Brain study shows shared neural code between vision and imagination

Yesterday 08:20

By: Dakir Madiha

Brain study shows shared neural code between vision and imagination

When people picture a familiar face or recall a place, the brain activates many of the same neurons involved in seeing it. A study published on April 9 in Science by researchers at Cedars-Sinai provides detailed evidence at the single-neuron level that visual perception and mental imagery rely on a shared neural code in the human brain.

The research team studied 16 adults with epilepsy who had temporary electrodes implanted as part of routine diagnostic monitoring. Participants were shown images of faces and objects while scientists recorded the activity of individual neurons in the ventral temporal cortex, particularly the fusiform gyrus, a region central to high-level visual processing.

The findings showed that about 80 percent of visually responsive neurons encoded objects using a distributed axis-based system. In this system, each neuron responds in proportion to a specific visual feature dimension.

When some participants were later asked to imagine the same images from memory, about 40 percent of these neurons reactivated using the same coding pattern, with similar intensity to the original visual response. The signal was strong enough for researchers to reconstruct what a participant was imagining, marking a first in this type of study, according to collaborators at Caltech.

Ueli Rutishauser, director of the Center for Neuroscience and Medicine at Cedars-Sinai and co-author of the study, said mental images are formed by reactivating the same brain cells used during initial perception.

Artificial intelligence played a central role in the research. The team used generative AI to create synthetic images designed to maximally stimulate specific neurons, then confirmed that neural responses matched predictions. Varun Wadia, the study’s lead author, said advanced AI tools were essential throughout the investigation.

The findings may have clinical implications. Researchers said a better understanding of how the brain generates and controls mental imagery could support new treatments for conditions such as post-traumatic stress disorder and obsessive-compulsive disorder, which involve intrusive mental images. A program officer at the National Institutes of Health said the results could help explain psychiatric disorders linked to disrupted mental imagery and difficulty distinguishing reality.

Researchers said key questions remain, including what triggers neural reactivation and how the brain selects the precise group of neurons needed to recreate a specific memory.