Cortical and subcortical brain regions involved in rule-based category learning.

The brain regions contributing to rule-based category learning were examined using fMRI. Participants categorized single lines that varied in length and orientation into one of two categories. Category membership was based on the length of the line.

Selective activation of the nucleus accumbens during risk-taking decision making.

This study implemented a risk-taking task during fMRI to probe the brain circuitry involved in risk-taking decision-making in 12 healthy control subjects. Partially supporting the initial hypotheses, deliberation prior to selection of safe relative to risky responses generated greater activation in the inferior frontal cortex, superior temporal gyrus, and middle temporal gyrus; and deliberation prior to selection of risky relative to safe responses generated greater activation in medial frontal cortex, occipital cortex, nucleus accumbens and caudate. Additionally, accumbens activation correlated positively with the harm avoidance subscale of the Temperament and Character Inventory (TCI) 125.

Anticipation of emotionally aversive visual stimuli activates right insula.

Understanding the neural substrates of anticipation is required for a comprehensive model of the ways in which anxiety influences information processing. While it is apparent that the insula and medial frontal cortex are involved in processing anticipation of physical (i.e.

Functional subdivisions within anterior cingulate cortex and their relationship to autonomic nervous system function.

The anterior cingulate cortex (ACC) has diverse functions and several functional subdivisions. This study implemented a counting Stroop task that presented incongruent (INC) and congruent (CON) stimuli at two speeds to probe dorsal (dACC) and ventral (vACC) using functional magnetic resonance imaging (fMRI). Eighteen healthy subjects completed the task twice: once outside the scanner while heart rate variability (HRV) was recorded and once during fMRI.

Anterior cingulate activation in high trait anxious subjects is related to altered error processing during decision making.

Background: Individuals with high trait anxiety (HTA) can be studied to examine the effect of elevated levels of anxiety on the processing of stimuli and the selection of actions. The anterior cingulate cortex has been implicated in the detection and processing of errors. This investigation examined the hypothesis that HTA subjects are more sensitive to errors than nonanxious comparison subjects during a simple decision-making task and show increased activation in the anterior cingulate, particularly at low error rates.

Substitutions in hamster CAD carbamoyl-phosphate synthetase alter allosteric response to 5-phosphoribosyl-alpha-pyrophosphate (PRPP) and UTP.

CPSase (carbamoyl-phosphate synthetase II), a component of CAD protein (multienzymic protein with CPSase, aspartate transcarbamylase and dihydro-orotase activities), catalyses the regulated steps in the de novo synthesis of pyrimidines. Unlike the orthologous Escherichia coli enzyme that is regulated by UMP, inosine monophosphate and ornithine, the mammalian CPSase is allosterically inhibited by UTP, and activated by PRPP (5-phosphoribosyl-a-pyrophosphate) and phosphorylation. Four residues (Thr974, Lys993, Lys954 and Thr977) are critical to the E.

Increased activation in the right insula during risk-taking decision making is related to harm avoidance and neuroticism.

Decision making and risk taking are interrelated processes that are important for daily functioning. The somatic marker hypothesis has provided a conceptual basis for processes involved in risk-taking decision making and has been used to link discrete neural substrates to risk-related behaviors. This investigation examined the hypothesis that the degree of risk-taking is related to the degree of activation in the insular cortex.

Documenting the prominence of forensic neuropsychology at national meetings and in relevant professional journals from 1990 to 2000.

Numerous authors have opined that forensic activities have become more prominent within clinical neuropsychology. To investigate the merits of these claims, the entire contents of Archives of Clinical Neuropsychology (ACN), Journal of Clinical and Experimental Neuropsychology (JCEN), and The Clinical Neuropsychologist (TCN) from 1990 through 2000 were reviewed and cataloged. These three journals were selected because they are the highest-ranking clinical subscription journals according to surveys of neuropsychology practitioners.