Paired associative stimulation (PAS) is a form of transcranial magnetic stimulation in which paired pulses can induce plasticity at cortical synapses, producing long-term potentiation (LTP) or long-term depression (LTD) effect. The investigators use paired associative stimulation (PAS) protocols to target cortico-cortical and cortico-subcortical networks (frontoparietal control pathway) by using different intervals between the paired pulses to explore the mechanism of cognitive deficits in methamphetamine addiction. The investigators hypothesize that different temporal sequences of cortical stimulation could produce facilitation or inhibition effect.
The investigators use paired associative stimulation (PAS) protocols to target cortico-cortical and cortico-subcortical networks to study cognitive deficits in methamphetamine addiction.