Dissociable cortical regions represent things and stuff in the human brain

Extensive prior work has identified regions of the human brain associated with visual perception of objects (lateral occipital complex [LOC]) and their physical properties and interactions ("frontoparietal physics network" [FPN]). However, this work has nearly exclusively tested the response of these regions to rigid objects. Deformable or nonsolid substances, or "stuff," including liquids such as water or honey and granular materials such as sand or snow, are of similar importance in everyday life but have different physical properties and invite different actions. Little is known about the brain basis of stuff perception. Here, we scan participants with functional MRI (fMRI) while they view videos of rigid and non-rigid objects ("things") and liquid and granular substances (stuff). We find double dissociations between the processing of things and stuff within both the ventral and dorsal visual pathways. These findings suggest that distinct mental algorithms are engaged when we perceive things and stuff, as they are in artificial physics engines.