Does body motion influence arithmetic

« Embodiment theory » proposes that bodily actions impact the quality of mental representations. Two recent studies (Loetscher, et al., 2008; Hartmann, et al., 2011) have shown that leftward movements of the head or the body enhanced small number generation while rightward movements increased the generation of larger numbers.

The present study aimed to investigate the influence of passive whole-body movement on arithmetic-problem solving. Our design was elaborated in the context of operational momentum effect (Pinhas, & Fischer, 2008; McCrink, et al., 2007). In the domain of arithmetic this effect refers to the fact that outcomes of additions are systematically estimated to be larger than the outcomes of subtractions and vice versa for subtraction (Knops, et al., 2009; Lindemann, et al., 2011). Interestingly this bias is present for non-carry but not for carry problems. To account for the operational momentum effect it has been proposed that subtractions involve an attentional motion towards the left of the mental number line and additions towards the right inducing the above-mentioned under- and over-estimation. In line with these findings we reasoned that passive body motion might orient attention towards the side of the body movement and consequently enhance the attentional shifts supposed to underlie the operational momentum effects that occur during numerical tasks.

In the present paradigm participants were sitting blindfolded on a swivel chair. While they were rotated alternatively 180° towards the left and the right with a pace of 49°/sec., they were asked to orally solve different kinds of calculations presented via headphones. Calculations consisted in additions and subtractions (first operand: from 1 to 98; second operand: from 1 to 13 and results: from 3 to 89) that were composed of carry and non-carry problems and had different levels of difficulty (easy: results from 1 to 9; medium: results from 11 to 19; difficult: from 21 to 89). Contrary to our predictions, results indicate that the direction of passive body motion (i.e. leftwards vs. rightwards) did not influence arithmetic performance. Indeed the ANOVA for repeated measures with the factor Motion (left, right), Problem type (carry, non-carry) and Operation type (addition, subtraction) revealed no main effect of motion (F(1,33)= 0,856, p=0.361). In contrast we observed a main effect of Problem type (F(1,33)=29.065, p<0.001), a main effect of Operation type (F(1,33)= 20,721, p<0.001) and a significant interaction of Problem type x Operation type (F(1,30)=5.605,p=0.024). As would be expected from the results observed with classical stationary experiment settings, participants were more accurate while solving additions than subtractions and made less errors with non-carry problems. Moreover the carry effect was larger for subtractions than additions. Analyses of the reaction times led to the same conclusions. These results indicate that orally solving arithmetic problems is not influenced by the direction (leftwards vs. rightwards) of passive rotary body-motion. This finding contrasts with previous observations that active head movements and/or passive translational movements impacts numerical task performance. Future studies which systematically contrast the effects of the different movement types on numerical tasks should help to clarify this discrepancy.