Table 3.

Inter-group differences

		Frequency band
Task	Area	alpha	beta	gamma
C2	Frontal	–	–	–
	Central left	–	0.004c	–
	Central	–	0.019c	–
	Central right	–	–	–
	Posterior	< 0.001a	0.015c	< 0.001d
NC2	Frontal	–	–	–
	Central left	–	0.039c	–
	Central	0.013b	–	–
	Central right	–	–	–
	Posterior	< 0.001a	–	–
C4	Frontal	< 0.001a	< 0.001a	< 0.001a
	Central left	–	–	–
	Central	0.012b	–	–
	Central right	–	–	–
	Posterior	< 0.001a	0.003c	< 0.001d
NC4	Frontal	< 0.001a	< 0.001a	< 0.001a
	Central left	–	–	–
	Central	0.017b	–	–
	Central right	–	–	–
	Posterior	< 0.001b	0.003c	< 0.001d

Superscripts indicate which groups show significant differences. ^a HC higher TRP than ET and PD; ^b HC higher than ET; ^c ET higher TRP than HC; ^dPD and ET higher TRP than HC; C2 Cued tapping task at 2 Hz, NC2 Non-cued tapping task at 2 Hz, C4 Cued tapping task at 4 Hz, NC4 Non-cued tapping task at 4 Hz