The current study presents a unique opportunity to measure the direct effects of transcranial magnetic stimulation (TMS) by using intracranial electrodes to record neural activity in deep brain regions when TMS single pulses are delivered. If TMS can evoke downstream responses in neural networks of the human brain, it can be a feasible way to study circuit engagement and connectivity.

Inclusion Criteria:

1. Patients who received (or are scheduled to receive) intracranial electrode implantation surgery as part of standard clinical care or as participation in an ongoing research study for the treatment of neurological and/or psychiatric conditions at Pennsylvania Hospital
2. Adult patients, 21 to 75 years of age
3. Patients considered to be in a stable medical condition, in the opinion of the PI
4. Patients who are able to demonstrate comprehension of instructions in the English language, in the opinion of the PI
5. Patients who are able to provide informed consent and fully comply with all study requirements, in the opinion of the PI

Exclusion Criteria:

1. Patients with chronic alcohol abuse history
2. Patients who are unable to have an MRI scan
3. Patients who are unable to tolerate TMS
4. Patients with additional implanted devices, such as an aneurysm clip or a cardiac pacemaker, that would increase the TMS risk profile
5. Patients who are pregnant at the time of screening or patients who get pregnant during the course of the study
6. Patients with any past or present medical condition, disease, disorder, or injury that, in the opinion of the PI, may reduce or hinder the participant's ability to fully comply with all study requirements or may impact, compromise, or affect the integrity of the data or the results of the study