Affective modulation of the startle eyeblink and postauricular reflexes in autism spectrum disorder

Abstract

Eyeblink and postauricular reflexes to standardized affective images were examined in individuals without (n = 37) and with (n = 20) autism spectrum disorders (ASDs). Affective reflex modulation in control participants replicated previous findings. The ASD group, however, showed anomalous reflex modulation patterns, despite similar self-report ratings of pictures. Specifically, the ASD group demonstrated exaggerated eyeblink responses to pleasant images and exaggerated postauricular responses to unpleasant images. Although ASD is often conceptualized in terms of specific deficits in affective responding in the social domain, the present results suggest a domain-general pattern of deficits in affective processing and that such deficits may arise at an early phase in the stream of information processing.

Fig. 1

Startle eyeblink reflex responses during affective pictures by both diagnostic groups. Error bars are standard errors of the mean. Magnitude is expressed as within subjects T-scores

Fig. 2

Postauricular reflexes during affective pictures by both diagnostic groups. Error bars are standard errors of the mean. Magnitude is expressed as within subjects T scores

Fig. 3

Valence ratings of both diagnostic groups. Error bars are standard errors of the mean. The range and direction of the ratings are −4 (extremely unpleasant) to +4 (extremely pleasant)

Fig. 4

Arousal ratings of both diagnostic groups. Error bars are standard errors of the mean. The range and direction of the ratings are 0 (not at all aroused) to +8 (extremely aroused)