Child Study Center, Yale University School of Medicine, New Haven, CT 06510, USA.
J Child Psychol Psychiatry. 2012 Aug;53(8):903-13. doi: 10.1111/j.1469-7610.2012.02538.x. Epub 2012 Mar 17.
In typical development, the unfolding of social and communicative skills hinges upon the ability to allocate and sustain attention toward people, a skill present moments after birth. Deficits in social attention have been well documented in autism, though the underlying mechanisms are poorly understood.
In order to parse the factors that are responsible for limited social attention in toddlers with autism, we manipulated the context in which a person appeared in their visual field with regard to the presence of salient social (child-directed speech and eye contact) and nonsocial (distractor toys) cues for attention. Participants included 13- to 25-month-old toddlers with autism (autism; n = 54), developmental delay (DD; n = 22), and typical development (TD; n = 48). Their visual responses were recorded with an eye-tracker.
In conditions devoid of eye contact and speech, the distribution of attention between key features of the social scene in toddlers with autism was comparable to that in DD and TD controls. However, when explicit dyadic cues were introduced, toddlers with autism showed decreased attention to the entire scene and, when they looked at the scene, they spent less time looking at the speaker's face and monitoring her lip movements than the control groups. In toddlers with autism, decreased time spent exploring the entire scene was associated with increased symptom severity and lower nonverbal functioning; atypical language profiles were associated with decreased monitoring of the speaker's face and her mouth.
While in certain contexts toddlers with autism attend to people and objects in a typical manner, they show decreased attentional response to dyadic cues for attention. Given that mechanisms supporting responsivity to dyadic cues are present shortly after birth and are highly consequential for development of social cognition and communication, these findings have important implications for the understanding of the underlying mechanisms of limited social monitoring and identifying pivotal targets for treatment.
在典型的发展过程中,社交和沟通技能的展开取决于将注意力分配和维持在人身上的能力,这种能力在出生后立即出现。自闭症患者的社交注意力缺陷已得到充分记录,但潜在机制仍知之甚少。
为了剖析导致自闭症幼儿社交注意力有限的因素,我们根据存在的突出社交(儿童指向的言语和眼神接触)和非社交(分心玩具)注意线索,操纵了人在他们视野中出现的背景。参与者包括 13 至 25 个月大的自闭症(自闭症;n=54)、发育迟缓(DD;n=22)和典型发育(TD;n=48)的幼儿。他们的视觉反应由眼动追踪器记录。
在没有眼神接触和言语的情况下,自闭症幼儿在社交场景关键特征之间分配注意力的方式与 DD 和 TD 对照组相似。然而,当引入明确的二元线索时,自闭症幼儿对整个场景的注意力减少,当他们看场景时,他们看说话者的脸和监测她嘴唇运动的时间比对照组少。自闭症幼儿花在探索整个场景上的时间减少与症状严重程度增加和非语言功能降低有关;异常的语言模式与对说话者面部和嘴巴的监测减少有关。
虽然在某些情况下,自闭症幼儿以典型的方式关注人和物体,但他们对二元注意线索的注意力反应减少。鉴于支持对二元线索反应的机制在出生后不久就存在,并且对社交认知和沟通的发展具有重要意义,这些发现对理解社交监控受限的潜在机制和确定治疗的关键目标具有重要意义。