Functions of Brain Stem Nuclei in Controlling Subconscious, Stereotyped Movements
Rarely, a baby is born without brain structures above the mesencephalic region, a condition called anencephaly. Some of these babies have been kept alive formany months. They are able to perform some stereo-typed movements for feeding, such as suckling, extru-sion of unpleasant food from the mouth, and moving the hands to the mouth to suck the fingers. In addition, they can yawn and stretch. They can cry and can follow objects with movements of the eyes and head. Also, placing pressure on the upper anterior parts of their legs causes them to pull to the sitting position. It is clear that many of the stereotyped motor functions of the human being are integrated in the brain stem.