Poster E98, Monday, March 26, 2:30-4:30 pm, Exhibit Hall C
Responsivity of a human mirror neuron system to the transitivity of an action when the end result of a movement is visible but not when it is obscured
Jonathan Silas1, James Munro2, Margot Crossman3, Joseph Levy3; 1Middlesex University, 2Edinburgh Napier University, 3University of Roehampton
The human mirror neuron system (MNS) has been hypothesised to have a functional role in action understanding. Previous research has shown that, in the macaque, mirror neurons only respond to observed actions that are directed towards an object (transitive actions). In humans, a broadly distributed MNS does respond to observed actions, even when they are not directed towards an object (intransitive actions). However, some evidence has shown that the degree to which the MNS is activated in humans is modulated by transitivity. Given that the presence of an object provides more explicit information about the purpose of the action, it is suggested that a modulation of the MNS in response to transitivity is indicative of the functional role the system plays in action understanding. In the current study, 17 participants observed transitive and intransitive movements under two conditions while we recorded BOLD response using fMRI. In the first condition, the action and object were completely visible. In the second, the end of the action and what the action was directed towards (an object or nothing) was hidden from view. We show that areas within the MNS, in the left hemisphere, are responsive to transitivity only when the action and object are fully visible. We suggest that this demonstrates a limited role of an MNS in action understanding. When the goal is obvious and visible the MNS contributes to action understanding. However, when an inference is required for the goal to be achieved, the MNS does not contribute to action understanding.
Topic Area: PERCEPTION & ACTION: Other