Abstract: When participants are asked to judge the parity of presented digits, smaller numbers are associated with faster left-hand responses, and larger numbers with faster right-hand responses. This association of numbers with space is called as the Spatial-Numerical Association of Response Codes (the SNARC effect). The effect has been examined and confirmed in an ever growing literature in cognitive psychology. Some researchers argue that the origin of SNARC can be attributed to the existence of a left-to-right oriented “mental number line”. Some others favor that a dual-route cognitive model can account for the SNARC effect. Both accounts above focus on the cognitive processing of the SNARC effect. However, few studies have investigated the impact of body form and social environment on the SNARC effect. In this study, the SNARC effect was further explored from the perspective of Embodied Cognition. According to Embodied Cognition, the mind, brain, body and environment are organized into an integrative system because the brain is embedded in the body and the body is embedded in the environment. Therefore, the states of body and its environment play a great role in cognitive processes. With 127 college students and three experimental tasks including a parity decision task, a Go/No-go task and a joint Go/No-go task, the present study aimed to explore the impact of body form and social environment on the SNARC effect. Participants were asked to respond to both even and odd numbers in Experiment 1, which served as a baseline for the following experiments. Consistent with previous studies, the SNARC effect was observed in this experiment. In Experiment 2, subjects were administered the Go/No-go task and required to respond to only one mode of parity with only one response key. It was found that the SNARC effect disappeared. We speculated that the disappearance of the SNARC effect could be due to that a point of body instead of a line was represented. It seemed that the physical form could affect the SNARC effect. In Experiment 3, two participants performed complementary actions, termed the joint Go/No-go task, with one responding to odd and the other to even. According to the consistency between sitting sides and hands, four conditions were designed. In the condition 1, the sitting sides and hands were completely consistent: The persons on the left responded with their left hands while those on the right responded with their right hands. In the condition 2, the sitting sides and hands were completely opposite: The left participants responded with their right hands while the right ones responded with their left hands. In the condition 3 and 4, the sitting sides and hands were partly consistent. Specifically, both left and right participants responded with their left hands in the condition 3 while both left and right participants responded with their right hands in the condition 4. Interestingly, the SNARC effect appeared only in the condition 1, which might be attributed to the role of human mirror neuron that could map the observation of external action on internal motor representation. In the joint Go/No-go task, actions of one person as well as actions of his/her cooperator were likely to be represented in the person, leading to the appearance of the SNARC effect. However, the SNARC effect did not appear in the other three conditions, suggesting that the effect only appeared when the sitting side was consistent with the hand. The results of Experiment 3 indicated that the SNARC effect could be affected by social environment and physical form.

Key words: the SNARC effect, embodied cognition, a parity decision task, a Go/No-go task