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Thursday, May 7, 2009
Northwest Hall (Chicago Hilton)
2:30 PM
Background: Cross-modal integration is a critical prerequisite to the development of higher-level cognitive functions, including language and social communication. However, information sharing between auditory and visual modalities and between sensory and attentional domains appears to be severely impaired in individuals with autism spectrum disorder (ASD).
Objectives: To evaluate the effects of attention on cross-modal integration in children with ASD.
Methods: Participants were 17 high-functioning children with ASD and 15 age- and NVIQ-matched typically developing (TD) children. Stimuli consisted of pictures and sounds of animals or musical instruments. For each trial, a sound and picture were presented together in either a matched or mismatched condition. Matched trials consisted of either a picture of an animal or instrument paired with a congruent sound (e.g. a picture of a dog with a ‘bark’ sound; congruent condition). Mismatched trials consisted of a picture of an animal or instrument paired with a cross-category sound (e.g. a picture of a dog with a violin sound; incongruent condition). Participants completed two separate tasks using identical stimuli described above: (1) they were asked to respond as to whether the picture was an animal or an instrument (visual attention task) and (2) they were asked to respond to whether the sound and the picture were matched or mismatched (integrated attention task). Participants were instructed to respond as quickly as possible without making mistakes.
Results: Groups did not differ in error rate in either experiment. For the visual attention experiment, there was a marginally significant interaction between stimulus congruency and group. Follow-up ANOVAs on the incongruent-congruent difference scores revealed that the ASD group had significantly larger difference scores as compared to the TD group. Additional single-sample t-tests showed that difference scores for the ASD group, but not the TD group, were significant.
For the integrated attention experiment, there was no significant stimulus congruency by group interaction. Follow-up ANOVAs revealed no significant group differences for incongruent-congruent difference scores. Single-sample t-tests showed that difference scores for both groups were significant. For the ASD group, there was a significant correlation between difference scores and ADOS algorithm scores for the visual attention but not the integrated attention condition.
Conclusions: Results for the visual attention experiment suggest that for the TD group top-down, inhibitory filtering may preclude cross-modal integration of audio-visual stimuli. However, the ASD group evidenced a significant slowing in the incongruent relative to congruent condition, indicating that the top-down inhibitory filter may be impaired. Results of the integrated attention experiment suggest that both ASD and TD children demonstrate cross-modal integration. Finally, divergent outcomes between the two experiments as well as the significant relationship between difference scores and ASD symptomatology suggest that attention plays an important role in cross-modal integration in both TD and ASD.
Objectives: To evaluate the effects of attention on cross-modal integration in children with ASD.
Methods: Participants were 17 high-functioning children with ASD and 15 age- and NVIQ-matched typically developing (TD) children. Stimuli consisted of pictures and sounds of animals or musical instruments. For each trial, a sound and picture were presented together in either a matched or mismatched condition. Matched trials consisted of either a picture of an animal or instrument paired with a congruent sound (e.g. a picture of a dog with a ‘bark’ sound; congruent condition). Mismatched trials consisted of a picture of an animal or instrument paired with a cross-category sound (e.g. a picture of a dog with a violin sound; incongruent condition). Participants completed two separate tasks using identical stimuli described above: (1) they were asked to respond as to whether the picture was an animal or an instrument (visual attention task) and (2) they were asked to respond to whether the sound and the picture were matched or mismatched (integrated attention task). Participants were instructed to respond as quickly as possible without making mistakes.
Results: Groups did not differ in error rate in either experiment. For the visual attention experiment, there was a marginally significant interaction between stimulus congruency and group. Follow-up ANOVAs on the incongruent-congruent difference scores revealed that the ASD group had significantly larger difference scores as compared to the TD group. Additional single-sample t-tests showed that difference scores for the ASD group, but not the TD group, were significant.
For the integrated attention experiment, there was no significant stimulus congruency by group interaction. Follow-up ANOVAs revealed no significant group differences for incongruent-congruent difference scores. Single-sample t-tests showed that difference scores for both groups were significant. For the ASD group, there was a significant correlation between difference scores and ADOS algorithm scores for the visual attention but not the integrated attention condition.
Conclusions: Results for the visual attention experiment suggest that for the TD group top-down, inhibitory filtering may preclude cross-modal integration of audio-visual stimuli. However, the ASD group evidenced a significant slowing in the incongruent relative to congruent condition, indicating that the top-down inhibitory filter may be impaired. Results of the integrated attention experiment suggest that both ASD and TD children demonstrate cross-modal integration. Finally, divergent outcomes between the two experiments as well as the significant relationship between difference scores and ASD symptomatology suggest that attention plays an important role in cross-modal integration in both TD and ASD.