Referntial Activity as a Measure of Episodic Memory.

A computerized measure of Referential Activity (RA), the High WRAD Proportion (HWP), which assesses the proportion of high RA language in a text, was compared to a widely used measure of episodic memory, the proportion of internal details (IP), those pertaining directly to the main event being described. Both measures, along with several additional computerized measures, were applied to narratives of past and future events, produced by two groups of speakers varying in age. The HWP and IP showed correlations with high effect sizes for all age groups and narrative time periods, providing strong validation for the RA concept and for HWP as a computerized measure of episodic memory. Differences were also found between the results for both narrative time and participant age based on the two measures. HWP scores for narratives of past experience were higher than for future narratives; these differences were supported by other computerized measures applied to the narratives. The differences were in the same direction but were not significant for IP. Older participants showed significantly lower levels of episodic memory, according to IP; the differences were in the same direction but were not significant for HWP. The implications of these results for the RA concept and for the multiple code theory of episodic memory are discussed.