Visualizing how one brain understands another: a PET study of theory of mind.
OBJECTIVE
Theory of mind (TOM), or "mentalizing," refers to the ability to attribute mental states to self and others. Inferring what people are thinking and feeling is an important aspect of human social interaction, and it is also an important aspect of both psychiatric diagnosis and treatment. The authors conducted a positron emission tomography (PET) study to examine the neural substrates of TOM, using a task that mimics real-life social interaction.


METHODS
Thirteen healthy volunteers underwent [(15)O]H(2)O PET while performing an experimental task and a control task. During the experimental task they created a "story" about the mental state of a stranger whom they imagined encountering on a park bench. During the control task, they read aloud a story requiring no mental state attribution.


RESULTS
The TOM task activated an extensive neural network that included the medial frontal cortex, the superior frontal cortex, the anterior and retrosplenial cingulate, and the anterior temporal pole; most of these activations were limited to the left hemisphere. In addition, the largest activation was in the contralateral right cerebellum, as well as the anterior vermis.


CONCLUSIONS
A language-based TOM task activated distributed brain regions that are important for representing mental states of the self and others, retrieving memory of personal experiences, and coordinating and monitoring the overall performance of the task. The activations in the medial frontal cortex replicate findings in previous TOM studies, while the activations in the cerebellum reinforce the growing evidence that the cerebellum performs cognitive functions in the human brain.
Department of Psychiatry, University of Iowa Health Care, 200 Hawkins Drive, Iowa City, IA 52242-1057, USA.
Chadi
C
Calarge
Nancy C
NC
Andreasen
Daniel S
DS
O'Leary
D000328:Adult; D001364:Awareness / Q000502:physiology; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007092:Imagination / Q000502:physiology*; D007398:Interpersonal Relations; D008279:Magnetic Resonance Imaging; D008297:Male; D008606:Mental Processes / Q000502:physiology*; D008959:Models, Neurological; D009415:Nerve Net / Q000000981:diagnostic imaging / Q000502:physiology; D010104:Oxygen Radioisotopes; D012649:Self Concept; D012919:Social Behavior; D012938:Social Perception; D013850:Thinking / Q000502:physiology; D014055:Tomography, Emission-Computed; D014867:Water
D010104:Oxygen Radioisotopes; D014867:Water