Lauren E. Marsh

Dissociation of mirroring and mentalising systems in autism.

The role of mirror neuron systems and mentalising systems in causing poor social and communication skills in individuals with autistic spectrum conditions is hotly debated. We studied 18 adults with autistic spectrum conditions in comparison to 19 age and IQ matched typical individuals. Behavioural assessments revealed difficulties in mental state attribution and action comprehension in the autism sample. We examined brain responses when observing rational and irrational hand actions, because these actions engage mirror and mentalising components of the social brain respectively. Both typical and autistic participants activated the left anterior intraparietal sulcus component of the mirror system when viewing hand actions compared to moving shapes. The typical but not autistic participants activated the posterior mid cingulate cortex/supplementary motor area and bilateral fusiform cortex when viewing hand actions. When viewing irrational hand actions, the medial prefrontal cortex of typical participants deactivated but this region did not distinguish the different stimuli in autistic participants. These results suggest that parietal mirror regions function normally in autism, while differences in action understanding could be due to abnormal function of cingulate, fusiform and medial prefrontal regions. Thus, brain regions associated with mirroring and mentalising functions are differentially affected in autistic spectrum conditions.

Children with autism do not overimitate

Copying the behaviour of others is important for forming social bonds with other people and for learning about the world [1]. After seeing an actor demonstrate actions on a novel object, typically developing (TD) children faithfully copy both necessary and visibly unnecessary actions [2]. This ‘overimitation’ is commonly described in terms of learning about the object, but may also reflect a social process such as the child’s motivation to affiliate with the demonstrator [3] or to conform to perceived norms [4]. Previous studies of overimitation do not separate object learning and social imitation because they use novel objects. Even though researchers consider these objects to be causally transparent in their mechanism, young children’s causal reasoning about novel objects is unclear [4]. The present study measures the social component of overimitation by using familiar objects, which preclude the learning component of the task. Here we report a significant reduction in overimitation in children with autism spectrum conditions (ASC). This is coherent with reports that these children have profound difficulties with social engagement [5] and do not spontaneously imitate action style [6] (see also [7]).

The Social Modulation of Imitation Fidelity in School-Age Children

Children copy the actions of others with high fidelity, even when they are not causally relevant. This copying of visibly unnecessary actions is termed overimitation. Many competing theories propose mechanisms for overimitation behaviour. The present study examines these theories by studying the social factors that lead children to overimitate actions. Ninety-four children aged 5- to 8-years each completed five trials of an overimitation task. Each trial provided the opportunity to overimitate an action on familiar objects with minimal causal reasoning demands. Social cues (live or video demonstration) and eye contact from the demonstrator were manipulated. After the imitation, childrens ratings of action rationality were collected. Substantial overimitation was seen which increased with age. In older children, overimitation was higher when watching a live demonstrator and when eye contact was absent. Actions rated as irrational were more likely to be imitated than those rated as rational. Children overimitated actions on familiar objects even when they rated those actions as irrational, suggesting that failure of causal reasoning cannot be driving overimitation. Our data support social explanations of overimitation and show that the influence of social factors increases with age over the 5- to 8-year-old age range.

Using Other Minds as a Window Onto the World: Guessing What Happened from Clues in Behaviour

It has been proposed that mentalising involves retrodicting as well as predicting behaviour, by inferring previous mental states of a target. This study investigated whether retrodiction is impaired in individuals with autism spectrum disorders (ASD). Participants watched videos of real people reacting to the researcher behaving in one of four possible ways. Their task was to decide which of these four “scenarios” each person responded to. Participants’ eye movements were recorded. Participants with ASD were poorer than comparison participants at identifying the scenario to which people in the videos were responding. There were no group differences in time spent looking at the eyes or mouth. The findings imply those with ASD are impaired in using mentalising skills for retrodiction.

Predictive Gaze During Observation of Irrational Actions in Adults with Autism Spectrum Conditions

Understanding irrational actions may require the observer to make mental state inferences about why an action was performed. Individuals with autism spectrum conditions (ASC) have well documented difficulties with mentalizing; however, the degree to which rationality understanding is impaired in autism is not yet clear. The present study uses eye-tracking to measure online understanding of action rationality in individuals with ASC. Twenty adults with ASC and 20 typically developing controls, matched for age and IQ watched movies of rational and irrational actions while their eye movements were recorded. Measures of looking time, scan path and saccade latency were calculated. Results from looking time and scan path analyses demonstrate that participants with ASC have reduced visual attention to salient action features such as the action goal and the hand performing the action, regardless of action rationality. However, when participants with ASC do attend to these features, they are able to make anticipatory goal saccades as quickly as typically developing controls. Taken together these results indicate that individuals with autism have reduced attention to observed actions, but when attention is maintained, goal prediction is typical. We conclude that the basic mechanisms of action understanding are intact in individuals with ASC although there may be impairment in the top-down, social modulation of eye movements.

Responses to irrational actions in action observation and mentalising networks of the human brain

By observing other people, we can often infer goals and motivations behind their actions. This study examines the role of the action observation network (AON) and the mentalising network (MZN) in the perception of rational and irrational actions. Past studies in this area report mixed results, so the present paper uses new stimuli which precisely control motion path, the social form of the actor and the rationality of the action. A cluster in medial prefrontal cortex and a large cluster in the right inferior parietal lobule extending to the temporoparietal junction distinguished observation of irrational from rational actions. Activity within the temporoparietal region also correlated on a trial-by-trial basis with each participants judgement of action rationality. These findings demonstrate that observation of another person performing an irrational action engages both action observation and mentalising networks. Our results advance current theories of action comprehension and the roles of action observation and mentalising networks in this process.

Cognitive Mechanisms underlying visual perspective taking in typical and ASC children

Previous research has suggested that people with Autism Spectrum Conditions (ASC) may have difficulty with visual perspective taking (VPT) but it is not clear how this relates to different strategies that can be used in perspective taking tasks. The current study examined VPT in 30 children with autism and 30 verbal mental age matched typical children, in comparison to mental rotation (MR) abilities and body representation abilities. Using a similar paradigm to Hamilton, Brindley, and Frith [2009] all children completed three tasks: a VPT task in which children decided what a toy on a table would look like from a different points of view; a MR task in which the child decided what a toy would look like after it had been rotated; and a body posture matching task, in which children matched pictures of a body shown from different viewpoints. Results showed that children with ASC performed better than the typically developing children on the MR task, and at a similar level on the VPT task and body matching task. Importantly, in the typical children VPT performance was predicted by performance on the body matching task, whereas in the ASC children VPT performance was predicted by MR ability. These findings suggest that differences in VPT in ASC may be explained by the use of a spatial rotation strategy rather than the embodied egocentric transformation strategy used by typical children. Autism Res 2015.

Thinking of me: Self-focus reduces sharing and helping in seven- to eight-year-olds

By 7-to 8-years of age, most children readily adhere to prosocial norms aimed at benefiting others through giving up time and effort (helping) or resources (sharing). Two studies explored whether sharing and helping by 7-to 8-year olds (N = 180) could be influenced by priming children’s attention on themselves or their friends through a semi-structured interview. Results revealed that self-priming led to reductions in both sharing and helping compared to friendship-priming or a control condition. These findings are considered as indicative of the fragile state of prosocial behaviours at this age that can be easily shifted towards more selfish biases by simple priming.