Abstract

Recent empirical findings have shown difficulties in assessing age group differences in executive processes and their role in executive functioning. More specifically, inhibition is an executive control process whose role in executive functioning has been poorly defined. The purpose of the current study was to extend the findings of sequential action research by examining the processes that govern sequential behaviour (i.e., self-inhibition), and to relate these findings to other measures of executive functioning (Stroop task, Visual Span, Random Generation Task). We also investigated intraindividual variability and examined the correlations between intraindividual variability and level of performance in executive measures. As hypothesized, individuals showed evidence of self-inhibition on the Sequential Action (SA) paradigm. Results on the other executive measures revealed that older adults performed significantly worse than younger adults, with modest intercorrelations between executive measures and the SA paradigm. This suggests that executive functioning is a multifaceted construct. Furthermore, these correlations were stronger for younger adults suggesting that executive functioning may be more differentiated in older adults. Older adults exhibited greater intraindividual variability on the SA paradigm. Intraindividual variability was correlated across only some measures. The pattern of correlations underscores the need to consider both intraindividual variability and level of performance when examining age group differences in executive functioning.