Nonverbal autism is a subset of autism where the person does not learn how to speak. It is estimated that 25% to 50% of children diagnosed with autism spectrum disorder (ASD) never develop spoken language beyond a few words or utterances. Most of the existing body of research in nonspeaking autism focuses on early interventions that predict successful language outcomes. Research suggests that acquiring language before age five is a good indicator of positive child development, and the likelihood of acquiring functional language in the future past this age is minimal, that early language development is crucial to educational achievement, employment, independence during adulthood, and social relationships. The most obvious signs of autism, such as atypical social and language development, and restricted or repetitive behaviors and interests, often present themselves between the ages of two and three, and most children with ASD can be diagnosed in early childhood as a result. Other disorders such as epilepsy, ADHD, gastrointestinal problems, sleep disorders, depression and anxiety often accompany ASD. The causes of nonspeaking autism are unknown. However, there appears to be a relationship between joint attention and verbal communication. Joint attention occurs between two individuals when one draws the other's attention to an object through gesturing (i.e. eye gazing, pointing). The ability to achieve joint attention at an early age plays a significant role in language development, and studies indicate severe lapses in joint attention in children with autism. In one study, researchers suggest that a displayed pattern of delays, absences, or a general impaired response to stimuli (hyporesponsiveness) and a fascination with intense or repetitive stimulation (sensory seeking) is more likely in nonspeaking children with autism, suggesting that both hyporesponsiveness and sensory seeking is related to poor communication outcomes in children with ASD. There is a growing body of tentative evidence indicating the amygdala's involvement in the development of autism.
Nouchine Hadjikhani, Loyse Hippolyte, Ophélie Rogier, Torsten Ruest, Britt Russo
Henry Markram, Kamila Markram, Mônica Regina Favre