孤独症谱系障碍者的前注意加工能力

Pre-attentive processing in autism spectrum disorder

孤独症谱系障碍(autism spectrum disorder, ASD)是一种神经发育障碍, 其典型症状为社交障碍、刻板行为和限制性兴趣。此外, 感知觉障碍也是ASD个体的常见症状。前注意加工是发生在注意之前, 无需意识参与的自动化加工过程, 反映大脑对环境变化的自动探测能力。研究表明, ASD患者的感觉异常及社会能力障碍可能与前注意加工缺陷有关。失匹配负波(mismatch negativity, MMN)是测量前注意加工能力最常用的指标。ASD个体对非社会性和社会性刺激的前注意加工都存在一定程度的异常, 其中, 对非社会性刺激的前注意加工缺陷表现为由单音、语音和视觉刺激诱发的MMN波幅或潜伏期异于正常人。对社会性刺激的前注意加工缺陷表现为由情绪性语音、情绪性面孔诱发的MMN波幅或潜伏期异于正常人。这为寻找ASD个体感知觉障碍和社交障碍的生理机制提供了帮助, 也为MMN作为ASD的一项辅助诊断指标提供了理论支持。未来, 可通过丰富MMN测量范式、采用更多样的社会性刺激来研究ASD个体的前注意加工能力。同时, ASD遗传因素对MMN的影响也可作为关注点之一。

Autism spectrum disorder(ASD)is a neurodevelopmental disorder.Its typical symptoms include social disorder,stereotyped behavior and restrictive interest.In addition,sensory abnormality is also a common symptom of ASD individuals.Pre-attentive processing is an automatic cognitive process that takes place before attention and is independent of consciousness,which reflects the ability to automatically detect changes in the environment of brain.Many researches show that the sensory abnormality and social ability disorder in ASD patients may be related to the defects in the pre-attentive processing stage.Mismatch negativity(MMN)is the most commonly used indicator of pre-attentive processing.ASD individuals show abnormal MMN in response to both social and non-social stimulus.Among them,the pre-attentive processing defect of non-social stimuli in ASD individuals is manifested as the amplitude or latency of MMN induced by single tones,voice or visual stimuli,which is different from that of normal people.The pre-attentive processing defect of social stimuli in ASD individuals is manifested as the amplitude or latency of MMN induced by emotional voice and emotional face,which is different from that of normal people.This result not only helps to find the physiological mechanism of sensory and social disorders in ASD individuals,but also provides theoretical support for MMN as an auxiliary diagnostic index of ASD.Future research on the pre-attentive processing of ASD individuals should pay more attention to enriching the research paradigms of MMN and adopting more kinds of social stimuli.At the same time,the influence of ASD genetic factors on MMN can also be one of the concerns of future research.