Table 1.

Description of the single-pulse and paired-pulse TMS paradigms and their associated cortical mechanisms. The TMS paradigms were performed in the order listed in the table.

TMS Paradigm	Description of Paradigm	Primary Underlying Cortical Mechanism
Measures of Cortical Excitability
(1) Resting motor threshold (RMT)	Minimum stimulator intensity that elicited a ≥50μV MEP in 5 of 10 consecutive trials at rest.	Neuronal membrane excitability
(2) 1mV stimulator intensity (SI1mv)	Suprathreshold stimulator intensity that elicited an average MEP amplitude of approximately 1mV at rest.	Neuronal membrane excitability
(3) Coefficient of variation (CV) of MEP amplitudes	Trial-to-trial CV of the MEP amplitudes elicited by single-pulse TMS (12 trials delivered at SI1mv).	Variability of cortical excitability
Measures of Intracortical Inhibition and Facilitation
(4) Short-interval intracortical inhibition (SICI)	Paired-pulse TMS: Conditioning pulse (80% of RMT) preceded test pulse (SI1mv) by 2ms (12 trials per condition).	GABAA receptor-mediated inhibitory neurotransmission
(5) Intracortical facilitation (ICF)	Paired-pulse TMS: Conditioning pulse (80% of RMT) preceded test pulse (SI1mv) by10ms (12 trials per condition).	NMDA receptor-mediated excitatory neurotransmission
(6) Cortical silent period	Single-pulse TMS (140% of RMT) during tonic muscle contraction (10 trials).	GABAB receptor-mediated inhibitory neurotransmission
Measures of Cortical Plasticity
(7) Average paired associative stimulation (PAS)-induced plasticity	Pre-PAS: Single-pulse TMS (SI1mV) PAS: Right median nerve stimulation preceded TMS by 25ms (180 pairings). Post-PAS: Single-pulse TMS (SI1mv) immediately after, and 15, 30 and 60 mins after PAS (20 trials per timepoint). Average potentiation calculated.	Long-term potentiation-like cortical plasticity
(8) Maximum PAS-induced plasticity	Same PAS procedures. Maximum potentiation calculated.	Long-term potentiation-like cortical plasticity