Advanced Functional and Structural MRI Techniques for Neuropharmacological Imaging

* Subjects must be between the ages of 18-80, be generally healthy and male or non-pregnant female. Smokers, non-smokers, drug using and non-drug using populations will participate in this study. INCLUSION CRITERIA: General: * Male and non-pregnant female adults between the ages of 18-80. * All subjects must be able to provide informed consent. EXCLUSION CRITERIA: Subjects will be excluded if they: * Are pregnant. Urine pregnancy tests will be performed on all female volunteers of child-bearing potential before each experimental session. * Are unable to undergo MRI scanning due to implanted metallic devices (cardiac pacemaker or neurostimulator, some artificial joints, metal pins, surgical clips or other implanted metal parts including Copper 7 IUD) or claustrophobia. * Have major medical illnesses severe enough to impact data being gathered. Potential exclusions may include a history of chronic uncontrolled hypertension, diabetes, HIV, or other clinically significant medical conditions that may alter the signal being measured. * Have current major psychiatric disorders to include, but not limited to, mood, anxiety, psychotic disorders. * Have neurological illnesses severe enough to impact data being gathered. Potential exclusions may include seizure disorders, migraine, multiple sclerosis, movement disorders, or history of significant head trauma, CVA, or CNS tumor. The MAI will assess the severity in relation to the potential impact on data. * Are non-English speaking. Justification: There is no direct benefit to participants in this study, and some of the study procedures involve more than minimal risk. To include non-English speakers, we would have to translate the consent and other study documents and hire and train bilingual staff, which would require resources that we do not have and could not justify given the small sample size for each experiment. Additionally, the data integrity of some of the cognitive tasks and standardized questionnaires used in this study would be compromised as they have only been validated in English. Most importantly, ongoing communication regarding safety procedures is necessary when participants are undergoing MRI and TMS/TRPMS procedures. The inability to effectively communicate MRI and TMS/TRPMS safety procedures could compromise the safety of non-English speaking participants. * Are cognitively impaired, as assessed by medical history. A validated IQ test such as the WASI or Shipley-2 may also be considered. Justification: Cognitive impairment and learning disabilities are associated with alterations in brain regions used to accomplish tasks, and, therefore, may introduce significant variably into the data. Cognitive impairment may affect one s ability to give informed consent. Subjects to be considered for Non-Invasive Brain Stimulation (NIBS) will also be excluded if they: -Are unable to safely undergo a NIBS procedure as assessed by a TMS safety screening form. Additional information will be gathered during screening for some experiments. As the purpose of this protocol is to develop imaging techniques, this information will be gathered as needed, depending on the phase of development and specific technique requirements. Based on the scientific and medical requirements of the particular experiment, participants may also be assessed for: * Age (some experiments may want to target a particular age range. For example, cognitive tasks generally exclude participants over 60, an age when cognitive issues tend to become more commonplace) * Left-handedness (if desired for a particular task) * Color-blindness (if using a task requiring color discrimination) * Drug use diagnosis * Use of psychoactive or vascularly active medications (if a functional fMRI technique that is sensitive to hemodynamic changes is being used). MAI discretion regarding timeframe of allowed use will be based on clinically relevant factors including drug half-life, pharmacology of the drug in question and pattern of use by the participant.