Digital natives and dual task: Handling it but not immune against cognitive-locomotor interferences

Abstract

Digital natives developed in an electronic dual tasking world. This paper addresses two questions. Do digital natives respond differently under a cognitive load realized during a locomotor task in a dual-tasking paradigm and how does this address the concept of safety? We investigate the interplay between cognitive (talking and solving Raven's matrices) and locomotor (walking on a treadmill) tasks in a sample of 17 graduate level participants. The costs of dual-tasking on gait were assessed by studying changes in stride interval time and its variability at long-range. A safety index was designed and computed from total relative change between the variability indices in the single walking and dual-task conditions. As expected, results indicate high Raven's scores with gait changes found between the dual task conditions compared to the single walking task. Greater changes are observed in the talking condition compared to solving Raven's matrices, resulting in high safety index values observed in 5 participants. We conclude that, although digital natives are efficient in performing the dual tasks when they are not emotional-based, modification of gait are observable. Due to the variation within participants and the observation of high safety index values in several of them, individuals that responded poorly to low cognitive loads should be encouraged to not perform dual task when executing a primate task of safety to themselves or others.

Fig 1. Typical plots of the SI time series obtained in the three conditions.

The same subject (8) has been chosen.

Fig 2. Violin plots of the spatio-temporal indicators SI, w and DS versus experimental conditions.

The maximal and minimal data set the limits of the violin plots, and the median, first and third quartiles are also shown (horizontal bars). Significant differences between two conditions are marked by a gray line linking the concerned violin plots. The behaviour of two participants (3, circles, and 8, triangles) when going from CTRL condition to TALK or RAVEN conditions is displayed.

Fig 3. Violin plots of the the variability indicators CV, D and H versus experimental conditions.

The maximal and minimal data set the limits of the violin plots, and the median, first and third quartiles are also shown (horizontal bars). Significant differences between two conditions are marked by a gray line linking the concerned violin plots. The behaviour of two participants (3, circles, and 8, triangles) when going from CTRL condition to TALK or RAVEN conditions is displayed.

Fig 4. Safety index s computed for each participant.

Fig 5. Upper left panel: Violin plots of the Pearson correlation coefficients r of the duration vs question number in a given set.

The horizontal line r = 0.4 has been added to guide the eyes. Upper right panel: Violin plots of the duration differences Δt between the last question of a given set and the first question of the next set. The horizontal line Δt = 0 has been added to guide the eyes. Lower panel: Typical plot of the duration vs question number for the complete Raven test. Data of participant 8 have been plotted. Linear regressions of the duration vs question number within a given set are shown.