The Use of rTMS to Improve Theory of Mind Among Adults With Autism and Asperger's Disorder

Autism and Asperger's disorder are life-long neurodevelopmental disorders that involve significant social, communicative, and behavioural abnormalities. Social impairments are arguably the most debilitating aspect of these disorders, and persist into adulthood, creating difficulties in various domains including employment, education, and interpersonal relationships. This impairment is also frequently associated with additional mental health concerns, including depression and anxiety, with the former affecting as many as 40% of individuals with autism (Stewart, Barnard, Pearson, Hasan, & O'Brien, 2006). It has been suggested that the core deficit underlying social dysfunction in autism and Asperger's disorder is impairment in "theory of mind" (ToM) (Baron- Cohen et al., 2005).

An important aspect of social cognition, ToM refers to the ability to use environmental cues to infer others' mental states. It includes the recognition that other individuals experience thoughts, feelings, intentions, and desires that may be different to our own. ToM is crucial to social functioning, allowing us to predict others behaviour and gain an appreciation of their perspective, thereby facilitating effective social interactions.

ToM has been assessed using an array of behavioural tasks. Such tasks typically illustrate a social scenario, and the aim of the task is to identify various aspects of a character's mental state. Increasingly, researchers distinguish between cognitive ToM, which encompasses inferences of another individual's beliefs, knowledge or memory, and affective ToM, which is concerned with predicting others' emotional states (Shamay-Tsoory & Aharon-Peretz, 2007).

Cognitive ToM measures include false-belief tasks, successful completion of which requires an understanding that another individual can hold a mistaken belief (first-order false-belief), and that are therefore different to their own belief, or that another individual can hold a mistaken belief about the mental state of a third person (second-order false-belief; Harrington, Siegert, & McClure, 2005). Another cognitive ToM task involves inferring intention from a series of short animations that demonstrate interactions between non-human objects (e.g., geometric shapes; Castelli, Frith, Happe, & Frith, 2002).

By contrast, affective ToM measures include the "eyes task" (Baron- Cohen, Wheelwright, Hill, Raste, & Plumb, 2001), which requires the inference of another individual's emotional experience through the presentation of their eyes only. The eyes task is considered a ToM measure in that it involves the inference of another individual's mental state from environmental stimuli, but unlike false-belief tasks there is a central affective component.