People have long practiced yoga as an aid to relaxation; recently there has been some interesting research done showing that switching off the brain can help with cognitive function. So when we switch off, we exercise a different part of the brain known as the default mode network. This is the part of the brain that allows us to day-dream and importantly allows us to consolidate memories, in particular it seems, episodic and emotional memories. In switching off from the external world, as we do in Savasana, the deeper relaxation which is an integral part of most yoga classes, we allow that part of the brain to do its’ job in looking after us.
That deeper level of relaxation can also help stress hormones, such as cortisol, return to more useful levels. High levels of cortisol over a period of time can be damaging to the hippocampus – the part of the brain crucial for memory formation. So after any kind of period of prolonged stress we have to find ways of allowing these hormones to reduce to more helpful levels.