50 gray-scale digital images each of upright faces, inverted faces, and houses; an additional 50 images of pieces of furniture were presented as target items for ...
Facial Processing in Low-Functioning Individuals with Autism: An N170 Event- Related Potential Study Chernenok,
1 M. ,
Coderre,
1 E. ,
Gordon,
1,2 B. ,
& Ledoux,
1 K.
1Department
of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD; 2Department of Cognitive Science, The Johns Hopkins University, Baltimore, MD
Introduction
Results
Normal Controls
Individuals with autism spectrum disorder (ASD) have been reported to have a bias towards towards feature-based rather than configural face processing. This processing bias suggests that individuals with ASD have less experience processing faces holistically, which may be reflected in the N170 component of the event-related potential (ERP). The N170 is a negative deflection over lateral poster electrodes, peaking between 130-200 ms post-stimulus onset (Bentin et al., 1996), that has been uniquely tied to the encoding of the structural configuration of faces. In normal controls (NC), increases in the negative amplitude of the N170 are observed to upright and inverted faces, relative to non-face stimuli (such as houses) over the right hemisphere. Additionally, the N170 to inverted faces is often larger in amplitude but slightly delayed in latency, reflecting the increased challenge of configural processing for these stimuli.
Left Hemisphere
For each group, we conducted 3 (condition) x 2 (site) ANOVAs; significant effects were followed by post-hoc paired sample t-tests reported here.
Normal Adults Right Hemisphere
N170 Amplitude NCs: Across hemispheres, the amplitude of the N170 was larger for upright faces than houses (t (19) = -5.25, p
