The first type of memory is our very short lived and very fragile sensory store (Short Information Store, SIS). It is the afterimage when seeing something, it is the aftersound when hearing something, it stays in your mind for just a couple of seconds at the most.
A second type of our storage system is our Working Memory (WM). It used to be called Short Term Memory (STM). It lasts for only a couple of seconds to roughly a minute. It is also fragile and it can roughly store 7 ± 2 units of information, whether that is a word, a sound, numbers or images. On my page about Attention: what is it I will explain why this Working Memory actually is Attention. The description ‘Working’ refers to the fact that this is the short term storage where information is being worked on in order to store it more permanently in our Long Term Store (LTM).Very important to remember is that this WM capacity is NOT fixed: it changes every second due to our bio-dynamical brain system.
Our third type of storage is the Long Term Memory (LTM): it can last for years and its capacity seems unlimited (in reality it is nót unlimited of course). It takes hours till a couple of days to form a reliable LTM of something and that is largely a biochemical process called Long term potentiation or the Consolidation process. Usually, repeating the same information several times and having nights of sleep between repetitions is most desirable to form solid LTM.
more –> memory training after brain injury: is it possible?.
TBI Rehabilitation 