Autism – Processing of the Human Figure
Autism – Processing of the Human Figure
In the case of autism, the processing of the human figure in early childhood is important to discuss, as this is a primary condition necessary for establishing social interaction (the ability to distinguish people).
The perception of the human figure is of two types:
recognizing the person’s identity (through the features of the face)
recognition of the emotional (emotional) state of an individual.
Babies, from the beginning, are fascinated by human figures, the preference explained by a subcortical mechanism, which focuses attention on the facial configuration. From the second month of life, this mechanism replaced by a cortical (cerebral) learning mechanism,.Which leads to acquiring knowledge about facial features.
Babies perceive the human figure by focusing on certain parts of it (eyes, nose, mouth, head shape), putting these parts together. As they grow and perceive the figure more and more (“holistic” strategy, encountered in adults).
At first, therefore, the normal child learns to “categorize” the features of the human figure in part, then processes them in its entirety.
At one month, the child “scans” only the areas with high contrast, and at two months the scan is complete (after Maurer and Salapatek 1976).
On two months it still makes no distinction between figures. İn which the features are in the normal position (in a drawing) or mixed.
From three months he prefers human figures drawn with the features in the normal position.
Bhatt and Colab. (2005) show that at five months children perceive the difference between a human figure with normal features . And one in which the distances between eyes and between mouth and nose have been increased. This ability disappears if the faces reversed (reversed).
Children under the age of six, however, have a much finer ability to recognize inverted figures (using analytical feature scanning).
As children see human figures every day. They become experts in their recognition and lose the ability to make a difference between other figures (such as animals). In a 2002 study, it was shown that six-month-old babies are able to differentiate between familiar and non-familiar human figures of monkeys, but nine-month-olds are no longer capable.
Autism and processing of the human figure
Unlike normal children, there is a lot of evidence that shows the disability of the child affected by autism in the perception of the human figure.
There is a lack of interest for the faces of others in the first six months of life.
Although people affected by autism have no difficulty in recognizing the identity of a person in figures and can recognize sex and age in human figures, they have bizarre methods of analyzing the human figure. While ordinary individuals oriented toward the region of the eyes to get information about what another person thinks and wants, people affected by autism have difficulty interpreting this information through eye tracking.
In 2002, Klin and Colab., use infrared tracking techniques of eye movements. Tracked the visual “reading” paths and the time a particular region of the human figure seen in a group of adolescents with autistic disorder. While following a close-up video of two people arguing (the sequence in “Who’s afraid of Virginia Woolf?”). The study showed that people with autism look at the eyes and not at all.
Autism and processing
The identification of human figures performed in an area located in the temporal lobe of the brain, called the fusiform facial area. Which was found to have 6 layers of cells. İn persons affected by autism layer 3 and 5 having fewer cells than in the normal ones. Affecting this area leads to a disorder in which patients no longer recognize famous faces, friends, relatives, or even their own faces in the mirror.
People affected by autism not even decipher the facial expression of emotions, an important role in this. Especially in the primary stages, having a formation from the base of the brain called the amygdala. It seems that people affected by autism do not recognize the complex emotions – surprise – .But they recognize the primary ones – sadness, joy. The amygdala activated by visual stimuli and involved in judging personality traits in pictures. Its activity increases when there is eye contact with a figure with facial expression of fear – especially in the right amygdala. The amygdala transmits “critical” information, with emotional meanings – threats, frightening figures – to specific brain areas. In children affected by autism the amygdala is less activated than normal (it is hypoactive).
Concurrent with the lack of interest for human figures, children affected by autism are often concerned with objects, parts of objects (edges, wheels, scales).
The lesions of the temporo-occipital lobe of the brain lead to the inability to differentiate human figures (prosopagnosia). Autism seems to be a natural form of developmental associative prosopagnosia. The person affected by autism being unable to associate information about a person’s identity with that person’s figure and to appreciate the affective state of another person (expressed by facial expressions).