Hallucinations can be a terrifying part of post-traumatic stress disorder (PTSD) and other psychiatric conditions such as schizophrenia. But according to a new study from Western University and the University of Cambridge, being able to visualize things in our mind's eye is useful as it allows us to examine our memories, simulate possible future events and solve abstract problems.

As far back as the ancient Greek philosophers, humanity has contemplated how we visualize an object. Do we recreate a picture of it in our mind? Do we recall our knowledge of what the object is? Or do we tap the emotional feeling associated with the object? Knowing how we visualize has many applications.

A new study published by Nature Scientific Reports from Rhodri Cusack from Western's Brain and Mind Institute and Daniel Mitchell from Cambridge Neuroscience may just answer the question of how we visualize objects.

The neuroscientists used a new type of real-time functional magnetic resonance imaging (fMRI) to compare brain activity patterns of study participants when they imagined objects to the activity patterns of the same individuals when they actually viewed many different objects on a screen. The study showed that when something is imagined, the participants didn't recreate a picture of the object in their mind's eye, but rather recalled their knowledge of it and their emotional response to it.

Nineteenth century scientist Francis Galton found differences in how vividly people can form mental images, showing that most scientists are actually worse at imagery than artists. Mitchell and Cusack discovered that the vividness in imagery is associated with the strength and type of neural codes (or brain representations).

Cusack emphasizes the power of the new fMRI techniques, explaining, "This new brain scanning method provides a powerful tool to decode the mind, guiding the development of therapies to support those with disturbing imagery, such as veterans and refugees from war zones."

These findings have implications for recent clinical uses of mental imagery, including treating emotional disorders, diagnosing conscious awareness, and driving brain-computer interfaces.