ABSTRACT
Executive functions have been described as the “brain of the brain” and to include a variety of processes, including, but not limited to, abstraction, formulation of intentions, reasoning, formulation of strategies, monitoring their success, working memory, and the self-regulation of behavior. Executive functions have been determined to be associated with the integrity of the frontal lobes. On the other hand, intelligence has also been described in similar terms, and the concept of general intelligence, or the g factor has also been associated with the frontal lobes. As constructs, intelligence and executive functions have been also described as “overlapping” in many features, while maintaining a certain degree of conceptual independence. The purpose of this study was to compare the intellectual functioning of a sample of patients with mild traumatic brain injury, obtained by means of the Reynolds Intellectual Assessment Scales (RIAS), with their performance in a number of neuropsychological measures of executive functions, such as the Halstead Category Test (HCT), the Wisconsin Card Sorting Test (WCST), the Stroop Word and Color Test (SWCT), and the Trail Making Test (TMT). Pearson Product Moment Correlations were obtained between the various measures of the RIAS and the measures of executive functions (HCT, WCST, SWCT, TMT). Whereas the magnitudes of the correlations were within the moderate range, intelligence, particularly non-verbal intelligence and working memory were noted to be significantly correlated with the measures of executive functions. The conclusion was reached that intelligence and executive functions are related to each other as constructs, but yet maintain a certain degree of independence.