关键词: 孤独症谱系障碍, 粘滞性注意, 注意解离, 空白重叠范式, 眼动研究

Abstract: Autism spectrum disorder (ASD) is a lifelong neurodevelopmental condition characterized by impairments in social interaction and communication, and the presence of restricted interests and repetitive behaviours (APA, 2013). Though not a diagnostic feature, differences in how attention is deployed in ASD are commonly observed in young ASD children. Although it is usually thought that some core behaviours manifest in ASD are a consequence of social impairments, attentional deficits could also influence such behaviours. Attentional orienting, is composed of three operations, which are disengaging, shifting and engaging. Visual disengagement is a widely discussed component in eye-tracking studies related to ASD, which refers to the attentional breaking from the current fixation during visual orienting. In several prospective studies (e.g., Bryson et al., 2018), sticky attention (attentional disengagement deficit) is an early hallmark in high-risk ASD infants. If individuals exhibit sticky attention, they will need a longer saccadic reaction time to disengage from the current focus or fail to start eye movements to a new target. Although prospective research found the relationship between sticky attention and later ASD diagnosis, findings conflicted on whether sticky attention still exhibits in young children with ASD. Through the past twenty years, the actual evidence for attentional disengagement deficits has been equivocal. Several researchers concluded that attentional disengagement is impaired in children with ASD, and others reported no atypical. For young autistic children, it is unknown whether sticky attention would continue, or they may show normal disengaging performance and catch up to typically developing (TD) children by nurture development. Beyond that, currently, studies related to attentional disengagement in young ASD children are pretty rare. Therefore, in these individuals, we know little about their eye-movement behaviours during attentional disengagement. It should be noted that the gap-overlap paradigm is a classic visual saccadic paradigm used to explore participants’ oculomotor disengagement behaviours. In this paradigm, the time taken to initiate an eye movement to a peripherally presented target is compared across conditions where a central stimulus remains on display all through when the target is presented (overlap trials), where a central stimulus disappears when the target shows up simultaneously (baseline trials). The current study aimed to the gap-overlap paradigm to reveal attentional disengagement ability in young children with high-functioning ASD. 15 high-functioning ASD young children (IQ>70) and 18 chronological age, WPPSI-IV IQ matched TD children participated in the current study. The experimental design was a 2 (group: ASD vs TD) ×2 (task: baseline vs overlap) mixed design. During the experiment, two simple stimuli appeared on the screen, circles (central stimuli) and squares (target stimuli). All young children were told to find the target square when it appeared, and the eye-tracker, EyeLink portable DUO, was adopted to collect all children’s eye movement data. The results were as follows: (1) Attentional disengagement abilities normally developed in high-functioning ASD preschoolers, which showed no sign of impaired attentional disengagement. (2) Compared to TD children, ASD individuals showed normal attentional shifting behaviours. (3) Young children with high-functioning ASD exhibited faster saccadic reaction, especially in the overlap condition, which may be due to a lower level of attentional engagement or abnormal saccadic initiating. In a nutshell, this experiment showed no evidence to prove sticky attention for basic figures in high-functioning ASD preschoolers, though other attentional deficits they exhibited. It seems unlikely that disruptions of attentional disengagement abilities lie at the root of ASD.

Key words: Autism Spectrum Disorder, sticky attention, attentional disengagement, gap-overlap paradigm, eye-movement study