​We've probably all been frustrated at one time or another, not able to remember something that feels desperately important, while countless clear images and nuggets of useless information and past experiences flit through our minds. Why is it that we remember some things and not others?

Leun Otten of UCL's Institute of Cognitive Neuroscience thinks she may have discovered the answer. It turns out that 'brain states' play an extremely important role in creating new memories so, put simply, you have to be in the right frame of mind in order to remember things. This 'right' frame of mind isn't necessarily dependent on mood - good and right are not interchangeable in this case.

By running a series of experiments, Leun Otten and her team were able to accurately predict whether or not a participant would be able to recall information shown to them based on what kind of brain activity was recorded in the moments just before they were shown the information in question. The participants were, as predicted, able to recall information that had been shown to them when they had been exhibiting a good 'brain state'. A common characteristic of a conducive brain state is the presence of alpha waves.

Alpha waves bridge the gap between our subconscious and conscious mind, making it easier for us to make connections. They occur largely during sleep, dreaming, and deep relaxation. Closing your eyes is a straightforward way to boost the number of alpha waves in your brain and this is thought to be one of the reasons why meditating, typically with eyes closed, is an excellent tool for managing emotions, stress and thoughts. And it perhaps also explains why we often close our eyes when striving to remember something though that's me speculating . High levels of stress can cause 'alpha blocking' - making it harder for us to make associations and set down new memories in times of crisis or distress.

The more we find out about these brain states, the more likely it is that we can clue into exactly how to produce, or at least encourage, them. Perhaps in the not-so-distant future, we'll have schools that only feed children information at times when they are exhibiting good brain states, beamed onto a monitor above their heads. Or perhaps, hopefully more likely, our deeper understanding of how to establish productive brain states will equip teachers, mentors, and relationship partners how to best get their message across, understood and remembered.