A recent study conducted by a team from UHN’s Krembil Brain Institute (KBI) has revealed the part of the brain responsible for conscious imagining during a process called “visualization” in athletes. Their work could be the first step in revealing the brain activity behind imagination. 

“Imagination plays a critical role in many everyday tasks, yet how the brain generates this process is not well understood," says Dr. Richard Wennberg, senior author of the study and Clinician Investigator at UHN’s Krembil Brain Institute (KBI). "By studying how high-level athletes use visualization techniques to train movement and reactivity, we are able to pinpoint consistent patterns of brain activity, offering new insights into the underlying processes that control imagination.”

High-level athletes, like professional ice hockey players, use motor imagery—also known as visualization—to rehearse movements and train their brain’s ability to perform complex tasks, even when not actively playing a sport. An optimized technique, called PETTLEP (Physical, Environment, Task, Timing, Learning, Emotion, and Perspective), gives players a structured scenario, or script, to guide their visualization practice. While the use of the technique is well established, the underlying brain activity associated with PETTLEP visualization has not been well understood until now.

In a recent study, a KBI team, led by Dr. Wennberg, assessed the brain activity of eight high-level female ice hockey players during PETTLEP visualization using magnetoencephalography (MEG). MEG identifies active parts of the brain by measuring the magnetic signals produced when large groups of neurons in the same area fire simultaneously.

The research team found that the greatest activation during visualization occurred in the back (posterior) of the left hemisphere’s cortex, primarily around the intraparietal sulcus—a fold on the brain’s surface that runs horizontally from the middle to the back of the left hemisphere. This is the first time researchers have identified one specific area activated during visualization. Further, it offers a look at how the brain activity changes millisecond to millisecond. 

Importantly, the activated brain area was consistent in both the goalie and players of other positions, even though the goalie used a different PETTLEP script. This suggests the activation of the posterior left hemisphere cortex may reflect a conscious act of visualization—or imagination itself.

The study’s findings provide preliminary insight into the brain activity associated with visualization, laying the groundwork for future research into imaginative processes. Further studies will be needed to determine whether these results are replicable in non-athletes and extend to other forms of conscious or unconscious imagining, such as dreaming. 

Dr. Audrey Alice Potts, first author of the study, is a Family and Sports Medicine physician at the Mayo Clinic in Rochester, Minnesota, USA.

Dr. Richard Wennberg, senior author of the study, is a Clinician Investigator at UHN’s Krembil Brain Institute, Director of UHN’s Mitchell Goldhar Magnetoencephalography (MEG) Unit, and Professor of Neurology at the University of Toronto’s Temerty Faculty of Medicine.

This work was supported by UHN Foundation

Potts AA, Garcia Dominguez L, Gold D, McAndrews MP, Wennberg R. Complex motor imagery in elite female ice hockey players: a cortical arena of imagination revealed by magnetoencephalography. Front Hum Neurosci. 2026 Feb 27;20:1754371. doi: 10.3389/fnhum.2026.1754371.