Psychology

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    Effects of Prenatal Drug Exposure on Adolescent Brain Activation During a Visuospatial Working Memory Task
    (2008-11) Riggins, Tracy; Schweitzer, Julie; Kurup, Pradeep; Ross, Thomas; Black, Maureen; Salmeron, Betty Jo
    Background: Previous research examining effects of prenatal drug exposure (PDE) has yielded mixed results regarding cognitive performance during school age years. Associations between PDE and tests of global functioning (IQ and academic achievement) tend to be minimal and are typically attenuated by environmental variables (e.g., caregiving environment). On the other hand, significant negative associations have been reported in tests of executive functioning (sustained attention, inhibitory control, and behavioral regulation), even with covariate control. These findings are consistent with animal models of PDE that report developmental abnormalities in brain regions associated with strong dopaminergic innervation including the striatum, anterior cingulate cortex, and prefrontal cortex. In humans, these regions are putatively involved in executive functions that coordinate the basic cognitive processes required for goal-directed action (e.g., attention inhibitory control, planning, working memory). The objective of the present study was to assess the effects of PDE on brain functioning during adolescence. Methods: fMRI was used to examine visuospatial working memory (VSWM) in 35 adolescents (mean: 14.3 years); 20 with intrauterine exposure to cocaine, heroin, or both and 15 unexposed children from the same community. All participants performed a 2-back VSWM paradigm that required dynamic storage and manipulation of spatial information. Whole-brain functional EPI scans were acquired using a 3T Siemens Scanner with standard parameters. Participants completed one 6-minute block-design run that alternated between a 30 second control condition (which required observation of visual stimuli, sustained attention, and a motor response) and 30 seconds of the VSWM condition. Brain responses were analyzed using the AFNI software package with appropriate contrasts and p < 0.05 corrected for multiple comparisons. Results: Across all participants, the VSWM task activated the frontal-parietal attention network including bilateral superior parietal lobules, precuneus, middle frontal gyri, superior frontal gyri, and insular cortex. Significant deactivations were observed in regions of the “default network,” including the left anterior cingulate gyrus, medial frontal gyrus, posterior cingulate, and bilateral parahippocampal cortices. Whole-brain between group comparisons with both age and gender entered as covariates revealed 3 regions that were differentially activated in the drug-exposed compared to the non-exposed group. These regions included right inferior parietal lobe, right precentral gryus, and left cuneus. The drug-exposed group showed deactivation of the right inferior parietal lobule compared to no change in the non-exposed group. The non-exposed group showed activations in both the right precentral gyrus and left cuneus compared to no change in the drug-exposed group. These differences in activations were detected despite equivalent behavioral performance on the task (i.e., accuracy and response time) and after statistically controlling environmental variables that differed between the groups, including placement in nonmaternal care, maternal age at time of birth and prenatal exposure to cigarettes. Discussion: Despite similar task performance, adolescents with a history of PDE showed different neural activations than the comparison group. Regions that were differentially activated are implicated in sequencing task information (i.e., right parietal lobe), working memory performance in healthy control children (i.e., right precentral gyrus), and visual attention (i.e., left cuneus). These results suggest regions and components of working memory processing that may be differentially affected by PDE in adolescence.
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    fMRI reveals long-term effects of prenatal drug exposure on visuospatial working memory networks during adolescence.
    (2008-05) DeBoer, T.; Schweitzer, J.; Kurup, P.K.; Ross, T.J.; Ernst, M.; Nair, P.; Black, M.; Salmeron, B.J.
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    Examining Associations Between Funtional Brain Activation and Behavior in Adolescents With a History of Prenatal Drug Exposure
    (2008-08) Graham, M.; Riggins, T.; Ackerman, J.; Black, M.; Schweitzer, J.; Salmeron, B.J.
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    Relationship between disinhibition and metabolic control in adolescents with type 1 diabetes
    (2006-12-05) Sanchez, Lisa; Lejuez, Carl; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Given that adolescence poses a high-risk period for diabetes mismanagement, and consequently, threats to long-term health status, it is important to examine factors that contribute to individual differences in the propensity to exhibit poor management and engage in health incompatible behaviors. Importantly, researchers have identified personality constructs related to disinhibition, including impulsivity, sensation seeking, and risk-taking propensity, to be prospectively linked to engagement in real-world risk behaviors such as use of alcohol, nicotine, illegal drugs, and risky sexual behavior (Lejuez et al., 2002, 2003). However, this relationship has yet to be explored in adolescents with diabetes. Thus, the purpose of the current study was to examine whether disinhibition was related to metabolic control, and the extent to which self-management behavior and drug/alcohol use mediated this potential relationship. The sample consisted of 43 subjects with Type 1 diabetes aged 13-18 years who were recruited from diabetes clinics at Children's National Medical Center. Teens were assessed with self-report and behavioral measures of risk-taking and participated in an interview regarding self-management behaviors. Substance use and diabetes knowledge were measured by self report, and the glycosylated hemoglobin (HbA1c) test was used as a proxy for metabolic control. Results of partial correlational analyses indicated that disinhibition was not directly related to behavioral adherence, engagement in health incompatible behaviors, or glycemic control after controlling for race, gender, and insulin regimen type. Rather, results of regressional analyses suggested that sample characteristics, particularly race and insulin regimen, are the key variables in assessing overall management in adolescence. Results may have important implications for the prevention and treatment of morbidity associated with diabetes.
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    DOES NEGATIVE SELF-IMAGERY PLAY A CAUSAL ROLE IN SOCIAL PHOBIA AMONG ADOLESCENTS?
    (2005-04-20) Alfano, Candice Ann; Beidel, Deborah C; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    The current study was designed to examine whether negative self-imagery is a significant factor in the development of social phobia among adolescents. Although some adult models of social phobia posit that negative self-imagery serves to increase anxiety and decrease performance within social contexts, few studies have directly examined this relationship and no study has examined self-imagery among socially-phobic adolescents. For the current study, negative self-imagery was manipulated among a group of non-anxious adolescents (IMAG) during two social tasks. Levels of anxiety, specific thoughts, expected and self-rated performance, and observer-rated performance and social skill were compared to both socially-phobic and control adolescents. Results revealed few differences in terms of observer-rated performance and specific social skill between the IMAG and control groups of adolescents, although the socially-phobic group was consistently rated to exhibit poorer performances and decreased social skill. The IMAG group reported marginally significant increases in their anxiety levels during both social tasks. Interestingly, these adolescents reported similar (increased) rates of anxiety during an additional social interaction task where they were instructed to use positive self-imagery. The IMAG group also reported decreases in performance compared to the control group. This finding appears to be explained primarily based on the adolescents' belief that they were unable to hide their anxiety rather than a decrease in social skill (such as reported by socially-phobic youth). Further, the IMAG group reported an overall fewer number of cognitions than both groups during the social interaction task, potentially indicating a significant decrease in cognitive resources based on the use of self-imagery. Overall findings from this investigation do not support the hypothesis that negative self-imagery plays a causal role in the development of social phobia among adolescents. Rather, results indicate that excessive self-focused attention within social contexts, together with normal developmental increases in self-consciousness during the adolescent years may pose a specific risk for development of the syndrome. These findings provide a developmental understanding of the factors involved in the onset of social phobia, as well as those symptoms that may be germane to the maintenance of the disorder over time.