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Tracy Butler

Publications and source records attributed to Tracy Butler.

7 recordsLinked to original sources
PubMed2006

Sex differences in mental rotation: top-down versus bottom-up processing.

Functional MRI during performance of a validated mental rotation task was used to assess a neurobiological basis for sex differences in visuospatial processing. Between-sex group analysis demonstrated greater activity in women than in men in dorsalmedial prefrontal and other high-order heteromodal association cortices, suggesting women performed mental rotation in an effortful, "top-down" fashion. In contrast, men activated primary sensory cortices as well as regions involved in implicit learning (basal ganglia) and mental imagery (precuneus), consistent with a more automatic, "bottom-up" strategy. Functional connectivity analysis in association with a measure of behavioral performance showed that, in men (but not women), accurate performance was associated with deactivation of parieto-insular vestibular cortex (PIVC) as part of a visual-vestibular network. Automatic evocation by men to a greater extent than women of this network during mental rotation may represent an effective, unconscious, bottom-up neural strategy which could reasonably account for men's traditional visuospatial performance advantage.

Brain↗
PubMed2006

The relation between computerized and paper-and-pencil mental rotation tasks: a validation study.

The present study aimed at validating a computerized mental rotation task developed for use in functional Magnetic Resonance Imaging (fMRI) studies. Eighty-three females and 74 males completed the computerized task, two pencil-and-paper tests of mental rotation, and reported their high school grades in mathematics, English, and history. The computerized task involved the presentation of pairs of three-dimensional stimuli that differed in orientation by 0, 40, 80, 120, or 160 degrees. Results showed significant gender differences in favor of males in the three main tasks, although gender interacted with angle of rotation in the computerized task. Evidence for concurrent validity was obtained in the form of significant correlations between performance on tasks relevant to mental rotation (paper and pencil tests and mathematics grades), whereas discriminant validity was demonstrated by a lack of correlation with tasks deemed irrelevant to mental rotation (English and history grades). These findings support the use of our computerized mental rotation task as a valid measure of mental rotation abilities in fMRI studies.

Adolescent↗
PubMed2006

Lack of ventral striatal response to positive stimuli in depressed versus normal subjects.

OBJECTIVE: Most of the functional neuroimaging studies of depression have focused primarily on the resting state or responses to negatively valenced stimuli. However, depression consists not only of an accentuation of negative affective processing but of an inability to experience pleasure or positive motivation. The authors tested the hypothesis that depressed subjects would show less activation than healthy comparison subjects, in response to positive stimuli, in ventral striatal regions associated with processing of reward and positive stimuli. METHOD: Positive, negative, and neutral words were presented to 10 unmedicated depressed patients and 12 healthy comparison subjects in the context of a 3T functional magnetic resonance imaging (MRI) paradigm. Image processing and analysis were performed using statistical parametric mapping with a mixed-effects model. Significant differences in neural responses were assessed, examining group, condition, and interaction effects of interest within the context of a general linear model. RESULTS: Relative to comparison subjects, depressed patients demonstrated significantly less bilateral ventral striatal activation to positive stimuli, correlating with decreased interest/pleasure in and performance of activities. They also displayed decreased activation to positive stimuli in a dorsomedial frontal region associated with processing of self-related stimuli. Responses of depressed subjects to negative stimuli were consistent with the growing literature on frontolimbic dysfunction in depression. CONCLUSIONS: This finding 1) supports a pathophysiological model of depression that includes reward/motivational pathway dysfunction, 2) suggests a contributing neural substrate of the inability to experience pleasure or engage in rewarding activities, 3) provides greater specification of abnormalities of basal ganglia function in depression, and 4) may help guide treatment approaches.

Adult↗
PubMed2005

Fear-related activity in subgenual anterior cingulate differs between men and women.

Functional magnetic resonance imaging in association with an instructed fear/anticipatory anxiety paradigm was used to explore sex differences in the human fear response. During anticipation of mild electrodermal stimulation, women, as compared with men, demonstrated increased activity in the subgenual anterior cingulate cortex and functionally related regions of the insula and brainstem. The subgenual anterior cingulate cortex is a region critical for emotional control implicated in the pathogenesis of psychiatric disease. Present findings suggest a contributory neural substrate for the greater susceptibility of women to anxiety and affective disorders, and emphasize the importance of considering participant sex when designing and interpreting functional neuroimaging studies.

Adult↗
PubMed2004

The hazards of lack of co-registration of ictal brain SPECT with MRI: A case report of sinusitis mimicking a brainstem seizure focus.

BACKGROUND: Single photon emission computed tomography (SPECT) following injection of radiotracer during a seizure is known as ictal SPECT. Comparison of an ictal SPECT study to a baseline or interictal study can aid identification of a seizure focus. CASE PRESENTATION: A young woman with encephalitis and refractory seizures underwent brain SPECT during a period of frequent seizure-like episodes, and during a seizure-free period. A focal area of increased radiotracer uptake present only when she was experiencing frequent seizure-like episodes was originally localized to the brainstem, but with later computerized co-registration of SPECT to MRI, was found to lie outside the brain, in the region of the sphenoid sinus. CONCLUSION: Low-resolution SPECT images present difficulties in interpretation, which can be overcome through co-registration to higher-resolution structural images.

Journal Article↗