As pictured in Figure 1, this model notes that caregiving experienced early in life regulates the activity of critical stress-sensitive systems, which in turn influence the development of systems involved in rapid appraisal and response to threat. Low parental nurturance results in chronic stress to the infant. This biases the developing threat system to rapidly orchestrate larger defense responses (fight/flight/freeze). Overactivity of both stress-response and threat-response systems may then impact the development of prefrontal regulatory systems, hence increasing the risk for both attention- and emotion-regulatory problems. The neural systems that orchestrate endocrine, autonomic, and behavioral rapid defense responses are expected to be plastic during early childhood. If the child’s care improves, stress- and threat- systems have the possibility to re-organize in order to become less reactive and more modulated. However, children exposed to particularly severe and prolonged inadequate nurturance may be less capable of reorganizing with improved care and this, in turn, may make it difficult for caregivers to sustain appropriate responsiveness to the child’s needs. One hypothesis is that re-organization of the stress- and threat-response systems requires that the
