Thursday, May 15, 2008
Champagne Terrace/Bordeaux (Novotel London West)
Background: Intermodal perception describes the capacity to simultaneously process and organize sensory information that is arriving from more than one modality. One method to assess the development of auditory-visual intermodal perception is the preferential looking technique (Spelke, 1976). This involves two side-by-side visual displays, with an auditory track matched to only one display. Intermodal perception is considered to be present if the child shows a preference for one of the displays as assessed by calculating the total amount of time spent looking at either the left, or right screen. Using this technique, Bebko et al. (2006) have identified a deficit in the processing of audio-visual intermodal information in children with autism. However, typically the sizes of difference observed are small due to a chance level of 50%. In this study we modified the methodology to lower the chance level in order to significantly sharpen the effects that distinguish the groups.
Objectives: To develop a preferential looking technique that can be more sensitive to differences between autism and comparison groups.
Methods: 10 children (ages 6-10 years) with autism were shown a video with four screens, one in each quadrant of the display with an audio track that was temporally matched to only one of the screens. Preferential looking was assessed based on a) total time spent looking at each screen and b) longest look.
Results: Results are compared to data previously collected with children with autism using a 2-screen video presentation. Analysis is ongoing.
Conclusions: These findings will demonstrate which of two methodologies is more sensitive and accurate in detecting differences in intermodal processing between children with autism and typical children.