Understanding Actions of Others: The Electrodynamics of the Left and Right Hemispheres. A High-Density EEG Neuroimaging Study
Open Access
- 13 August 2010
- journal article
- research article
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 5 (8), e12160
- https://doi.org/10.1371/journal.pone.0012160
Abstract
When we observe an individual performing a motor act (e.g. grasping a cup) we get two types of information on the basis of how the motor act is done and the context: what the agent is doing (i.e. grasping) and the intention underlying it (i.e. grasping for drinking). Here we examined the temporal dynamics of the brain activations that follow the observation of a motor act and underlie the observer's capacity to understand what the agent is doing and why. Volunteers were presented with two-frame video-clips. The first frame (T0) showed an object with or without context; the second frame (T1) showed a hand interacting with the object. The volunteers were instructed to understand the intention of the observed actions while their brain activity was recorded with a high-density 128-channel EEG system. Visual event-related potentials (VEPs) were recorded time-locked with the frame showing the hand-object interaction (T1). The data were analyzed by using electrical neuroimaging, which combines a cluster analysis performed on the group-averaged VEPs with the localization of the cortical sources that give rise to different spatio-temporal states of the global electrical field. Electrical neuroimaging results revealed four major steps: 1) bilateral posterior cortical activations; 2) a strong activation of the left posterior temporal and inferior parietal cortices with almost a complete disappearance of activations in the right hemisphere; 3) a significant increase of the activations of the right temporo-parietal region with simultaneously co-active left hemispheric sources, and 4) a significant global decrease of cortical activity accompanied by the appearance of activation of the orbito-frontal cortex. We conclude that the early striking left hemisphere involvement is due to the activation of a lateralized action-observation/action execution network. The activation of this lateralized network mediates the understanding of the goal of object-directed motor acts (mirror mechanism). The successive right hemisphere activation indicates that this hemisphere plays an important role in understanding the intention of others.Keywords
This publication has 71 references indexed in Scilit:
- Spatio-Temporal Dynamics of Human Intention Understanding in Temporo-Parietal Cortex: A Combined EEG/fMRI Repetition Suppression ParadigmPLOS ONE, 2009
- Right hemisphere dominance for understanding the intentions of others: evidence from a split-brain patientCase Reports, 2009
- Intention Understanding in AutismPLOS ONE, 2009
- Impairment of actions chains in autism and its possible role in intention understandingProceedings of the National Academy of Sciences of the United States of America, 2007
- Intact automatic imitation of human and robot actions in autism spectrum disordersProceedings Of The Royal Society B-Biological Sciences, 2007
- Action-Related Properties Shape Object Representations in the Ventral StreamNeuron, 2007
- A possible role for primary motor cortex during action observationProceedings of the National Academy of Sciences of the United States of America, 2007
- Cortical Networks Related to Human Use of ToolsThe Neuroscientist, 2006
- Parietal Lobe: From Action Organization to Intention UnderstandingScience, 2005
- Grasping the Intentions of Others with One's Own Mirror Neuron SystemPLoS Biology, 2005