SNARC effects for color decision to non-symbolic representations of quantity

The SNARC (spatial-numerical association of response codes) effect is evidenced when people are faster to respond to smaller numbers with a left-sided response and larger numbers with a right-sided response. It has been reported for a range of tasks for symbolic representations of number (e.g., digits), but evidence for SNARC effects for non-symbolic representations of number (i.e., quantities of objects) is mixed and usually restricted to tasks where numerical properties are relevant. Here, we report six studies where participants made color decisions to circles. We manipulated the stimuli so that displays formed structured, familiar patterns (dice-like arrangements, Experiments 1-2), structured but unfamiliar patterns (symmetrical arrangements, Experiments 3-4), or unstructured and unfamiliar patterns (scattered arrangements, Experiments 5-6). We additionally manipulated whether aggregate surface area was controlled or uncontrolled and whether individual elements within displays remained constant in size or differed across the experiment. The SNARC effect was present when (1) circles were arranged in a structured familiar manner, or (2) aggregate surface area increased congruently with quantity, although some effects were weak by Bayesian standards. Our results are consistent with the view that non-symbolic quantities offer a route to magnitude and its spatial representations, but that this may be modulated by the consistency of high- and low-level visual cues to magnitude.