Imagination as predictive perception: mental imagery predictively biases perceptual judgments of observed action kinematics.

Recent approaches conceptualize mental imagery as a simulatory mode of perceptual experience, which relies on the voluntary engagement of the same top-down prediction processes that shape our perception of the external world. If so, then imagery should induce similar predictive biases as those that are known to govern the perceptual representation of others behaviour. In four experiments, participants saw object-directed approach and avoidance actions and reported the hands last seen location after their sudden disappearance. All revealed robust predictive biases, showing that perceptual judgments are illusorily distorted towards the implied goals of the actions and away from obstacles. Importantly, the experiments also showed that prior action imagery suffices to induce similar biases, so that perceptual judgments become distorted not only towards the actions expected next steps but also the imagined ones. These imagery-induced biases were robust across stimulus sets and measurement methods. They reflect prior knowledge of how people move and can be induced not only through imagery of the actions itself, but also through imagery of situations in which the actions are merely expected. These data show that imagery induces similar perceptual expectations as other prediction processes, in line with the proposal that imagery reflects the voluntary control of predictive pathways that govern an events perceptual representation. Moreover, imagery can drive prediction processes, inducing expectations about events likely to occur in the imagined (not observed) realities, suggesting shared pathways through which imagery and prediction may support mental simulation and counterfactual reasoning. Public Significance StatementThis study uses the perception of other peoples behaviour as a testing bed to advance the hypothesis that imagery can be understood as predicted perception: that, when people imagine, they make voluntary use of the same prediction mechanisms that otherwise allow them to anticipate - and visualise - how a situation will develop further. In four experiments, the study shows (1) that imagining anothers behaviour induces the expectation that their actions will develop in the imagined manner, (2) that imagining situations elicits expectations about how people will behave within them, (3) that these imagery-induced expectations are integrated with other expectations people have about others behaviour and (4) subtly distort how these behaviours are visuospatially represented. The findings demonstrate a link between imagery and predictive perceptual abilities and reveal how imagery can act as a key tool in peoples ability to anticipate relevant futures and explore counterfactual realities.