Learn More
"Is there a biology of intelligence which is characteristic of the normal human nervous system?" Here we review 37 modern neuroimaging studies in an attempt to address this question posed by Halstead (1947) as he and other icons of the last century endeavored to understand how brain and behavior are linked through the expression of intelligence and reason.(More)
Positron emission tomography of cerebral glucose metabolism in adult human subjects was used to investigate amygdaloid complex (AC) activity associated with the storage of long-term memory for emotionally arousing events. Subjects viewed two videos (one in each of two separate positron emission tomography sessions, separated by 3-7 days) consisting either(More)
Total brain volume accounts for about 16% of the variance in general intelligence scores (IQ), but how volumes of specific regions-of-interest (ROIs) relate to IQ is not known. We used voxel-based morphometry (VBM) in two independent samples to identify substantial gray matter (GM) correlates of IQ. Based on statistical conjunction of both samples (N = 47;(More)
Creativity has long been a construct of interest to philosophers, psychologists and, more recently, neuroscientists. Recent efforts have focused on cognitive processes likely to be important to the manifestation of novelty and usefulness within a given social context. One such cognitive process - divergent thinking - is the process by which one extrapolates(More)
We examined the relationship between structural brain variation and general intelligence using voxel-based morphometric analysis of MRI data in men and women with equivalent IQ scores. Compared to men, women show more white matter and fewer gray matter areas related to intelligence. In men IQ/gray matter correlations are strongest in frontal and parietal(More)
Regional cerebral glucose metabolic rate (GMR) quantified with positron emission tomography (PET) with 18-fluoro-2-deoxyglucose (FDG) was measured twice in 8 young men performing a complex visuospatial/motor task (the computer game Tetris), before and after practice. After 4-8 weeks of daily practice on Tetris, GMR in cortical surface regions decreased(More)
A unifying theory of general anesthetic-induced unconsciousness must explain the common mechanism through which various anesthetic agents produce unconsciousness. Functional-brain-imaging data obtained from 11 volunteers during general anesthesia showed specific suppression of regional thalamic and midbrain reticular formation activity across two different(More)
BACKGROUND Although the effects of propofol on cerebral metabolism have been studied in animals, these effects have yet to be directly examined in humans. Consequently, we used positron emission tomography (PET) to demonstrate in vivo the regional cerebral metabolic changes that occur in humans during propofol anesthesia. METHODS Six volunteers each(More)
BACKGROUND Neuro-imaging studies demonstrate plasticity of cortical gray matter before and after practice for some motor and cognitive tasks in adults. Other imaging studies show functional changes after practice, but there is not yet direct evidence of how structural and functional changes may be related. A fundamental question is whether they occur at the(More)
We scanned 18 patients with schizophrenia who had never received neuroleptic medication and 20 age- and sex-matched controls by positron emission tomography with 18-F-fluorodeoxyglucose (fludeoxyglucose F 18) as a tracer of glucose metabolism. Subjects performed the Continuous Performance Test during 18-F-fluorodeoxyglucose uptake. Scan results were(More)