How the brain uses memory to imagine what might have been

Philosopher Felipe De Brigard, a 2026 MacArthur "genius grant" recipient, explores the intriguing connection between memory and imagination. De Brigard, a professor at Duke University, recounts a surprising moment when he received a call from the MacArthur Foundation, informing him he had been awarded the prestigious fellowship. This article delves into the fallibility of memory and the intertwined nature of memory and imagination.

De Brigard's research reveals that our brains employ similar mental processes to reconstruct past events and imagine future possibilities. This phenomenon is known as episodic "counterfactual" thinking, where we consider what could have happened differently in the past or might occur in the future. The hippocampus, a brain region crucial for episodic memory, plays a significant role in imagining alternative scenarios, as demonstrated in his experiments.

The evolutionary advantage of this interconnected memory and imagination system lies in its ability to efficiently store and retrieve information. Since it's impossible to remember every detail of every experience, our brains fill in gaps during memory retrieval with the most likely possibilities, enabling quicker and more flexible recollection. Furthermore, maintaining a strong link between memory and imagination allows us to generate hypotheses and explore alternative outcomes, helping us navigate uncertainty.

De Brigard also discusses the impact of false memories and the role of forgiveness in memory formation. He suggests that imagining alternative actions of a person in a given situation, like in a courtroom setting, requires drawing upon personal experiences to generate a plausible counterfactual narrative. This emotional engagement in imagining alternatives underscores the moral significance of imagination in our daily lives.