Half and half is less than one-eighth and seven-eighths: Asymmetry affects judgment of numerosity

Our visual perception is not perfect. It is prone to interference of configuration of elements and irrelevant dimensions. In this study, we aimed to investigate whether combinations of white and black dots can interfere with the perception of numerosity. Participants were asked to judge numerosity of two serially presented sets of dots, while the ratio of black and white dots in the second set changed. Our results showed that the interference follows a 4th order effect. Further studies needs to be done to investigate underlying mechanisms.