Chenye Bao¹ (), Kyle Hardman¹, Jake Sauer¹, Nelson Cowan¹; ¹University of Missouri

Modern life often requires managing dual information streams, such as driving while following GPS directions. This study examines why dual sources are challenging by investigating visual working memory’s capacity and precision limits. Forty-eight adults (mean age = 20.21 years, SD = 4.88) performed recall tasks involving one or two sequentially presented arrays of colors and line orientations. We manipulated inter-array similarity to explore interference effects. Participants reported stimuli features using response rings, enabling assessments of both capacity and precision. Results show consistently poorer performance when recalling two arrays compared to one, regardless of their similarity. Our psychological process modeling revealed that this difficulty arises from reduced item availability in visual working memory rather than precision degradation. Additionally, the absence of significant inter-array similarity effects challenges interference-based theories, suggesting that capacity limitations rather than similarity drive working memory constraints. These findings contribute to understanding visual working memory by highlighting capacity as a fundamental limitation, overriding similarity effects. Future research could investigate how factors like temporal organization or item distinctiveness influence interference and capacity constraints.

Acknowledgements: The work was funded by NICHD Grant R01-HD021338. We thank Bret Glass for assistance. The program, results, and analyses are available online at https://osf.io/hu83r/?view_only=11c45592c6804e70aa332e635b2dae81