New Brain Theory Challenges Understanding of Visual Imagination

A version of this article appeared on Nation.Africa

The long-held scientific consensus regarding how the human mind conjures images is facing a significant challenge from a new theory published in Psychological Review. For years, neuroscientists operated under the assumption that visual imagination is essentially the process of seeing, but performed in reverse.

In standard vision, light entering the eyes triggers neural signals that move through a sequence of regions. This process, known as feedforward activity, starts with early regions identifying simple edges and lines before higher-level areas assemble these components into recognizable faces or objects.

The traditional model of imagination suggests that when a person thinks of a friend, the abstract memory travels back down this same path. These downward signals, called feedback activity, supposedly use the early visual areas as a workshop to reconstruct specific details like the shade of an eye or a jawline.

However, the newly proposed theory suggests that the brain does not simply recreate these signals from the top down. Instead, it argues that imagination sculpts images by carving into existing background brain activity.

Under this new framework, the act of imagining may depend more on the specific brain activity that the mind chooses to silence rather than the activity it creates. It positions the brain as a sculptor removing excess material to reveal a form, rather than a builder starting from a blank slate.

This shift in understanding could have implications for how researchers view cognitive diversity. Variations in imagery vividness, such as aphantasia, where individuals cannot visualize mental images, or hyperphantasia, where imagery is intense, may be linked to how this background activity is managed.

By rethinking these mechanisms, scientists hope to better understand how the mind's eye functions. This research provides a different perspective on the biological foundations of creativity and internal thought.