Researchers have said that rate of change in the thickness of one's brain's cortex is an important factor associated with that person's change in IQ.
The study has potentially wide-ranging implications for the pedagogical world and for judicial cases in which the defendant's IQ score could play a role in determining the severity of the sentence.
Dr. Sherif Karama, assistant professor of psychiatry at McGill University, psychiatrist at Douglas Mental Health University Institute and affiliate at The Neuro, said that often, small differences in IQ scores are observed when people's IQs are tested twice over a period of time. However, in some instances, dramatic changes in IQ scores are observed.
He said that these dramatic changes are generally attributed to measurement errors rather than assumed to reflect real changes in general cognitive ability.
This study by Professor Karama and his colleagues involved 188 children and adolescents over a period of two years. MRIs of the study participants were taken at six sites across the US. They found that within a relatively short period of 2 years:
1. People with a significant increase in IQ did not have the expected cortical thinning,
2. People whose IQ stayed the same had the normal expected cortical thinning,
3. People with a significant decrease in IQ had exaggerated cortical thinning.
This paper has been published in the journal NeuroImage.
