Do implicit and explicit measures of the sense of agency measure the same thing?

Abstract

The sense of agency (SoA) refers to perceived causality of the self, i.e. the feeling of causing something to happen. The SoA has been probed using a variety of explicit and implicit measures. Explicit measures include rating scales and questionnaires. Implicit measures, which include sensory attenuation and temporal binding, use perceptual differences between self- and externally generated stimuli as measures of the SoA. In the present study, we investigated whether the different measures tap into the same self-attribution processes by determining whether individual differences on implicit and explicit measures of SoA are correlated. Participants performed tasks in which they triggered tones via key presses (operant condition) or passively listened to tones triggered by a computer (observational condition). We replicated previously reported effects of sensory attenuation and temporal binding. Surprisingly the two implicit measures of SoA were not significantly correlated with each other, nor did they correlate with the explicit measures of SoA. Our results suggest that some explicit and implicit measures of the SoA may tap into different processes.

Figure 1. Illustration of test trials in the (A) Sensory attenuation task; and (B) Temporal binding task.

Figure 2. Mean point of subjective equality (PSE) for each condition of the sensory attenuation task.

Error bars indicate standard errors of the mean. The ‘1' on the y-axis indicates the point of objective equality where the standard and comparison tones were of equal intensity.

Figure 3. Mean interval reproduction for each condition of the temporal binding task. Error bars indicate standard errors of the mean.