Bruno Jennifer Lynn, Garrett Amy S, Quintin Eve-Marie, Mazaika Paul K, Reiss Allan L
Am J Psychiatry. 2014 Oct;171(10):1099-106. doi: 10.1176/appi.ajp.2014.13111464.
The authors sought to investigate neural system habituation to face and eye gaze in fragile X syndrome, a disorder characterized by eye-gaze aversion, among other social and cognitive deficits.
Participants (ages 15-25 years) were 30 individuals with fragile X syndrome (females, N=14) and a comparison group of 25 individuals without fragile X syndrome (females, N=12) matched for general cognitive ability and autism symptoms. Functional MRI (fMRI) was used to assess brain activation during a gaze habituation task. Participants viewed repeated presentations of four unique faces with either direct or averted eye gaze and judged the direction of eye gaze.
Four participants (males, N=4/4; fragile X syndrome, N=3) were excluded because of excessive head motion during fMRI scanning. Behavioral performance did not differ between the groups. Less neural habituation (and significant sensitization) in the fragile X syndrome group was found in the cingulate gyrus, fusiform gyrus, and frontal cortex in response to all faces (direct and averted gaze). Left fusiform habituation in female participants was directly correlated with higher, more typical levels of the fragile X mental retardation protein and inversely correlated with autism symptoms. There was no evidence for differential habituation to direct gaze compared with averted gaze within or between groups.
Impaired habituation and accentuated sensitization in response to face/eye gaze was distributed across multiple levels of neural processing. These results could help inform interventions, such as desensitization therapy, which may help patients with fragile X syndrome modulate anxiety and arousal associated with eye gaze, thereby improving social functioning.
作者试图研究脆性X综合征患者神经系统对脸部和目光注视的习惯化情况。脆性X综合征是一种除了存在其他社交和认知缺陷外，还以目光回避为特征的疾病。
参与者（年龄15 - 25岁）包括30名脆性X综合征患者（女性14名）以及一个由25名无脆性X综合征的个体组成的对照组（女性12名），两组在一般认知能力和自闭症症状方面相匹配。功能性磁共振成像（fMRI）用于评估在注视习惯化任务期间的大脑激活情况。参与者观看四张具有直接或回避目光注视的独特面孔的重复呈现，并判断目光注视方向。
四名参与者（男性，4/4；脆性X综合征患者，3名）因在fMRI扫描期间头部运动过多而被排除。两组之间的行为表现没有差异。在脆性X综合征组中，扣带回、梭状回和额叶皮质对所有面孔（直接和回避注视）的神经习惯化程度较低（且有显著的敏感化）。女性参与者左侧梭状回的习惯化与脆性X智力低下蛋白更高、更典型的水平直接相关，与自闭症症状呈负相关。没有证据表明组内或组间对直接注视与回避注视的习惯化存在差异。
对面孔/目光注视的习惯化受损和敏感化加剧分布在多个神经处理层面。这些结果可为脱敏疗法等干预措施提供参考，这可能有助于脆性X综合征患者调节与目光注视相关的焦虑和唤醒，从而改善社交功能。
