Brain-imaging studies reveal many areas in which the amount of gray matter (neuron bodies) correlates with intelligence test scores. The color patches above indicate the approximate location of the Brodmann areas—structural groupings of neurons numbered according to historical tradition. The letters on each Brodmann area indicate which intelligence factors it is associated with: general (g); spatial (s); and crystallized (c), or factual knowledge. Every individual has a unique pattern of gray matter in these areas, giving rise to different cognitive strengths and weaknesses. Fourteen of the Brodmann areas (colored orange above) are consistently implicated in studies of intelligence-related brain structure and function. Neuropsychologist Rex E. Jung of the University of New Mexico and I reviewed the studies and identified this network, calling it the parieto-frontal integration theory (P-FIT ) because areas in the parietal (green) and frontal (blue) lobes were consistent across the most studies. Most of the P-FIT areas are involved in computation (frontal areas) and sensory integration (parietal areas), the processing and conscious understanding of sensory information.
Source of Information : Scientific American Mind November-December 2009