Absence of electroencephalographic evidence of implicit action-effect intentional binding with varying effect probability

The subjective experience of an attraction in time of an action, and the event caused by the action, is known as the intentional binding phenomenon. Intentional binding is a robust phenomenon and has previously been associated with subjective sense of agency, but recent studies have shown that binding can take place in the absence of action intentions. In this study, we tested possible electrophysiological equivalents to the intentional binding phenomenon under a simple action-effect task, where pressing of a button caused tones to occur at different pitches or delays with different probabilities. Changing the probabilities of the effect of an action has in some previous studies shown to influence the intentional binding phenomenon. We tested whether changes in action-effect probability gave rise to differences in movement related cortical potentials (MRCP) slopes, peak latency and auditory event related potential (aERP) changes of amplitude or latency of the N1, P2, P3 and N4 components of the central aERP, of which some has been related to sense of agency or intentional binding. We also tested differences in MRCP across the whole scalp prior to movements, and to differences in aERP across the whole scalp after the tone is played. We found no electrophysiological indications of intentional binding when action-effect contingencies were changed in accordance with conditions that have given rise to intentional binding in previous experiments. Our results are in line with several recent studies that have questioned whether intentional binding follows all voluntary actions and can be related to sense of agency at all.