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Biomedical subjects

Abigail A Baird

Publications and source records attributed to Abigail A Baird.

9 recordsLinked to original sources
PubMed2006

Anatomical changes in the emerging adult brain: a voxel-based morphometry study.

Research has consistently confirmed changes occur in brain morphometry between adolescence and adulthood. The purpose of the present study was to explore anatomical change during a specific environmental transition. High-resolution T1-weighted structural magnetic resonance imaging (MRI) scans were acquired from 19 participants (mean age at initial scan = 18.6 years) during their freshman year. Scans were completed during the fall term and 6 months later before the conclusion of the school year. Voxel-based morphometry was used to assess within-subject change. Significant intensity increases were observed along the right midcingulate, inferior anterior cingulate gyrus, right caudate head, right posterior insula, and bilateral claustrum. Regional changes were not observed in two control groups; one controlling for method and another controlling for age-specific change over time. The results suggest that significant age-related changes in brain structure continue after the age of 18 and may represent dynamic changes related to new environmental challenges. Findings from the regions of change are discussed in the context of specific environmental demands during a period of normative maturation.

Adolescent↗
PubMed2005

Differential role of the orbital frontal lobe in emotional versus cognitive perspective-taking.

Lesions of the orbital frontal lobe, particularly its medial sectors, are known to cause deficits in empathic ability, whereas the role of this region in theory of mind processing is the subject of some controversy. In a functional magnetic resonance imaging study with healthy participants, emotional perspective-taking was contrasted with cognitive perspective-taking in order to examine the role of the orbital frontal lobe in subcomponents of theory of mind processing. Subjects responded to a series of scenarios presented visually in three conditions: emotional perspective-taking, cognitive perspective-taking and a control condition that required inferential reasoning, but not perspective-taking. Group results demonstrated that the medial orbitofrontal lobe, defined as Brodmann's areas 11 and 25, was preferentially involved in emotional as compared to cognitive perspective-taking. This finding is both consistent with the lesion literature, and resolves the inconsistency of orbital frontal findings in the theory of mind literature.

Adolescent↗
PubMed2005

Developmental precipitants of borderline personality disorder.

Traditional theories regarding the etiology of borderline personality disorder have focused on poor attachment figures and/or traumatic experience. The present review posits an additional pathogenic course for this disorder. Specifically, the proposed mechanism involves a basic disruption of the neural hardware that supports the formation and maintenance of unconscious emotional memory, hardware essential for the formation of early attachments. It is further theorized that this early disruption has ongoing effects on both behavioral and concomitant neural development. Within this model, adolescence is described as a period of intense change that serves as the tipping point for the onset of borderline personality disorder.

Adaptation, Psychological↗
PubMed2005

Functional connectivity: integrating behavioral, diffusion tensor imaging, and functional magnetic resonance imaging data sets.

In the present study, we combined 2 types of magnetic resonance technology to explore individual differences on a task that required the recognition of objects presented from unusual viewpoints. This task was chosen based on previous work that has established the necessity of information transfer from the right parietal cortex to the left inferior cortex for its successful completion. We used reaction times (RTs) to localize regions of cortical activity in the superior parietal and inferior frontal regions (blood oxygen level-dependent [BOLD] response) that were more active with longer response times. These regions were then sampled, and their signal change used to predict individual differences in structural integrity of white matter in the corpus callosum (using diffusion tensor imaging). Results show that shorter RTs (and associated increases in BOLD response) are associated with increased organization in the splenium of the corpus callosum, whereas longer RTs are associated with increased organization in the genu.

Adult↗
PubMed2004

The emergence of consequential thought: evidence from neuroscience.

The ability to think counterfactually about the consequence of one's actions represents one of the hallmarks of the development of complex reasoning skills. The legal system places a great emphasis on this type of reasoning ability as it directly relates to the degree to which individuals may be judged liable for their actions. In the present paper, we review both behavioural and neuroscientific data exploring the role that counterfactual thinking plays in reasoning about the consequences of one's actions, especially as it pertains to the developing mind of the adolescent. On the basis of assimilation of both behavioural and neuroscientific data, we propose a brain-based model that provides a theoretical framework for understanding the emergence of counterfactual reasoning ability in the developing mind.

Adolescent↗
PubMed2004

Functional differences among those high and low on a trait measure of psychopathy.

BACKGROUND: It has been established that individuals who score high on measures of psychopathy demonstrate difficulty when performing tasks requiring the interpretation of other's emotional states. The aim of this study was to elucidate the relation of emotion and cognition to individual differences on a standard psychopathy personality inventory (PPI) among a nonpsychiatric population. METHODS: Twenty participants completed the PPI. Following survey completion, a mean split of their scores on the emotional-interpersonal factor was performed, and participants were placed into a high or low group. Functional magnetic resonance imaging data were collected while participants performed a recognition task that required attention be given to either the affect or identity of target stimuli. RESULTS: No significant behavioral differences were found. In response to the affect recognition task, significant differences between high- and low-scoring subjects were observed in several subregions of the frontal cortex, as well as the amygdala. No significant differences were found between the groups in response to the identity recognition condition. CONCLUSIONS: Results indicate that participants scoring high on the PPI, although not behaviorally distinct, demonstrate a significantly different pattern of neural activity (as measured by blood oxygen level-dependent contrast)in response to tasks that require affective processing. The results suggest a unique neural signature associated with personality differences in a nonpsychiatric population.

Adult↗
PubMed2003

An fMRI investigation of the impact of interracial contact on executive function.

We investigated whether individual differences in racial bias among white participants predict the recruitment, and potential depletion, of executive attentional resources during contact with black individuals. White individuals completed an unobtrusive measure of racial bias, then interacted with a black individual, and finally completed an ostensibly unrelated Stroop color-naming test. In a separate functional magnetic resonance imaging (fMRI) session, subjects were presented with unfamiliar black male faces, and the activity of brain regions thought to be critical to executive control was assessed. We found that racial bias predicted activity in right dorsolateral prefrontal cortex (DLPFC) in response to black faces. Furthermore, activity in this region predicted Stroop interference after an actual interracial interaction, and it statistically mediated the relation between racial bias and Stroop interference. These results are consistent with a resource depletion account of the temporary executive dysfunction seen in racially biased individuals after interracial contact.

Adult↗
PubMed2002

Frontal lobe activation during object permanence: data from near-infrared spectroscopy.

The ability to create and hold a mental schema of an object is one of the milestones in cognitive development. Developmental scientists have named the behavioral manifestation of this competence object permanence. Convergent evidence indicates that frontal lobe maturation plays a critical role in the display of object permanence, but methodological and ethical constrains have made it difficult to collect neurophysiological evidence from awake, behaving infants. Near-infrared spectroscopy provides a noninvasive assessment of changes in oxy- and deoxyhemoglobin and total hemoglobin concentration within a prescribed region. The evidence described in this report reveals that the emergence of object permanence is related to an increase in hemoglobin concentration in frontal cortex.

Female↗