Right hemisphere dominance for understanding the intentions of others: evidence from a split-brain patient

• Published in: BMJ case reports Vol. 2009; no. may21 1; p. bcr0720080593
• Main Authors: Ortigue, Stephanie, King, Danielle, Gazzaniga, Michael, Miller, Michael, Grafton, Scott
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group LTD 2009; BMJ Publishing Group
• Series: Findings that shed new light on the possible pathogenesis of a disease or an adverse effect
• Subjects: Accuracy; Behavior; Brain damage; Female; Findings That Shed New Light on the Possible Pathogenesis of a Disease or an Adverse Effect; Neural networks; Patients; Specialization; Studies; Therapists; USA/Canada; White
• ISSN: 1757-790X; 1757-790X
• DOI: 10.1136/bcr.07.2008.0593

Understanding the actions performed by other people is a key aspect of social interaction, including in clinical settings where patients are learning from therapists and caregivers. While lesions of the left cerebral hemisphere induce praxic disorders, the hemispheric specialisation of intention understanding remains unclear. Do patients with a right hemispheric lesion understand the intentions of other people properly? The present study investigates how a split-brain patient understands the means (what) and intentions (why) of the actions of other people. Results show a significant left hemispheric dominance for understanding what is done, and a significant right hemispheric dominance for understanding why an action is carried out. This discovery might have important clinical implications in neurological patients, especially when those with right hemisphere lesions are faced with important decisions related to the interpretation of other’s intentions.