Table III.

Qualitative comparison of different motor mapping approaches

	fMRI			TMS
Aim	Identification of position with highest task‐related neural activity			Identification of position with lowest electrophysiological threshold to elicit MEPs of the respective peripheral muscle
Assessed via	Neurovascular coupling			Cortico‐spinal excitability
	GRE‐BOLD	SE‐BOLD	ASL‐CBF
Measured variable(s)	BOLD (Deoxy‐Hb, CBF, CBV)	BOLD (Deoxy‐Hb, CBF, CBV)	CBF	Peripheral EMG signals
Main advantages	High CNR	High spatial specificity	High spatial specificity	Independent of vascular effects
Main disadvantages	Low spatial specificity	Low CNR	Low CNR	Restricted to superficial areas (limited penetration depth)
Main source of signal	Large draining veins	Microvasculature (≥3 T)	Arterioles and capillaries	Indirect trans‐synaptic excitation of cell bodies and direct excitation of axons
Localized structure	BA6	BA4a	BA4p	BA6
Distance to surface	+	++	+++	n/a

Please see text body for references.