Associative deficit in recognition memory in a lifespan sample of healthy adults

Abstract

Advanced age is associated with decrements in episodic memory, which are more pronounced in memory for associations than for individual items. The associative deficit hypothesis (ADH) states that age differences in recognition memory reflect difficulty in binding components of a memory episode and retrieving bound units. To date, ADH has received support only in studies of extreme age groups, and the influence of sex, education, and health on age-related associative deficit is unknown. We address those issues using a verbal paired-associate yes-no recognition paradigm on a lifespan sample of 278 healthy, well-educated adults. In accord with the ADH, greater age was associated with lower hit and greater false alarm rates and more liberal response bias on associative recognition tests. Women outperformed men on recognition of items and associations, but among normotensive participants, women outperformed men only on memory for associations and not on item recognition. Thus, although supporting ADH in a large lifespan sample of healthy adults, the findings indicate that the effect may be partially driven by an age-related increase in liberal bias in recognition of associations. Sex differences and health factors may modify the associative deficit regardless of age.

Figure 1

Performance on the word pair task by a continuous lifespan sample of healthy adults. In all figures, solid black circles and the solid regression line depict items, and open circles and the broken regression line represent association scores. A. Scatterplot of the relationship between signal detection measure A′ reflecting recognition performance for items and associations between words and participant age in years. B. Scatterplot representing participants’ ages and response bias measure B″_D from recognition performance of items and associations. Scores less than 0 reflect more liberal bias, and scores greater than zero indicate more conservative bias. C. Scatterplot of participants’ ages and hit rate scores for items and associations. D. False alarm rate scores for items and associations by age in years.

Figure 2

Response times in the word pair task by a continuous sample of healthy adults. A. Scatterplot depicting the relationship between log transformed response times and participant age in years for women (solid black circles, dashed regression line) and men (open circles, solid regression line). B. Scatterplot of the relationships between log transformed response times to items (solid black circles, solid regression line) and associations (open circles, dashed regression line) and participant age in years.