Processing in working memory boosts long-term memory representations and their retrieval

Prior research has explored how working memory influences the formation of
new long-term memories, but its role in modifying existing representations
remains unclear. This study examines whether attentional prioritization
and testing in working memory enhance long-term memory retrieval and
investigates the underlying neural mechanisms. Eighty-six participants
completed a three-phase memory task combining a long-term memory- with a
working memory retro-cue paradigm. First, participants learned
object-location associations. Next, during a working memory task, some
objects have undergone attentional prioritization and testing, others have
only been tested in working memory. Finally, participants retrieved the
object locations from long-term memory. Three key findings emerged: (1)
both attentional prioritization and testing in working memory improved
long-term memory retrieval; (2) serving as a probe in working memory
further contributed to long-term memory enhancement, with benefits
observed at behavioral and neural levels; and (3) cross-phase decoding
revealed a comparable representational format for location information
across task phases, possibly explained by the neural reinstatement of
location information across phases. These results suggest that working
memory dynamically shapes long-term memory representations, playing a more
active and integrated role in long-term memory formation than previously
thought.