Nurullah Ertas¹, Eren Gunseli¹; ¹Sabanci University

Chunking helps us mitigate working memory (WM) capacity limits, but it may reduce flexibility in accessing individual elements. We investigated whether accessing a single element automatically activates the entire chunk even when doing so is unnecessary (Experiments 1 & 2) or harmful (Experiment 3). Participants first learned four chunks of three colors each. In a subsequent WM task, six colors were presented, followed by a retro-cue indicating the location of the to-be-tested item. In half the trials, a second cue followed, requiring reporting only the second-cued item. If chunks are accessed as a whole, response times (RT) should be faster when the second cue targets the same chunk as the first, compared to an item outside that chunk. In Experiment 1, each trial presented one studied chunk and three novel non-chunk items. RTs were faster when both cues targeted the chunk than when the first cue was a non-chunk. Experiment 2 ruled out a memory-type switch explanation by presenting two studied chunks, rather than one chunk and three non-chunk items: RTs were faster when the second cue remained within the same chunk vs switched to the other chunk. Drift diffusion modeling across experiments revealed that this RT benefit was driven by more efficient information processing (drift rate), rather than decision strategy or encoding delays. Experiment 3 manipulated the blockwise probability of within- vs across-chunk transitions between cues as 72% or 28%, making whole-chunk access advantageous or disadvantageous, respectively. While within-chunk RT benefit was weakly attenuated when holistic access was disadvantageous, it remained robust in both block types. These results suggest that accessing an individual element triggers an automatic activation of the entire chunk. Although slightly reduced by rare probabilities, the robust persistence of the holistic benefit across all contexts highlights limited flexibility and strategic control over item-level access within chunks.