Relationship between intelligence and the size and composition of the corpus callosum

Hutchinson, Amanda D, Mathias, J L , Jacobson, B L ,Ruzic,L ,Bond,A N ,Banich, Marie T. Relationship between intelligence and the size and composition of the corpus callosum. Experimental Brain Research. New York: Jan 2009. Vol. 192, Iss. 3, p. 455-64 (10 pp.)

http://proquest.umi.com/pqdweb?did=1617600391&Fmt=6&clientId=3856&RQT=309&VName=PQD

The article I chose is looking at the relationship between the corpus callosum and IQ scores. The study used a total of 71 participants. Thirty one males and forty females between the ages of fourteen and twenty five participated in the study. Participants were given two subtest versions of the Wechsler abbreviated scale of intelligence (WASI), which consisted of a Vocabulary subtest portion which provided and estimate of verbal IQ and a Matrix Reasoning subtest which estimated performance IQ. The researchers then measured the corpus callosum. This was performed by a making a midsagittal slice in which the cerebral aqueduct could be observed clearly. The corpus callosum was then divided into five different regions to be studied. These regions were defined by drawing a line between the most anterior and posterior points of the CC. These subdivisions connect from anterior to posterior and were divided into prefrontal regions , premotor and supplementary motor regions , primary motor cortices , primary sensory cortices and parietal , temporal and occipital cortices. The results found that a higher estimated performance IQ was associated with smaller area in the posterior regions of the CC. Results also found that a higher estimated verbal IQ was associated with decreased fractional anisotropy of the genu , which is an anterior portion of the CC. The research did find some evidence for the relationship between IQ and corpus callosum size. The smaller posterior regions were associated with higher IQ .Further research into the size and morphology of the corpus callosum would help understand areas of cognitive processing and intelligence development.