Visual Recognition of Biological Motion is Impaired in Children With Autism

Abstract

Autistic children and typically developing control children were tested on two visual tasks, one involving grouping of small line elements into a global figure and the other involving perception of human activity portrayed in point-light animations. Performance of the two groups was equivalent on the figure task, but autistic children were significantly impaired on the biological motion task. This latter deficit may be related to the impaired social skills characteristic of autism, and we speculate that this deficit may implicate abnormalities in brain areas mediating perception of human movement.

Brief Report: Recognition of Emotional and Non-emotional Biological Motion in Individuals with Autistic Spectrum Disorders

“…Results showed that children with autism [mean chronological age (CA) = 14.1 years; mean verbal mental age: 7:11 years] were as able as non-autistic children with learning disabilities matched on verbal mental age and CA in recognizing point-light displays of walking people or moving objects, even after very brief exposures of less than that of half a second. This finding seems to contradict those of Blake et al (2003).…”

“…It may be that the identification task used by Moore et al makes fewer attentional demands on children with autism than the prolonged discrimination task used by Blake et al Unfortunately, as the control task used by Blake was very different from the target task, and their control group was not intelligence quotient (IQ)-comparable, it is not possible to discount effects that IQ-related information processing abilities might have had on the PLD task performance of the autistic children. Another explanation could rest in the different age range of the autistic participants in the two studies, participants being younger in the Blake et al (2003) than in the Moore et al (1997) study. It may be that the ability to recognize and discriminate between human and nonhuman point-light displays improves with age.…”

“…Consequently, improvement with age may occur more for the recognition of basic actions in human point-light displays than for the recognition of emotional and subjective states. Alternatively, if, as Blake et al (2003) propose, all abilities for the perception of human movement are impaired in people with autism, then one might expect poorer abilities in the perception of all types of human point-light displays relative to controls, but expect the perception of non-human point-light displays of non-human objects to be relatively unimpaired and similar to that of mental age controls.…”

“…Blake, Turner, Smoski, Pozdol, and Stone (2003) presented participants with point-light displays which represented a human person engaged in actions such as throwing, jumping and kicking or out-of phase, scrambled, and thereby meaningless, versions of these original actions. Performance of children with autism aged from 8 to 10 years was compared to that of typically developing children matched on mental age.…”

“…Whereas Moore et al (1997) used a task that required participants to identify from brief video clips an object or a person only once, Blake et al (2003) employed a task in which participants had to discriminate over many trials between 1 s clips of point-light displays of a person or a scrambled version of a display. It may be that the identification task used by Moore et al makes fewer attentional demands on children with autism than the prolonged discrimination task used by Blake et al Unfortunately, as the control task used by Blake was very different from the target task, and their control group was not intelligence quotient (IQ)-comparable, it is not possible to discount effects that IQ-related information processing abilities might have had on the PLD task performance of the autistic children.…”