Advances in neuromodulation techniques offer the promise of new therapeutic interventions for patients with neuropsychiatric maladies. Several complex social, ethical and policy issues will attend developments in this area. In this paper an ethical framework for clinical research in interventional cognitive neuroscience is advanced. Deep brain stimulation in traumatic brain injury is considered as a paradigm case to examine ethical obligations in human subject research. These include balancing access to novel therapies versus protection of vulnerable study populations, rational evaluation of study design and research strategies, informed consent, and the importance of achieving societal consensus for this line of scientific inquiry.