The effects of variable encoding contexts on item and source recognition

How repeated encoding affects retention of item details is an unresolved question. The Competitive Trace theory (Yassa & Reagh, Frontiers in Behavioral Neuroscience, 7, 107, 2013) assumes that even slight variations in encoding contexts across item repetitions induce competition among non-overlapping contextual traces, leading to semanticization and decontextualized memory traces. However, empirical support for this assumption is mixed. In extension of previous research, the current study attempted to increase the competition between contextual traces by increasing encoding context variability. In three experiments we tested how repeated encoding in the same context or different contexts affects target recognition, similar lure discrimination, and source memory. Participants viewed images of objects once, three times in the same or three times in different contexts. Context variability was implemented through variations in background color or encoding tasks. Repeated encoding improved memory for item details, independent of context variability. Background color was poorly remembered but answering different encoding questions for repeated items impaired recollection of specific encoding tasks, in comparison to encoding items only once or repeatedly with the same encoding task. Our findings show that repetitions enhance memory for perceptual details but can impair memory for contextual elements, a dissociation that needs to be considered by the Competitive Trace Theory and other consolidation theories.