Faculty Bibliography

This study evaluated a calibration technique for scaling the fMRI-BOLD response during a simple motor task. A novel scaling parameter, resting state physiological fluctuation amplitude (RSFA), was tested using previously established scaling factors such as breath hold or 5% CO(2). RSFA was hypothesized to contain vascular reactivity information present in the resting state fMRI signal. Subjects were scanned under various stimulus conditions: (a) rest while breathing room air, (b) bilateral fingertapping, (c) breath holding and (d) moderate hypercapnia (breathing 5% CO(2)+air). In all subjects who breathed 5% CO(2), RSFA correlated highly with the BOLD response amplitude during 5% CO(2) inhalation. Also, RSFA correlated highly with the amplitude of the BOLD response elicited by breath hold. RSFA was therefore used as a hemodynamic scaling factor to calibrate both the amplitude and spatial extent of the fMRI-BOLD response during the motor task (fingertapping). Results revealed that amplitude scaling using RSFA was similar to that using breath hold or 5% CO(2), where the spatial extent of activation diminished by 20-37% over all subjects. Spatial extent of activation changed significantly after scaling and only 30-40% of the activated area overlapped with the unscaled activation. RSFA-scaled task-induced fMRI-BOLD response in both amplitude and spatial extent was comparable to that obtained using breath hold or 5% CO(2). We conclude that RSFA may be used to hemodynamically scale the fMRI-BOLD response and does not require the use of a hypercapnic challenge (which may not be purely non-neural), which can be difficult to implement in special populations

We studied the spatio-temporal characteristics of the resting state low-frequency fluctuations in fMRI-BOLD signal in isoflurane-anesthetized rats. fMRI-BOLD measurements at 9.4 T were made during normal and exsanguinated condition previously known to alter cerebral blood flow (CBF) fluctuations in anesthetized rats. fMRI signal time series were low pass filtered and studied by spectral analysis. During normal conditions, baseline mean arterial pressure (MAP) was 110+/-10 mm Hg and low-frequency fluctuations in BOLD signal were observed in the frequency range of 0.01 to 0.125 Hz. Following blood withdrawal (exsanguination), MAP decreased to 68+/-7 mm Hg, resulting in an increase in the amplitude of the low-frequency fluctuations in BOLD signal time series and an increase in power at several frequencies between 0.01 and 0.125 Hz. Spatially, the BOLD fluctuations were confined to the cortex and thalamus spanning both hemispheres with sparse presence in the caudate putamen and hippocampus during both normal and exsanguinated states. Spatial distribution of the low-frequency fluctuations in BOLD signal, from cross-correlation analysis, indicates substantial inter-hemispheric synchrony similar to that observed in the conscious human brain. The behavior of the resting state BOLD signal fluctuations similar to CBF fluctuations during exsanguination indicates a myogenic dependence. Also, a high inter-hemispheric synchrony combined with different phase characteristics of the low-frequency BOLD fluctuations particularly in the hippocampus relative to the cortex emphasizes distinct functional networks

Racial socialization is receiving research attention because of growing evidence that it can be a protective developmental process in African American families. The present study was an exploration of the relationship of parental mental health, discipline effectiveness, monitoring and racial socialization strategies on child externalizing behaviors in a sample of 140 African American parent/caregivers. Findings indicated that certain types of racial socialization-particularly, spirituality and religious coping-in conjunction with discipline effectiveness was related to child behavior problems. Specifically, among parents who felt they used more effective discipline strategies, moderate to high rates of spiritual and religious coping were associated with a reduction of child behavior problems. These findings support the hypothesis that racial socialization is an important aspect of parenting in African American families that can be associated with the effective management of children's behavior. Implications for parenting interventions and future research are discussed.

OBJECTIVE: ADHD is associated with significant functional impairment in adults. The present study examined functional outcomes following 6-month double-blind treatment with either atomoxetine or placebo. METHOD: Patients were 410 adults (58.5% male) with DSM-IV-defined ADHD. They were randomly assigned to receive either atomoxetine 40 mg/day to 80 mg/day (n = 271) or placebo (n = 139). The primary functional outcome measure was the Endicott Work Productivity Scale (EWPS), and the secondary measure was the Adult ADHD Quality of Life (AAQoL). Patients were seen for four visits in 6 months. RESULTS: At 6 months, both groups had nonsignificantly different improvements in EWPS total scores. Atomoxetine-treated patients showed significantly greater improvement than placebo-treated patients on the AAQoL after controlling for baseline severity of ADHD. Both treatment groups had low 6-month study completion rates. CONCLUSION: Following 6-month treatment with atomoxetine, adults with ADHD showed significantly greater improvement in functioning on disease-specific measures of quality of life than patients treated with placebo

CONTEXT: Vigilance for threat is a key feature of generalized anxiety disorder (GAD). The amygdala and the ventrolateral prefrontal cortex constitute a neural circuit that is responsible for detection of threats. Disturbed interactions between these structures may underlie pediatric anxiety. To date, no study has selectively examined responses to briefly presented threats in GAD or in pediatric anxiety. OBJECTIVE: To investigate amygdala and ventrolateral prefrontal cortex activation during processing of briefly presented threats in pediatric GAD. DESIGN: Case-control study. SETTING: Government clinical research institute. PARTICIPANTS: Youth volunteers, 17 with GAD and 12 without a psychiatric diagnosis. MAIN OUTCOME MEASURES: We used functional magnetic resonance imaging to measure blood oxygenation level-dependent signal. During imaging, subjects performed an attention-orienting task with rapidly presented (17 milliseconds) masked emotional (angry or happy) and neutral faces. RESULTS: When viewing masked angry faces, youth with GAD relative to comparison subjects showed greater right amygdala activation that positively correlated with anxiety disorder severity. Moreover, in a functional connectivity (psychophysiological interaction) analysis, the right amygdala and the right ventrolateral prefrontal cortex showed strong negative coupling specifically to masked angry faces. This negative coupling tended to be weaker in youth with GAD than in comparison subjects. CONCLUSIONS: Youth with GAD have hyperactivation of the amygdala to briefly presented masked threats. The presence of threat-related negative connectivity between the right ventrolateral prefrontal cortex and the amygdala suggests that the prefrontal cortex modulates the amygdala response to threat. In pediatric GAD, amygdala hyperresponse occurs in the absence of a compensatory increase in modulation by the ventrolateral prefrontal cortex.

CONTEXT: Children and adults with psychopathic traits and conduct or oppositional defiant disorder demonstrate poor decision making and are impaired in reversal learning. However, the neural basis of this impairment has not previously been investigated. Furthermore, despite high comorbidity of psychopathic traits and attention-deficit/hyperactivity disorder, to our knowledge, no research has attempted to distinguish neural correlates of childhood psychopathic traits and attention-deficit/hyperactivity disorder. OBJECTIVE: To determine the neural regions that underlie the reversal learning impairments in children with psychopathic traits plus conduct or oppositional defiant disorder. DESIGN: Case-control study. SETTING: Government clinical research institute. PARTICIPANTS: Forty-two adolescents aged 10 to 17 years: 14 with psychopathic traits and oppositional defiant disorder or conduct disorder, 14 with attention-deficit/hyperactivity disorder only, and 14 healthy controls. MAIN OUTCOME MEASURE: Blood oxygenation level-dependent signal as measured via functional magnetic resonance imaging during a probabilistic reversal task. RESULTS: Children with psychopathic traits showed abnormal responses within the ventromedial prefrontal cortex (Brodmann area 10) during punished reversal errors compared with children with attention-deficit/hyperactivity disorder and healthy children (P < .05 corrected for multiple comparisons). CONCLUSIONS: To our knowledge, this study provides the first evidence of abnormal ventromedial prefrontal cortex responsiveness in children with psychopathic traits and demonstrates this dysfunction was not attributable to comorbid attention-deficit/hyperactivity disorder. These findings suggest that reversal learning impairments in patients with developmental psychopathic traits relate to abnormal processing of reinforcement information.

Compared two groups of children with anxiety disorders served at a single mental health clinic whose referral source differed: private referrals (i.e., parent/legal guardian initiated) and public referrals (e.g., via state contracts--Departments of Health and Education, juvenile justice system). Comparisons were made across three domains of variables: (a) symptoms/diagnoses, (b) functioning, and (c) environments. Few symptom differences emerged. However, large differences were evident for contextual variables like family income and life stressors. Overall, the pattern of differences point to possible directions for adaptation of treatments for use with children with anxiety disorders served in public mental health systems.

The articles in this special issue are a significant contribution to the literature pertaining to racial socialization, which is defined as messages parents communicate about race and culture, how African Americans are perceived societally, and how to cope with discrimination due to their skin color. More specifically, these articles examine the relationship between racial socialization and parental mental health status, child socio-behavioral functioning, and the utilization of mental health and prevention services for both parent and child. Overall, the results of these articles indicate that various racial socialization practices do indeed influence key variables such as the child's behavioral functioning and decision-making, parental mental health status, and the receipt of prevention and mental health services. Implications of these findings suggest that racial socialization beliefs and practices may in fact influence the health and functioning of African American youth and families.