Differential Complexity of Information Processing During Motor Imagination in Adults Versus Children

Motor imagination is a dynamic mental state that simulates a similar brain mechanism to actual physical movement. This brain mechanism could be traced using Electroencephalography (EEG) recording during motor imagination. Nevertheless, it is still unclear how development changes this mechanism. As the brain mechanism of motor imagination must gain expertise during development to enable a subject to perform better motor actions, we hypothesized that the brain mechanism of imagination in adults must have a more complex pattern of information processing than in children.

We recorded the EEG signals of 10 boys and 9 male adults during right- and left-hand motor imaginations. Subsequently, the complexity of EEG signals was estimated by applying Higuchi's fractal dimension (HFD) to the cleaned EEG data.

The results presented a significant increase of HFD in the adults (P<0.05, family-wised error corrected) in all the EEG channels compared to the children. An increase in HFD presents a more complex pattern of information processing in adults, which advances their ability to perform motor tasks.

This advancement in adults could be created by information compression at higher levels than in children. We hope these findings pave the way to a better understanding brain functions and mechanisms.