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Probing the Role of Feature Dimension Maps in Visual Cognition: Manipulations of Relevant Locations on Salience Processing? (Expt 3.1 Pilot)

Probing the Role of Feature Dimension Maps in Visual Cognition: Expt 3.1 (Pilot)

Status
Enrolling by invitation
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06852521
Enrollment
240
Registered
2025-02-28
Start date
2025-02-06
Completion date
2027-02-01
Last updated
2026-04-22

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Attention, Basic Science: Visual Attention in Healthy Participants

Brief summary

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).

Interventions

OTHERStimulus Properties: Target Location

The location of the target item in the display will be varied across trials (appear left, right, up, or down)

OTHERStimulus Properties: Distractor Presence

A proportion of all trials will contain a task-irrelevant, singleton distractor defined in a non-target dimension (e.g., color target and motion distractor)

OTHERStimulus properties: Cue Validity

Varied across trials, the validity of the cue will be determined by the match or mismatch between direction of the visual cue (an arrowhead around the fixation pointing to the right, left, up, or down) and actual target location

Sponsors

University of California, Santa Barbara
Lead SponsorOTHER
National Eye Institute (NEI)
CollaboratorNIH

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE

Masking description

Participants will typically be unaware of the conditions presented, though because these involve manipulations of stimuli or task demands, they may be aware of the manipulation. This is not expected to impact the primary outcome measures (e.g., behavioral performance).

Intervention model description

This is a basic science study in which all participants will participate in all task conditions within each experiment (repeated-measures design).

Eligibility

Sex/Gender
ALL
Age
18 Years to 55 Years
Healthy volunteers
Yes

Inclusion criteria

* between 18 and 55 years of age * normal or corrected-to-normal vision

Exclusion criteria

• N/A

Design outcomes

Primary

MeasureTime frameDescription
Behavioral response (button press)Through study completion, an average of two weeksParticipants will be required to report the orientation of a line (horizontal or vertical) within the target via a speeded button press. The specific values of color, shape, and motion will vary randomly from trial to trial. Participants will complete separate sessions with each session directing participants to search for a different target feature dimension.
Gaze positionThrough study completion, an average of two weeksThe investigators will use the measured gaze position in (x,y) coordinates to verify stable fixation throughout the experiment. The data will be used to establish gaze fixation and/or track where participants look as they perform the visual search task. Trials with poor fixation performance may be excluded from further analyses.

Countries

United States

Contacts

PRINCIPAL_INVESTIGATORTommy C Sprague

University of California, Santa Barbara

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Apr 23, 2026