In a relatively short period of time, we have made several ground-breaking discoveries within the study of working memory. First, we have uncovered novel mechanisms of how anticipatory (pre-stimulus) brain states prioritise the processing of (to-be-remembered) targets over temporally-competing distractors – namely by boosting target processing as well as delaying the interference on the targets caused by temporally-adjacent distractors (van Ede et al., Nature Communications, 2018). This project has also pushed a methodological advance by revealing how multivariate analyses can be used to simultaneously track target and distractor stimuli, even when these are presented in close temporal proximity. Second, we have developed a novel working memory task in which we have uniquely associated memory representation to their associated actions. In doing so, we were able to investigate the mechanisms by which both visual representations and their associated actions are accessed from working memory when individual memory representations become relevant for behaviour. This revealed the surprising observation that action plans are not selected after the relevant visual representation has been selected. Instead they are selected in parallel with the relevant visual representation, suggesting that parallel action plans are held available jointly with visual working memories – a hitherto unexplored concept (van Ede et al., submitted). Third, we have discovered that that accessing of visual information from working memory biases gaze in the direction of the attended memory item – even when there is nothing to look at in external space (van Ede et al., submitted). This uniquely reveals that the human oculomotor system is not only recruited for covert shifts of attention in the external space of perception (which has been known for a long time), but also within the internal space of memory.
These results contribute primarily to a better and more comprehensive understanding of the basic cognitive and neural mechanisms that support access to and from working memory. Ultimately these insights and developed methods and tasks may be useful for also for gaining a better understanding of the potential breakdown of such basic mechanisms in increasingly prevalent cognitive disorders, such as ADHD.
