Do you know that some people can't see images in their minds? It's a fact and the condition is called Aphantasia. Health experts don't define it as a medical disease, disorder, or disability. It is a condition when the brain doesn't form images either by thinking or imagination. Instead, it is a characteristic form like, “ which hand you use to write naturally.” To our understanding, it is much like, “People with aphantasia can't visualise images in their mind.” ⁽¹⁾

The reason behind aphantasia can’t visualize images-different wiring in the brain.

Mostly, the brain tries to generate images and the primary visual cortexes even light up in the same way. The work that was published in the journal, “Current Biology” on Jan 10, gave up a piece of early evidence, that in people with aphantasia, the brain can light up as if they were generating mental images in the primary visual cortex. The primary visual cortex is the main part of the brain that is responsible for processing visual information.

Yet, the signals get lost during the process of translation.

A study co-author, Joel Pearson, a professor of psychology at University of New South Wales in Australia has shared his view on Live Science, a new research suggested that the signal “warps or stretches” before it is perceived consciously by the person with aphantasia. ⁽²⁾

There is still no clear data about the condition but it explains that the condition is different from normal. Pearson and his colleagues have conscripted 18 people without aphantasia and 14 people with aphantasia in the research. The team included a “binocular rivalry” trick that involved flashing two striped patterns of different colours in front of the participant's eyes.

The brain continuously merges visual information from the right and left eyes to construct one cohesive image and it cannot process the binocular rivalry. Its attempt to process the flashing stripes results in a visual illusion in which both patterns fluctuate, one image seems to be dominating for a few seconds. ⁽¹⁾

Pearson explained that people with aphantasia are less likely to be influenced by bias compared to normal people who can see images in their mind's eye. The stronger the mental imagery, the more likely it is to see bias in how they see the binocular rivalry pattern.

Pearson presented this technique as a way to test the aphantasia in the previous paper. 

The new study goes beyond simply asking people to fill up the questionnaire and this adds strength to the study.

The team also used the functional MRI that tracks the oxygenated blood flow in the brain which can help in testing brain activity. The oxygenated blood is increased to a specific region of the brain that in turn proportionally represents the active brain region location.

During the experiment, both the people with and without aphantasia showed an uptick in activity in the primary visual cortex. The brain activity was observed in both cases, one observing the striped patterns called perception, the other being when the participant was asked to imagine the patterns called imagery.

So, Pearson explained that people with aphantasia showed a little weaker brain activity compared to the normal participants. By this, it gives a clear idea that the processing level is different in both cases. The type of processing in people with aphantasia is quite different “ when they are directly observing an image.” ⁽²⁾

Pearson also mentioned surprising findings, generally, our brain processing is like this,” The patterns spotted in the right field of view are processed in the left side of the brain and vice-versa. In people with aphantasia, the opposite is true giving a hint that the wiring is different in the brain.

To understand further, scientists have tested the computer algorithms to recognise the brain activity that has appeared during tests.

It included the brain activity alone, where the algorithms accurately deduced the visual patterns, the participants were perceiving or attempting to imagine. This has been worked in both groups. Researchers tested how well algorithms could cross-decode these signals. ⁽¹⁾

To understand, “how closely did the brain activity triggered during perception match that triggered by mental imagery?”

In people with no aphantasia, signals are very similar and the signals are quite overlapping which could cause the brain to get confused with the algorithms. 

People with aphantasia have shown no cross-decoding, so a fundamentally different process is occurring.

The above findings do not explain why people with aphantasia are not able to visualize images in their conscious mind, even though their brain cells are firing. Pearson is planning to further conduct experiments in the field, it's a new field of research to be carried on and a lot of questions are unanswered. ⁽²⁾

References

1. Caramela, Sammi. “Aphantasia: Inside the Brains of People Who Have No Mind’s Eye.” Vice, January 28, 2025. Accessed January 31, 2025. https://www.vice.com/en/article/aphantasia-inside-the-brains-of-people-who-have-no-minds-eye/.

2. Guenot, Marianne. “People Who Can’t ‘See with Their Mind’s Eye’ Have Different Wiring in the Brain.” Live Science, 2025. Accessed January 31, 2025. https://www.livescience.com/health/neuroscience/people-who-cant-see-with-their-minds-eye-have-different-wiring-in-the-brain.

(Input from various sources)

(Rehash/Dr. Lakshmi Sahithi Tanneru/MSM)