Salience Level for Visual Attention

Recruiting in Palo Alto (17 mi)

Overseen ByTommy Sprague

Age: 18 - 65

Sex: Any

Travel: May be covered

Time Reimbursement: Varies

Trial Phase: Academic

Waitlist Available

Sponsor: University of California, Santa Barbara

No Placebo Group

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 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.

Eligibility Criteria

This trial is for individuals aged 18 to 55 with normal or corrected-to-normal vision. It's designed to explore how people focus their attention on different parts of a visual scene, like finding Waldo in a busy picture.

Inclusion Criteria

I am between 18 and 55 years old.

My vision is normal or corrected to normal.

Participant Groups

The study tests how the brain identifies important locations in a visual scene based on feature types such as color or motion. Participants will view stimuli while eye-tracking data is collected to analyze where they look and how salient features capture their attention.

1Treatment groups

Experimental Treatment

Group I: Manipulations of graded feature salience (Expt 1.1)Experimental Treatment2 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