Intelligence Correlates With Cortical Thickness

McGill University scientists have studied data from the NIH "MRI Study of Normal Brain Development" and discovered that the thickness of the cortex correlates with the person's intelligence scores on cognitive tests.

The association between regional cortical thickness and intelligence has been little studied and most previous studies of normal children had a relatively small sample. So with improvements in MRI-based quantification of cortical thickness and a much larger sample, researchers aimed to examine this relationship and to further characterize and identify brain areas where cortical thickness was associated with cognitive performance.

Cortical thickness may in part reflect the amount of complex connections between nerve cells. In other words, thicker cortices are likely to have more complex connections with consequences on cognitive ability. A positive link between cortical thickness and cognitive ability was detected in many areas of the frontal, parietal, temporal and occipital lobes. The regions with the greatest relationship were the 'multi-modal association' areas, where information converges from various regions of the brain for processing.

"A principal finding of this study is that it supports a distributed model of intelligence where multiple areas of the brain are involved with cognitive ability difference instead of the view that there is just one centre or structure important for intelligence differences in the brain," says Dr. Sherif Karama, psychiatrist at the MNI and co-investigator in the study. "Previous studies have shown a link between intelligence differences and individual brain structure or function. This is the first time that a correlation between a general cognitive ability factor and essentially most, if not all, cortical association areas is demonstrated in the same study." _PO

This type of research is a refreshing departure from the PC thought police suppression and persecution of IQ oriented research on many university campuses. Recent brain imaging research comparing mono- and di-zygotic twins reinforces the heritable nature of intelligence and brain processing speed. A better understanding of the origins and nature of human intelligence will allow better treatments for cognitive disorders of all types.

Prevailing dysfunctional leftist oppression of research into human cognition may have set back treatment for cognitive dysfunction by decades. Fortunately, as the tools for studying the structural, physiological, genetic, and biochemical basis of intelligence improve, leftist suppression of research (in many areas of science) will grow more difficult.