**6. Conclusion**

Individuals with autistic disorders and Asperger's syndrome experience abnormalities in the perception of faces. It has been shown that healthy individuals have increased activation in the fusiform gyrus during face processing and increased activation in the inferior temporal gyrus during processing object activation, while individuals with autistic disorders or Asperger's syndrome have less activation in the right fusiform gyrus and more activation during face discrimination (this is not the case for objects). The autism group tends to use more of the inferior temporal gyrus during face processing when compared to controls. This finding shows that they process faces like objects [87]. The basic zone associated with face processing in healthy individuals is the lateral fusiform gyrus (called as "fusiform face area"). It has been reported to decrease activation in the fusiform gyrus and other areas associated with process‐ ing face detection such as the inferior occipital gyrus, superior temporal gyrus and amygdala in individuals with autism during face detection tasks. It has also been reported that autistic individuals use different neuronal systems for seeing faces and have individual-specific,

In a fMRI study with high-function autistic adults, detected decreased activation in the fusiform gyrus during the identification of the person who has been seen before, in contrast to previous studies. Social dysfunction in autism has been associated with common abnor‐ malities observed in the social brain network. The severity of impairment in social functioning is associated with a reduction in the connections between fusiform face area and amygdala and also increment in the connections between fusiform face area and right inferior frontal cortex.. This result indicates neuronal abnormalities in the limbic system to be associated with

Neuronal activation fields associated with working memory have been studied using fMRI methods. Luna et al. [90] reported lower activation in the dorsolateral prefrontal cortex and posterior cingulate regions during spatial working memory. Koshino et al. [91] showed that autistic individuals had lower activation in the inferior left prefrontal area (verbal processing and working memory-related) and right posterior temporal area (associated with theory of mind) during a working memory task that used photographic facial stimuli. The same study noted activation in the different division of the fusiform area in autistic individuals. It has also been shown that fusiform activation is in the lower and lateral division and also displaced from the typical region activated during face detection, compared to the region activated during object detection in an autistic group. These findings support the notion that face processing in autism analyse face characteristics as an object in terms of humanitarian significance. Abnormal fusiform activation showing a lower-level link with the frontal area is associated with the presence of the neuronal communication network, which has reduced

A study conducted by Müller et al. [92] determined activation on opposite sides of the primary sensorimotor (the most powerful) cortex, premotor and/or supplementary motor areas during a simple finger movement task completed by healthy individuals in contrast, autistic groups showed no significant activation. [92]. Autistic individuals showed activation in regions that are not associated with these tasks, e.g., the superior parietal lobe and posterior neuronal

scattered activation patterns when compared to normal individuals [88].

a prevalence of poor social impairment in autism [89].

40 Autism Spectrum Disorder - Recent Advances

synchronization [91].

precuneus.

In autism, common neuroanatomical defects in the early stages of brain development such as hypoplasia at specific areas and excessive cerebral growth leads to abnormalities in the development of functional systems. If the developing brain is traumatized by genetic or environmental factors, the functional organization and hence, functional activities, are disrupted. Abnormal functional activity and organization affect different structures in different ways, because autism is associated with neural defects in many types and locations. Many structures that have been shown as affected by autism can in turn affect the different functional areas of cerebral and cerebellar organization, as these structures function as intermediaries for the development of different types of neural defects. Therefore, more obvious abnormalities have been observed in some functions [94].

Functional imaging studies pose various limitations, for example, these studies include patients with autism and Asperger's syndrome together so study groups have heterogeneous diagnostic measurement. It is proposed that in future studies, working groups can be created to be a homogeneous diagnostic measurement comprised of different age groups and different levels of mental development when testing different tasks.
