The effect of retrospective attention on memory systems

Prior research has shown that visual working memory (VWM) performance can be improved via retrospective cues (“retro-cues”) that spatially indicate which item currently being held in working memory will be probed at test. These studies have utilized electroencephalography (EEG) methods to monitor contralateral delay activity (CDA) event related potentials (ERPs) and assert that retro-cues benefit memory by reducing effective memory load. Here, we investigated the potential relationship between CDA amplitude and future long-term memory (LTM) performance. Emerging evidence from ERP and fMRI studies suggest that working memory maintenance can contribute to LTM formation, which suggests that memory systems are not as discrete as some models suggest. We investigated the hypotheses that A) the benefits afforded by the retro-cue in VWM will carry over into LTM, and B) CDA amplitude will be modulated by subsequent LTM performance. Results revealed that retro-cuing improved item accuracy at both VWM and LTM delays, suggesting that the two memory systems are interactive. Due to an insufficient amount of subsequent LTM misses, we were unfortunately too underpowered to detect a CDA depending on long-term memory performance. However, we found that posterior slow-wave potentials during the maintenance period did differ by subsequent LTM performance, which further suggests an interactive systems account of memory. We also sought to investigate what exactly the retro-cue cues. Prior research has focused on memory for items, but no study has questioned if the retro-cue also enhances memory for item location. To this end, the present study investigated the effect of retro-cueing on both item identity and item location. LTM Behavioral results revealed a retro-cue benefit for item accuracy but no benefit for item location, suggesting that the retro-cue selectively cues item identity.M.S