Self-referential encoding of source information in recollection memory

Abstract

Information that is encoded in relation to the self has been shown to be better remembered, yet reports have disagreed on whether the memory benefit from self-referential encoding extends to source memory (the context in which information was learned). In this study, we investigated the self-referential effect on source memory in recollection and familiarity-based memory. Using a Remember/Know paradigm, we compared source memory accuracy under self-referential encoding and semantic encoding. Two types of source information were included, a "peripheral" source which was not inherent to the encoding activity, and a source information about the encoding context. We observed the facilitation in item memory from self-referential encoding compared to semantic encoding in recollection but not in familiarity-based memory. The self-referential benefit to source accuracy was observed in recollection memory, with source memory for the encoding context being stronger in the self-referential condition. No significant self-referential effect was observed with regards to peripheral source information (information not required for the participant to focus on), suggesting not all source information benefit from self-referential encoding. Self-referential encoding also resulted in a higher ratio of "Remember/Know" responses rate than semantically encoded items, denoting stronger recollection. These results suggest self-referential encoding creates a richer, more detailed memory trace which can be recollected later on.

Fig 1. Encoding task example.

Example images shown to the participants taken from the encoding task. The leaf symbols indicate the “living/non-living” question (semantic encoding). The face symbols indicated the “I like it / do not like or do not care about” question (self-referential encoding).

Fig 2. Remember and Familiar mean accuracy.

Mean memory accuracy rates for “Remember” and “Familiar” trials from the self-referential and semantic encoding conditions. Accuracy was calculated as the rate of “Remember” and “Familiar” trials minus the false alarm rate for “Remember” and “Familiar” respectively. Familiar rate was estimated with the IRK procedure. Error bars denote the standard errors of the mean. * p < .001.

Fig 3. Mean source accuracy.

Source accuracy estimate for getting both source information correct for Remember responses from studied trials, categorized by encoding condition (Self vs Semantic). Error bars denote the standard errors of the mean. * p < 0.05.

Fig 4. Mean background accuracy.

Mean proportion of trials with correct judgement of the background image or encoding question in Remember trials. Error bars denote the standard errors of the mean. * p < 0.05.

Fig 5. MPT conditional probabilities.

Mean (standard deviation) conditional probabilities of all participants’ test results, organized by source memory. Each box represents an answer option on the memory test.