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Saturday, May 17, 2008
Champagne Terrace/Bordeaux (Novotel London West)
10:30 AM
Background: Abnormalities in functional connectivity, or synchronicity of time courses in neural networks, has been implicated in Autism Spectrum Disorders (ASD). ASD individuals display underconnectivity during the resting state in the default mode network, which is activated when not doing a specific task. As default mode has been associated with social-emotional and introspective concepts, including theory of mind, this has implications for understanding the social-emotional deficits of ASD. However, no study has yet directly related degree of default mode connectivity to symptom severity in ASD. Moreover, no study has examined connectivity of amygdala, also involved in social-emotional processing, during baseline in ASD individuals.
Objectives: This study examines connectivity in socially relevant parts of the brain, default mode network and amygdala, in relation to ASD symptoms. Social symptom severity is hypothesized to be related to underconnectivity within default mode network and abnormal connectivity of amygdala to frontal cortex. Additionally, ASD individuals are expected to have altered connectivity of amygdala with frontal cortex compared to normal controls.
Methods: 12 adults with ASD and 12 matched controls were instructed to “let your mind wander” while looking at a fixation cross for 10 minutes during fMRI acquisition.
Results: Preliminary analyses indicate both groups show default mode connectivity, but without significant between-group differences. Additionally, amygdala connectivity with left middle frontal gyrus (lMFG) was significantly higher in ASD participants compared to controls. Although ASD and control participants showed positive connectivity, the ASD group had a much larger degree of synchrony between amygdala and lMFG. Analyses correlating symptom severity to connectivity in default mode and amygdala-lMFG networks are underway.
Conclusions: Preliminary evidence suggests ASD individuals exhibit abnormal coupling between emotional and social centers of the brain, which may relate to social-emotional symptoms. This approach revealed altered interactions among structures in the absence of a driving task.
Objectives: This study examines connectivity in socially relevant parts of the brain, default mode network and amygdala, in relation to ASD symptoms. Social symptom severity is hypothesized to be related to underconnectivity within default mode network and abnormal connectivity of amygdala to frontal cortex. Additionally, ASD individuals are expected to have altered connectivity of amygdala with frontal cortex compared to normal controls.
Methods: 12 adults with ASD and 12 matched controls were instructed to “let your mind wander” while looking at a fixation cross for 10 minutes during fMRI acquisition.
Results: Preliminary analyses indicate both groups show default mode connectivity, but without significant between-group differences. Additionally, amygdala connectivity with left middle frontal gyrus (lMFG) was significantly higher in ASD participants compared to controls. Although ASD and control participants showed positive connectivity, the ASD group had a much larger degree of synchrony between amygdala and lMFG. Analyses correlating symptom severity to connectivity in default mode and amygdala-lMFG networks are underway.
Conclusions: Preliminary evidence suggests ASD individuals exhibit abnormal coupling between emotional and social centers of the brain, which may relate to social-emotional symptoms. This approach revealed altered interactions among structures in the absence of a driving task.