The Place Model was originally inspired by Jeffrey Alberts 1994 article in a Supplement of Acta Paediatrica. He used the terms "habitat and niche", which I have replaced with place and behaviour. But the very simple concept is that the Place determines the behaviour, and for the newborn there is a basic binary choice with respect to place. For rats this can be the mother or the nest, but for primates it is the mother's chest.
Mother's sensory environment as a totality is needed for the baby, who then feels safe. This sense of safety is in the neruotransmitters, the ciruclating hormones, the neural circuits ... the only part we can see is the resulting behaviour, which for the newbron mammal is breastfeeding.The result is internal (vagal) regulation along with development through external bonding and attachment (emotional and social intelligence).
The absence of that enviornment tells the newborn that it is UNSAFE. Maternal absence is a severe threat to an organism totally depednent on mother, and in response the neuroendocrine milieu alters rapidly, and the objective of the observed behaviour is survival, development is on hold till mother returns.. This survival comes at a cost: high cortisol and other stress mediators damage neuronal pathways in critical or sensitve periods of development. These are the amygdala and hippocampus, and areas of the frontal lobes, those responsible for emotional and social IQ.
This model is well established in all mammalian neuroscience. It is my contention that it is as applicable in humans newborns, from the moment of birth.