View clinical trials related to Normal Physiology.
Filter by:Background: Brain activity produces magnetic fields. These fields can be measured outside the head. Existing technology, called MEG, measures these fields. Researchers are testing a new type of magnetic field sensor called OPM. They hope it can help pinpoint with very high accuracy where brain activity is generated. Objective: To develop and test a new type of sensor for measuring the magnetic fields produced by brain activity. Eligibility: Healthy people ages 18-65 who had a magnetic resonance imaging (MRI) scan under protocol 17-M-0181. Design: Participants may be asked to complete sessions on both the traditional MEG instrument and the OPM array. For the MEG, 3 small coils will be placed on the participant s face with tape. Their head will be positioned inside the MEG device. For the OPM, sensors are housed in a 3d printed array. The sensors will be attached to a cap placed on the participant s head. For both scans, participants will be seated in a chair inside a magnetically shielded room. They may complete several tasks. In one task, plastic cells will be placed on their fingers. Puffs of air will be sent to these cells, which will stimulate the sense of touch. Other tasks may include the following stimuli: visual (such as checkerboards), auditory (such as beeps and tones), or language (words and letters). Researchers may also obtain recordings while they stimulate the nerve in the participant s forearm using electrical current in small electrodes. Participation is expected to last for 1 day. Additional optional scans may be offered for up to 1 year....
Background: Alcohol use disorder (AUD) is a major public health problem. In the U.S., 16 to 18 million adults have an AUD. Researchers want to test an assessment tool called the ANA. It uses self-report and behavioral measures to assess 3 neuroscience domains of addiction. They hope to better understand, manage, prevent, and treat AUD. Objective: To learn how people s brains function related to their drinking. Eligibility: People ages 18 years and older who have enrolled in NIAAA natural history study 14-AA-0181. Design: Participants will complete surveys and tasks on a computer. The surveys and tasks assess a range of aspects of thinking and making decisions. The surveys and tasks also assess behaviors and feelings about alcohol and other rewards, and negative emotions. Participants will spend 90 minutes on the computer. Then they will take a break. In total, they will spend 4 blocks of time on the computer. Each block will last 90 minutes. They will take a break in between each block of time. They can take more breaks if needed. Outpatient participants and healthy volunteers will complete this study in 1 visit. It will last about 6 hours. A second visit may be scheduled if needed. Outpatient participants will take a breath alcohol test. If their test is positive, their visit may be rescheduled or they may be withdrawn from the study. Inpatient participants will complete this study over several days. Data collected from participants in this study may be combined and analyzed with their data from NIAAA study 14-AA-0181 and/or NIAAA imaging study 14-AA-0080.
Background: Transcranial magnetic stimulation (TMS) of the brain has been used to change the activity and connections in the brain to improve memory. Researchers are interested in how these brain changes cause memory improvements and how activity at the time of stimulation may change the effects of TMS. Objective: To learn how brain stimulation can be used to improve memory. Eligibility: Healthy adults ages 18-40 Design: Participants will be screened with a medical record review. Participants will have 3 study visits. At visit 1, participants will have a physical exam and will talk about their health. They will have magnetic resonance imaging (MRI). The MRI scanner is a metal cylinder surrounded by a strong magnetic field. During the MRI, participants will lie on a table that can slide in and out of the scanner. A coil will be placed over the head. Participants will be asked to keep their eyes focused on a small cross on a computer screen inside the scanner. The scanner makes loud noises. Participants will get earplugs. At visits 2 and 3, participants will have TMS and perform tasks. For TMS, a wire coil encased in plastic is held on the scalp. When the coil is triggered, a brief electrical current passes through the coil and creates a magnetic pulse that stimulates the brain. During TMS, an electroencephalogram (EEG) will record brain activity. For the EEG, a cloth cap with electrodes is fitted on the participant s head. Participants will complete a memory task and a spatial processing task. They will also complete surveys about their mental state. Participation will last 2-3 weeks. ...
Background: Training in a new motor skill often involves periods of active practice and periods of rest. During early motor skill learning, improvements in performance usually happen during the short rest periods between practice sessions. Researchers want to use improved imaging techniques to study the contributions of specific parts of the brain to how people learn and retain movement skills. Objective: To learn the part played by different layers in the brain in retaining a newly learned movement skill. Eligibility: Healthy, right-handed, English-speaking people age 18-50. Design: Participants will be screened with: - Medical and neurological history - Medicine review - Physical exam - Neurological exam. Participants may have 2 magnetic resonance imaging (MRI) scans of the brain. During the MRI, they will lie in the scanner. The scanner makes noise. They will get earplugs. Participants will have behavior testing. A specific order of keys will be displayed on a computer screen. Participants will practice typing the keys with their left hand 36 times (in 10-second blocks). They will repeat this test with a random order of keys. Participants will see single numbers displayed one after the other on the computer screen. They will make single tap responses using the finger that corresponds with the number on the screen. Participants will have up to 4 study sessions. Each session will take about 5 hours.
Background: 'Free will' can be defined as the belief that people have control over their thoughts and movements. The topic of free will is controversial and is still being debated. Science has only partial answers to questions about free will, so researchers want to learn more about it. They want to assess the role of consciousness when intentions are present with behavior. This could help to explain the causal role of consciousness in movement or decisions. Objective: To learn more about free will. Eligibility: Healthy, right-handed adults ages 25-45 Design: Participants will be screened with medical history, physical exam, and neurological exam. Participants will have 1 study visit. It will last up to 4 hours. Participants will sit in a comfortable chair in front of a screen. They will perform some or all of the following tasks. Visual Task. Participants will watch different stimuli on the screen and answer simple questions. Electroencephalography (EEG). An EEG records the electrical activity of the brain ('brain waves'). For the EEG, small electrodes are put on the scalp with an electrode cap. A gel is placed in the space between the electrodes and the scalp. Participants' brain waves will be recorded, including while they decide whether to move their thumb. Choice/Reaction Time Task. Participants will watch different stimuli on the screen and react to them by moving their wrist. During this task, they will wear an EEG cap on their head and electrodes on their arms and wrists. Electromyography. Small electrodes will be attached to participants' skin. Their muscle activity will be recorded while they decide whether to move their wrist and during the movement itself. Transcranial Magnetic Stimulation (TMS): TMS is a non-invasive brain stimulation that uses magnetic field to stimulate nerve cells in your brain. TMS can increase or decrease brain activity in particular area of your brain. TMS operates completely outside of the body and is generally very well tolerated....
Background: Much is known about how people perceive light touch, temperature, and pain. But less is known about how deep pressure is perceived. Deep pressure is an important part of many touch therapies, like massage therapy. Researchers want to learn more to help people with chronic pain and other disorders. Objective: To find out which sensory nerve fibers are involved in feeling the sensation of deep pressure. Eligibility: Healthy people ages 18 50 enrolled in study number 16-AT-0077 Design: Participants will be screened under study number 16-AT-0077 Participants will have 1 visit that lasts about 2 hours. Participants will have a brief medical interview. They will have a urine test. Participants will have ischemic nerve block on 1 arm. A blood pressure cuff will be inflated until the arm is numb for up to an hour. Participants will have tests to see how they perceive different sensations. They will rate gentle brushing on the hands and forearms. They will rate gentle pressure squeezing from a hand massager on the hands and forearms. Participants will receive other sensations such as vibration, cool, warm, pinprick without piercing the skin, finger movement, and pressure. They will be asked to rate or respond to the sensations. They will be asked to rate any pain or discomfort from the nerve block on an ongoing basis.
Background: People tend to pay more attention to one side of space than the other and this may be due to differences in the structure and function of the two sides of the brain. We are interested in whether we can detect those difference with magnetic resonance imaging (MRI), transcranial magnetic stimulation (TMS), and electroencephalography (EEG). Objective: The purpose of the study is to understand how differences in brain structure may cause people to pay more attention to one side than the other. Eligibility: Healthy adults ages 18-35 Design: Participants will be screened with a neurological exam. Participants will have 2-3 visits for a total duration of about 7/8 hours. Women of childbearing age must have a negative pregnancy test before each MRI scan. Visits may include: Physical exam Tests of attention, and thinking TMS. A brief electrical current will pass through a wire coil on the scalp. Participants will hear a click and may feel a pull. They may be asked to tense muscles or do tasks. Magnetic resonance imaging (MRI) scan for a maximum of 1 hour. Participants will lie on a table that slides into a cylinder in a strong magnetic field. They will do tasks on a computer screen or lie still. They will get earplugs for loud noise. EEG for no longer than 5 hours, with most lasting 3 hours. Gel and a cap with electrodes will be placed on the scalp. They will record brain waves while the participant gets TMS or does nothing. Questions about participants dominant hand and about the MRI.
Background: Research shows that the parietal and prefrontal areas of the brain are involved in short-term memory. Researchers want to look at the effects of transcranial magnetic stimulation (TMS) of these areas on short-term memory and brain activity. They will use functional magnetic resonance imaging (fMRI) to look at brain activity. Objective: To look at the effects of TMS on brain pathways involved in memory. Eligibility: Healthy, right-handed adults ages 18-50 Design: Participants will have 3 or 4 visits at least 1 week apart. They cannot drink alcohol for at least 48 hours before each visit. The screening visit lasts about 1 (Omega) hours. It can be combined with the first testing visit. Screening includes: - Medical history - Physical exam - Neurological exam - Urine tests - Questionnaires about being left or right handed and about their ability to imagine physical activities. The first testing visit lasts about 1 (Omega) hours and includes an MRI. For the MRI, participants lie on a table that slides into a machine. They will lie still or perform simple memory tasks on a computer screen. The second and third testing visits last about 3 hours. Participants will have: - 2 MRIs - TMS: A wire coil is held to the scalp. A brief electrical current passes through the coil to create a magnetic pulse that affects brain activity. They will perform simple memory tasks. - EMG: Small electrodes are taped to the skin to record muscle activity while they rest. After the study, participants will complete a questionnaire about any discomfort they experienced during the study.
Background: When people see and hear, the brain changes signals from the eyes and ears into perceptions and thoughts. No one fully understands how this happens. Researchers want to explore how healthy brains process sights and sounds. Objectives: To explore how people understand what they see and hear when the brain processes sights and sounds. Eligibility: Adults ages 18-65 who have at least 20/40 vision in at least one eye and do not use a hearing aid. Design: Some participants will take tests online anonymously. They will do computer tasks related to colors and behavior. In-person participants will be screened with medical history and physical exam. They will complete questionnaires and vision and hearing tests. Participants will plan how many testing sessions they will have and when. Sessions last 2-5 hours. They may include: Magnetic Resonance Imaging: Magnets and radio waves to take pictures of the brain. Participants will lie on a table that slides in and out of a tube. They will do a task during the scan. Magnetoencephalography: Records magnetic field changes from brain activity. Participants will sit or lie down. A cone will be lowered onto their head. They may do a task during the test. Electromyography: Electrodes attached to the skin will measure the electrical activity of muscles. Electroencephalogram: Electrodes on the scalp will record brain waves. Electrocardiography: Electrodes on the chest will record heart electrical activity. Tests of memory, attention, thinking, vision, and hearing. Eye Tracking: Cameras will follow participants eye movements. They may wear a cap with infrared cameras in front of their eyes. During the sessions, participants vital signs may be monitored.
Background: Noninvasive brain stimulation (NIBS) may help diagnose and treat psychiatric and neurological illness. But there is not enough research on how to apply NIBS. This includes how strong to make it, where on the brain to apply it, and for how long. Researchers also want to see what the brain is doing when it receives NIBS. Objective: To increase the effectiveness of NIBS. Eligibility: Healthy native English speakers ages 18-65 Design: Participants will be screened under another protocol with: Medical and psychiatric history Psychiatric evaluation Physical exam Urine tests All participants will start with a 2-hour visit for screening. (see below). They may learn how to do tasks that will be used later. After the screening session, they will be scheduled for an MRI session. The next part of the study is 4 substudies. Each substudy includes up to 4 sessions. A session is usually 2-3 hours but can last up to 8 hours. Participants can join multiple substudies, but only 1 at a time. They can do only 1 session on a given day. Each substudy includes the following: Behavioral tests: Interviews; questionnaires; simple tasks; and tests of memory, attention, and thinking Electromyography: Small sticky electrodes on the skin measure muscle activity. Transcranial magnetic stimulation: A wire coil is held to the scalp. A brief electrical current passes through the coil and affects brain activity. Magnetic resonance imaging (MRI): Participants lie on a table that slides into a machine that takes pictures of the brain. A coil is placed over the head. They will perform simple tasks while in the scanner. They may also get TMS. Electroencephalography: Small electrodes on the scalp record brain waves. Sponsoring Institution: National Institute of M