Abstract
Although researchers agree that number and other magnitudes are represented in analog format, there is disagreement about whether these representations form part of an integrated system, the so-called 'general magnitude system' (Walsh, 2003). Here we used a subliminal priming paradigm to test for interactions between different magnitudes (number and area) when one magnitude (number) was not consciously detectable. On each trial, participants were presented with a pair of black and white Arabic digits as subliminal primes (e.g., white 4 and black 8). Each digit pair was presented for a short duration (43 ms) and sandwiched between two masks, preventing conscious detection. Participants were then presented with target displays of black and white two-dimensional shapes (lasting 200 ms), and tasked with judging which array was larger in cumulative surface area (Experiment 1). We found significant congruity effects. That is, participants were both more accurate and faster on trials in which the mapping between color and relative number for the Arabic digits matched the mapping between color and relative surface area in the non-symbolic arrays (e.g., a prime display with a white 4 and a black 8 followed by a target display with smaller white surface area and larger black surface area) than when there was a mismatch (white 4 and black 8 followed by large white area and small black area; ps < .01). These findings suggest direct connections, or overlap, between representations of number and area, and because the primes were subliminal, mediation by common verbal labels was not a viable alternative explanation. Moreover, in a subsequent experiment (Experiment 2), we ruled out an alternative account that would explain congruity in terms of post-representational (i.e., decision) effects. Taken together, these experiments provide unique support for a general magnitude system that integrates numerical and non-numerical magnitudes
Meeting abstract presented at VSS 2016