In practice, scientists must convey data in a “representational style” (e.g., as a numerical array or visual representation). Various authors seek to explain the epistemic role of scientific visual representation in terms of formal conventions (e.g., Goodman, Perini, and Kulvicki). Goodman also tends to dismiss the epistemic relevance of human cognition. My position is that visual conventions are nonarbitrary, in that they play to scientists’ cognitive abilities and limitations. My account draws on Perini's formal analysis, scientific case studies, and empirical literature on global pattern detection in neurotypicals, autistics, and dyslexics.