Differential effects of valence and encoding strategy on internal source memory and judgments of source: exploring the production and the self-reference effect

The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fpsyg.2019.01326/full#supplementary-materialItem memory studies show that emotional stimuli are associated with improved memory performance compared to neutral ones. However, emotion-related effects on source memory are less consistent. The current study probed how emotional valence and specific encoding conditions influence internal source memory performance and judgments of source (JOSs). In two independent experiments, participants were required to read silently/aloud (Experiment 1) or to perform self-reference/common judgments (Experiment 2) on a list of negative/neutral/positive words. They also performed immediate JOSs ratings for each word. The study phase was followed by a test phase in which participants performed old-new judgments. In Experiment 1, the production effect was replicated for item memory, but the effects of valence on item and source memory were not significant. In Experiment 2, self-referential processing effects on item and source memory differed as a function of valence. In both experiments, JOSs ratings were sensitive to valence and encoding conditions, although they were not predictive of objective memory performance. These findings demonstrate that the effects of valence on internal source memory and JOSs are modulated by encoding strategy. Thus, the way information is encoded can shed light on how emotion might enhance, impair or exert no influence on source memory.This work was supported by a Ph.D. Fellowship (PD/BD/105964/2014), awarded to DP, funded by the Portuguese Science Foundation (FCT) through national funds and cofunded by the European Social Fund (ESF) through the Operational Programme for Human Capital (POCH). It was also supported by a research grant (PTDC/MHC-PCN/0101/2014) funded by FCT and awarded to AP. The study was conducted at the Psychology Research Centre (PSI/01662), School of Psychology, University of Minho, and supported by FCT and the Portuguese Ministry of Science, Technology and Higher Education (UID/PSI/01662/2019), through the national funds (PIDDAC) and co-funded by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007653)