Before information enter short-term memory, they go through the sensory memory or sensory register. This process lasts only a few milliseconds and can embrace a wide range of auditory, visual, sensory and other stimuli. These stimuli go through the filter (we only keep the ones important for us) and we keep or save them for a short period of time.
The most important thing in this phase is our attention. Attention allows us to save some of the stimuli and to ignore the other. The information that are useless are left out of our memory, that is why we cannot recall them anymore. The stimuli that we decided that are important are left in the memory and transferred into the long-term memory.
Our body activates different area of the brain, regarding on which stimuli we are dealing with (location, space, shape, colour, name, object).
Usually we can hold up to 7 units (minus, plus 2 units) of information. This is how much our mind is capable of processing.
From sensory register the information is temporary stored in short-term memory. Short-term memory has limited space of withholding information that are later transferred into more permanent memory. At the same time, it has limited capacity of information recalling. The information is stored in this memory for a few seconds (usually 15-10). When we combine information into larger units, we can remember multiple complex information. Short-term memory is prone to forgetting, because the information can overlap and are not related, or they are insufficient. If we put some meaning to the information, or we use it, it has a better chance of getting into the long-term memory. We know that gained knowledge can be forgotten if we do not use it. But if we learn something and we use if often, the chances of forgetting are low.
Short-term memory is divided onto sensory, motoric and cognitive. We can therefore store sensual imprints, physical and mind information.