ABSTRACT
In this chapter, the authors introduce some reflections on the construction of the self related to the body–mind development in the case of dicephalic parapagus twins, usually called conjoined twins, who have one body and two heads. This will be followed by some considerations related to a clinical case of mother–child symbiosis. The brain’s intrinsic or spontaneous activity encodes Self-specific information (subjective) of the past and future, so the difference in intrinsic activity allows for constructing the Self and, in this case, the subjectivity of these individuals, even if their internal (interoception) and external (exteroception) stimulus inputs are the same. Singletary points to maladaptive plasticity as one of the mechanisms that produce the severity of the disorder if no timely intervention is undertaken. He assumes that the child, due to its neurobiological vulnerability, experiences its inability to interact with the environment, i.e. social isolation and social deprivation, and that this causes stress and an allostatic load.
