Yoonsang Lee¹ (), Jason Tsukahara², Randall Engle¹; ¹Georgia Institute of Technology, ²University of Miami

Although visual discrimination is often treated as a low-level perceptual task, many forms of discrimination—especially those requiring comparisons across time—likely depend on higher-order cognitive mechanisms. In particular, sequential discrimination may draw on the same attentional-control and maintenance processes that support individual differences in working memory capacity (WMC) and fluid intelligence (gF). To examine whether different forms of visual discrimination rely on distinct cognitive abilities, 150 participants completed a battery measuring gF, WMC, and attention control (AC). A subset of 112 participants additionally completed both a sequential and a simultaneous line-length discrimination task. Structural equation modeling revealed a clear dissociation: sequential discrimination was predicted by both WMC and AC, with little contribution from gF, whereas simultaneous discrimination showed its strongest association with WMC and only a weak relationship with gF once AC was included. These patterns suggest that discrimination tasks differ substantially in their cognitive demands depending on how stimuli must be compared. More broadly, the results demonstrate that the link between perceptual discrimination and higher cognition depends on task format, and that separating maintenance-based WMC from executive and sustained-attention components of AC is essential for understanding individual differences in perceptual fidelity.

Acknowledgements: ONR Multidisciplinary University Research Initiative (MURI)