I have included this diagram of the limbic system, because it shows so clearly why our sense of smell can trigger such powerful memory recall, or, at other times, a smell can bring back an emotional memory that is powerful in its sense of ‘atmosphere’, even when there is no autobiographical detail attached. The olfactory bulb goes straight from our nasal region to the limbic system!

THE PRIMITIVE BRAIN

[S. Parker, The Human Body Book]

“Human behaviour is not always rational. In times of stress or crisis, deep-seated instincts well up from deep within and take over our awareness. Such events involve the ‘primitive brain’, which is based mainly in a series of parts known as the Limbic System.

The limbic system influences subconscious, instinctive behaviour, similar to animal responses that relate to survival and reproduction. In humans, many of these innate, early-evolved ‘primitive’ behaviours are modified by conscious, thoughtful considerations found in upper regions of the brain, as we take into account moral, social and cultural codes, and the results of our actions. However, primal urges sometimes prevail, and this is when the limbic system and associated structures take over. At other times they play lesser, but still complex and important roles in the expression of instincts, drives and emotions.”