Objective The goal of this protocol is to improve spatial resolution and contrast in MRI studies of brain anatomy and function, by developing novel hardware, and image acquisition and reconstruction techniques. Specifically, by improving MRI image quality and manipulating MRI contrast, we aim to better characterize and quantify structural, chemical, and blood flow variations across the brain, and study their relationship with neuronal activity. For this purpose, we will develop and optimize novel MRI techniques on normal, healthy volunteers, and combine these with EEG and recording of other physiological signals. Study Population Any healthy, male or female volunteer 18 years of age and older; the subjects must be capable of understanding the procedures and requirements of this study and be willing to sign an informed consent document. Design This is a technical development study design to develop and evaluate new MR technology for performing MRI and functional MRI in the CNS with novel contrasts and with a high spatial resolution. Outcome Measures The primary outcome of this study will be the ability to acquire anatomical and functional images of the human brain with high spatial resolution, i.e. 200-300 micron and 750-1000 micron respectively. In addition, developed techniques will allow the robust measurement of specific tissue properties, including diffusion, structural anisotropy, iron and myelin content, perfusion, and metabolite concentrations. The relative merits of blood flow and blood oxygenation level dependent (BOLD) functional MRI (fMRI) techniques, and their particular spatial and temporal signal characteristics will be established. It will be determined whether information valuable to interpret BOLD fMRI can be derived from EEG and other physiological signals
- INCLUSION CRITERIA: - 18 years of age and older - in good general health - able to understand the procedures and requirements and give informed consent EXCLUSION CRITERIA: All Subjects will undergo a neurological physical and answer the Healthy volunteer form, and the most-recent version of the NMR safety screening A subject will be excluded if he/she: 1. has any metal implant or objects of unknown identity or composition, or if it s known to be non-compatible with MRI, such as pacemakers, medication pumps, aneurysm clips, metallic prosthesis (such as heart valves or cochlear implants), certain orthopedic implants (pins and rods), shrapnel, or small metal fragments in the eye; 2. has claustrophobia; 3. cannot lie comfortably for up to 120 minutes; 4. underwent brain surgery or suffered a head trauma 5. has migraines that require medication; 6. has a psychiatric disorder (defined by the DSM-5); 7. has a neurological lesion or history of neurological disorders; 8. has known hearing problems; 9. is pregnant; 10. has permanent eye liner; 11. has medical problems such as, diabetes mellitus, hypertension, pulmonary or airway disease, heart failure, coronary artery disease, or history of sleep apnea. 12. has a diagnosable substance dependence 13. a member of the NINDS Laboratory of Functional and Molecular Imaging. The contraindications to MRI at the various field strengths are almost identical, except the 7 T also excludes subjects with a ferromagnetic dental crown or a bridge.