Cognitive research on the plasticity of fluid intelligence has demonstrated that older adults benefit markedly from guided practice in cognitive skills and problem-solving strategies. We examined to what degree older adults are capable by themselves of achieving similar practice gains, focusing on the fluid ability of figural relations. A sample of 72 healthy older adults was assigned randomly to three conditions: control, tutor-guided training, self-guided training. Training time and training materials were held constant for the two training conditions. Posttraining performances were analyzed using a transfer of training paradigm in terms of three indicators: correct responses, accuracy, and level of item difficulty. The training programs were effective and produced a significant but narrow band of within-ability transfer. However, there was no difference between the two training groups. Older adults were shown to be capable of producing gains by themselves that were comparable to those obtained following tutor-guided training in the nature of test-relevant cognitive skills. Several research programs have demonstrated that older adults have a substantial reserve capacity and are capable of increasing their performance on tests of fluid intelligence as a consequence of guided instruction in problem-solving strategies by an "expert" tutor (Baltes & Lindenberger, 1988; Willis, 1987). What is not known, however, is to what degree older adults are able to generate similar training benefits by themselves without guided instruction in test-relevant cognitive skills by a tutor. Research on memory functioning (Kausler, 1982; Treat, Poon, & Fozard, 1981), for example, has demonstrated that some older adults are able to generate useful learning strategies on their own.

Examination of the range and limits of cognitive developmental reserve capacity (plasticity) by means of cognitive training has been proffered as a promising diagnostic strategy for the early identification of Alzheimer's disease. Previous findings of differential gains after cognitive training for healthy older persons and older persons at risk for dementia were supported, rendering cognitive plasticity a criterion by which the overlap in performance distributions between healthy older persons and older persons at risk can be reduced. Stepwise hierarchical regression analyses demonstrated that posttraining scores, which represented developmental reserve capacity, explained significantly more variance in mental health status than pretest or baseline performance. Older persons at risk profited significantly less from training in 2 components of fluid intelligence, figural relations, and inductive reasoning. The authors discuss the possibilities of turning this testing-the-limits procedure into an instrument for screening purposes in clinical practice.

This study results from an effort to examine the relationship between the diagnostic potentials for detecting risk status for dementia of a cognitive plasticity approach and a traditional status-oriented procedure (test battery) by Storandt et al. [Arch Neurol 1984;41:497–499]. The aim is to compare prediction accuracy for risk for developing dementia with these two approaches. A sample of 106 community-dwelling elderly adults were tested with both procedures, and their scores on the Structured Interview for the Diagnosis of Dementia used as external criterion for predicting risk status. The findings show that figural relations pretest and training gains account for a considerable amount of individual differences in mental status similar to that explained by the traditional test battery. In addition, the accuracy of discrimination between healthy and at-risk participants appears slightly higher when using the figural pretest and training gains. These results suggest the conclusion that use of figural relations tests and the cognitive plasticity approach represents a viable alternative to the traditional, status-oriented test battery as a means of early diagnosis of dementia in nonclinical populations.

Zusammenfassung: Im Konzept der kognitiven Plastizität wird zwischen einem Leistungsstatus («Baseline Performance») und latenten Leistungsreserven («Baseline Reserve Capacity» und «Developmental Reserve Capacity») unterschieden. «Baseline Reserve Capacity» bezeichnet aktuell vorhandene kognitive Leistungsreserven, die beispielsweise durch kurzzeitiges Üben erfaßbar werden. «Developmental Reserve Capacity» kennzeichnet das zukünftig mögliche Entwicklungspotential einer Person und wird über die Ermittlung von Leistungsgrenzen nach Interventionsmaßnahmen abgeschätzt. Diese Studie richtete sich auf den Stellenwert der beiden Konzepte «Baseline Reserve Capacity» und «Developmental Reserve Capacity» bei der Früherkennung dementieller Erkrankungen. Es wurde untersucht, ob Kennwerte zur «Developmental Reserve Capacity» eine bessere diagnostische Differenzierung ermöglichen als Kennwerte zur «Baseline Reserve Capacity». Die Ergebnisse zeigen erwartungsgemäß, daß beide Plastizitätsmaße die Vorhersage der psychiatrischen Befunde signifikant verbessern. Eine Überlegenheit der Kennwerte zur «Developmental Reserve Capacity» konnte nicht abgesichert werden.

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