An ERP Study Examining False-Belief Understanding in Adolescents

To allow successful communication to occur, we need to compute and attribute mental states to other people, allowing understanding of what they may believe, think, or know. These abilities are often referred to as possession of a Theory of Mind (ToM), and a core part of ToM is understanding of belief-states. This study explored belief-reasoning abilities across adolescence, with participants aged 10-21 years old. Electroencephalograpy (EEG) measures were recorded whilst participants listened to a series of short stories regarding a character who is in possession of a true or false belief about an object’s location. The character is described as acting in a manner that is either consistent or inconsistent with this true/false-belief state, such as looking for an object in a location that matches where they believe the object to be, or which contradicts their belief about the objects location. Analysis revealed that when the character was in possession of a false-belief, the N400 waveform was more negative going for belief-consistent actions, compared to belief-inconsistent actions, from 250ms after critical word onset. In contrast, when the character was in possession of a true-belief, inconsistent actions triggered a more negative-going deflection than consistent actions. These results suggest that, across adolescence, participants were biased towards an initial egocentric interpretation of the stories, although behavioural measures demonstrated that this egocentrism could be overcome, with participants accurately able to rate the characters’ actions as appropriate/inappropriate when they acted in a manner consistent or inconsistent with their belief state.