Working Memory Training Combined With Transcranial Magnetic Stimulation in Smokers

The Working Memory Training condition: This condition will include 30 sessions across 4 weeks (10 remote sessions prior to initiation of the rTMS stimulation, and 20 lab sessions on rTMS stimulation days). Participants will complete three distinct WM tasks in each session: a visuospatial WM task, a backward digit span task, and a letter span task. In the training condition, the difficulty level of all three WM tasks will be automatically adjusted on a trial-by-trial basis. An identical protocol and software have demonstrated efficacy in increasing WM capacity, and this improvement in WM predicts reduction in addictive behavior.

In the Sham WMT condition, the difficulty level of the WM tasks will not be adjusted; instead it will remain at the initial easy level throughout each task (i.e., three items in each sequence). All other aspects of the condition are identical to the active WMT condition.

"The rTMS Condition: rTMS will be delivered with a Magstim Rapid2 system using Magstim Air Film Coils. rTMS pulses will be delivered at 10 Hz (100% resting motor threshold, RMT) in 40, 5 second trains, with 15 second inter-train interval, for a total of 2000 pulses per session. Active or sham rTMS will be applied over the left DLPFC; corresponding with the standard F3 location on scalp (F3=left frontal lobe, location #3 for electrode placement using international 10-20 system for scalp measurements). Five consecutive daily sessions will occur on two consecutive weeks, for a total of 10 sessions. RMT, defined as the amount of energy required to induce movement in the contralateral abducer pollicis brevis in at least 50% of stimulations, will be assessed on first day of application."

Sham rTMS will be identical to active treatment, with the exception that mu-metal plates attached to the sham coil block the magnetic field while providing a sensation of stimulation.