Friday, May 21, 2010
Franklin Hall B Level 4 (Philadelphia Marriott Downtown)
11:00 AM
Background: Previous studies have reported reduced cortical connectivity during a resting state in individuals with autism. However, little is known about the nature of cortical connectivity during the processing of social information in autism.
Objectives: (1) To compare differences in EEG coherence during a social perception task between adolescents with high functioning autism (HFA) and typical development (TD). (2) To examine relations between individual differences in EEG coherence and performance on a social cognition task.
Methods: Thirty-seven adolescents (11-19 years old) participated in this study (HFA =19, TD =18). Participants watched 12 videos of a male looking towards a dot appearing at one of the four corners of the screen. During congruent videos, the male’s direction of gaze matched the area in which the dot appeared. For the incongruent videos, the male’s direction of gaze did not match the location of the dot. EEG was continuously recorded during video presentations and during a baseline (BL) condition in which participants sat still with their eyes open but no video stimulus was presented. Due to no differences in EEG coherence between congruent and incongruent videos, an average was calculated to obtain a single social perception (SP) coherence measure. Coherence was calculated, bilaterally, between pairs of sensor sites located over a short distance frontal area, a short distance temporal-parietal area, a short distance temporal-central area, and a long distance frontal-posterior area. Coherence was calculated for the alpha, beta, delta, and theta frequency bands. Participants were administered theReading the Mind in the Eyes task.
Results: Overall, attenuated coherence among HFA participants was observed only in the alpha frequency band. This result was qualified by interactions with condition and hemisphere. Specifically, the HFA group showed reduced left coherence during BL and reduced right coherence during the SP condition F(1, 35) = 6.95, p < 0.05. Both groups showed reduced bilateral EEG (alpha) coherence during the SP condition in the temporal-central area, F(3,33) = 5.55, p < 0.05. A planned diagnostic group comparison showed HFA participants with reduced EEG (alpha) coherence in the following areas: BL left temporal-parietal (p < 0.05) and BL temporal-central (p < 0.01). In addition, greater right frontal (r = .58, p < 0.05) and temporal-central (r = .59, p < 0.05) EEG coherence in the alpha frequency band in the SP condition was associated with better performance in the Eyes task for the TD group but not for the HFA group. No associations were observed in the other frequency bands. Conclusions: Results indicate that adolescents with HFA show reduced cortical connectivity over areas associated with social information processing during a resting state. However, connectivity does not differ significantly from TD adolescents during social perceptual processing suggesting that the neural basis of social information processing deficits in autism may be one of greater effort exerted by the cortex when transitioning from a resting state to social perceptual processing. These results also support the validity of using EEG coherence to study inter/intra-group differences on cortical connectivity and social information processing in autism.
Objectives: (1) To compare differences in EEG coherence during a social perception task between adolescents with high functioning autism (HFA) and typical development (TD). (2) To examine relations between individual differences in EEG coherence and performance on a social cognition task.
Methods: Thirty-seven adolescents (11-19 years old) participated in this study (HFA =19, TD =18). Participants watched 12 videos of a male looking towards a dot appearing at one of the four corners of the screen. During congruent videos, the male’s direction of gaze matched the area in which the dot appeared. For the incongruent videos, the male’s direction of gaze did not match the location of the dot. EEG was continuously recorded during video presentations and during a baseline (BL) condition in which participants sat still with their eyes open but no video stimulus was presented. Due to no differences in EEG coherence between congruent and incongruent videos, an average was calculated to obtain a single social perception (SP) coherence measure. Coherence was calculated, bilaterally, between pairs of sensor sites located over a short distance frontal area, a short distance temporal-parietal area, a short distance temporal-central area, and a long distance frontal-posterior area. Coherence was calculated for the alpha, beta, delta, and theta frequency bands. Participants were administered the
Results: Overall, attenuated coherence among HFA participants was observed only in the alpha frequency band. This result was qualified by interactions with condition and hemisphere. Specifically, the HFA group showed reduced left coherence during BL and reduced right coherence during the SP condition F(1, 35) = 6.95, p < 0.05. Both groups showed reduced bilateral EEG (alpha) coherence during the SP condition in the temporal-central area, F(3,33) = 5.55, p < 0.05. A planned diagnostic group comparison showed HFA participants with reduced EEG (alpha) coherence in the following areas: BL left temporal-parietal (p < 0.05) and BL temporal-central (p < 0.01). In addition, greater right frontal (r = .58, p < 0.05) and temporal-central (r = .59, p < 0.05) EEG coherence in the alpha frequency band in the SP condition was associated with better performance in the Eyes task for the TD group but not for the HFA group. No associations were observed in the other frequency bands. Conclusions: Results indicate that adolescents with HFA show reduced cortical connectivity over areas associated with social information processing during a resting state. However, connectivity does not differ significantly from TD adolescents during social perceptual processing suggesting that the neural basis of social information processing deficits in autism may be one of greater effort exerted by the cortex when transitioning from a resting state to social perceptual processing. These results also support the validity of using EEG coherence to study inter/intra-group differences on cortical connectivity and social information processing in autism.