Thursday, May 20, 2010
Franklin Hall B Level 4 (Philadelphia Marriott Downtown)
1:00 PM
Background: Deficits in face recognition in older children and adults with autism spectrum disorders (ASD) are well documented. Recent studies suggest that in ASD difficulties in this domain can be detected as early as at 2-3 years and that these deficits are likely to be associated with atypical scanning strategies (Chawarska & Shic, 2009; Chawarska & Volkmar, 2007) and attentional processing of faces (Chawarska, Volkmar, & Klin, 2010). It is not clear however, if deficits in face recognition in toddlers and preschoolers with ASD are due to the complexity of facial stimuli or more specifically, to their social content.
Objectives: This study examined whether deficits in recognition in ASD are specific to faces, or whether they also extend to other nonsocial classes of stimuli.
Methods: Study participants were 21 children with ASD (age: M=39 months, SD=10) and 21 typically developing (TD) children (age: M=36 months, SD=7). Best estimate diagnosis was based on assessment of developmental skills (Mullen Scales) and social interaction, communication, and play skills (ADOS-G), as well as review of medical and developmental history. The Visual Paired Comparison (VPC) paradigm was used to test recognition of three classes of stimuli: common objects, complex geometric block figures, and affectively neutral faces. Visual scanning patterns were recorded using an eye-tracker. Each condition was tested with six trials, with each trial consisting of a Familiarization phase and a Recognition phase. During Familiarization, a stimulus was displayed until the child had looked at the screen for a total of 10 seconds. Following Familiarization, a 5s blank interstimulus interval was shown, followed by the Recognition phase. During Recognition, two images were presented side-by-side for 5 seconds, one familiar and one novel. A measure of recognition, novelty preference, was calculated for each trial as the ratio of looking at the novel stimulus to looking at both the novel and familiar stimulus during the Recognition phase.
Results: There were no between group differences in total amount of time scanning the scenes in any phase or condition. The ASD group exhibited a novelty preference significantly above chance for objects (M=.57, SD=.11, t(11)=2.3, p<.05) and blocks (M=.54, SD=.06, t(13)=2.3, p<.05), but not for faces (M=.50, t(17)=-.245, p=.81). However, the TD group was able to recognize objects (M=.57, SD=.09, t(13)=2.5, p<.05) and faces (M=.60, SD=.06, t(16)=5.8, p<.001), but not blocks (M=.53, SD=.09, t(16)=1.1, p=.28)
Conclusions: Findings from this study confirm that children with ASD have a deficit in encoding and recognizing faces. In contrast to their inability to recognize faces, they were able to recognize both simple objects and complex block figures. The TD children were able to recognize objects and faces; however they found complex block patterns more challenging. These findings suggest that recognition deficits in toddlers with ASD are specific to faces and do not extend to other complex but non-social stimuli. The pattern of results has important implications for understanding social deficits in young children with ASD and for identifying candidate marker tasks for ASD in infancy.
Objectives: This study examined whether deficits in recognition in ASD are specific to faces, or whether they also extend to other nonsocial classes of stimuli.
Methods: Study participants were 21 children with ASD (age: M=39 months, SD=10) and 21 typically developing (TD) children (age: M=36 months, SD=7). Best estimate diagnosis was based on assessment of developmental skills (Mullen Scales) and social interaction, communication, and play skills (ADOS-G), as well as review of medical and developmental history. The Visual Paired Comparison (VPC) paradigm was used to test recognition of three classes of stimuli: common objects, complex geometric block figures, and affectively neutral faces. Visual scanning patterns were recorded using an eye-tracker. Each condition was tested with six trials, with each trial consisting of a Familiarization phase and a Recognition phase. During Familiarization, a stimulus was displayed until the child had looked at the screen for a total of 10 seconds. Following Familiarization, a 5s blank interstimulus interval was shown, followed by the Recognition phase. During Recognition, two images were presented side-by-side for 5 seconds, one familiar and one novel. A measure of recognition, novelty preference, was calculated for each trial as the ratio of looking at the novel stimulus to looking at both the novel and familiar stimulus during the Recognition phase.
Results: There were no between group differences in total amount of time scanning the scenes in any phase or condition. The ASD group exhibited a novelty preference significantly above chance for objects (M=.57, SD=.11, t(11)=2.3, p<.05) and blocks (M=.54, SD=.06, t(13)=2.3, p<.05), but not for faces (M=.50, t(17)=-.245, p=.81). However, the TD group was able to recognize objects (M=.57, SD=.09, t(13)=2.5, p<.05) and faces (M=.60, SD=.06, t(16)=5.8, p<.001), but not blocks (M=.53, SD=.09, t(16)=1.1, p=.28)
Conclusions: Findings from this study confirm that children with ASD have a deficit in encoding and recognizing faces. In contrast to their inability to recognize faces, they were able to recognize both simple objects and complex block figures. The TD children were able to recognize objects and faces; however they found complex block patterns more challenging. These findings suggest that recognition deficits in toddlers with ASD are specific to faces and do not extend to other complex but non-social stimuli. The pattern of results has important implications for understanding social deficits in young children with ASD and for identifying candidate marker tasks for ASD in infancy.