42 Clinical Trials for Various Conditions
The goal of this study is to examine attention elicited by icon, text-only, and control front-of-package food labels. The study also aims to explore whether English language proficiency moderates the impact of icon vs. text-only labels on attention.
This study investigates whether visual attention can be improved in individuals with schizophrenia by stimulating the brain via transcranial Direct Current Stimulation (tDCS).
The proposed SBIR Phase I study tests the feasibility of PATH neurotraining for improving cognitive skills in older adults and, potentially, forestalling or protecting against cognitive decline and dementia. The feasibility of PATH neurotraining will be evaluated by comparing it with another cognitive training program, Brain HQ's Target Tracker, and ascertaining the relative advantage(s) of PATH neurotraining for enhancing cognition in older adults between 55 and 75 years of age whose cognition is either in the age-normative range or in the mild cognitive impairment (MCI) range of standardized psychometric measures. MEG/MRI source imaging will be used on 12 of the PATH group participants to determine whether the behavioral results are verified by improvements in the dorsal, attention, and executive control networks.
The purpose of this study is to provide information about how the brain processes sensory inputs using visual stimuli throughout various psychophysical experiments.
Acetylcholinesterase inhibitors (AChE-I) comprise a class of drugs used to treat Alzheimer's disease (AD), but controversy about their usefulness remains. Modest response rates of treated versus placebo groups, small effect sizes with respect to efficacy, drug costs, and clinical relevance of the effects are problematic. Standard efficacy measures of efficacy are not sufficiently sensitive, and trying to assess cognitive change after 4-6 months of therapy confounds the drug effect and the natural progression of the disease. Surprisingly, attention has never been included in the assessment of AChE-I drugs. The rationale for using attentional measures are that (1) Attentional deficits are recognized as a critical cognitive change in the earliest phases of AD; (2) Attentional function is directly mediated by the cholinergic system, and responds rapidly to cholinergic augmentation, particularly on tasks that tax available attentional capacity are dose dependent; and (3) Acetylcholine is depleted in AD. However, the link between attention and cholinergic depletion in AD has not been fully explored, especially with regard to response to cholinergic treatment. The study tests if attentional performance can be a more sensitive marker of response. In a longitudinal study we measure attentional, as well as cognitive and behavioral performance in de novo AD patients undergoing donepezil treatment. The investigators develop visual attentional measures and contrast them to global and domain-specific cognitive scores on three occasions (T1) baseline pre-treatment, (T2) after approximately 6 weeks, and (T3) after 6 months treatment. The T1-to-T2 arm is a double-blind placebo control period, after which members of the placebo group start open-label treatment. The assessment at 6 months allows us to determine whether the changes seen earlier at T2 can predict patients who respond, or determine which measures best predict response. We hypothesize that attention measures are more sensitive than standard global measures or other cognitive domains and that the change of attentional function can be detected after only after approximately 6 weeks treatment. Knowledge from this project will facilitate and inform our decisions about individual patients undergoing pharmacological treatment.
The objective of this proposal is to evaluate the effectiveness of rehabilitation for visual attention deficits in U.S. military service members across three programs: Visual Attention and Working Memory Programs (UCR Games), Speech Pathologist-Directed Treatment, and General Cognitive Rehabilitation Games (Lumosity). In addition to the above prospective component, this study also has a retrospective component in which archival data collected from routine clinical care will be examined for analysis. The investigators hope to gain a better understanding of the unique and cumulative influence different cognitive rehabilitation programs have on improving attention complaints in mTBI.
The purpose of this study is to learn more about how the brain allows people to focus on important objects and filter out unimportant ones when looking at visual images. Our senses provide us with a vast amount of information at any given moment in time. For example, visual scenes contain many different objects that cannot be processed simultaneously because of the limited processing capacity of the brain's visual system. Evidence suggests that a a network of brain regions selects relevant information and filters out irrelevant information when people view cluttered visual scenes. This study will use transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) to determine how the different brain regions involved in attentional control and filtering interact. Participants in this study will undergo computer tests, an MRI scan, and TMS. During the MRI, participants will look at pictures and count objects appearing on a screen. During the TMS, participants will perform a computer test. Participants' ability to pay attention will be tested with and without TMS. Participants may be asked to return for additional tests in the future....
How does one know what to look at in a scene? Imagine a "Where's Waldo" game - it's challenging to find Waldo because there are many 'salient' locations in the picture, each vying for one's attention. One can only attend to a small location on the picture at a given moment, so to find Waldo, one needs to direct their attention to different locations. One prominent theory about how one accomplishes this claims that important locations are identified based on distinct feature types (for example, motion or color), with locations most unique compared to the background most likely to be attended. An important component of this theory is that individual feature dimensions (again, color or motion) are computed within their own 'feature maps', which are thought to be implemented in specific brain regions. However, whether and how specific brain regions contribute to these feature maps remains unknown. The goal of this study is to determine how brain regions that respond strongly to different feature types (color and motion) and which encode spatial locations of visual stimuli extract 'feature dimension maps' based on stimulus properties, including feature contrast. The investigators hypothesize that feature-selective brain regions act as neural feature dimension maps, and thus encode representations of salient location(s) based on their preferred feature dimension. The investigators will collect eye-tracking data while participants view visual stimuli made salient based on different combinations of feature dimensions. From the eye-tracking data, the investigators will construct fixation heat maps on the feature dimensions for all levels of salience, allowing them to connect behavioral data to the latter fMRI dataset. Each participant will freely view the stimuli as they appear on the computer display. Across trials, the investigators will manipulate 1) the 'strength' of the salient locations based on how different the salient stimulus is compared to the background, 2) the number of salient locations, and 3) the feature value(s) used to make each location salient. Altogether, these manipulations will help the investigators fully understand these critical salience computations in the healthy human visual system.
How do we know what's important to look at in the environment? Sometimes, we need to look at objects because they are 'salient' (for example, bright flashing lights of a police car, or the stripes of a venomous animal), while other times, we need to ignore irrelevant salient locations and focus only on locations we know to be 'relevant'. These behaviors are often explained by the use of 'priority maps' which index the relative importance of different locations in the visual environment based on both their salience and relevance. In this research, we aim to understand how these factors interact when determining what's important to look at. Specifically, we are evaluating the extent to which the visual system considers locations that are known to be irrelevant when considering the salience of objects. We're testing the hypothesis that the visual system always computes maps of salient locations within 'feature maps', but that activity from these maps is not read out to guide behavior for task-irrelevant locations. We'll have people look at displays containing colored shapes and/or moving dots and report aspects of the visual stimulus (e.g., orientation of a line within a particular stimulus). We'll measure response times across conditions in which we manipulate the presence/absence of salient distracting stimuli and provide various kinds of cues about the potential relevance of different locations on the screen. The rationale is that by measuring changes in visual search behavior (and thus inferring computations performed on brain representations), we will determine how these aspects of simplified visual environments impact the brain's representation of important object locations. This will support future studies using brain imaging techniques aimed at identifying the neural mechanisms supporting the extraction of salient and relevant locations from visual scenes, which can inform future diagnosis/treatment of disorders which can impact our ability to perform visual search (e.g., schizophrenia, Alzheimer's disease).
How does one know what to look at in a scene? Imagine a "Where's Waldo" game - it's challenging to find Waldo because there are many 'salient' locations in the picture, each vying for one's attention. One can only attend to a small location on the picture at a given moment, so to find Waldo, one needs to direct their attention to different locations. One prominent theory about how one accomplishes this claims that important locations are identified based on distinct feature types (for example, motion or color), with locations most unique compared to the background most likely to be attended. An important component of this theory is that individual feature dimensions (again, color or motion) are computed within their own 'feature maps', which are thought to be implemented in specific brain regions. However, whether and how specific brain regions contribute to these feature maps, along with their role in supporting memory of visual information over brief delays, remains unknown. The goal of this study is to determine how brain regions that respond strongly to different feature types (color and motion) and which encode spatial locations of visual stimuli contribute to memory of visual features. Based on previous studies, the investigators hypothesize that feature-selective brain regions act as neural feature dimension maps, and thus encode representations of relevant location(s) based on their preferred feature dimension, such that the stimulus representation in the most relevant feature map is maintained over a memory delay period to support adaptive behavior. The investigators will scan healthy human participants using functional MRI (fMRI) in a repeated-measures design while they view and remember different features of visual stimuli (e.g., color or motion). The investigators will employ state-of-the-art multivariate analysis techniques that allow them to reconstruct an 'image' of the stimulus representation encoded by each brain region to dissect how neural tissue identifies salient locations. Each participant will recall the remembered feature value (color or motion) of a stimulus presented in the periphery. Across trials the investigators will manipulate the remembered feature value (color, motion, or attend to nothing). This manipulation will help the investigators fully understand these critical relevance computations in the healthy human visual system.
How does one know what to look at in a scene? Imagine a "Where's Waldo" game - it's challenging to find Waldo because there are many 'salient' locations in the picture, each vying for one's attention. One can only attend to a small location on the picture at a given moment, so to find Waldo, one needs to direct their attention to different locations. One prominent theory about how one accomplishes this claims that important locations are identified based on distinct feature types (for example, motion or color), with locations most unique compared to the background most likely to be attended. An important component of this theory is that individual feature dimensions (again, color or motion) are computed within their own 'feature maps', which are thought to be implemented in specific brain regions. However, whether and how specific brain regions contribute to these feature maps remains unknown. The goal of this study is to determine how brain regions that respond strongly to different feature types (color and motion) and which encode spatial locations of visual stimuli transform 'feature dimension maps' based on stimulus properties as a function of task instructions. The investigators hypothesize that feature-selective brain regions act as neural feature dimension maps, and thus encode representations of relevant location(s) based on their preferred feature dimension, such that the stimulus representation in the most relevant feature map is up-regulated to support adaptive behavior. The investigators will scan healthy human participants using functional MRI (fMRI) in a repeated-measures design while they view visual stimuli made relevant based on a cued feature dimension (e.g., color or motion). The investigators will employ state-of-the-art multivariate analysis techniques that allow them to reconstruct an 'image' of the stimulus representation encoded by each brain region to dissect how neural tissue identifies salient locations. Each participant will perform a challenging discrimination task based on the cued feature (report motion direction or color of stimulus dots) of a stimulus presented in the periphery, which are identical across trial types. Across trials the investigators will manipulate the attended feature value (color, motion, or fixation point). This manipulation will help the investigators fully understand these critical relevance computations in the healthy human visual system.
How does one know what to look at in a scene? Imagine a "Where's Waldo" game - it's challenging to find Waldo because there are many 'salient' locations in the picture, each vying for one's attention. One can only attend to a small location on the picture at a given moment, so to find Waldo, one needs to direct their attention to different locations. One prominent theory about how one accomplishes this claims that important locations are identified based on distinct feature types (for example, motion or color), with locations most unique compared to the background most likely to be attended. An important component of this theory is that individual feature dimensions (again, color or motion) are computed within their own 'feature maps', which are thought to be implemented in specific brain regions. However, whether and how specific brain regions contribute to these feature maps remains unknown. The goal of this study is to determine how brain regions that respond strongly to different feature types (color and motion) and which encode spatial locations of visual stimuli extract 'feature dimension maps' based on stimulus properties, including feature contrast. The investigators hypothesize that feature-selective brain regions act as neural feature dimension maps, and thus encode representations of salient location(s) based on their preferred feature dimension. The investigators will scan healthy human participants using functional MRI (fMRI) in a repeated-measures design while they view visual stimuli made salient based on different combinations of feature dimensions. The investigators will employ state-of-the-art multivariate analysis techniques that allow them to reconstruct an 'image' of the stimulus representation encoded by each brain region to dissect how neural tissue identifies salient locations. Each participant will perform a challenging task at the center of the screen to ensure they keep their eyes still and ignore the stimuli presented in the periphery, which are used to gauge how the visual system automatically extracts important locations without confounding factors like eye movements. Across trials and experiments the investigators will manipulate 1) the 'strength' of the salient locations based on how different the salient stimulus is compared to the background, 2) the number of salient locations, and 3) the feature value(s) used to make each location salient. Altogether, these manipulations will help the investigators fully understand these critical salience computations in the healthy human visual system.
The goals of this study are to 1) use EEG steady-state visual evoked potentials as a noninvasive measure of the neuroplasticity induced by repetitive transcranial magnetic stimulation (rTMS), 2) use visual contrast detection paradigms as a behavioral measure of rTMS effects, and 3) to investigate how visual spatial attention augments or suppresses the neuroplastic impact of rTMS. Participants will observe visual stimuli on a screen while allocating their attention to different parts of the visual field and making responses when they observe changes in the visual stimuli. rTMS is performed to visual cortex using MRI-retinotopy neuronavigation. Then the visual task paradigm is performed again.
In "Mixed Hybrid Search", participants look for 3 specific target (e.g. this boot, this cat, this hat) and 3 categorical items (ANY fruit, ANY car, ANY game). In this task, participants tend to miss many categorical items. This is analogous to radiologists missing "incidental findings" when reading medical images. In this experiment, participants were given a checklist to help them to find categorical targets.
Teens with Attention-Deficit/Hyperactivity Disorder (ADHD) have high rates of negative driving outcomes, including motor vehicle crashes, which may be caused by visual inattention (i.e., looking away from the roadway to perform secondary tasks). Two versions of a driving intervention that trains teens to reduce instances of looking away from the roadway will be tested in teens with ADHD.
The goal is to look for qualitative differences in visual search behavior when one search is performed many times in a row compared to when multiple search tasks are intermixed. Four search tasks are tested. The target is the same in every task but the types of distractors change from task to task. In this version, observers get some degree of choice in what they are searching.
The goal is to look for qualitative differences in visual search behavior when one search is performed many times in a row compared to when multiple search tasks are intermixed. Four search tasks are tested. The target is the same in every task but the types of distractors change from task to task. In the Mixed condition, the four tasks are randomly changed from trial to trial. In the Blocked condition, each task is run as a block of 100 trials.
The goal is to look for qualitative differences in visual search behavior when one search is performed many times in a row compared to when multiple search tasks are intermixed. Four search tasks are tested. In the Mixed condition, the four tasks are randomly changed from trial to trial. In the Blocked condition, each task is run as a block of 100 trials.
The objective of this study is to determine the effects of electrical brain stimulation (EBS) on visual search in natural scenes in humans.
Background: Parkinson Disease (PD) is a nervous system disorder that affects movement. Dopamine is an important neurotransmitter in the brain. As PD progresses, there is less and less dopamine in the brain. Researchers think there may be a relationship between differences in attention and dopamine in people with PD. Objective: To learn if people with PD that is worse on one side also have differences in how much attention they pay to the two sides of space on their left and right. Eligibility: English-speaking, right-handed people age 35-80 with PD. Design: Participants will be screened with medical and neurological history and exam, and medicine review. Participants will have 1 study visit. It will last 7-8 hours. They will stop taking their Parkinson medicine 12 hours before the visit. Participants will complete questionnaires. Participants will do tasks on a computer screen. They will judge the middle of lines, react to stimuli, and search and identify items that appear on the screen. Participants may have functional and structural magnetic resonance imaging (MRI). MRI uses a strong magnetic field and radio waves to take pictures of the brain. During the MRI, participants will lie on a table that slides in and out of the MRI scanner. While inside the scanner, they will look at a cross on a screen, relax, and think about nothing. Participants will undergo prism adaptation. They will sit in front of a board while their chin rests on a support. They will point to 1 of 2 dots on the board while they wear prism glasses that shift their vision to the left or right....
Teens with Attention-Deficit/Hyperactivity Disorder (ADHD) have high rates of negative driving outcomes, including motor vehicle crashes, which may be caused by visual inattention (i.e., looking away from the roadway to perform secondary tasks). A driving intervention that trains teens to reduce instances of looking away from the roadway will be tested in teens with ADHD.
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 relation between eye movement and brain function is a subject of interest to the National Eye Institute. * By comparing eye movement in healthy volunteers to research conducted on patients who have difficulty moving their eyes, the National Eye Institute hopes to develop and improve diagnostic procedures for people with eye diseases. Objectives: -The purpose of this study is to understand how we see visual patterns and how we move our eyes to see. Eligibility: * Normal volunteers: * must have no serious illnesses and must be 18 years of age or older * are able to follow directions and pay attention to visual stimuli and respond as appropriate * individuals with a history of eye or brain diseases, or previous eye or eye muscle surgery, are not allowed to participate in this study. Individuals who are currently using eye medications also are not eligible for the study. * Patients: * who are 18 years of age or older * are able to follow directions and pay attention to visual stimuli and respond as appropriate Design: * Participants will visit the National Eye Institute outpatient clinic for examination and testing. * Participants will be screened with a medical history and eye examination (including eye pressure and eye movement tests). * Participants with healthy eyes will participate in eye movement testing experiments: * One or more sessions lasting less than three hours each. * Eye movements will be recorded with a video/infrared camera system. * For the majority of the studies done under this protocol, only one or two sessions will be required. A few studies recording very small eye movements will require three or more sessions.
The goal of the study is to see if the use of music improves attention during visual field exams for pediatric glaucoma patients.
This study in, healthy human subjects using fMRI and MRS (magnetic resonance spectroscopy) characterizes, how attention and acetylcholine affect visual perception and the brain's representation of the visual environment. Levels of acetylcholine in the cerebral cortex will be enhanced by administration of donepezil, an inhibitor of acetylcholinesterase. Half the subjects will receive donepezil and other half will receive placebo.
During visual fixation, small eye movements of which we are usually not aware, prevent the maintenance of a steady direction of gaze. These eye movements are finely controlled and shift retinal projection of objects within the fovea, the region of the retina where visual acuity is highest. This program of research examines the link between these eye movements and attention, and tests the hypothesis that attention, similarly to eye movements, can be controlled at the foveal level. Psychophysical experiments with human subjects, using state-of-the-art techniques, high resolution eyetracking and retinal stabilization are conducted to address these questions. Gaze-contingent calibration procedures are employed to achieve high accuracy in gaze localization. A custom developed gaze-contingent display is used to shift in real-time visual stimuli on the monitor to compensate for the observer eye movements during fixation periods and to maintain stimuli at a desired location on the retina. Experiments involve visual discrimination/detection tasks with stimuli presented at selected eccentricities within the fovea. Participants' performance and reaction times are examined under different conditions, in which various types of attention are manipulated. In addition to advancing our basic understanding of visual perception, this research leads to a better understanding of attentional control at the foveal scale and of the contribution of microscopic eye movements to the acquisition and processing of visual details.
The NIMH is conducting studies aimed at gaining a better understanding of the areas of the brain that are involved in different types of mental processes. This study will focus on brain regions involved in visual perception and attention. Healthy normal volunteers and people who have had a stroke or undergone neurosurgery may be eligible for this study. Candidates must be 18 years of age or older, They must not have a history of a psychiatric disorder, including depression, anxiety, psychosis, or neurological disease other than stroke or the previous neurosurgery. Participants undergo the following tests and procedures during four or more visits to the NIH Clinical Center: * Physical and neurological examinations and depression rating scale. * Cognitive testing: Subjects complete written tests, sit at a computer and make decisions about what they are shown by pressing keys, or answer questions from a test examiner. * Behavioral training: Subjects practice performing a cognitive task that involves looking at and making decisions about visual images that appear on a computer screen. * Magnetic resonance imaging (MRI): Subjects undergo MRI scanning while they perform the task they previously practiced. The MRI scanner is a metal cylinder surrounded by a strong magnetic field. During the procedure, subjects lie still for up to 10 minutes at a time on a table that can slide in and out of the cylinder. The entire MRI scanning session takes about one hour. There are multiple scans which each can take up to 10 minutes. They may be asked to return for one or two additional scanning sessions. During the behavioral training or MRI scanning, special pieces of equipment that monitor eye movements may be used. Some subjects may be asked to return to NIH for an additional visit to participate in a magnetoencephalographic scan. This test uses several sensors applied to the scalp to measure very small changes in magnetic fields. This is another way to measure brain activity.
The goal of this study is to investigate the finding that there are large individual differences in how participants move their eyes during active visual search. For example, some individuals tend to fixate, that is point their eyes steadily at a single location, for longer than other individuals before moving to another location. This experiment will use behavioral tasks to measure an individual's attentional and inhibitory functioning, and then see how each of these contributes to between-participant variability in eye movement behavior during visual search.
EEG Measures during Visual Search Task. In this line of research, the researchers having participants receive a positive (target) template cue, negative (distractor) template cue, or neutral (non-informative) template cue. Note: This is a re-analysis of previously collected data.
In this line of research, the researchers are examining a basic science question regarding the working memory representations underlying visual search using a positive template (looking for a target) or a negative template (avoiding a distractor).