Abstract
Motor imagery relies strongly on motor representations. It is widely accepted that both the imagery and execution of actions share the same neural representations (Jeannerod, 2001). As a result, studying mental durations in relation to actual durations of movements opens a window to examine this relationship. The present experiment examined mental durations of imagined walking with and without an additional load while actually carrying versus not carrying the same load during the imagery trials. Participants (N = 32) walked different distances without or with an additional load of 20% of their own bodyweight. They then had to imagine the same walking distances for both load conditions. Half of the participants actually wore an additional load during imagery trials; the other half did not wear a rucksack actually. Mental durations were contrasted with the actual walking durations. Results showed a robust effect of imagining the load with longer durations for imagining walking with an additional load, F(1,30) = 28.18, p < .001, η2 = .484. However, the actual load during imagery trials had no substantial influence on mental durations, F(1,30) = 1.88, p = .18, η2 = .059. This dissociation of load-related effects can be interpreted as a cognitive but not as a motor effect of load on mental duration.
