Effects of Age on Specificity and Control of Recollected Content

University Of Texas At Dallas, Richardson TX

Investigators

Abstract

The United States is an aging society. Presently, about 9% of the population is aged 70 years or older. This proportion will have grown to around 15% by 2030, bringing with it a dramatic increase in the economic and social costs of age-related cognitive and physical impairment, and fuelling an urgent need for research in aging. Advancing age is associated with an accelerating trajectory of decline in several important cognitive abilities, including episodic memory, the ability to accurately recollect the details of a recent event. Importantly, age-related decline in memory accuracy is not always accompanied by a decline in memory confidence, the strength of our conviction that a memory is accurate. This increases their risk of basing important choices and decisions on erroneous information. The present research aims to understand why a mismatch between the feeling that a memory is accurate and its actual accuracy is more common in older than in younger people. The findings will shed new light on why older people are prone to make inaccurate, confident memory judgments and will contribute to the development of interventions that ameliorate this tendency. The research will also provide training in the cognitive neuroscience of aging for masters and PhD students, and for postdoctoral trainees. An important additional broader impact will be the contribution of the research to the outreach and education activities of the Center for Vital Longevity at the University of Texas at Dallas. These activities include frequent talks on age-related research by Center members (including trainees) to a wide range of community organizations, public lectures, and a biennial international scientific conference. The research will use functional magnetic resonance imaging (fMRI) to monitor the brain activity of older (65-75 yrs.) and younger (aged 18-30 yrs.) people. The research is motivated by findings that although accuracy of episodic memory is highly age-sensitive, the subjective experience of remembering is less affected. Thus, older individuals are more likely to report a strong sense of recollection in concert with an inaccurate memory judgment than are young individuals. We will examine two possible accounts of this age-related dissociation between 'objective' and 'subjective' measures of episodic memory. The first account proposes that the dissociation reflects age differences in the 'precision' of recollection. Experiment 1 will assess this account by using multi-voxel pattern analyses to examine whether the fidelity with which information about a study event is 'reinstated' in the cerebral cortex is lower in older people. The second account proposes that older individuals are as capable of recollecting detailed information as young individuals, but are less able to control recollection so as to align its content with the goal of the retrieval attempt.