Subjective organization, verbal learning, and forgetting across the life span: from 5 to 89

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.

Digit span changes from puberty to old age under different levels of education

The goal of this study is to demonstrate the age-related changes in multimodality digit span under a research design in which level of education is controlled. Volunteer participants (n = 1183) were distributed over levels of age (13-98 years) and education (5-8, 9-11, and 12+ years). Digit span was measured through 11 scores of the Visual Aural Digit Span Test-Revised on aural or visual stimulation and oral or written response execution, thus allowing for the measurement of intra- and intersensory integration. The increase in digit span scores reversed to a decrease with early adulthood. The slope of the regression line was small but significant. A 4 x 3 x 2 multivariate analysis of variance showed a significant effect of age and education on a combined score comprising the 11 digit span scores. Differences of age and education were predicted by the auditory and visual input scores. The article discusses the cognitive correlates and the age-related changes in digit span from the biological standpoint.