Static Versus Dynamic Emotion Faces Influences the Pattern of Performance and Visual Perusal in Those with High Functioning Autism and Aspergers Syndrome

Background:  Difficulties with emotion processing are part of the current diagnostic criteria for autism. However studies of emotion processing in autism have shown highly inconsistent results, particularly for adults with high functioning autism (HFA) or Aspergers syndrome (AS).  Differences in task demands may explain these inconsistent results.  For example adults with HFA/AS show more difficulties when interpreting complex emotions from the eye region of faces (e.g. Baron-Cohen et al. 2001; Boraston et al. 2008), particularly when stimuli are dynamic and include vocal cues (e.g. Roeyers et al. 2001; Golan et al. 2006).  This could be due to a delay in looking to pertinent social information such as the eyes (e.g. Freeth et al. 2010; Fletcher-Watson et al. 2009; Speer et al. 2007) and increased reliance on verbal as opposed to visual information (e.g. Klin et al. 2003; Golan et al. 2006).  However there are few tasks that assess how adults with HFA/AS process emotions in realistic social situations.

Objectives:  To investigate whether adults with HFA/AS attend to and interpret emotion cues from the eyes more easily from static as opposed to dynamic emotion faces.

Methods:  Thirty typically developing adults and 28 adults diagnosed with HFA/AS viewed 21 videos and pictures of people reacting to being given one of three gifts (chocolate, monopoly money or a homemade novelty) and then inferred what gift the person received and the emotion expressed by that person. Participants' eye movements were recorded while they viewed the stimuli.

Results:  Both participants with HFA/AS and typical controls gave consistent gift and emotion responses significantly above chance (e.g. genuine positive emotion labels for reactions to the chocolate gift, feigned positive for home-made and confused for monopoly money). Participants with HFA/AS significantly improved in the static condition for recognition of genuine positive reactions to chocolate and feigned positive reactions to a home-made gift, however performance fell significantly for recognition of confused reactions to monopoly money. In addition those with autism only showed significantly less attention to the eye region of faces when viewing dynamic stimuli and significantly less attention to the face of the person when viewing static stimuli. 

Conclusions:  These results indicate that stimuli characteristics significantly affect the pattern of visual perusal and emotion recognition performance of those with HFA/AS.  Participants with HFA/AS were only able to distinguish genuine from feigned positive emotion reactions when stimuli were static, not dynamic, along with similar attention to the eye region of faces as controls.  This could be due to social information being less salient to those with HFA/AS (e.g. Freeth et al. 2010; Fletcher Watson et al. 2009), which impacts processing of dynamic expressions that require automatic orientation to pertinent social cues.  Those with HFA/AS were only able to distinguish genuine from confused emotion reactions when stimuli were dynamic, not static. This could be due to increased reliance on verbal as opposed to visual cues in this instance (e.g. Golan et al. 2006).  These results may explain why adults with autism have difficulty processing emotions in realistic social situations.