Children With Autism Spectrum Disorders

Children with autism spectrum disorders (ASD) struggle with a broad range of communication and social tasks. The ability to recognize emotional states in the faces of others, and the ability to imitate an observed state, are two impairments associated with ASD. Based on previous studies that suggest a neurobiological mechanism underlying imitation, the authors hypothesized that the mirror neuron system (MNS) may be impaired in children with ASD. Moreover, previous research also establishes the existence of an intermediary network that helps translate an observation of an emotion into a felt experience of that emotion: a type of mirror response. In other words, mirroring may enable sympathetic understanding. Such social and communication tasks are notably impaired in children with ASD, which signals a possible malfunction of the MNS.

The researchers used functional magnetic resonance imaging (fMRI) to observe the neurological responses of study participants. Participants included ten high-functioning children with ASD, and ten typically developing children, all with an average age of 12 years. All participants were prepped, and twice shown a series of 80 faces with different emotional expressions such as fear or anger. Faces were shown to the participants for two seconds each, interspersed with blank fixation screens to encourage glances in the eye region. Moreover, the faces were presented in a random sequence. Each participant was shown the sequence of faces twice for two separate scans: once for simple observation, and once for imitation. Data was collected for both scans.

During both observation and imitation trials, all participants exhibited robust activity in the visual cortex. Both groups were able to fix their gaze on the eyes. Moreover, all participants were able to perform the imitation task. Thus, the participants with ASD were as able to attend to the images as the control group and imitate the perceived emotional state. However, only the typically-developing children showed activity in the pars opercularis during the imitation task. The pars opercularis is associated with some mirroring functions.

As expected, the scans revealed that the participants with ASD had far less activity throughout the MNS. Also as predicted, results indicated an inverse relationship between MNS activity and autism symptom severity. Symptom severity was assessed by the Autism Diagnostic Observation Schedule and the Autism Diagnostic Observation Interview.