The thesis of this chapter is that the neurological phenomena discussed and numerous others omitted or not yet recognized relate primarily to a release of primitive activity when diffuse brain damage erodes cerebral inhibition mechanisms. Anatomical correlations are always difficult when there are multiple lesions, and those that have been made have not completely explained these phenomena. A phylogenetic explanation is not completely adequate either but certainly does not bar further investigations. Indeed such a concept points out the necessity to continue to search for other fetal or developmental responses in dementia, to assess the interrelationships between these reflexes, and to quantify the stimulus as well as the response. The prognostic value of these reflexes is not emphasized, because it is not known. In the evaluation of dementia, one of the last obvious frontiers of neurological science, both specific observations and general principles await discovery.