Recordings from electrodes acutely and chronically implanted in patients undergoing neurosurgical evaluation or treatment for epilepsy can provide a window into the human brain at the single neuron and local field potential level. Recordings are extracellular and often include measurements from brain areas such as the hippocampus, entorhinal cortex, amygdala, orbitofrontal cortex, and anterior cingulate. Research studies explore the relationship between single neurons and local fields to cognition while patients participate in various behavioral tasks.

Deep brain stimulation is a neuromodulation technique where implanted electrodes can deliver electrical stimulation to a specific brain target. DBS is FDA approved for treatment of Parkinson’s disease, essential tremor, dystonia, and chronic and severe obsessive-compulsive disorder. Recently, clinical trials are exploring the efficacy of DBS for treatment of post-traumatic stress disorder, depression and Alzheimer’s disease. Stimulation is controlled by a pacemaker like device implanted under the skin usually in the chest that is connected through a wire to the DBS electrode. Delivery of electrical impulses with DBS electrodes can affect underlying neuronal tissue through temporary disruption or enhancement of endogenous activity. Various frequencies and protocols of DBS stimulation can be used and adjusted according to the patient and specific disorder being treated.

Functional magnetic resonance imaging or functional MRI (fMRI) is a neuroimaging procedure using MRI technology that measures brain activity by detecting associated changes in blood oxygenation levels. fMRI is a safe non-invasive procedure that can be used to measure changes in brain activation during various cognitive states and behaviors including functions that are impaired in neurological and psychiatric disorders.