The stereotypical image of psychotherapy shows a patient lying on a couch, exploring their deepest traumas. This leads to awareness of unconscious habits, thoughts, and drives and has long been a cornerstone of psychotherapy. However, the cognitive processes underlying the new awareness that emerges—what's actually happening in the patient's brain on that couch—remain a mystery.
"Part of the problem with psychotherapy is that we haven't had good insights into the mechanistic problems," said Jaan Aru, an associate professor at the University of Tartu, in an interview with the Observer. "So, it's very hard to design a therapy."
In a 2025 paper in Perspectives on Psychological Science , Aru and Nick Kabrel, Aru's graduate student at the University of Zurich, wrote that becoming aware of unrecognized psychological and behavioral challenges is the most crucial mechanism in conversation-based psychotherapy. Furthermore, they argue that becoming aware can be best framed as a process that expands one's cognitive map and changes the way one navigates through the mind. This framework also provides a testable theory about the neural correlates behind successful psychotherapy.
Kabrel came to this theory through personal experience. He noticed how a therapist's questions could prompt him to search through his memories and beliefs , and the introspection was surprisingly powerful. He wondered what was happening in his brain in those moments and noticed something that sparked his interest.
"When I search through memory or search in my mind, it always feels as if I am navigating in some kind of environment," he said.
As he looked into this idea of mental navigation, he realized he was not alone. In a 2024 paper, he and Aru showed that patients and therapists used more spatial language—such as "this is unexplored territory" or "I'm going in circles"—during psychotherapy sessions than during everyday conversation.
In the new paper, Aru and Kabrel proposed a framework based on how individuals construct their internal worlds in the form of cognitive maps: structured representations of phenomena like objects, concepts, people, and memories, and the relationships among them. Research revealing how the brain represents three-dimensional space helped inspire how this navigation may occur in the brain (O'Keefe and Dostrovsky, 1971; Hafting, 2005). In the hippocampus, place cells fire when animals are in a specific location, while the entorhinal cortex's grid cells act like a coordinate map. More recent research revealed these cells also encode abstract concepts, such as time, sound, social hierarchies, and word meanings (MacDonald, 2011; Aronov, 2017; Park, 2021; Solomon, 2019; Viganò, 2021).
"The brain is highly likely to make use of this mapping system in these other domains, too," Aru said. "This idea of mental navigation could be a very general framework to understand thinking and abstract cognition."
Framing introspection in this way may help people realize that changing the way they navigate through their thoughts could help them out of a pathological way of thinking.
For example, someone suffering from depression might think they are flawed, and any interaction with someone else that ends negatively will be interpreted as their fault because of these perceived flaws. As they continue to view the world through this same negative lens, this thought pattern gets reinforced. It's analogous to hiking through a forest: The more a path is used, the wider it gets and the more likely it is to be used again.
But a therapist helping them see a different interpretation—a different navigational route—may allow them to reframe their thoughts and not see everything as their fault. Kabrel recommends a psychotherapist say something like, "This is the place where we are stuck. We come back here every time, but we need to expand this."
Aru thinks this idea is not just for people with mental illness, but for everyone.
"Often the problem is that people have very narrow maps, very narrow ways of thinking. And it's a very general problem," he said. "Our goal as a society could be to expand the way people actually think."
On a smaller scale, the goal of the paper is to encourage psychological scientists and neuroscientists to design experiments to test this new framework and the possible neural correlates involved. In the meantime, Aru knows that some scientists may be doubtful.
"It's completely understandable if there are scientists who would say, 'Oh, you're stretching it too far. How do you know that it's really related to grid cells?'" he explained. "For me, this is the fun thing about science. You can try to make these links, and sometimes these links are actually there. Then suddenly we might be understanding something that we previously didn't, and we might be expanding our own mental maps with that."
References
Aronov D., Nevers R., Tank D.W. (2017). Mapping of a non-spatial dimension by the hippocampal-entorhinal circuit . Nature, 543(7647):719-722.
Hafting T., Fyhn M., Molden S., Moser M.B., & Moser E.I. (2005). Microstructure of spatial map in the entorhinal cortex . Nature, 436, 801-806.
Kabrel N., & Aru J. (2025). Becoming aware through internal exploration: Understanding psychotherapy on conceptual and neurobiological levels . Perspectives on Psychological Science, 0(0).
Kabrel M., Tulver K., & Aru J. (2024). The journey within: Mental navigation as a novel framework for understanding psychotherapeutic transformation . BMC Psychiatry, 24, Article 91.
MacDonald C.J., Lepage K.Q., Eden U.T., Eichenbaum H. (2011) Hippocampal "time cells" bridge the gap in memory for discontiguous events. Neuron, 71(4):737–49.
O'Keefe J., & Dostrovsky J. (1971). The hippocampus as a spatial map. Preliminary evidence from unit activity in the freely-moving rat. Brain Research, 34(1): 171-5.
Park S. A., Miller D. S., & Boorman E. D. (2021). Inferences on a multidimensional social hierarchy use a grid-like code. Nature Neuroscience, 24(9), 1292-1301.
Solomon E. A., Lega B. C., Sperling M. R., & Kahana M. J. (2019). Hippocampal theta codes for distances in semantic and temporal spaces . Proceedings of the National Academy of Sciences, 116(48), 24343-24352.
Viganò S., Rubino V., Di Soccio A., Buiatti M., & Piazza M. (2021). Grid-like and distance codes for representing word meaning in the human brain. NeuroImage, 232, 117876.
