Why do children with autism spectrum disorder have abnormal visual perception?

Abstract

Autism spectrum disorder (ASD) is associated with severe impairment in social functioning. Visual information processing provides nonverbal cues that support social interactions. ASD children exhibit abnormalities in visual orientation, continuous visual exploration, and visual-spatial perception, causing social dysfunction, and mechanisms underlying these abnormalities remain unclear. Transmission of visual information depends on the retina-lateral geniculate nucleus-visual cortex pathway. In ASD, developmental abnormalities occur in rapid expansion of the visual cortex surface area with constant thickness during early life, causing abnormal transmission of the peak of the visual evoked potential (P100). We hypothesized that abnormal visual perception in ASD are related to the abnormal visual information transmission and abnormal development of visual cortex in early life, what's more, explored the mechanisms of abnormal visual symptoms to provide suggestions for future research.

Keywords: abnormal visual perception; autism spectrum disorder; retina-lateral geniculate nucleus-visual cortex pathway; review and hypotheses; visual cortex neurodevelopment.

Figure 1

The potential pathogenesis of abnormal visual perception in ASD children with ASD have abnormal visual perception as visual avoidance, visual exploration, and visual–spatial disorientation, which are listed as the “five no” behavioral markers in early clinical practice with strong evidence. ASD is defined as a neurodevelopmental disorder, studies have found that children with ASD have rapid development of the visual cortex between the ages of 1–2 years, as evidenced by rapid expansion of cortical area and slow changes in thickness. Is this related to the rapid expansion of the visual cortex? The transmission of visual information is accomplished following the sequence of retina-LGN-visual cortex, the balance of corresponding signaling between the layers is the key to the preservation of visual–spatial location information. Is the abnormality of visual–spatial perceptual information related to the disturbance of the level of visual information transmission? The FFG of visual cortex is the core area of face and facial expression recognition. There are functional abnormalities in this area in ASD children. Is this the cause of abnormal face recognition in ASD children? There is a transmitter balance between excitement and inhibition in the transmission of visual information. Studies have shown that there is an imbalance in children with ASD. Is there a relationship between the enhancement and weakening of excitatory transmitters and the symptoms of continuous visual exploration? In the visual cortex, there is the transmission of ventral flow and dorsal flow signals when processing visual information. The ventral pathway is good at shape perception, the dorsal pathway is good at spatial position perception, and most ASD children are good at shape perception while visual–spatial perception is abnormal. Is there a correlation between them?