MEG and Aphantasia

Brief Summary

Covert actions are cognitive processes that involves the motor system. They include motor imagery, movement preparation, action observation or action language. They imply mental simulations, based on activations of neural networks, involved in specific operations such as perceiving or acting. These mental phenomena have intrigued and still intrigue philosophers, psychologists, and neuroscientists, as they are complex and introspective processes, which play a major role in human cognition. To decipher similarities and differences between these types of covert actions, the investigators will focus on persons living with aphantasia, which is a neurocognitive specificity present in a small proportion of the population (5 to 8%). Aphantasia is characterized by the alteration or the absence of explicit mental representations. This population offers an ideal testbed to disentangle the involvement of cognitive and motor processes in different forms of covert actions. By means of magnetoencephalography, this study aims to identify and compare brain patterns and their temporal dynamics in alpha and beta bands during covert actions in two groups of healthy volunteers: aphantasics and non-aphantasics (i.e., having a non-altered imagery capacity). If covert actions indeed share brain networks, the investigators expect aphantasics to present reduced neural and behavioral activation during the explicit (i.e., motor imagery) and implicit (movement preparation, action language and action observation) forms of covert actions.