View clinical trials related to fMRI.
Filter by:Background: - People who are dependent on alcohol drink even when they know something bad might happen. Researchers want to learn more about why they do this. Objectives: - To study brain response when a person plays a game in different threat conditions. Eligibility: - Healthy right-handed adult heavy drinkers age 21 60 - Healthy right-handed adult light drinkers age 21 60 Design: - Participants will be screened with medical history, physical exam, and blood and urine tests. They will have an EKG and psychiatric interview. - Participants will have one or two clinic visits. - Participants will be asked about their alcohol drinking. - They will choose a snack and alcoholic beverage that they must drink in 5 minutes. After their breath alcohol content (BrAC) is zero, they will play a game in the MRI scanner. - The scanner is a metal cylinder that takes pictures of the brain. Participants lie on a table that slides in and out of the cylinder. They will be in it for about 90 minutes, lying still for up to 20 minutes. - During the MRI, participants will play a simple computer game to earn food or drink points under different threats of electric shock. Points can be exchanged for food or alcohol after the game. Sometimes, participants will receive a mild electric shock through a metal disk on the wrist. Electric shocks will only happen if the participant tries to earn a reward point. - After the MRI, participants use their points for another drink and snack. They will stay at the clinic until their BrAC is low, usually within 3 hours. Participants cannot drive themselves home. - Participants will have a follow-up phone call the next day.
Background: - People can learn to use feedback about brain activity to change that activity. Researchers want to see if people who have had a stroke can change their brain activity by practice and thought with feedback, and if that improves motor control. They will study brain activity in people who have and have not had strokes. Objectives: - To see if people with stroke can change their brain activity and improve motor control by practice and thought. Eligibility: - Adults 18 80 years old who have had a stroke. - Healthy volunteers 18 80 years old. Design: - Participants will be screened with a medical history, MRI, and physical exam. For MRI, a magnetic field and radio waves take pictures of the brain. Participants lie on a table that slides in and out of a cylinder. They will be in the scanner less than 2 hours, lying still for up to 15 minutes at a time. The scanner makes loud noises. Participants will get earplugs. - Participants will have up to 3 scanning visits and up to 3 follow-up visits within 24 weeks. Visits may include screening, MRI, functional MRI (fMRI), questionnaires, and simple motor tests. Stroke participants may take additional motor tests, including transcranial magnetic stimulation (TMS). - fMRI: During this MRI, small metal disks may be taped to the skin or a fabric glove with small wires in it may be used to monitor hand movements. Heart rate and breathing may also be monitored. Participants may be monitored by video and asked to perform tasks. - TMS: A brief electrical current goes through a coil on the scalp. It creates a magnetic pulse that stimulates the brain. Participants may be asked to perform simple actions. Finger or hand movements may be recorded.
Background: - Some children and teenagers have conditions known as conduct disorders. They often have long-term chronic behavior problems, such as defiant behavior or violence. Conduct disorders are often treated with antipsychotic medication. Researchers want to study two types of newer antipsychotics (aripiprizole and risperidone) for children and adolescents with conduct disorders. They will look at how these drugs affect brain activity. To do so, they will give brain activity tests using magnetic resonance imaging (MRI). The tests will compare the results from healthy volunteer children and teens to those of others with behavior problems. Objectives: - To see how atypical antipsychotics affect brain activity of children and teenagers with conduct disorders. Eligibility: - Children and teenagers between 10 and 18 years of age who have a conduct disorder and are taking aripiprizole. - Children and teenagers between 10 and 18 years of age who have a conduct disorder and are taking risperidone. - Children and teenagers between 10 and 18 years of age who have a conduct disorder and are not taking an atypical antipsychotic. - Healthy volunteers between 10 and 18 years of age. Design: - Participants will be screened with a physical exam and medical history. Parents/guardians will be asked questions about their child s feelings, experiences, and behavior. Participants will also answer questions about their feelings and moods. - This study will involve two visits. Each visit will involve MRI scanning. - At the first visit, participants will have memory and thinking tests. The tests will involve making decisions or playing games. Some of these tests will use MRI scanning to look at brain activity. - The second visit will be 3 to 5 months after the first visit. The tests from the first visit will be repeated.
Background: - Ghrelin is a hormone in the human body that is mostly produced by the stomach. It makes people feel hungry, and also is connected with the desire to drink alcohol. Researchers want to test ghrelin to see if it can be used to control alcohol cravings and use. They will compare doses of ghrelin with a placebo in people who drink heavily. Objectives: - To study the effects of ghrelin on alcohol craving and use. Eligibility: - Individuals between 21 and 60 years of age who are heavy drinkers but are not seeking treatment for alcohol use. - Participants must on average have more than 20 drinks per week for men, and more than 15 drinks per week for women. Design: - Participants will have a screening visit, four 2-night study visits, and a follow-up visit. - Participants will be screened with a physical exam and medical history. They will provide urine and breath samples for drug testing. They will also answer questions about mood and physical symptoms, and about alcohol and other cravings. - At the study visits, participants will stay overnight at the National Institutes of Health clinical center. They will spend the night at the center, have tests on the next day, and go home on the following morning. At each visit, participants will receive a ghrelin or placebo infusion, and will complete a series of tasks. - For the first and second study visits, participants will have tests of alcohol craving and use. They will be able to receive alcohol infusions through a computer program that tests response time and craving reactions. At the same time, they will have a ghrelin or a placebo infusion. Blood alcohol levels, reaction time, and craving will be studied. - For the third and fourth study visits, participants will have a magnetic resonance imaging (MRI) study. They will have an initial MRI to provide a picture of the brain. They will then have a functional MRI during which they will respond to a computer test. The test will allow them to win points for snack food or alcohol. This test will look at the brain s response time and craving reactions. - There will be a follow-up visit 1 week after the fourth study visit. Some of the tests from the screening visit will be repeated.
Background: -The brain has two systems for recognizing objects. One system recognizes what an object is, and the other system recognizes where the object is located. However, there is much about how the brain handles and interprets the information from these two systems that is still unclear. Researchers want to study the parts of the brain that are involved in how vision is processed. They will use magnetic resonance imaging (MRI) and transcranial magnetic stimulation (TMS) or transcranial electrical stimulation (tES) on the brain. MRI measures what parts of the brain become more active when tasks are performed. TMS uses magnetic pulses to temporarily change the activity in parts of the brain. tES uses electrical current to temporarily change brain function. Objectives: -To better understand how people visually recognize different types of objects. Eligibility: -Healthy volunteers between 18 and 50 years of age, who only speak English. Design: - This study includes many different experiments on vision. Each experiment may combine visual tasks, MRI scans, and TMS or tES. Participants may be asked to have several different tests. Each test will require a separate visit to the National Institutes of Health. - Participants will be screened with a physical exam and medical history. They will have a baseline brain scan at the first visit. - Participants may do visual tasks alone, with MRI only, with TMS or tES only, or with MRI and TMS or tES combined. For the visual tasks, they will look at pictures of objects on a computer screen. Sometimes the images will appear very briefly (less than one-tenth of a second). Sometimes they will appear for up to 5 seconds. These images will be of things like faces, bodies, tools, and scenes. Participants will be asked to respond in different ways to the pictures. They may respond by typing on a computer keyboard or by pressing a button. Participants will have time to practice the tasks before the experiment. - Participants will remain on the study for up to 3 years.
Despite the clear importance of adolescence in the emergence of a number of disease states and processes, there is surprisingly little known about how the endocrine and metabolic events accompanying puberty in humans impact normal developmental neurobiology. Epidemiologic studies have identified sexual dimorphisms in the prevalence of several neuropsychiatric disorders, including depression, schizophrenia, and substance abuse. Many of these sex differences emerge during or shortly after puberty and are maintained until the 5th-6th decade of life. For example, the two-fold greater risk of unipolar depression in women compared with men does not appear until adolescence, and prior to puberty girls are not at increased risk relative to boys. Puberty is a structured, transitional process that can be influenced by both nutritional factors and environmental stressors; nonetheless, the variability in the timing and duration of puberty is largely determined by oligogenic inheritance. Basic neuroscience research has demonstrated that hormonal events accompanying puberty impact on many of the physiologic systems involved in the regulation of brain function (e.g., the appearance of new neurons in a brain-region specific pattern, neuronal remodeling, and the pruning of cortical connectivity). Additionally, not only does stress during puberty increase the risk of disturbances in affective adaptation during adulthood, but the events accompanying puberty modify stress responsivity (e.g., alterations in the duration and peak response of hypothalamic-pituitary-adrenal [HPA] axis hormones to stressors). Moreover, animal work has demonstrated that neural connectivity differs in a brain regional specific manner according to the stage of puberty (i.e., early versus late). In humans, puberty also occurs in stages, and although the endocrinology of puberty, surprisingly, has not been fully characterized with longitudinal data, studies have documented that the physical changes measured by Tanner stages I to V are accompanied by progressive increases in the secretions of both gonadal and adrenal steroids. Nonetheless, there remains considerable variability in the timing and duration of this otherwise highly structured reproductive transition. We propose to perform a longitudinal, naturalistic study examining changes in brain structure and function, behavior, and stress responsivity in boys and girls across the pubertal transition. Because the pubertal transition is defined by a complex series of physiologic events that emerge sequentially over several years and involve changes in multiple endocrine and growth systems, and because there is also considerable variability in the timing of these events reflecting the influence of both genetic and environmental factors, puberty cannot by delineated by age of the participants as has been done in most imaging and other neurobiological studies of adolescence. The present study will formally bridge this gap by defining pubertal events per se in participants. Participants will include healthy boys and girls whose pubertal status will be assessed, and in whom endocrine, metabolic, and brain imaging measures will be evaluated at eight - ten month intervals from age eight years (pre-puberty) until age 17 years (post-puberty). Reproductive endocrine, metabolic, and physical measures will be employed to characterize the stage and duration of pubertal development. Outcome measures will be derived via multimodal neuroimaging techniques, cognitive/behavioral assessments, metabolic measurements, and evaluations of HPA axis function. Additionally, the impact of genetic variation on the developmental trajectory of these parameters (both reproductive and CNS) will be determined. This cross-institute proposal will employ a multidisciplinary approach to evaluating the effects on CNS function of the process of puberty in both boys and girls. This work will not only serve to inform research on the mechanisms by which sexual dimorphisms in neuropsychiatric disorders develop, it will also have important implications for the prevention and treatment of these disorders. ...
Background: - Two areas on the surface of the brain, the dorsolateral prefrontal cortex (DLPFC) and motor cortex (MC), play a key role during learning. Researchers are interested in determining the effect that transcranial magnetic stimulation (TMS) on the DLPFC and MC has on participants' performance of learning tasks. By studying the effect of TMS on reaction time, learning, and memory, researchers hope to better understand how to treat conditions such as Parkinson's disease and traumatic brain injury that affect these parts of the brain. Objectives: - To study the effects of transcranial magnetic stimulation on the dorsolateral prefrontal cortex and motor cortex. - To learn which areas of the brain are used to perform certain learning and memory tasks. Eligibility: - Healthy, right-handed individuals between 18 and 70 years of age. Design: - Participants will be screened with a physical and neurological examination and a medical and psychiatric history. - Participants will be asked to take part in one of five different parts of this study. Most participants will have four 2-hour visits to the National Institutes of Health Clinical Center. Some participants (those involved in Part 5) will have only one 2-hour visit. - Parts 1 and 2 (four visits): Participants will have TMS, and then do a learning task that may provide a small monetary reward. On the first visit, before the TMS, participants will take an intelligence test based on reading aloud the words given on a card. Participants who have not had a routine magnetic resonance imaging (MRI) scan of the brain within the past year will also have a scan. - Parts 3 and 4 (four visits): Participants will have a functional MRI scan while doing a learning task that may provide a small monetary reward. On the first visit, before the functional MRI, participants will take an intelligence test based on reading aloud the words given on a card. Participants who have not had a routine magnetic resonance imaging (MRI) scan of the brain within the past year will also have a scan. - Part 5 (one visit): Participants will take an intelligence test based on reading aloud the words given on a card. Then, participants will have TMS followed by a functional MRI scan. During the functional MRI, participants will do a button-pressing task that may provide a small monetary reward. - Participants will also be asked to provide a small blood sample for genetic analysis.
Background: - Traumatic brain injury may have a range of effects, from severe and permanent disability to more subtle functional and cognitive deficits that often go undetected during initial treatment. To improve treatments and therapies and to provide a uniform quality of care, more research is needed into different treatments for traumatic brain injury. - Exercise has been shown to improve movement and balance in people with strokes, cerebral palsy, and other conditions that affect the brain, and can improve symptoms of memory problems or depression. Bright light therapy has also been shown to improve mood in people with depression. Researchers are interested in studying problems with movement, balance, thinking, and mood in people with traumatic brain injury. By comparing the effects of exercise and bright light exposure on brain function, new treatments may be developed for acute traumatic brain injury. Objectives: - To compare the effects of exercise and bright light therapy on the brain function of individuals with traumatic brain injury. Eligibility: - Individuals between 18 and 44 years of age who either have been diagnosed with traumatic brain injury or are healthy volunteers. Design: - Individuals with traumatic brain injury will have four outpatient evaluation visits at the clinical center, a 3-month home exercise program, and a 3-month bright light exposure program at home. Healthy volunteers will have one evaluation visit at the clinical center. - At the first study visit, all participants will have a full physical examination and medical history. Individuals with traumatic brain injury will also have an eye exam to determine if it is safe for them to receive light therapy. - All participants will have the following initial tests: - Tests of walking and movement, including monitoring by a physical therapist; tests to record joint movement and evaluate muscle function; tests that combine movement, thinking, and speaking; and balance and reaction time tests. - Magnetic resonance imaging scans - Tests of thinking and mood, including questionnaires, computerized tests, and simple action tests. - Participants with traumatic brain injury will have separate 3-month sessions of exercise and bright light therapy, with additional evaluation visits between each 3-month session and at the end of the study. Between the 3-month sessions, participants will have 1 month with no intervention. - Exercise sessions will involve regular workouts on an elliptical machine for 30 minutes for 5 days a week, and bright light therapy sessions will involve sitting in front of a light box for 30 minutes for 5 days a week. Participants will keep a journal to monitor the effects of the therapy.
Background: - Previous studies have shown that people with certain types of brain damage may have particular problems paying attention and processing things that they see. Researchers are interested in comparing how people with brain damage and without brain damage process visual images. Objectives: - To better understand the areas of the brain involved in paying attention to things that are seen. Eligibility: - Individuals at least 18 years of age who either have had damage to one or both sides of specific parts of the brain (e.g., stroke, injury, certain neurosurgery procedures) or are healthy volunteers. Design: - The study involves 4 to 10 visits to the NIH Clinical Center over 1 to 2 years. Each visit will last approximately 2 hours. - Participants will be screened with a medical history and physical examination, and may have the cognitive testing described below during the same visit. - On the first visit and for at least one visit thereafter, participants will have cognitive testing to evaluate thinking and memory. These tests will be either written tests or computer-based tests. - Some participants will qualify for functional magnetic resonance imaging (fMRI) as part of the study. This part will involve a decision-making task that will be performed on a computer during the fMRI scan. Additional scans may be required as directed by the study doctors. - Some randomly selected participants will be asked to have magnetoencephalography (MEG), a procedure to record very small magnetic field changes produced by brain activity. - During the behavioral training, or fMRI or MEG scanning, participants may be monitored with equipment to track eye movements.
Background: - The therapeutic modalities of cannabis have received more research attention recently with the discovery of its ability to stimulate appetite and to provide pain and nausea relief in patients with AIDS, cancer, and multiple sclerosis, among other diseases. Sativex(Registered Trademark), an experimental drug derived from the marijuana plant, contains tetrahydrocannabinol (THC) and cannabidiol (CBD), both of which affect brain activity. Sativex(Registered Trademark) is being tested to determine how and to what extent it affects brain activity. - Functional magnetic resonance imaging (fMRI) uses magnetic waves to study brain activity. Researchers are interested in using fMRI to study how Sativex(Registered Trademark) affects regional brain activity, including thinking abilities and behavior. Objectives: - To study changes in regional brain activity produced by Sativex(Registered Trademark) compared with THC and placebo. - To determine how Sativex(Registered Trademark) is processed by the body. Eligibility: - Individuals between 18 and 45 years of age who are either current users of cannabis (less than daily) or healthy volunteers who do not use cannabis. Design: - The study will involve one training session and five testing sessions on separate days. - At every session, subjects will receive either THC or placebo capsules and either Sativex(Registered Trademark) or placebo spray. - Participants will complete a training session in a mock fMRI scanner to adapt to the fMRI scanning environment. In the training session, participants will practice the tests that will track thinking ability, attention, working memory, and other cognitive tasks. - Participants will have five fMRI scanning sessions with the tests they have practiced previously, and will provide blood, urine, and saliva samples as required by the researchers. Participants will be discharged approximately 12 hours after they arrive for the study sessions....