The Influence Of Body Form And Social Environment On The SNARC Effect

When participants are asked to judge the parity of presented digits, small 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 Spatial-Numerical Association of Response Codes (SNARC effect). It has been examined in an ever growing literature in cognitive psychology, which has confirmed the universality of the SNARC effect. Some researchers argued that the origin of SNARC could be attributed to the existence of a left-to-right oriented "mental number line" (Dehaene et al.1993). Some others favored that a dual-route cognitive model could account for the SNARC effect(Gevers et al.2005). Both accounts above concerned the cognitive processing of the SNARC effect. And few studies have investigated the impact of body form and social environment on the SNARC effect.In this research, 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 151 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 research includes two studies, which aimed to explore the impact of body form and social environment on the SNARC effect.Study 1 includes three experiments: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 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, that was, the person on the left responded with left hand while the other on the right responded with right hand. In the condition 2:the sitting sides and hands were completely opposite, that was, the left participant responded with right hand while the right one responded with left hand. In the condition 3 and 4:the sitting sides and hands were partly consistent. Specifically, both participants responded with left hands in the condition 3 while both participants responded with right hands in the condition 4. It was very interesting that the SNARC effect appeared only in the condition 1, which might be attributed to the role of human mirror neuron which 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 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 last three conditions, suggesting that the SNARC 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.Study 2 combined the go/no-go task and the joint go/no-go task, and event-related potentials (ERPs) were measured in the brains. By analyzing the components N2 and P3, significant interaction of compatibility and social context was found. The results indicated that the social environment could affect the SNARC effect, and this phenomenon could also prove the Embodied Cognition, that is, the states of body and its environment play a great role in cognitive processes.