Electrophysiological evidence for encoding mechanisms underlying the formation of false recognitions with context retrieval.

The source-strength effect paradigm-in which strong and weak semantic associates of a critical lure are studied with distinct contexts-reveals that false memories vary in vividness. This is demonstrated by both attribution rate and context memory strength ratings. Specifically, when critical lures are falsely recognized, they are more frequently attributed to the contexts of their strong associates than to other contexts linked to weak associates or to other lists' associates. Previous research further shows that context memory strength ratings for lure attributions to strong associates' contexts are higher than those for lure attributions to other contexts, indicating that the former were experienced more vividly. A recent event-related potentials (ERPs) study (Liu et al., 2025) has shown that distinct retrieval processes - recollection and reconstruction - underlie these different memorial outcomes. However, their encoding neurocognitive origins remain unknown. To address this gap, the current study reanalyzed data from our prior ERPs investigation (Liu et al., 2025) by applying the subsequent memory paradigm to dissociate the encoding subprocesses that produce various memorial responses to critical lures. Results revealed a pronounced early parietal subsequent memory effect (SME), which may be related to schema-based integration, for strong associates whose corresponding lures were later attributed to strong associates' contexts-the outcome associated with higher subjective vividness. Conversely, a strong late frontal SME indexing elaborative associative processing emerged for weak associates whose lures were later attributed to other contexts-the outcome associated with lower vividness. Associates linked to correctly rejected lures elicited neither SME. These findings demonstrate that schema-based integration and elaborative associative processing forge the distinct traces that later support false memories with different levels of contextual vividness.