Individual Differences in Subjective Organization and Verbal Learning in Old Age

Abstract

Background/Study Context: Previous research has shown an increase of subjective organization of stimuli and of recall performance across learning trials. However, up to date, it has not been examined whether subjective organization and recall performance are positively related also at the level of the individual. To close this gap, parameters of verbal learning were regressed on growth parameters of subjective organization.

Methods: The sample for this investigation involved N = 205 subjects (65 to 80 years old). Participants learned a word list containing 27 unrelated words, presented randomly across five trials. Subjective organization was measured by using the Paired Frequency measure.

Results: Overall, there were reliable individual differences with regard to both subjective organization and verbal learning. Results showed that the learning parameters were positively correlated with the initial level and linear slope of subjective organization. Furthermore, growth parameters of subjective organization turned out to be reliable predictors of verbal learning.

Conclusion: The present study emphasized the role of analyzing individual differences in subjective organization. Implications are discussed, in particular, regarding the interdependency of subjective organization and verbal learning in old age.

Notes

¹ Subjective organization as well as the related concept of categorical clustering (see Bousfield, 1953), which emerges from using categorized lists, may be subsumed as secondary memory organization. By contrast, other order effects in memory, for example, the serial position effect, are part of the primary memory organization (Shuell, 1969; Tulving, 1968).

² However, it is important to note that the chosen list length might have an effect on the relation between subjective organization and verbal learning for different age groups. Witte et al. (1990) argued that different list lengths might moderate an age-related effect in subjective organization. Short lists may not reveal an association between age and a decreased subjective organization because younger people need to make only a small organizational effort to learn them. We thank an anonymous reviewer for this comment.

³ Note, in principle, it is also possible to compute scores reflecting the degree of concordance between recall orders of Trial 1 and Trial 3, Trial 1 and Trial 4, and so on. However, according to Tulving (1962), subjective organization is reflected in concordant recall patterns between two adjacent trials.

⁴ Upon the request of an anonymous reviewer, we also conducted all analyses using the ARC´ and ITR(2) measures of subjective organization (Sternberg & Tulving, 1977). Results regarding the regression of learning parameters (α, δ, γ) on level and slope of subjective organization very closely matched those obtained using the PF measure.