Abstract
Working memory (WM) is suggested to constitute a mental workspace for performing operations. However, its role for mental operations on previously learned information remains unclear. Using a novel behavioral index, we assessed WM reactivation of information retrieved from long-term memory (LTM) during mental integration and recognition. In the learning phase, participants (N=21) studied eight color-position associations. In the experimental session, participants were given a novel position and a color retrieval cue on each trial. At the end of the trial, they received a probe position. The task was to indicate if the probe position matched any of the memory positions (recognition) or was equidistant to both memory positions (mental integration). Before the memory probe, participants were given a brief perceptual discrimination task to report the orientation of a tilted line. Given that WM involves selective attention and selective attention facilitates perceptual discrimination, we hypothesized that discrimination should be facilitated for targets that appear at LTM positions compared to other, irrelevant positions if the LTM position is reactivated in WM. We observed this LTM position benefit in the mental integration but not in the recognition condition. Thus, our results suggest that information retrieved from LTM is reactivated in WM mainly for mental operations as opposed to mere remembering, supporting the role of WM as a mental workspace for mental operations.