Developmental change in the ERP responses to familiar faces in toddlers with autism spectrum disorders versus typical development

Abstract

Individuals with autism spectrum disorder (ASD) show differences in face processing abilities from early in development. To examine whether these differences reflect an atypical versus delayed developmental trajectory, neural responses to familiar and unfamiliar faces in twenty-four 18- to 47-month-old children with ASD were compared with responses of thirty-two 12- to 30-month-old typically developing children. Results of 2 experiments revealed that neural responses to faces in children with ASD resembled those observed in younger typically developing children, suggesting delayed development. Electrophysiological responses to faces were also related to parent report of adaptive social behaviors for both children with ASD and typical development. Slower development of the face processing system in ASD may be related to reduced self-directed "expected" experience with faces in early development.

Figure 1

Sensors included in each analysis region. Anterior components were analyzed over left (24,25,21,30,29,36,28,35), central (4,5,10,11,12,16,19,20) and right (3,124,119,118,117,111,112) regions. Posterior components were analyzed over left (51,52,58,59,60,65,66), central (67,68,72,73,76,77,78), and right (85,86,91,92,93,97,98) regions. 10-20 electrode names are presented for reference.

Figure 2

Developmental change in N290 latency, and N290 amplitude: (A) Grand average waveform for the TD-18to30 and TD-12to17 groups, averaged across posterior regions and conditions; (B) Grand average waveform for the ASD-18to30 (Experiment 1) and ASD-32to47 (Experiment 2) groups, averaged across posterior regions and conditions; (D) N290 peak latency by region and group; (D) N290 peak amplitude by region and group. Error bars indicate +/- 1 standard error.

Figure 3

Grand average waveforms of response to familiar and unfamiliar averaged across anterior regions in (A) TD-12to17; (B) TD-18to30; (C) ASD-18to30 and (D) ASD-32to47 groups; (E) Mean amplitude of the Nc response (350 to 750ms) to familiar and unfamiliar faces in the four groups, averaged across region. Error bars indicate +/- 1 standard error.

Figure 4

Relations between the Nc familiarity effect (mean amplitude of response to familiar minus mean amplitude of response to unfamiliar face across central regions) and (A) chronological age and (B) socialization age-equivalent scores. Relation between the N290 peak latency and (C) chronological age and (D) socialization age.