The eye-tracking of social stimuli in patients with Rett syndrome and autism spectrum disorders: a pilot study

Abstract

Although Rett syndrome (RS) has been considered a manifestation of autism spectrum disorders (ASD) as well as a genetic model of ASD 1 , many aspects peculiar to each of these conditions make them very different and deserve to be even more clarified, so that diagnosis and therapeutic and educational interventions can be as effective as possible for one and other condition.RS is characterized by severe neuromotor, cognitive and communicative impairments. The severity of neuromotor impairments determines the level of global apraxia, resulting in loss or non-development of gait and purposeful use of hands, and in serious respiratory, gastrointestinal and orthopedic disturbances. Most of them do not develop any kind of speech. About 60%-70% develop with epileptic seizures. The empirical observation of RS patients points to a relative preservation of social domain, as they have a very intense look and somehow respond to social stimuli. The etiology of RS has strongly been associated with mutations in MECP2 gene 2,3,4 , and more recently with alterations in CDKL5 and FOGX1 in some cases 5,6 . Although it has been ABSTRACT Objective: To compare visual fixation at social stimuli in Rett syndrome (RT) and autism spectrum disorders (ASD) patients. Method: Visual fixation at social stimuli was analyzed in 14 RS female patients (age range 4-30 years), 11 ASD male patients (age range 4-20 years), and 17 children with typical development (TD). Patients were exposed to three different pictures (two of human faces and one with social and non-social stimuli) presented for 8 seconds each on the screen of a computer attached to an eye-tracker equipment. Results: Percentage of visual fixation at social stimuli was significantly higher in the RS group compared to ASD and even to TD groups. Conclusion: Visual fixation at social stimuli seems to be one more endophenotype making RS to be very different from ASD.

The perception of emotional facial expressions by children with autism using hybrid multiple factorial design and eye-tracking

“…Klin等人 [27] 最早利用眼动追踪报道了 ASD特异性面孔加工模式, 并得到后续研究证实 [28] . ASD对面孔情绪的识别缺陷, 可能来源于该人群对 面孔核心情绪特征区域(眼部、嘴部和鼻子等)的注意 不足和无序处理 [29,30] . 有眼动研究指出, ASD眼部区 域的注视减少很可能是导致该人群观看面部表情时 梭状回激活减弱的原因, 并且通过设置注视点以维 持ASD被试对眼部的注意, 结果发现ASD患者的梭 状回激活水平与正常被试并无差异 [31] .…”

Rett syndrome – biological pathways leading from MECP2 to disorder phenotypes

“…RTT was also classified as an autism spectrum disorder as patients often develop autistic features like social withdrawal but only during a certain stage of development [10]. Although RTT has some autistic features/phases these usually disappear with time and adult RTT females are quite socially active again [11]. MECP2 mutations are rarely found in autism patients and if, they are termed “Autism with MECP2 mutation” [7].…”

Oculomotor Function in Individuals With Rett Syndrome

“…Eye tracking technology has also been used as a medium for assessing the cognitive and receptive language skills of individuals with RTT. [47][48][49][50][51][52][53][54][55][56][57] Most common eye tracking systems used for communication depend upon a camera measuring the reflection of near infrared light on the cornea and pupil of each eye to determine where the gaze is directed on screen. 58 Grids or "pages" of pictures and/or words are presented and selected by the user fixing his or her gaze on an item of choice for a specified length of time ("dwell time").…”