Subjective Organization, Verbal Learning, and Forgetting Across the Life Span: From 5 to 89

Abstract

Background/Study Context: Previous tests of the relationship between subjective organization during encoding, aging, and recall have produced inconsistent findings. The present study investigates subjective organization and the acquisition and recall of verbal material across the life span (from 5 to 89 years of age) using two measures, the intertrial repetition paired frequency (PF) measure and the unidirectional subjective organization (SO) measure.

Methods: Participants (N = 2656) were administered a version of the Rey Auditory Verbal Learning Test, including a delayed recall trial. Analyses of variance (ANOVAs) were performed to examine the relationship between age and subjective organization and between age and recall. Mediation and growth curve analyses were performed to further examine the relationship between age, verbal acquisition, and subjective organization.

Results: Subjective organization was not predictive of verbal forgetting. Deficits in verbal acquisition and subjective organization were detected among children and elderly adults. Mediational analyses showed that age affected the number of words recalled as well as subjective organization, and that subjective organization affected the number of words recalled in children, young adults and elderly. Latent growth curve modeling suggests that increases in subjective organization over time are related to increases in recall over time for each age group.

Conclusion: Subjective organization is predictive of recall, and both subjective organization and recall are lowest among children and elderly individuals. Age has direct effects on recall but this effect is partially mediated by subjective organization. Brain imaging studies showing increased prefrontal cortex activation during encoding of remembered words bolster our findings that age affects the relationship between verbal learning and organization of material during encoding.

Notes

¹Although Sternberg and Tulving (1977) recommend that the PF measure should be used when examining age differences, results from the less preferable SO measure are briefly summarized here for the purpose of comparison with previous studies. A comparison of SO across all age groups was conducted using a one-way ANOVA; the result was significant but not meaningful, F(9, 2669) = 2.88, MSE = .02, p = .002, η² = .01. This result indicated that the SO measure would be ineffectual in statistical tests of mediation between age and acquisition. Furthermore, higher levels of SO were generally concurrent with greater amounts of acquisition, but this relationship did not hold strongly for all age groups (see Table 4). SO was also used as a covariate in an analysis of forgetting (Trial 5 minus Trial 6) across age; the effect of the SO covariate was nonsignificant and not meaningful, F(1, 626) = 6.17, MSE = 2.40, p = .01, η² = .01, indicating no relationship between SO and forgetting scores.

Note. b (SE), β = unstandardized path coefficient (standard error), standardized path coefficient; PF = subjective organization measure; recall change = the growth curve parameter indicating logarithmic change.

*p < .05; **p < .01; ***p < .001.

Note. n > 100 for all individual age categories.

*p < .01.

^†Meets 5% criterion for a meaningful effect size.