How To Test For Aphantasia At Home Using Binocular Rivalry

Discover if you have aphantasia using a simple binocular rivalry test you can do at home. Learn about objective measurement techniques and what your results could mean.
Binocular Rivalry, binocular rivalry aphantasia test
Illustration by Holly-Anne Drowne. Red and Blue Horse (3D Effect): Behance

Table of Contents

What is Aphantasia?

Aphantasia is a condition where otherwise healthy individuals completely lack the ability to visualize mental images. While most people can easily imagine a red apple or recall visual memories, those with aphantasia experience no visual imagery in their “mind’s eye.”

Visualizing thoughts, past memories, or images of the future is ubiquitous in our daily lives. However, this visualization experience is entirely unknown for approximately 1-3% of the population who have aphantasia. Testing for this condition has evolved from subjective questionnaires to more objective methods like the binocular rivalry aphantasia test.

Current Aphantasia Assessment Methods

The Vividness of Visual Imagery Quiz (VVIQ)

To determine whether someone has aphantasia, many researchers conduct an initial evaluation using the Vividness of Visual Imagery Quiz (VVIQ). This assessment asks you to rate the vividness of different scenarios to test the strength of your visual imagery.

The VVIQ is a proven psychometric tool for measuring individual differences in visual imagination and is considered a reliable self-assessment for identifying potential aphantasia. However, it relies on subjective reporting, which led scientists to seek more objective measurement methods.

The Need for Objective Measurement

Until recently, it was unclear to scientists whether people with aphantasia:

  • Could not imagine visually at all, or
  • Had images in their minds but were simply unaware of them

To objectively address this question, a team of researchers from UNSW led by Dr. Joel Pearson conducted a study using binocular rivalry and a technique called perceptual priming. These studies are typically conducted in controlled laboratory environments with specialized equipment to ensure accurate results.

What is Binocular Rivalry Testing?

Important Note: Professional binocular rivalry testing is typically conducted in controlled laboratory environments with specialized equipment, standardized protocols, and trained researchers. The home version described in this article is a simplified adaptation that can provide insights but will not have the same accuracy as laboratory testing.

Understanding Visual Perception

When light enters our eyes, it sends information to our brains about the world around us. The brain collects visual data from both eyes and combines this information to show us one unified image. However, the brain can get confused when both eyes receive completely different sensory information.

How Binocular Rivalry Works

Binocular rivalry is a phenomenon of visual perception where perception alternates between different images presented to each eye. Instead of overlapping conflicting images, only one image dominates, and that’s what you consciously see.

In the red-blue superimposed images used for aphantasia testing, the red image is filtered to one eye while the blue image is filtered to the other eye through the colored glasses. For example, when viewing a superimposed red zebra and blue kangaroo image through red-blue glasses, your left eye might see only the red zebra while your right eye sees only the blue kangaroo. Your brain will “choose” to show you either the red zebra or the blue kangaroo, but not both simultaneously.

BinocularRivalry Zebra Kanga
Test Image 1 – Kangaroo (blue) and Zebra (red) superimposed. Record which animal appears more dominant. Illustration by Helmo. Rabbit-Leopard: Brad Wilson/Getty Image.

Perceptual Priming and Mental Imagery

Here’s where it gets interesting: perceptual priming occurs when visualizing a specific image or color in your mind makes you more likely to see that image during binocular rivalry.

  • People without aphantasia: Can visualize colors mentally, which primes their brain to see that color more often
  • People with aphantasia: Cannot visualize colors mentally, so no priming occurs, and they see both images equally often

How to Test for Aphantasia at Home

Important Disclaimer: This is a simplified home version of laboratory binocular rivalry testing. Professional testing in controlled environments with specialized equipment and trained researchers provides more accurate and reliable results. This home test should be considered exploratory and not diagnostic.

What You’ll Need

  • Red-blue 3D glasses (old-school theater glasses work perfectly)
  • A computer or mobile device
  • A stable surface to rest your chin on (stack of books works well)
  • Paper and pen to record results
Binocular Rivalry Aphantasia Test
Photo by Sigmund on Unsplash

Step-by-Step Binocular Rivalry Experiment

Phase 1: Baseline Testing

  1. Set up your workspace
    • Put on the red-blue glasses
    • Stabilize your head by resting your chin on a stack of books
    • Have your recording materials ready
  2. View the test images
    • Look at each binocular rivalry image (red and blue animals superimposed)
    • For each image, record which color appears more dominant
    • Repeat excercise up to 10 times
    • Note: One image will be visible through the red lens, another through the blue lens
  3. Record your baseline results
    • Which image was more dominant: red or blue?
    • Count total red vs. blue dominance across all images
    • Note any unclear or mixed results
binocularrivalry Rabbit Leopard
Test Image 2 – Rabbit (blue) and Leopard (red) superimposed. Note which color dominates your perception. Illustration by Helmo. Rabbit-Leopard: Brad Wilson/Getty Images.

Phase 2: Priming Test

  1. Prepare for priming
    • Before looking at the images again, focus on the color red
    • Try to visualize red in your mind for 30 seconds
    • Think of red objects: apples, stop signs, fire trucks, roses
  2. Repeat the viewing test (up to 10 times)
    • Look at the same images while maintaining focus on red
    • Record which color appears dominant for each image
    • Note any changes from your baseline results
  3. Record your priming results
    • Count red vs. blue dominance
    • Compare to your baseline results

Phase 3: Results Analysis

Compare your results from Phase 1 and Phase 2:

  • Did you see red more frequently in Phase 2?
  • Was there a significant difference between the two phases?
  • Record the percentage increase (if any) in red dominance
binocularrivalry butterflyspider
Test Image 3 – Butterfly (blue) and Spider (red) superimposed. Record your dominant perception. Illustration by Helmo. Tarantula: Davies and Starr/Getty Images.

Results Tracking Template

PhaseRed DominanceBlue DominanceUnclearNotes
Baseline__/ 10__/ 10__/ 10
Priming__/ 10__/ 10__/ 10
Differrence+/-__+/-__+/-__

Interpreting Your Results

Likely Non-Aphantasic Results

  • Significant increase in red dominance during priming phase
  • 6-8 out of 10 times seeing red when priming for red
  • Clear difference between baseline and priming phases

Potential Aphantasia Indicators

  • Little to no change between baseline and priming phases
  • Difficulty or inability to visualize red during priming
  • Random or equal distribution of red/blue dominance in both phases

Important Considerations

This home test provides insight into your mental imagery abilities but has limitations:

Laboratory vs. Home Testing

  • Professional labs use calibrated displays, controlled lighting, precise timing, and standardized protocols
  • Home testing variables include screen quality, lighting conditions, glasses quality, and individual setup differences
  • Research standards typically require multiple sessions with dozens of trials for reliable results

General Limitations

  • Not a diagnostic tool: Only a qualified professional can diagnose aphantasia
  • Requires repetition: Multiple trials increase accuracy
  • Individual variation: Results may vary due to factors like fatigue or concentration

Are There Other Objective Tests For Aphantasia?

Researchers use several objective measures, typically in laboratory settings.

Laboratory-Based Tests

  • fMRI studies measuring brain activity during imagery tasks in controlled scanner environments
  • Pupillometry measuring pupil responses to imagined bright/dark scenes using specialized eye-tracking equipment
  • EEG studies recording electrical brain activity during mental imagery tasks
  • Reaction time studies measuring responses to imagery-based tasks with precise timing equipment

Clinical and Research Assessments

  • Standardized drawing tasks comparing memory-based drawings under controlled conditions
  • Multi-session binocular rivalry testing with calibrated equipment and statistical analysis
  • Comprehensive imagery questionnaires administered by trained researchers
  • Behavioral paradigms testing imagery across different sensory modalities

What Should I Do If I Think I Have Aphantasia?

If you think you might have aphantasia, consider:


This article is for educational purposes only and does not constitute medical advice. If you have concerns about your mental imagery abilities, consult with a qualified professional.

Keogh, R., & Pearson, J. (2018). The blind mind: No sensory visual imagery in aphantasia. Cortex; a Journal Devoted to the Study of the Nervous System and Behavior, 105, 53–60. doi:10.1016/j.cortex.2017.10.012
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My mind’s eye disappeared after a long period of anxiety, which then was intensified thus creating a total loss. I noticed it at first, when I was lying awake at night trying to count animals to go back to sleep. I noticed I could not see the animals in my minds eye, yet had clear memory of the same, when my eyes were open. Now there is nothing at all in my mind’s eye, it is similar to the projector or the screen not being present. I close my eyelids and see nothing but a blank. With regards to the experiment of binocular rivalry, I see both images partially and thinking of red or blue, [even after looking at red / blue images], there is currently no difference. I will see if there is a difference after a session of visual meditation via audio, which in itelf is a challenge due to the lack of the mind’s eye.

I found I could see much the same in both. I could see what I wanted to see somehow, depending on how I chose to look, if that makes sense. I got better at ‘looking’ by the 2nd time and so could perceive more of the blue animals, which tended to be dominated by the red when I first looked. I can’t say that picturing the colours made much difference, though I was able to picture them in my mind, sort of (the red was a easier than the blue to imagine).