Science + Technology

UCLA Neuroscientists Pinpoint New Function for Mirror Neurons; Specialized Brain Cells Predict Intentions as Well as Define Actions


The road to interpreting intentions is paved with mirrorneurons.

A study by UCLA neuroscientists featuring functionalmagnetic resonance imaging and a well-stocked tea service suggests for thefirst time that mirror neurons help people understand the intentions of others— a key component to social interaction.

Reporting Feb. 22 in the online edition of PLoS Biology, the UCLA team found that pre‑motormirror neuron areas of the brain — areas active during the execution and theobservation of an action — ascribe intentions to actions when presented withina context. Previously, these neurons were thought to be involved only in actionrecognition.

In addition to expanding knowledge of how the brainfunctions, the findings support a growing body of evidence that imitation-basedforms of treatments in patients with autism and similar disorders may helpstimulate the function of these neurons, helping these patients improve theirability to understand the intentions of others and empathize with their thoughtsand feelings.

"Understanding the intentions of others while watching theiraction is a fundamental building block of social behavior," said principalinvestigator Dr. Marco Iacoboni, an associateprofessor in-residence of psychiatry and biobehavioralsciences at the UCLA Neuropsychiatric Institute'sAhmanson Lovelace Brain Mapping Center and the David Geffen School of Medicineat UCLA. "Our findings show for the first time that intentions behind actionsof others can be recognized by the motor system using a mirror mechanism in thebrain. The same area of the brain responsible for understanding behavior canpredict behavior as well."

Twenty-three research subjects underwent functional MRIwhile alternately viewing three stimuli presented in the form of short videos:1) a hand grasping a cup without context; 2) a tea service stocked with foodand drink before use and after use, or context only; and 3) the grasping of atea cup within each of the two contexts, signaling intent either to drink or toclean.

Actions embedded in context, compared with the other twoconditions, increased blood flow in the posterior part of the brain's inferiorfrontal gyrus, known to be important for graspingcontrol, and in the adjacent sector of the ventral premotorcortex, where hand actions are represented. Increased blood flow is anindicator of increased neural activity.

The research was supportedby the Brain Mapping Medical Research Organization, Brain Mapping SupportFoundation, Pierson-Lovelace Foundation, The Ahmanson Foundation, Tamkin Foundation, Jennifer Jones-Simon Foundation, CapitalGroup Companies Charitable Foundation, Robson Family, William M. and Linda R. Dietel Philanthropic Fund at the Northern PiedmontCommunity Foundation, Northstar Fund, and grants fromthe National Center for Research Resources, National Science Foundation andNational Institute of Mental Health.

Iacoboni also is affiliated withthe UCLA Brain Research Institute and the UCLA Center for Culture, Brain andDevelopment. Other members of the research team included Istvan Molnar‑Szakacs and John C. Mazziotta ofUCLA, and Vittorio Gallese,Giovanni Buccino and GiacomoRizzolatti of the University of Parma, Italy.

The UCLA NeuropsychiatricInstitute is an interdisciplinary research and education institute devoted tothe understanding of complex human behavior, including the genetic, biological,behavioral and sociocultural underpinnings of normalbehavior, and the causes and consequences of neuropsychiatricdisorders. In addition to conducting fundamental research, the institutefaculty seeks to develop effective treatments for neurological and psychiatricdisorders, improve access to mental-health services, and shape national healthpolicy regarding neuropsychiatric disorders.

Online resources:

       UCLA NeuropsychiatricInstitute:

       David Geffen School of Medicine at UCLA:

       UCLA Brain Research Institute:

       UCLA Center for Culture, Brain and Development:

       University of Parma, Italy:



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