View clinical trials related to fMRI.
Filter by: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: - 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.