustment Is Associated with Functional Abnormalities in the Temporal Cortex in Children with ADHD 
Background
Error processing is reflected, behaviorally, by slower reaction times (RT) on trials immediately following an error (post-error). Children with Attention-Deficit Hyperactivity Disorder (ADHD) fail to show RT slowing and demonstrate increased intra-subject variability (ISV) on post-error trials. The neural correlates of these behavioral deficits remain unclear. The dorsal anterior cingulate cortex (ACC) and lateral prefrontal cortex (PFC) are key regions implicated in error processing and subsequent behavioral adjustment. We hypothesized that children with ADHD, compared to typically developing (TD) controls, would exhibit reduced PFC activation during post-error (versus post-correct inhibition) trials and reduced dACC activation during error (versus correct inhibition) trials.
Methods
Using fMRI and a Go/No-Go task, we analyzed the neural correlates of error processing in 13 children with ADHD and 17 TD children.
Results
Behaviorally, children with ADHD showed similar RT slowing but increased ISV compared to controls. The post-error contrast revealed a relative increase in BOLD signal in the middle/inferior temporal cortex (TempC), the ACC/supplementary motor area (SMA) and the somatosensory/auditory cortex (AudC) in children with ADHD compared to controls. Importantly, in the ADHD group, increased post-error temporal cortex activity was associated with lower ISV. During error (versus correct inhibition) trials, no between group differences were detected. However, in children with ADHD lower ISV was associated with decreased insula and increased precentral gyrus activity.
Conclusions
In children with ADHD, post-error neural activity suggests first, a shift of attention towards task-irrelevant stimuli (AudC) and second, a recruitment of compensatory regions that resolve stimulus conflict (TempC) and improve response selection/execution (ACC/SMA). ADHD children with higher temporal cortex activation showed lower ISV, suggesting that functional abnormalities in the compensatory temporal regions contribute to increased variability. Moreover, increased ISV may be related to an over-sensitivity to negative outcomes during error trials in ADHD (insula correlation).
doi:10.1111/j.1469-7610.2010.02356.x
PMCID: PMC3110592  PMID: 21175614
error processing; variability; temporal cortex; medial frontal cortex; ADHD; children; fMRI
5.  Enhanced Right Amygdala Activity in Adolescents during Encoding of Positively-Valenced Pictures 
While studies among adults implicate the amygdala and interconnecting brain regions in encoding emotional stimuli, few studies have examined whether developmental changes occur within this emotional-memory network during adolescence. The present study examined whether adolescents and adults differentially engaged the amygdala and hippocampus during successful encoding of emotional pictures, with either positive or negative valence. Eighteen adults and twelve adolescents underwent event-related fMRI while encoding emotional pictures. Approximately 30 minutes later, outside the scanner, subjects were asked to recall the pictures seen during the scan. Age group differences in brain activity in the amygdala and hippocampus during encoding of the pictures that were later successfully and unsuccessfully recalled were separately compared for the positive and negative pictures. Adolescents, relative to adults, demonstrated enhanced activity in the right amygdala during encoding of positive pictures that were later recalled compared to not recalled. There were no age group differences in amygdala or hippocampal activity during successful encoding of negative pictures. The findings of preferential activity within the adolescent right amygdala during successful encoding of positive pictures may have implications for the increased reward and novelty seeking behavior, as well as elevated rates of psychopathology, observed during this distinct developmental period.
doi:10.1016/j.dcn.2010.08.004
PMCID: PMC2993431  PMID: 21127721
adolescents; adults; encoding; positive stimuli; amygdala; hippocampus
6.  EFFECTS OF YOHIMBINE AND HYDROCORTISONE ON PANIC SYMPTOMS, AUTONOMIC RESPONSES AND ATTENTION TO THREAT IN HEALTHY ADULTS 
Psychopharmacology  2009;204(3):445-455.
Rationale
Research in rodents and non-human primates implicates the noradrenergic system and hypothalamic-pituitary-adrenal axis in stress, anxiety, and attention to threat. Few studies examine how these two neurochemical systems interact to influence anxiety and attention in humans.
Objective
To examine the effects of exogenous yohimbine and hydrocortisone, as well as their combination (Y+H) on panic symptoms and attention to social threat cues.
Methods
32 healthy adults underwent a pharmacological challenge in which they were blindly randomized to either: yohimbine, hydrocortisone, Y+H, or placebo. Thirty minutes after drug infusion, attention to threat was measured using the dot probe task, a visual attention task that presents angry, happy and neutral faces and measures the degree of attention allocated towards or away from the emotional faces. Panic and autonomic measures were assessed before and 30 minutes after drug infusion.
Results
There was a significant increase in panic symptoms in the yohimbine and Y+H groups but not in the hydrocortisone or placebo groups. Yohimbine resulted in a greater increase in panic symptoms than Y+H. On the dot probe task, the placebo group exhibited an attention bias to angry faces whereas this bias was absent after yohimbine. When collapsing across groups, increased panic symptoms was associated with less attention to angry faces.
Conclusions
Exogenous hydrocortisone may attenuate noradrenergic-induced panic symptoms. The inverse relationship between panic symptoms and attention to angry faces extends prior research demonstrating attention modulation by stressful conditions.
doi:10.1007/s00213-009-1475-x
PMCID: PMC2740930  PMID: 19266185
yohimbine; hydrocortisone; panic symptoms; attention; threat cues; adults
7.  Attention Bias Toward Threat in Pediatric Anxiety Disorders 
Objective
To examine attention bias towards threat faces in a large sample of anxiety-disordered youths using a well-established visual probe task.
Method
Study participants included 101 children and adolescents (ages 7- 18 years) with generalized anxiety disorder, social phobia and/or separation anxiety disorder enrolled in a multi-site anxiety treatment study. Non-anxious youths (n = 51; ages 9 - 18 years) were recruited separately. Participants were administered a computerized visual probe task that presents pairs of faces portraying threat (angry), positive (happy) and neutral expressions. They pressed a response-key to indicate the spatial location of a probe that replaced one of the faces on each trial. Attention bias scores were calculated from response times to probes for each emotional face type.
Results
Compared to healthy youths, anxious participants demonstrated a greater attention bias towards threat faces. This threat bias in anxious patients did not significantly vary across the anxiety disorders. There was no group difference in attention bias towards happy faces.
Conclusions
These results suggest that pediatric anxiety disorders are associated with an attention bias towards threat. Future research might examine the manner in which cognitive bias in anxious youth changes with treatment.
doi:10.1097/CHI.0b013e3181825ace
PMCID: PMC2783849  PMID: 18698266
anxiety disorders; children; adolescents; attentional bias; threat
8.  Prevalence of Aggressive Behaviour after Severe Paediatric Traumatic Brain Injury 
Brain injury : [BI]  2008;22(12):932-939.
Objective
The goals of this study were to explore the prevalence of aggressive behaviours after severe paediatric traumatic brain injury (TBI) and identify predictors of aggressive behaviours one year postinjury.
Methods
A cohort of 97 children aged 4 to 19 years at time of severe TBI (GCS 3–8) were prospectively followed for one year. Preinjury psychiatric status was obtained retrospectively at enrollment and postinjury behavioural and functional concerns were assessed at one year. Aggression was measured with a modified version of the Overt Aggression Scale (OAS).
Results
Results revealed aggressive behaviour increased from preinjury to postinjury. Preinjury factors including aggression, attention problems, and anxiety were associated with increased postinjury aggressive behaviour. Children with greater disability after injury were also at increased risk for aggressive behaviours.
Conclusions
Aggression is a prevalent symptom after paediatric TBI and can significantly impede rehabilitation. Awareness of these predictors can aid in early identification of children at risk in order to help appropriately design rehabilitation programs.
doi:10.1080/02699050802454808
PMCID: PMC2782953  PMID: 19005885
Traumatic Brain Injury; Aggression; Predictors of Aggression; Overt Aggression Scale

Results 1-8 (8)