The present study evaluated the association between episodic memory, executive function and processing speed in a sample with different age ranges. We tested the hypothesis that processing speed, executive function and memory are more strongly associated during childhood and old age. We evaluated 571 participants, aged six to 92 years, divided into four age groups: children/adolescents, young adults, middle-aged adults and older adults. Correlation analyses suggested that the shared variance between the processing speed and memory is strong in childhood but weak across other age ranges. Executive function, however, had a stronger association both in childhood and in old age, when compared with the intermediate stages. We conclude that the effects of processing speed and executive function on memory are not stable across human development. These functions may be compensatory mechanisms for memory functioning in childhood and old age.

Objective: The present study investigates the difference between trials A6 and A7 of the Rey Auditory-Verbal Learning Test (RAVLT) test in three different groups of older adults-normal cognition (Controls), mild cognitive impairment (MCI), and Alzheimer's Dementia (AD). Method: The study comprises 180 subjects 60 years old or more. We compared scores in trials 6 and 7 of list A (A6 and A7) using the Wilcoxon signed ranks test. Subsequently, we computed its difference (A6-A7) and used Mann-Whitney to analyze which groups' differences were more relevant. Results: Comparison analysis showed a significant difference between A6 and A7 trial performance only in the AD group ( p < .01). When we compared these differences between groups, the only significant difference occurred between controls and AD ( p < .01). Conclusions: There is a significant difference in RAVLT trials A6 and A7 in the AD group, but this difference does not appear in the control and the MCI groups. The differences between A6 and A7 trials of RAVLT are restricted to comparing Controls × AD patients. Our study corroborates the instrument's effectiveness for the diagnosis of Alzheimer's dementia.