The effect of neurodegenerative disease on representations of self in discourse.

Four incontrovertible 'facts' are assumed for human emergence, survival and notion of a self: (1) the existence of neurobiological structures and mechanisms, (2) employment of cognitive problem solving mechanisms, (3) adoption of physiologically based emotional displays, and (4) aquisition of communal socio-culture knowledge through caregiver 'scaffolding' activities and situated practices. The 'self', therefore, is only viable with the simultaneous evolution of neurobiological, cognitive, emotional, and socio-cultural structures and processes. An emergent self presupposes an integration and continual interaction of a developing memory system, continual acquisition and reproduction of cognitive problem solving mechanisms and emotional displays, and acquisition and loss of distributed socio-cultural knowledge. The inability to reproduce coherent local displays of self becomes acutely evident in patients diagnosed with fairly advanced Alzheimer's disease, frontotemporal lobar degeneration, and related insults to the brain. Ten minutes of discourse between spouses with diagnoses unknown to the author are used to illustrate linguistic scaffolding provided by caregivers to simulate appropriate socio-cultural interaction; the value of such exchanges for diagnosing human brain dysfunction and loss of self is discussed.