Adaptive Encoding Speed in Working Memory

Abstract

Humans can adapt when complex patterns unfold at a faster or slower pace, for instance when remembering a grocery list that is dictated at an increasingly fast pace. Integrating information over such timescales crucially depends on working memory, but although recent findings have shown that working memory capacity can be flexibly adapted, such adaptations have not yet been demonstrated for encoding speed. In a series of experiments, we found that young adults encoded at a faster rate when they were adapted to overall and recent rate of incoming information. Interestingly, our participants were unable to use explicit cues to speed up encoding, even though these cues were objectively more informative than statistical information. Our findings suggest that adaptive tuning of encoding speed in working memory is a fundamental but largely implicit mechanism underlying our ability to keep up with the pace of our surroundings. Significance StatementHumans can store information very quickly. For instance, when we hear someone speak twice as fast as normal, we can still follow quite well. How is this possible? We hypothesized that when humans expect limited time to store a piece of information (e.g. when listening to a sped-up podcast) they would ideally store that information more quickly before its gone. Indeed, we found that young adults encoded more information per second when they implicitly expect that they have little time to do so. However, they were unable to use explicit cues about how much time they have. It seems that young adults can, at least implicitly, tune the pace at which they store information.