Brain Imaging for Visual Attention
Trial Summary
What is the purpose of this trial?
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.
Research Team
Tommy C Sprague
Principal Investigator
University of California, Santa Barbara
Eligibility Criteria
This study is for healthy individuals interested in how the brain processes visual information. Participants will undergo fMRI scans while performing memory tasks involving colors and motion. The goal is to understand how certain brain regions contribute to attention and memory of visual features.Inclusion Criteria
Exclusion Criteria
Timeline
Screening
Participants are screened for eligibility to participate in the trial
Experimental Task
Participants engage in visual working memory tasks while undergoing fMRI scanning. They remember and report features of visual stimuli, such as color or motion.
Anatomical & Retinotopic Mapping
Participants undergo anatomical and retinotopic mapping to identify brain regions for further analysis.
Follow-up
Participants are monitored for safety and effectiveness after the experimental tasks.
Treatment Details
Interventions
- Probing the Role of Feature Dimension Maps in Visual Cognition: Impact of Working Memory Maintenance (Expt 2.3)
Find a Clinic Near You
Who Is Running the Clinical Trial?
University of California, Santa Barbara
Lead Sponsor
National Eye Institute (NEI)
Collaborator