Abstract
The ability to recognize the actions of others and understand their underlying intentions is essential for adaptive success in social environments – and we as humans excel in this ability. How our brain is able to integrate and process multiple levels of information without direct knowledge is still poorly understood. For the past two decades much effort has been devoted to the study of sensorimotor resonance, the simulation of actions performed by others through the vicarious activation of the perceiver’s own motor system. However, little agreement has been reached as to its function. It’s been proposed that sensorimotor resonance is only involved in action identification. However, I believe it’s most prudent to consider sensorimotor resonance as the result of interactions within a network containing visual, cognitive, and motor areas whereby the action observation process does not rely on only one possible pathway of information processing. Therefore, I set out to investigate sensorimotor resonance as a dual action representation mechanism: neural mirroring and inferential processing. This approach classifies lower order action processing as a default mechanism carried out by motor simulation in mirroring areas. Conversely, under conditions of high perceptual complexity and/or cognitive load, this mechanism can be replaced or augmented by an inference-based mechanism. To that end, I tested how the EEG oscillatory activity that indexes sensorimotor resonance adapts to an increased need for inferential processing. To invoke inferential processing in chapter 1 I increased the involvement of an action observer from passive viewer to active player in a competitive game of rock-paper-scissors. To elicit inferential processing in chapter 2, participants engaged in a motor task that required error detection for an incorrect action choice. Participants also experienced a simultaneous n-back task to limit the availability of cognitive resources. My results will show two forms of action processing marked by the level of need for sensorimotor information processing resources and the direction of fronto-central information transfer over the course of observation. The results of these studies should provide important evidence for the existence of a hierarchical generative model for the inferential processing of actions.