Functionally, these neurons are either motor (conducting impulses that will cause activity such as the contraction of muscles) or association (conducting impulses and permitting 'communication' between neurons within the central nervous system).
The scant research that has been done on the causes of pica suggests that the disorder is a specific appetite caused by mineral deficiency in many cases, such as iron deficiency, which sometimes is a result of celiac disease or hookworm infection.
Other eating disorders. Other eating disorders include pica, rumination disorder and avoidant/restrictive food intake disorder. Pica. Pica is persistently eating nonfood items, such as soap, cloth, talcum powder or dirt, over a period of at least one month.