Local and Global Processing and the Effect of Context on Emotional Expression and Object Recognition in High Functioning Adolescents with ASD

Friday, May 18, 2012
Sheraton Hall (Sheraton Centre Toronto)
3:00 PM



Cognitive abnormalities in Autism Spectrum Disorders (ASD) have been attributed to a preference for local processing, alongside global processing difficulties. Whereas local processing focuses on the details, global processing aims for a more holistic, integrative picture. An important skill, often associated with global processing, is the ability to understand context. Yet, research findings regarding the ability of individuals with ASD to understand context have been inconclusive.

 A common paradigm that enables a separate assessment of local and global visual processing uses stimuli that have been filtered to reveal only low or high spatial frequencies. Studies that have used this paradigm with social stimuli, described a tendency for local processing among individuals with ASD. However, no such studies examined the high and low frequency processing of non-social stimuli (e.g., objects). Furthermore, the ability of individuals with ASD to use context in order to enhance their global visual processing has not been previously explored.


This study examined the ability of high functioning adolescents with ASD to use context when processing facial expressions and objects, and examined how the use of context could help them enhance their global processing of visual stimuli.


15 children and adolescents (aged 11-17) with ASD and 15 Typically Developing (TD) controls, matched on chronological and mental age, took two computerized recognition tasks, one presenting social stimuli (facial expressions) and another presenting objects (animal photos). In order to examine the ability to use context, each visual stimulus was preceded by an auditory prime that was congruent, incongruent, or neutral to it. In order to examine local and global processing in each task, the visual stimuli were presented in three spatial frequency conditions: high frequency, low frequency, and broad-band (i.e., with no filter). Response accuracy and response time (for correct responses) were measured for each condition.


A context effect was found for both groups in both face and object tasks. The participants responded faster to the congruent condition than to the incongruent or neutral conditions. Compared to the TD group, the ASD group showed altered local and global processing patterns for both faces and objects. No group differences were found for response accuracy.


High functioning adolescents with ASD can benefit from context for social and non-social stimuli, as congruent context speeds their processing of both. However, the global and local processes underlying context processing are altered in individuals with ASD, compared to typically developing individuals.

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