INTELLIGENCE AND THE STRUCTURES OF THE LINGUAL GYRI

Abstract: Finding neural correlates of intelligence and cognitive abilities in the developing brain during childhood may be important in many ways, such as predicting and understanding educational abilities or making clinical evaluations of patients. Even if substantial contemporary research has established relationships between brain structures and general intelligence, little is known about the lingual gyri and their links to IQ. In this thesis it is examined (1) whether cortical thickness in the right and left lingual gyri is associated with different levels of IQ in childrenand (2) if the rate of change in cortical thickness located in the lingual gyri is associated with change in Performance IQ (PIQ). Neuroimaging data originated from a study by Solé-Casals and colleagues (2019) as well as a dataset from a study by Suárez-Pellicioni and colleagues(2019). Both datasets were downloaded from the OpenNeuro library of brain imaging data. Neuroimaging metrics of twenty-nine boys of approximately twelve years of age were utilizedto test the hypothesis that higher IQ is related to thinner cortical thickness in lingual gyri. Neuroimaging metrics of twenty-one girls and fifteen boys under fourteen years of age utilized to examine if the rate of change in cortical thickness is related to a change in Performance IQ.Results revealed that high IQ was related to thinner cortical thickness at the age of twelve. Further results indicated that rate of thinning of the cortex in the lingual gyri is correlated to change in Performance IQ. The present thesis adds to the growing evidence that regional cortical thickness and change of cortical thickness are relevant biomarkers for intelligence. Future research with larger sample sizes and longitudinal design with additional points in timemight be needed to confirm the results of the present thesis.