Weak individualization of spontaneous eye movements in individuals with autism spectrum disorders

Aya Shirama(1,2,3), Nobumasa Kato(4), & Makio Kashino(1,2)

1 NTT Communication Science Laboratories, NTT Corporation, Kanagawa, Japan
2 CREST, JST, Kanagawa, Japan
3 Japan Society for the Promotion of Science, Tokyo, Japan
4 Department of Psychiatry, Showa University School of Medicine, Tokyo, Japan

We previously reported that humans spontaneously express their individual uniqueness through their eye movements when delivering a short speech and that human observers can identify others based on eye movement patterns alone (Shirama, Koizumi, & Kitagawa, ECVP 2012). We consider that the eyes communicate individual uniqueness to others. It is well known that individuals with autism spectrum disorder (ASD) also suffer from impairments in interpersonal communication via eye movements. In the present study, we measured spontaneous eye movements during speech for fifteen adults with ASD to examine whether individuals with ASD can express their identity implicitly through intrinsic eye movements. Although individuals with ASD showed intrinsic eye movement patterns regardless of speech content, the individualization of the spatial-temporal features was less apparent than the unique eye movement patterns expressed by individuals in a typically developing group. It is unlikely that the intergroup difference was caused by basic motor properties related to eye movement, because we confirmed that the individuals with ASD had normal eye movement functions by analyzing them in a simple saccade task and a visual search task. Presumably, the weak individualization in ASD participants' eye movement patterns reflects the impairment of higher brain functions.