Nancy Kanwisher Intuitive Physical Reasoning in the Human Brain

Intuitive Physical Reasoning in the Human Brain

Visual scene understanding requires much more than a list of the objects present in the scene and their locations. To understand a scene, plan action on it, and predict what will happen next we must extract the relationships between objects (e.g., support and attachment), their physical properties (e.g., mass and material), and the forces acting upon them. One view is that we do this with the use of a "mental physics engine" that represents this information and runs forward simulations to predict what will happen next. Over the last several years we have been testing this idea with fMRI. I will review evidence that certain brain regions in the parietal and frontal lobes behave as expected if they implement a mental physics engine: they respond more strongly when deciding about physical than visual properties and when viewing physical versus social stimuli (Fischer et al, 2016), and they contain scenario-invariant information about object mass inferred from motion trajectories (Schwettmann et al, 2019), and about the stability of a configuration of objects (Pramod et al, 2022). In ongoing work led by Pramod RT, we further find evidence that these regions contain information about object contact, a property critical for predicting what will happen next, and most tellingly we find that we can decode predicted future contact from observed current contact, implicating these regions in forward simulation. Another line of work with Vivian Paulun asks whether these brain regions process only the physics of "Things", or whether they also process "Stuff".  I will argue that these and other findings provide preliminary evidence for a physics engine in the brain, while also discussing the several key predictions yet to be tested to better nail this hypothesis.

Bio:

Nancy Kanwisher received her B.S. and Ph.D. from MIT, working with Professor Molly Potter. After a postdoc as a MacArthur Fellow in Peace and International Security, and a second postdoc in the lab of Anne Treisman at UC Berkeley, she held faculty positions at UCLA and then Harvard, before returning to MIT in 1997, where she is now an Investigator at the McGovern Institute for Brain Research, and a faculty member in the Department of Brain & Cognitive Sciences. Kanwisher uses brain imaging and other methods to discover the functional organization of the human brain as a window into the architecture of the mind. Kanwisher has received the Troland Award, the Golden Brain Award, the Carvalho-Heineken Prize, the Kavli Prize in Neuroscience, the António Champalimaud Vision Award, and a MacVicar Faculty Fellow teaching Award from MIT, and she is a member of the National Academy of Sciences and the American Academy of Arts and Sciences. You can view her the lectures from her undergraduate course The Human Brain here: https://ocw.mit.edu/courses/brain-and-cognitive-sciences/9-13-the-human-brain-spring-2019/