The Contribution of Motor Simulation to Action Recognition

Details

Supervisors

Vannuscorps, Gilles ; Carneiro, Sarah Pereira

Faculty

Faculté de psychologie, logopédie, sexologie et des sciences de la famille

Degree label

Master [120] en sciences psychologiques, à finalité approfondie

Abstract

The mere observation of the movements of others activates the similar imitative motor plans in one’s brain. This mirror activation is called motor simulation and can be defined as the covert and unconscious imitation of observed movements. Previous studies show mixed results about the contribution of motor simulation to the recognition of actions (correctly identifying body posture and movement as an action), showing that patients with damage to their premotor cortex or born without upper limbs (who can’t covertly and unconsciously imitate movements) can still efficiently recognise actions but have, in most cases, some difficulty in recognising actions that are presented in point light displays (minimalist motion sequence that contains only small lights). To investigate the effect of motor simulation in healthy participants we conducted two experiments where we used a motor interference paradigm, a dual task where participants must recognise actions in point light displays that get progressively more informative while performing a movement. In both experiments participants were randomly divided into two conditions, the first group was tasked to move the upper limbs, and the second group was tasked to move the lower limbs, because all the actions presented involved the upper limbs, participants in the first group couldn’t rely on effector-specific motor simulation to help them identify the actions while the participants in the second group were free to do so. In experiment 1, participants had to recognise videos of actions and in experiment 2, they had to recognise videos of actions and facial expressions, they also did a Random Dots Kinematogram (RDK) task as a control task. Results of experiment 1 showed that the first group needed more action steps (number of videos that gets progressively more informative) before correctly identifying the action, this result was also observed for experiment 2 only for the videos of actions and not facial expressions showing. The results of this study suggests that the motor system, through motor simulation, contributes to the recognition of actions when the core processes of action recognition fail and the action is not immediately and automatically recognised.