Date on Senior Honors Thesis


Document Type

Senior Honors Thesis

Degree Name



Psychological and Brain Sciences

Degree Program

College of Arts and Sciences

Author's Keywords

BMI; intelligence; morphometry; white matter; resting-state


The human brain underlies the complex cognitive processes of the mind, however, this is dependent upon the physiological processes of the body in order to receive adequate energy, oxygen, and blood flow. Therefore, physical measurements such as body mass index (BMI) and indices of cognitive functioning, such as intelligence, may be related via common neural features. Current analyses assessed morphometric differences in cortical and subcortical grey matter regions, white matter structural integrity, and resting-state functional activation in order to determine what combinations of neural variables predict BMI and intelligence (Wechsler Abbreviated Scale of Intelligence; WASI) with the best degree of accuracy. Data for eighty-five subjects was obtained from the Nathan Kline Institute, in connection with the 1000 Functional Connectomes neuroimaging database. Behavioral results indicated a negative correlation between BMI and WASI scores. Neural analyses revealed that increased BMI predicted changes in a frontolimbic network comprised of the anterior cingulate cortex, amygdala, and uncinate fasciculus, as well as increased cortical surface area of the left fusiform gyrus. These results indicate a relationship of BMI with emotional decision-making and visual recognition processes. Whereas, increased WASI scores predicted increased thickness and volume of prefrontal and parietal cortices, which reflect brain regions involved in the fronto-parietal attentional network. As well, increased WASI scores also related to a functional network that included increased activation of the postcentral gyrus and posterior hippocampal complex, regions involved with attention and memory. Taken together, these results indicate that BMI and intelligence are behaviorally anticorrelated, yet mediated by separate neuroanatomical substrates that associate with a variety of cognitive functioning measures.

Lay Summary

This study investigated the relationship between body mass index (BMI) and intelligence and how this relationship may be explained by brain structure and function. BMI and intelligence showed a negative correlation, suggesting that increased BMI relates to decreased intelligence. However, changes in BMI and intelligence related to separate brain regions, indicating that other factors of cognitive functioning may be involved with this relationship.