Top-Down Attentional Control of Visual-Processing
National Institute of Mental Health (NIMH)
Summary
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.
Description
Attention is required for most, if not all, perceptual processes. There is a converging body of evidence from single-cell recording studies in monkeys and neuroimaging, behavioral, and clinical studies in humans showing that the processing of attended information is enhanced relative to the processing of unattended information. What is the source of this attentional modulation? Because neuroimaging studies have demonstrated that multiple cortical regions are recruited during tasks involving selective attention, it has proven difficult thus far to determine the differential contributions of ea…
Eligibility
- Age range
- 18–100 years
- Sex
- All
- Healthy volunteers
- Yes
* INCLUSION CRITERIA: All Subjects 1. All subjects will be 18 years of age or older and have at least a high school education. 2. Capacity to provide their own informed consent, understand and cooperate with study procedures. 3. Able to read and write in English to guarantee understanding of all written and spoken instructions, which are in English. Patients: 1. Unilateral or bilateral focal lesions of prefrontal, parietal, occipital or temporal cortex, or amygdala. 2. At least three months post-stroke, lobectomy and or neurosurgical resection. Healthy volunteers: 1\. Neurologically norm…
Location
- National Institutes of Health Clinical CenterBethesda, Maryland