MENTAL CALCULUS AND PHYSICAL EDUCATION (PE) - EFFECT OF PHYSICAL EXERCISE

Several everyday activities (e.g.: shopping or board games) require mathematical abilities (Lefevre et al., 2009). These abilities may be grounded in sensorimotor experiences such as finger-counting (e.g.: Berteletti et al., 2015; Wasner et al., 2014). This is supported by experimental results showing that mental calculation in adults involve cerebral circuits responsible of hand movements (e.g.: Andres et al., 2012; Imbo et al., 2011). Another possible influence of sensorimotor experience on mental arithmetic may depend on a spatial representation of numerical magnitude (from the left to the right in the European culture and, more generally, along a vertical axis; Wiemers et al., 2014). Anelli et al. (2014) thus showed an enhancement of mental subtraction performance and of mental addition performance respectively during a leftward walk and during a rightward walk. Lugli et al. (2013) also found such influence of a descending displacement on mental subtraction and of an ascending displacement on mental addition. Beyond this so-called congruency effect, it was found that the height of a vertical squat jump is improved after a mental subtraction (Rabahi et al., 2013).

Such results raised the question of a possible physical preparation before performing mental calculations. The aim of the present study was thus to determine the possible influence of vertical squat jump on the performance of mental subtractions.

Fourty subjects participated to the study (19-22 years of age). All of them performed 2 series of 5 subtractions. These series were the following: (1) 17 – 8; 24 – 6; 34 – 7; 45 – 6; 56 – 8; (2) 15 – 6; 26 – 8; 36 – 7; 46 – 8; 53 – 6. The order of presentation of the 2 series was counterbalanced from one subject to another and the order of the subtractions in a given series was randomly assigned for each subject. The experimental task was designed by using the software SuperLab4©. The subtractions were shown on the screen of a 13 inches laptop and the subjects answered by using the keypad of an external keyboard.

The 40 subjects were divided in 2 groups:
(1) 25 subjects (experimental group, EG) realized a first series of 5 subtractions, followed by 5 vertical squat jumps (1 mn rest between 2 jumps), then by a second series of 5 subtractions,
(2) 15 control subjects (CG) performed the 2 series of 5 subtractions and simply sat during 5 mn between a series and the following one.

The results of a mixed-design analysis of variance (ANOVA with repeated measures and a between-subjects factor) showed both a main effect of time (i.e.: of the repetition of the two series of subtraction; p < 0.01) and an interaction effect between time and groups (p < 0.05). A between-subjects effects was also found (p < 0.05). The CG subjects improved RT by 5% from one series of subtractions to the other thus showing a possible effect oh habituation. The EG subject improved RT by 15% thus showing a possible influence of vertical squat jumps and implying a possible influence of PE on mental calculation.