Eye movements reveal the time-course of anticipating behaviour based on complex, conflicting desires

The time-course of representing others' perspectives is inconclusive across the currently available models of ToM processing. We report two visual-world studies investigating how knowledge about a character's basic preferences (e.g. Tom's favourite colour is pink) and higher-order desires (his wish to keep this preference secret) compete to influence online expectations about subsequent behaviour. Participants' eye movements around a visual scene were tracked while they listened to auditory narratives. While clear differences in anticipatory visual biases emerged between conditions in Experiment 1, post-hoc analyses testing the strength of the relevant biases suggested a discrepancy in the time-course of predicting appropriate referents within the different contexts. Specifically, predictions to the target emerged very early when there was no conflict between the character's basic preferences and higher-order desires, but appeared to be relatively delayed when comprehenders were provided with conflicting information about that character's desire to keep a secret. However, a second experiment demonstrated that this apparent 'cognitive cost' in inferring behaviour based on higher-order desires was in fact driven by low-level features between the context sentence and visual scene. Taken together, these results suggest that healthy adults are able to make complex higher-order ToM inferences without the need to call on costly cognitive processes. Results are discussed relative to previous accounts of ToM and language processing. (C) 2011 Elsevier B.V. All rights reserved.