Fig. 5

Power of different EEG band. a Shows the difference of power in θ, α, \({\beta }_{1}\) and \({\beta }_{2}\) band between highest load (Level 7) and lowest load (Level 1), and the result of 62 electrodes was averaged among 20 subjects in the scale map. b Shows the change trend of PSD in θ, α, β_1 and β_2 band of specific channel (O1, P4 and PO5) with task difficulty. The x-axis represents task difficulty level and the y-axis represents the power amplitude