Qualia

Our recent brain imaging study (Chambon et al. 2012) found evidence that the interaction between the angular gyrus of the parietal cortex, and the action selection centres in the prefrontal cortex, plays a key role in the prospective sense of agency. When incompatible primes interfered with the decision of which action to make, the angular gyrus activation at the time of action selection showed a negative correlation with sense of agency over action outcome. This negative correlation had been observed before, and was explained in terms of prediction‐outcome matching. In contrast, our study found that angular gyrus might compute non‐agency at the time of action selection, and not just retrospectively once outcomes were known. This study found no relation between angular gyrus activation and sense of control on compatibly‐primed trials, suggesting that this area monitors a signal related to difficulty and conflict during action selection, rather than the normal smooth flow of agency (Figure 1C). Moreover, the lateral prefrontal cortex, which is responsible for selecting between different possible actions, showed a negative correlation with the angular gyrus activation on incompatibly‐primed only, and no correlation on compatibly‐primed trials. These findings suggest a new model, in which sense of agency depends as much on how we choose what we do, as on actually doing it. The positive sense of agency, or feeling in control, could reflect the default state of the brain’s action selection networks, while the feeling of loss of control could reflect angular gyrus monitoring the conflict within frontal action selection mechanisms. On this view, the experience of agency would be a form of ‘metacognition’, or conscious experience corresponding to efficiency of action selection. In the computational framework above, the planner process, or inverse model, must contribute to the sense of agency, as well as the match between forward model prediction and outcome.