Neuroimaging intelligence testing: Difference between revisions

Revision as of 13:00, 27 January 2014

Revision as of 19:23, 29 May 2014

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===Brain size===

Using MRI, researchers are able to acquire volumetric measurements of [[brain size]]. Some studies have tried to explain the relationship between brain size (meaning volume) and intelligence, specifically in terms of IQ. In general, it has been found that Full Scale IQ and Verbal IQ have a stronger correlation with brain size than Performance IQ. It is thought by some that grey and white matter specifically relate to different IQs (grey matter with Verbal IQ and white matter with Performance IQ), but the results have not been consistent. It has been found thought that within the cortex, the correlation with IQ was very influenced by the volume of prefrontal grey matter.<ref name=deary2 />

A 2009 study examined intracerebral volumetric relationships in twins. Making use of high resolution MRI data, they found strong genetic connections correlations between cerebral structures. Specifically, the study suggests that a strong correlation exists between the tissue type or spatial proximity and genes. By examining the differences or lack thereof between the brain size of twin children, the researchers drew conclusions that individuals that share genes (i.e. twins) will show similar physiological brain properties compared to genetically-unrelated individuals.<ref>{{cite journal|last=Schmitt|first=JE|coauthors=Wallace, GL; Lenroot, RK; Ordaz, SE; Greenstein, D; Clasen, L; Kendler, KS; Neale, MC; Giedd, JN|title=A twin study of intracerebral volumetric relationships.|journal=Behavior genetics|date=March 2010|volume=40|issue=2|pages=114–24|pmid=20112130|doi=10.1007/s10519-010-9332-6|pmc=3403699}}</ref> This study provides evidence of the genetic influence of the brain structure and size, which are believed to both influence intelligence in some way.