Biomedical subjects

Michael W O'Boyle

Publications and source records attributed to Michael W O'Boyle.

4 recordsLinked to original sources

PubMed2006

Visuospatial processing and the function of prefrontal-parietal networks in autism spectrum disorders: a functional MRI study.

OBJECTIVE: Individuals with autism spectrum disorders typically have normal visuospatial abilities but impaired executive functioning, particularly in abilities related to working memory and attention. The aim of this study was to elucidate the functioning of frontoparietal networks underlying spatial working memory processes during mental rotation in persons with autism spectrum disorders. METHOD: Seven adolescent males with normal IQ with an autism spectrum disorder and nine age- and IQ-matched male comparison subjects underwent functional magnetic resonance imaging scans while performing a mental rotation task. RESULTS: The autism spectrum disorders group showed less activation in lateral and medial premotor cortex, dorsolateral prefrontal cortex, anterior cingulate gyrus, and caudate nucleus. CONCLUSIONS: The finding of less activation in prefrontal regions but not in parietal regions supports a model of dysfunction of frontostriatal networks in autism spectrum disorders.

Adolescent↗

PubMed2005

Mathematically gifted male adolescents activate a unique brain network during mental rotation.

Mental rotation involves the creation and manipulation of internal images, with the later being particularly useful cognitive capacities when applied to high-level mathematical thinking and reasoning. Many neuroimaging studies have demonstrated mental rotation to be mediated primarily by the parietal lobes, particularly on the right side. Here, we use fMRI to show for the first time that when performing 3-dimensional mental rotations, mathematically gifted male adolescents engage a qualitatively different brain network than those of average math ability, one that involves bilateral activation of the parietal lobes and frontal cortex, along with heightened activation of the anterior cingulate. Reliance on the processing characteristics of this uniquely bilateral system and the interplay of these anterior/posterior regions may be contributors to their mathematical precocity.

Adolescent↗

PubMed2004

Interhemispheric interaction during global-local processing in mathematically gifted adolescents, average-ability youth, and college students.

Interhemispheric interaction in mathematically gifted (MG) adolescents, average-ability (AA) youth, and college students (CS) was examined by presenting hierarchical letter pairs in 3 viewing conditions: (a) unilaterally to the right hemisphere (RH), (b) unilaterally to the left hemisphere (LH), or (c) bilaterally, with 1 member of the pair presented to each hemisphere simultaneously. Participants made global-local, match-no-match judgments. For the AA and CS, the LH was faster for local matches and the RH for global matches. The MG showed no hemispheric differences. Also, AA and CS were slower on cooperative compared with unilateral trials, whereas the MG showed the opposite pattern. These results suggest that enhanced interhemispheric interaction is a unique functional characteristic of the MG brain.

Adolescent↗

PubMed2003

Generating an image from an ambiguous visual input: an electroencephalographic (EEG) investigation.

Fourteen right-handed males were shown slides of common objects (e.g., wristwatch), familiar situations (e.g., two people shaking hands), and inkblots from a popular projective test (Holtzman, 1986) and then asked to name the object, assess the situation, or describe the most salient image emerging from the inkblot. Alpha power suppression was monitored over the left and right frontal, temporal, parietal, and occipital lobes to determine the brain circuitry responsible for the processing of each type of stimulus. When processing common objects and familiar situations there was bilateral activation of the parietal and occipital lobes; when processing inkblots, bilateral activation of the parietal and occipital lobes was again obtained, but complemented by selective activation of the right frontal lobe. The later suggests that anterior regions of the right cerebral hemisphere contribute to the generation of dynamic images like those evoked by visually ambiguous inkblots.

Adolescent↗