hello and welcome to memory lesson two where we are going to cover the multi-store model of memory now the multi-store model of memory was first proposed by atkinson and shifrin in 1968 and it is one of the earliest models of memory that was ever created the multi-store model suggests that memories are formed sequentially and that information is passed from one component in the model to the next in a linear fashion it also suggests that each specific component has its own type of coding its own capacity and its own level of duration and if you remember from memory lesson one these are all topics that came up then so just as a brief recap coding is the way that memories are processed and according to badly short-term memory is coded acoustically and long-term memory is coded semantically capacity refers to how much information can be held in a memory store and according to miller the capacity of short-term memory is seven plus or minus two items and long-term memory is thought to have an unlimited capacity and duration refers to how long information is available for retrieval and according to peterson and peterson the duration of short-term memory is 18 to 30 seconds and according to barrack the duration of long-term memory is potentially unlimited okay if you need a little bit of a recap on those three things then i would suggest that you go back and you have a look at memory lesson one where we go through all of the research all of the definitions and also the evaluation points now the multi-store model of memory suggests that everything starts with environmental stimuli okay so things that come in through our senses from the environment and those things go directly into the first store in the multi-store model and that is sensory memory okay so memory that is for our senses you have iconic memory which is for visual elements you have echoic memory which is for auditory elements and then you've got another generic store for other sensory information now the idea here is that the capacity of sensory memory is very very large because if you think about it you're always taking in information via your senses and so there's a lot of space in order to hold a lot of things in sensory memory however the duration of sensory memory is very very short again if you think about it given how much stuff actually comes in through our five senses we actually remember very very little of all of those things okay so duration is very short the bits of information that we pay attention to the bits of information that we think are important they get transferred to short-term memory okay short-term memory as i just said has a duration of 18 to 30 seconds a capacity of seven plus or minus two items and is coded acoustically now once the information is in short-term memory it can be kept in short-term memory via maintenance rehearsal maintenance rehearsal is essentially that thing that we do where we say things to ourselves over and over and over again in order to keep them in our minds and if we do that for long enough so if we do something that's known as prolonged rehearsal then that then moves the information from short-term memory to long-term memory okay now don't get put off by the fact that they're called different things maintenance rehearsal and prolonged rehearsal they are effectively the same thing the only difference is is that prolonged rehearsal is done for a longer period of time okay so maintenance rehearsal is a short-term rehearsal that keeps information in short-term memory whereas long-term rehearsal or prolonged rehearsal then moves information from short-term memory to long-term memory and then once it's in long-term memory but you need it for something maybe you need to access those memories then you need to use a process called retrieval which then brings long-term memories back into short-term memory so that we can do something with them now forgetting and memory loss can occur at every step of the way in sensory memory you have decay where information that isn't paid attention to just simply fades into nothingness in short-term memory you have decay but also something called displacement which you should hopefully have come across in the first memory lesson and it effectively means that new memories push old memories out of your short-term memory because there's only a limited capacity and then in long-term memory memories can get lost via interference or retrieval failure and those are both theories that you'll come across later on in the memory topic okay but that is your general multi-store model of memory it's very simple you can see here what i meant about it being sequential and linear everything starts with an environmental stimulus then it goes to sensory memory then it goes to short-term memory then it goes to long-term memory okay and you can also see that there is only one short-term memory store and there's only one long-term memory store as well something that's important to bear in mind particularly for when we get to our evaluation points now in case you missed anything that i just said i've got a slide there which just provides you with a note-taking opportunity so feel free to pause the video there and jot down anything that you may have missed okay and we are now going to move on to the evaluation points okay so i have four evaluation points for you obviously as always there are way more evaluation points than the four that i'm giving you so if you don't like any of them then that's fine check your textbooks and if there's something in there that you prefer then that's all good these are just the ones that i quite like and that i find quite easy to remember so the first one is research support now if you remember i said a couple of minutes ago that long-term memory and short-term memory are distinctly separate stores in the multi-store model now there's research support for this idea and it's research that you already know so for example in badly study into coding the one that you learned last lesson he found that if he gave participants a list of words to remember he found that acoustically similar words were harder to recall immediately and semantically similar words were harder to recall after 20 minutes and it was concluded that acoustic confusion was occurring in short-term memory and semantic confusion was occurring in long-term memory which suggests that short-term memory codes acoustically and long-term memory codes semantically highlighting the fact that the two types of memory are completely different entities okay so you can use battery's research to provide evidence for the fact that the two stores are different from each other okay you don't have to use battery though you can also talk about maybe the duration of short-term memory and long-term memory and you could compare peterson and peterson's research to barracks research okay because one of them shows that short-term memory has a short duration of 18 to 30 seconds whereas barracks research shows that long-term memory has a potentially unlimited duration which again shows that short-term memory and long-term memory are distinctly different from one another however there is also a counterpoint to this which focuses on the fact that a lot of research into memory uses artificial stimuli and artificial tasks okay so despite the apparent support provided for these separate stores of memory the reality is that actually in everyday life we form memories related to all sorts of useful information like people's faces and names and facts and places and all that kind of stuff but very often in memory studies none of those materials are actually used okay so instead people use things like nonsense syllables like peterson and peterson or they use digits or letters only in the very rare cases do they use words or other things that might be relevant to us so that means that the research into the multi-store model might not actually be an accurate or a valid model of how memory works in everyday lives because in everyday lives we don't remember individual letters or individual words or nonsense syllables we have to remember meaningful information and that isn't replicated in research studies which means that they may not actually be showing us how memory works in the real world okay so that is a counter argument to the research support another limitation is this idea that there may actually be different types of short-term memory and research support for that was provided by charlotte and warrington because they studied an amnesia patient known as kf now kf's short-term memory for digits was very very poor when they were read out loud to him but his recall was much better when he was able to to read the digits for himself and that suggests that there's more than one type of short-term memory store one for sounds and one for images and such research also challenges the multi-store model because it shows that there must be at least two types of short-term memory store rather than just one store which is what the multi-store model suggests and a final limitation of the multi-store model is that it is quite simply an outdated and oversimplified representation of memory okay so atkinson and schifrin based their model on the evidence that was available at the time um however there's been a lot of research done since then like the research using kf but also you know similar research that has um provided similar results for long-term memory as well so for example research has now shown that we have different long-term memory stores for things like facts and actions like motor memory and particular events in our lives okay and the multi-store model doesn't allow for these findings it just says we have one type of long-term memory when actually we've got at least three okay so that combined with the fact that we know that there's more than one type of short-term memory and combined with research as well that has shown that there's even more than one type of rehearsal suggests that the multi-store model is quite simply um outdated and doesn't live up to the research findings of modern psychology okay that being said it was obviously a very important model of memory at the time but these days there are more up-to-date models that more accurately represent how memory works in the real world okay so that is the final limitation and it is also the end of the video so i hope it has all made sense um please go back and re-watch anything that you missed or that you may need to just get your head around again and if you have any questions then please feel free to pop them in the comments section below and i will get back to you asap