The causal neural substrates underpinning prospective and retrospective sense of agency

Sense of agency (SoA) is the subjective feeling of authorship experienced over one's actions and their subsequent sensory outcomes. Despite extensive theoretical accounts of this experience, there remains a dearth of literature investigating its causal neural substrates. To address this, we modulated neural activity of two regions thought to be critical to the agentic experience, namely the left dorsolateral prefrontal cortex (l-dlPFC), and the left temporoparietal junction (l-TPJ). In a sham-controlled, double-blinded, crossover study 104 healthy young adults were stratified to receive anodal stimulation to either the l-dlPFC or the l-TPJ whilst completing an implicit SoA task. Participants performed either an action or outcome binding paradigm in which both prospective (action choice) and retrospective (outcome valence) agency cues were manipulated. Stimulation to the l-TPJ and l-dlPFC produced divergent effects on intentional binding. In the outcome binding condition specifically, anodal stimulation to either target region increased the difference in intentional binding scores between rewarding and punishing action outcomes. We also observed a dissociable, causal role for both the l-dlPFC and l-TPJ on intentional binding, identifying binding specific, but not site specific, effects related to outcome valence. We propose that excitatory stimulation may upregulate the attentional processes relevant to intentional binding.