RT Journal Article SR Electronic T1 Concurrent maintenance of both veridical and transformed working memory representations JF bioRxiv FD Cold Spring Harbor Laboratory SP 2022.10.28.514218 DO 10.1101/2022.10.28.514218 A1 Güven Kandemir A1 Michael J. Wolff A1 Aytaç Karabay A1 Mark G. Stokes A1 Nikolai Axmacher A1 Elkan G. Akyürek YR 2022 UL http://biorxiv.org/content/early/2022/10/28/2022.10.28.514218.abstract AB In a dynamic environment, the already limited information that human working memory can maintain needs to be constantly updated to optimally guide behaviour. Indeed, previous studies showed that working memory representations are continuously being transformed during delay periods leading up to a response. This goes hand-in-hand with the removal of task-irrelevant items. However, does such removal also include veridical, original stimuli, as they were prior to transformation? Here we aimed to assess the neural representation of task-relevant transformed representations, compared to the no-longer-relevant veridical representations they originated from. We applied multivariate pattern analysis to electroencephalographic data during maintenance of orientation gratings with and without mental rotation. During maintenance, we perturbed the representational network by means of a visual impulse stimulus, and were thus able to successfully decode veridical as well as imaginary, transformed orientation gratings from impulse-driven activity. On the one hand, the impulse response reflected only task-relevant (cued), but not task-irrelevant (uncued) items, suggesting that the latter were quickly discarded from working memory. By contrast, even though the original cued orientation gratings were also no longer task-relevant after mental rotation, these items continued to be represented next to the rotated ones, in different representational formats. This seemingly inefficient use of scarce working memory capacity was associated with reduced probe response times and may thus serve to increase precision and flexibility in guiding behaviour in dynamic environments.Competing Interest StatementThe authors have declared no competing interest.