Cases of catch up beyond first two years. Cases of insult after first two years that lead to deficits in functioning. Restoration of an adequate diet leads to catch up. Brain growth no less than physical growth is only stunted in the case of chronic long term deprivation. By the same token, good nutrition in the first two years is no guarantee of long term brain adequacy.
Malnutrition later can cause insult.
On analogy with this, the focus on love relationships in the first two years of life should not be taken to mean that once securely attached at one year, a child has a sinecure guaranteeing emotional well being from then on. Love relations throughout life contribute to one's on-going secure base function, intellectual stimulation throughout life contribute to one's mental functioning, etc. The imprinting model of development is as out moded as old models in physics. Imprinting implies critical periods and fixity, not plasticity. This again is a case of our metaphors leading us astray, leading to unwitting inferences that are not valid.