| Reference code: | PT/FB/BL-2004-047.05 |
| Location: | Arquivo PCA - Pasta 3/2004
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Title:
| Abnormal N1/P1 responses in children with ASD elicited by both low and high spatial frequency gratings
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| Publication year: | 2006
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URL:
| http://63.131.128.66/sites/default/files/imfar/abstracts/IMFAR2006_Program.pdf
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| Abstract/Results: | ABSTRACT:
BACKGROUND:
It has been suggested that individuals with autistic spectrum disorder (ASD) may display abnormalities in low level visual perception.
Objectives: To investigate low level visual perception in ASD by measuring visual evoked potentials elicited by a range of spatial frequency gratings.
METHODS:
High density visual evoked potentials were recorded from children and adolescents (aged between 9 and 18) diagnosed with ASD, and chronological and nonverbal mental age matched typically developing controls in response to sinusoidal gratings presented at 0.5, 1, 4 and 8 cycles per degree (cpd). The stimuli, which measured 7.5º x 7.5º of visual angle, were presented foveally and were visible for 500 msec.
RESULTS:
Analysis of EEG data at occipital leads indicated that the controls exhibited a typical N1 / P1 complex, with a clear N1 emerging between 80 and 95 msec in response to the higher frequency stimuli (4 and 8 cpd), and a P1 which increased in latency and decreased in amplitude with increasing spatial frequency. The ASD group however did not show a clear N1, and showed reduced P1 amplitude compared to the controls, at all four spatial frequencies.
CONCLUSION:
These data suggest that early perceptual mechanisms, across a range of spatial frequencies, are abnormal in children with autistic spectrum disorder.
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| Accessibility: | Document exists in file
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Copyright/Reproduction:
| By permission
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Language:
| eng
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Author:
| Milne, E.
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Secondary author(s):
| Scope, A., Vigon, L., Buckley, D., Pascalis, O.
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Document type:
| Unpublished document
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Number of reproductions:
| 1
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Reference:
| Milne, E., Scope, A., Vigon, L., Buckley, D., & Pascalis, O. (2006, June). Abnormal N1/P1 responses in children with ASD elicited by both low and high spatial frequency gratings. Poster presented at the International Meeting for Autism Research (IMFAR), Montreal, Canada.
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| Indexed document: | No
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| Keywords: | Psychophysiology / Visual perception / Autism spectrum disorder (ASD)
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Abnormal N1/P1 responses in children with ASD elicited by both low and high spatial frequency gratings |