The Influence of Age and Gender on Executive Functions of the Brain in an Iranian Sample of Healthy Adults

Executive functions refer to a group of higher-order cognitive processes responsible for self-regulated and targeted behaviors. This study aimed to investigate the effects of age and gender on executive functions focusing on three distinct areas of attentional control, planning and set-shifting among18-80 year-old healthy subjects. This cross-sectional study enrolled a total of 200 healthy adults (100 women and 100 men) 18-80 years of age living in Tehran. Sampling was done through a random stratified cluster procedure with regard to the inclusion and exclusion criteria. Each area of the executive functions was evaluated using Stroop test for attentional control, Tower of London (ToL) test for planning and problem-solving and Wisconsin test for set-shifting. The correlation between age and components of executive functions was evaluated through Pearson correlation test. Moreover, the differences between age groups were examined by ANOVA while the correlation between gender and components of the executive functions was examined by t-test. Age was significantly correlated with all subscales of Stroop test except time-interference, with the total number of errors and the overall result from ToL and all subscales of Wisconsin (P<0.001), R=0.49). There were no gender effect on executive functions except for the total time (t=-2.09, p=0.037) and the number of errors (t=-9.2, p=0.004) in ToL test which was significantly higher in women than men.  The executive functions including attentional control, planning and set-shifting was shown to be decreased by age. Problem-solving and planning were better in men than women.