Visual Features for Visual Attention

Overseen By Emily Machniak

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: University of California, Santa Barbara

Disqualifiers: Neurological disease, Implanted devices, Claustrophobia, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 2 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 3

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to understand how the brain decides where to focus attention in busy scenes, such as finding Waldo in a "Where's Waldo" puzzle. Researchers believe certain brain areas, which respond to features like color and motion, help identify important spots in a scene by creating "feature maps" that highlight unique locations. Participants will have their brains scanned with an fMRI while they view images with different feature contrasts to observe how these brain areas function. This trial suits individuals aged 18 to 55 with normal or corrected vision and no history of neurological disease. As an unphased trial, it offers participants the opportunity to contribute to foundational research on brain function and attention.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

What prior data suggests that this method is safe for participants?

Research shows that using fMRI to study visual attention is safe. Functional MRI (fMRI) is a common tool that reveals which brain areas activate during specific tasks. It doesn't use radiation or require injections, making it a low-risk method.

In similar studies, participants viewed images with varying colors, movements, or brightness to observe brain reactions. No serious side effects have been reported from this type of research. Participants might feel uncomfortable lying still in the MRI machine, and some may experience slight claustrophobia, but these are usually the only issues.

Overall, participants tolerate this method well. For those considering joining a trial using fMRI, it is reassuring to know that it is a safe way to explore brain function. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about this trial because it explores how different levels of visual salience affect our ability to focus on specific visual details. Unlike typical visual attention studies that might not vary the intensity of visual features, this trial manipulates feature contrast in terms of color, motion direction, and luminance to understand how these changes can enhance or hinder visual cognition. By probing these dimensions, the study aims to uncover new insights into how our brains prioritize visual information, potentially leading to innovative strategies for improving attention-related conditions.

What evidence suggests that this method is effective for understanding visual attention?

Research shows that the brain uses "feature dimension maps" to focus on important visual details, such as color or motion, guiding attention. Studies suggest these maps help the brain identify important elements in a scene by highlighting standout areas. When an object differs from its background, these maps direct the brain to focus on it. Computational models have demonstrated that these maps significantly influence automatic attention. This trial will explore how these brain processes work by manipulating graded feature salience, but past research has already shown their crucial role in directing visual attention. ^{1 2 3 6 7}

Who Is on the Research Team?

Tommy C Sprague

Principal Investigator

University of California, Santa Barbara

Are You a Good Fit for This Trial?

This trial is for healthy individuals interested in how the brain processes visual information. Participants should be able to focus on a task without moving their eyes, as they will view stimuli with varying levels of 'salience' or importance, like color and motion differences.

Inclusion Criteria

My vision is normal or corrected to normal with glasses or contacts.

Exclusion Criteria

Implanted medical devices (e.g., cardiac pacemaker; metallic aneurism clip)

I have reported having a neurological condition.

Non-removable metallic piercings

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Anatomical & Retinotopic Mapping

Participants undergo an anatomical and retinotopic mapping session to identify brain regions for further analysis

2 hours

1 visit (in-person)

Experimental fMRI Sessions

Participants engage in visual attention tasks during fMRI scanning to study the role of feature-selective brain regions

3-4 hours

2 visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after the experimental sessions

2 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Probing the Role of Feature Dimension Maps in Visual Cognition: Impact of Salience Level (Expt 1.1)

Trial Overview The study tests how certain brain regions create 'feature dimension maps' from visual stimuli properties using fMRI scans. It examines if these areas encode salient locations by feature contrast while participants perform a central screen task.

How Is the Trial Designed?

Group I: Manipulations of graded feature salience (Expt 1.1) Experimental Treatment 2 Interventions

Participants will view stimuli made salient based on feature contrast in one feature dimensions (color or motion direction; or checkerboard luminance contrast). The degree to which a location is salient will be manipulated based on the feature contrast across multiple values

Who Is Running the Clinical Trial?

University of California, Santa Barbara

Lead Sponsor

Trials

33

Recruited

3,100+

National Eye Institute (NEI)

Collaborator

Trials

572

Recruited

1,320,000+

Published Research Related to This Trial

This study provides evidence that specific regions in the human visual cortex act as 'feature dimension maps' that prioritize locations based on distinct visual features, such as color or motion, using fMRI to analyze brain activation patterns.

The results show a double dissociation where color-selective regions highlight color-defined salient locations while motion-selective regions do the same for motion-defined salience, supporting the idea that the brain processes different visual features independently to guide attention.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Feature-Specific Salience Maps in Human Cortex. Thayer, DD., Sprague, TC.[2023]

Bundesen's Theory of Visual Attention (TVA) can be effectively used to quantitatively measure the salience of visual features, which helps in understanding how differences between objects and their surroundings capture attention.

Through four experiments, including orientation pop-out displays and luminance assessments, the study demonstrates that TVA can be applied to various types of stimuli, enhancing our ability to analyze salience effects in visual attention research.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Fast and Conspicuous? Quantifying Salience With the Theory of Visual Attention. Krüger, A., Tünnermann, J., Scharlau, I.[2020]

Visual search performance is influenced by changes in target-defining dimensions rather than specific features, indicating that attention allocation is more sensitive to the overall dimension of stimuli.

Evidence suggests that feature contrast saliency signals are integrated early in the visual processing stage, supporting the idea that the effects of dimension changes occur before the selection of responses.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dynamic weighting of feature dimensions in visual search: behavioral and psychophysiological evidence. Krummenacher, J., Müller, HJ.[2021]

The study supports the feature integration theory (FIT) by demonstrating that detection tasks rely on dimension-specific mechanisms, while localization tasks utilize a more general approach across dimensions.

Results showed that switching between dimensions in detection tasks incurs costs, indicating that different cognitive processes are at play, which reinforces the idea that distinct mechanisms govern parallel and focal attention searches.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Feature integration theory revisited: dissociating feature detection and attentional guidance in visual search. Chan, LK., Hayward, WG.[2009]

The study demonstrated that visual attention can be influenced by top-down cues, as participants reacted faster to targets when they were precued with the correct dimension (color or orientation) compared to neutral cues.

Even with top-down cues, the previous target's dimension still affected reaction times, indicating that while attention can be directed, it does not completely override the influence of past stimuli.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Visual search for singleton feature targets across dimensions: Stimulus- and expectancy-driven effects in dimensional weighting. Muller, HJ., Reimann, B., Krummenacher, J.[2019]

Citations

1. clinicaltrials.gov clinicaltrials.gov/study/NCT06733467

Probing the Role of Feature Dimension Maps in Visual ... 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 ...

2. trialx.com trialx.com/clinical-trials/listings/289789/probing-the-role-of-feature-dimension-maps-in-visual-cognition-impact-of-salience-level-expt-11/

Probing the Role of Feature Dimension Maps in Visual ... The goal of this study is to determine how brain regions that respond strongly to different feature types (color and motion) and which encode ...

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10727177/

Feature-Specific Salience Maps in Human Cortex - PMC Priority map theory is a leading framework for understanding how various aspects of stimulus displays and task demands guide visual attention.

4. withpower.com withpower.com/trial/salience-level-for-visual-attention-744b5

Salience Level for Visual Attention · Info for Participants Research shows that the brain uses 'feature dimension maps' to focus on important visual details, like color or motion, which helps guide attention. This ...

5. frontiersin.org frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2025.1614468/full

Computational modeling of visual salience alteration and ... Computational saliency map models have facilitated quantitative investigations into how bottom-up visual salience influences attention.

6. ctv.veeva.com ctv.veeva.com/study/probing-the-role-of-feature-dimension-maps-in-visual-cognition-impact-of-salience-level-eye-tracki

Impact of Salience Level (Eye-tracking Follow-up Study) From the eye-tracking data, the investigators will construct fixation heat maps on the feature dimensions for all levels of salience, allowing ...

7. sciencedirect.com sciencedirect.com/science/article/abs/pii/S0165168412002058

Learning saliency-based visual attention: A review (2) Compute individual feature maps to quantify saliency in that particular feature dimension: This step uses biologically plausible filters such as Gabor or ...