Neural Basis of Implicit Sense of Agency in the Transition from Adolescence to Adulthood

Everyday voluntary actions are accompanied by an intrinsic feeling that we are in control of our actions and their outcomes. The current thesis investigated the brain mechanisms and development of this feeling of agency by focusing on perceived temporal relationship between voluntary actions and their outcomes. It used two phenomena that are central to SoA: temporal recalibration and intentional binding. The results add to the current knowledge by showing the sensory cortical involvement in temporal recalibration (Chapter 2), the developmental trajectory of intentional binding from childhood to adulthood (Chapter 3) and neural correlates of intentional binding from adolescence to adulthood (Chapter 4). The first study revealed that, temporal recalibration, a delay compensation process, can be modulated by a non-invasive brain stimulation technique and sensory specific cortical regions might be at play when the brain is regulating the temporal link between actions and outcomes. Then, taking a developmental approach, the second study revealed a U-shaped developmental trajectory for implicit SoA as indexed by intentional binding from childhood to adulthood, and it was lowest in late-adolescence. These findings suggest that adolescence, a period where final and key maturational changes in the brain observed, is an important period for SoA development. The third study, which investigated intentional binding from adolescence to adulthood using brain imaging (EEG), revealed that mid-adolescents show greater intentional binding and greater P2 attenuation compared to adults, both of which becomes adult-like during late-adolescence. Findings suggested a greater agency experience, which may be mediated by a neural over-attenuation (P2) of action outcomes and over-reliance on motor preparation (late readiness potential) in mid-adolescents, and this became adult-like in late-adolescence. There were intentional binding differences in adults across studies which might be related to different temporal contiguity levels across studies and should be further investigated. Overall, this doctoral work provided novel findings for understanding the neural basis and development of SoA from adolescence to adulthood.