ORCID Profile
0000-0001-8080-0582
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: American Psychiatric Association Publishing
Date: 10-2012
DOI: 10.1176/APPI.AJP.2012.12020191
Abstract: In children with conduct problems, high levels of callous-unemotional traits are associated with amygdala hypoactivity to consciously perceived fear, while low levels of callous-unemotional traits may be associated with amygdala hyperactivity. Behavioral data suggest that fear processing deficits in children with high callous-unemotional traits may extend to stimuli presented below conscious awareness (preattentively). The authors investigated the neural basis of this effect. Amygdala involvement was predicted on the basis of its role in preattentive affective processing in healthy adults and its dysfunction in previous studies of conduct problems. Functional MRI was used to measure neural responses to fearful and calm faces presented preattentively (for 17 ms followed by backward masking) in boys with conduct problems and high callous-unemotional traits (N=15), conduct problems and low callous-unemotional traits (N=15), and typically developing comparison boys (N=16). Amygdala response to fearful and calm faces was predicted to differentiate groups, with the greatest response in boys with conduct problems and low callous-unemotional traits and the lowest in boys with conduct problems and high callous-unemotional traits. In the right amygdala, a greater amygdala response was seen in boys with conduct problems and low callous-unemotional traits than in those with high callous-unemotional traits. The findings were not explained by symptom levels of conduct disorder, attention-deficit hyperactivity disorder, anxiety, or depression. These data demonstrate differential amygdala activity to preattentively presented fear in children with conduct problems grouped by callous-unemotional traits, with high levels associated with lower amygdala reactivity. The study's findings complement increasing evidence suggesting that callous-unemotional traits are an important specifier in the classification of children with conduct problems.
Publisher: Cambridge University Press (CUP)
Date: 19-03-2013
DOI: 10.1017/S0033291713000482
Abstract: Children with conduct problems (CP) are a heterogeneous group. Those with high levels of callous–unemotional traits (CP/HCU) appear emotionally under-reactive at behavioural and neural levels whereas those with low levels of CU traits (CP/LCU) appear emotionally over-reactive, compared with typically developing (TD) controls. Investigating the degree to which these patterns of emotional reactivity are malleable may have important translational implications. Instructing participants with CP/HCU to focus on the eyes of fearful faces (i.e. the most salient feature) can ameliorate their fear-recognition deficits, but it is unknown whether this is mediated by amygdala response. It is also unknown whether focusing on fearful eyes is associated with increased amygdala reactivity in CP/LCU. Functional magnetic resonance imaging (fMRI) was used to measure neural responses to fearful and calm faces in children with CP/HCU, CP/LCU and TD controls ( n = 17 per group). On half of trials participants looked for a blue dot anywhere within target faces on the other half, participants were directed to focus on the eye region. Reaction time (RT) data showed that CP/LCU were selectively slowed in the fear/eyes condition. For the same condition, CP/LCU also showed increased amygdala and subgenual anterior cingulate cortex (sgACC)/orbitofrontal cortex (OFC) responses compared with TD controls. RT and amygdala response to fear/eyes were correlated in CP/LCU only. No effects of focusing on the eye region were observed in CP/HCU. These data extend the evidence base suggesting that CU traits index meaningful heterogeneity in conduct problems. Focusing on regulating reactive emotional responses may be a fruitful strategy for children with CP/LCU.
Publisher: Center for Open Science
Date: 06-2020
Abstract: Adolescence is a period of heightened exploration relative to adulthood and childhood. This predisposition has been linked with negative behaviours related to risk-taking, including dangerous driving, substance misuse and risky sexual practices. However, recent models have argued that adolescents’ heightened exploration serves a functional purpose within the lifespan, allowing adolescents to develop experiential knowledge of their surroundings. Yet, there is limited evidence that heightened exploration in adolescence is associated with positive outcomes. To address this, the present pre-registered study utilised a foraging paradigm with a s le of adolescents aged 16-17 (N=68) and of adults aged 21 and above (N=69). Participants completed a patch foraging task, which required them to choose between exploiting a known resource which gradually yields fewer rewards, and exploring a novel, unknown resource with a fresh distribution of rewards. Findings demonstrated that adolescents explored more than adults, which – in the context of the current task – represented more optimal patch foraging behaviour. These findings indicate that adolescents’ heightened exploration can be beneficial, as they were able to effectively navigate unknown environments and accrue rewards more successfully than adults. This provides evidence that heightened exploration in adolescence, relative to adulthood, can lead to positive outcomes and contributes to our understanding of the role increased novelty-seeking plays at this point in the lifespan.
Publisher: Wiley
Date: 12-2010
DOI: 10.1002/AUR.161
Abstract: In iduals with an autism spectrum disorder (ASD) show difficulties identifying familiar faces, recognizing emotional expressions and judging eye-gaze direction. Recent research suggests that relatives of in iduals with AS also show impairments in some aspects of face processing but no study has comprehensively assessed the nature and extent of face-processing difficulties in a group of relatives. This study compared the performance of 22 parents/adult siblings of in iduals with ASD ("relatives" group), 26 adults with ASD, and 26 typically developing adults on tasks of face discrimination, facial expression recognition and judging eye-gaze direction. Relatives of in iduals with ASD were less able to discriminate subtle differences between faces than typically developing adults, but were more sensitive to such differences than adults with ASD. Furthermore, relatives were significantly worse at identifying expressions of fear and disgust than typically developing adults and failed to show the typical sensitivity to direct compared with averted eye-gaze direction--a strikingly similar pattern to that observed in adults with ASD. These findings show that atypical patterns of face processing are found in some relatives of in iduals with ASD and suggest that these difficulties may represent a cognitive endophenotype.
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Catherine Sebastian.