Enactment effects and integration processes in younger and older adults' memory for actions.

The positive effects of gesturing on memory are robust but their interpretation is still controversial. To clarify the issue, recognition and cued recall of action phrases were compared in 24 younger (M=20 years) and 20 older adults (M=68 years), in three encoding conditions--purely verbal tasks (VTs), subject-performed tasks (SPTs), and experimenter-performed tasks (EPTs)--for well- and poorly integrated phrases. As expected, the effects of these factors were significant, but there was no interaction between age-related differences, enactment effects, and semantic association. In particular, both SPT and EPT displayed similar advantages over VT conditions in both age groups and in the two memory tasks. These results are discussed in relation to the debate between Engelkamp on one side, and Kormi-Nouri and Nilsson on the other side, about the role of motor components in the episodic integration of verbs and nouns in action phrases.

Are there uniform age-related changes across tasks involving inhibitory control through access, deletion, and restraint functions? A preliminary investigation.

According to Hasher, Zacks, and May (Attention and performance XVII. Cognitive regulation of performance: Interaction of theory and application, pp. 653-675, MIT Press, 1999), a general age-related decline of inhibitory control affects the contents of working memory through three kinds of functions: limiting access to irrelevant information, deleting information that is no longer relevant, and restraining the production of dominant responses. Supportive evidence has been found in a wide variety of experimental tasks. In the present study, age-related changes were examined in the same group of 34 older (aged 60 to 82) and 30 younger (aged 19 to 30) adults performing the same set of tasks involving the access, deletion, or restraint function. The results indicate that age-related declines in inhibition are not uniform but vary depending on task-specific characteristics.

Pragmatic skills in the early stages of Alzheimer's disease: an analysis by means of a referential communication task.

BACKGROUND: Disordered discourse in cases of senile dementia of Alzheimer's type (DAT) has mainly been described in conversation and picture description tasks. The referential communication task provides researchers and clinicians with new insights on the nature of these disorders. AIMS: To study to what extent persons suffering from DAT can benefit from shared experience through trial repetition to achieve common reference. METHODS & PROCEDURES: Thirteen persons suffering from DAT at minimal or mild stage (MMSE score range = 18-27) were compared with 13 healthy elderly adults (64-86 years) in neuropsychological assessment of executive functions and in a referential communication paradigm. To study how the two partners achieve mutual understanding by progressively elaborating a common ground, the task was repeated three times. OUTCOMES & RESULTS: Persons with DAT produced a larger number of words than control participants and they benefited from the task repetition. However, they were less able to take into account previously shared information, used no definite referential expressions and were more idiosyncratic in their descriptions of the referent. This decline of communicative effectiveness was found not to relate closely to executive deficits. CONCLUSIONS: Collaborative exchanges allow healthy elderly persons to ground reference in common experience. This process is severely disturbed in persons with DAT, in relation to poor memory of preceding episodes or to other cognitive impairments.