You’ve got a ‘mind like a sieve’ is a common way of telling someone that things just fall through their heads and that they can’t remember anything. However sieves can retain some of the stuff that is being filtered through them. Is it that we filter out the ‘larger’ bits of information and allow the ‘smaller’ bits of information to fall through our minds?
Even people with awful memories do still remember some things. Maybe we all differ in the size of the holes in our sieve-like-minds. To a certain extent, whether we remember something depends on if we have paid any attention to it. If you are not aware of something, how could you remember it? There are many theories on attention, one particularly relevant one to this idiom is Donald Broadbent’s. He developed the filter model of attention which claimed that our selective attention occurs before any processing of the information due to our limited cognitive capacity. In other words, Broadbent was suggesting that our attention, and in turn our memory, works like a sieve, filtering out the unnecessary information in the early stages of processing leaving just the relevant stimuli to be processed to a higher level. These stimuli could be something you’ve heard or seen or anything that you are trying to remember. This is an early selection view of attention and is where there is a selective filter based on the physical properties of the stimulus before any higher level processing occurs.
However, there are some phenomena which can’t be explained by an early selection view of attention. For example, Colin Cherry coined the term ‘the cocktail party effect’ which many of us have experienced. Imagine you are at a party where there are lots of people and lots of conversations going on at the same time. It is possible to focus on a single conversation in a noisy room though also you can pick out words of importance from an unattended conversation such as your name. This implies that we don’t select what to pay attention to before any higher level processing occurs meaning that Broadbent cannot be completely correct with his filter theory of attention.
This might mean that our encoding of memories after the higher level processing of the stimuli is what acts as a sieve. The salience of the information plays an important role in whether something is encoded into our long term memory. Perhaps it is in recalling our memories that we filter out unimportant information. There is a trade-off between accuracy and actually remembering things. For every time we recall a memory we bring it into a labile state, a state where the memory can be easily altered as we think about it. But if we didn’t recall these memories we would forget them altogether.
There appears to be some truth to the saying ‘mind like a sieve’ though this act of filtering out unimportant information seems to occur at multiple stages of the processing of the stimuli. In some ways then we all have memories like sieves! This sounds like a bit of an ineffective system for remembering things. Though if you think of the fact that we have limited cognitive space for memories then it makes sense to filter out the unimportant things. If we didn’t, we wouldn’t be able to remember the important things that we really shouldn’t forget!