Abstract
The ability to discriminate visual number is supported by the Approximate Number System (ANS) and is linked to general math skill (Schneider et al., 2016). However, less is known about an adult's ability to perform visual non-symbolic mathematical operations. Previous work has shown that children can perform division across dot arrays with a symbolic divisor, but it is unknown whether non-symbolic division is possible with a non-symbolic divisor, and how this ability links to symbolic division skills and ANS acuity (McCrink & Spelke, 2016). Here we tested 75 undergraduates (mean age = 20.7, 51 female) on their ability to perform division using a non-symbolic divisor with both dot arrays and numerals. During training subjects calculated with divisors of 2, 5, and 8. During testing subjects had to generalize the division operation across novel divisors (3 and 6). We also measured subjects' ANS acuity and symbolic math skill. Subjects successfully generalized the division operation to novel non-symbolic divisors on both tasks (non-symbolic t74 = 47.6, p < .001; symbolic t74 = 68.8, p < .001). Subjects were better at symbolic vs. non-symbolic division (t74 = -10.3, p < .001), and performance and reaction time on the two tasks were correlated (accuracy r = .37, p = .001; RT r = .48, p < .001). Moreover, non-symbolic division accuracy fully mediated the relation between ANS acuity and symbolic division accuracy (bootstrapped indirect effect = -.15, p = .01), and partially mediated the relation between ANS acuity and fraction comparison performance (bootstrapped indirect effect = -.14, p = .03). These results suggest a close relation between basic visual numerical discrimination ability and the ability to perform non-symbolic mathematical operations in a visual modality. The ability to use non-symbolic number in a math operation mediates the established relation between visual numerical discrimination and math skill.
Meeting abstract presented at VSS 2018