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Models of memory
STM
LTM
Models

Forgetting
STM
LTM
Emotion

EWT
Reconstructive memory
Leading questions
Face recognition

Memory (top)

Memory is a complex and varied phenomenon.  Ideas about what constitutes memory and how it works can be traced back to ancient times.  Plato compared memory to an aviary, and in some respects his ideas have remained little changed into the modern era. 

Plato likened human memory to an aviary with memories (birds) flying around inside.  A new bird can be captured and added to the aviary (placing a new memory into storage), and at a later date the bird can be captured in a net and removed (retrieval of a memory).

Some modern theories of memory still use this principle of storage and retrieval, however it is becoming more popular now to see memory as a process rather than simply a storage system.  Research in recent years has shown that far from being a perfect recording of an event our memories do change over time and can be influenced by others and by later events.  Re-read this paragraph… this point is essential for your full understanding of the entire topic!

This topic, like all the others at AS can be split into three parts:

1.       Models of memory

Looks at the differences between the two storage systems and at various models that try to explain how human memory works.

2.       Forgetting

Examines possible ways that we may forget from our STM and LTM and whether forgetting is due to permanent loss of information or an inability to recall the information.

3.       Eye Witness Testimony (EWT)

Considers the reliability of eye witnesses and how testimony can be improved.  It also looks at the reconstructive nature of human memory in general.

The notes that follow are meant to provide a thorough overview of the topic as it is described by the AQA Specification.  They should be regarded as a bare minimum and consequently should be supplemented by class notes and independent notes following your own extensive background reading! 

Sensory Memory

This is essential to the way our memory works but interestingly not mentioned in the specification.  I shall therefore keep this bit brief.  If you’d like to know more please ask. 

Sensory memory acts as a filter with each sense having its own brief ‘storage system.’  Throughout the day and to some extent even when we are asleep, our senses are bombarded with information.  So as you are sat reading this there will be other visual stimuli around you, there will also be noises, smells etc.  Few if any of these will be remembered.  When you walk into town or to school you will pass dozens of cars, but unless they are in some way unusual you will recall no detail about them.  The sensory memory appears to hold information for a fraction of a second.  If we decide that the information is not important it disappears and will not be recalled later.  Only if it is important (particularly if it is threatening), unusual or meaningful will we pay attention to it and transfer it to STM.  Sensory memory therefore plays a vital role in filtering out the vast majority of useless stuff that impinges on our senses and enables us to focus our attention on important detail.

Short term memory and long term memory

We use the terms STM and LTM in everyday language, but do these separate storage systems really exist and if so how do they operate together?  

Short term memory (STM)

It is estimated that only about 1% of stimuli that hits our senses reaches STM.  99% of stimuli is filtered out at the first hurdle.  Of the 1% that does get this far approximately 5% is stored permanently in LTM.  The rest is lost by STM (Lloyd et al 1984). 

STM serves three main purposes:

1.       To keep information in mind until it is used, for example a telephone number

2.       To pass information to LTM where it can be stored for use at a later date

3.       To retrieve information from LTM and use it again

Long term memory (LTM)

A quick word about encoding: this refers to the format in which a memory is stored.  Information arrives at our senses as sound, vision, taste etc.  It is then transformed into a format that we can store.  If you are asked to remember a word… let’s take ‘Kylie’ as an example, you could encode this acoustically (by sound) by simply repeating the word over and over (although I’d recommend this not to be done out loud), or it could be done visually by imagining Kylie (by far the best method) or semantically by thinking about the meaning of Kylie: a short but kinda’ cute looking Aussie with an average voice and famous butt!

Evidence for two memory stores

This is a favourite on examination papers.  Clearly you could talk about research into the two main memory stores mentioned above.  In addition to this it would be essential to mention some, if not all, of the following:

• Multistore model of memory

Discussed in the next section, this would be a good start to the essay since it suggests how the two main stores work in conjunction with one another.

·         Primacy and recency effect.

Demonstrated using a free-recall test in which participants are presented with a list of words and then asked to recall them in any order.  We tend to recall words at the start and end of the list best.  The primacy effect (good recall of words at the start of the list) is evidence of LTM, we have had the opportunity to rehearse the first few words creating a stronger memory trace and transferring them to LTM.  The recency effect, (good recall of words at the end of the list), is evidence of STM.  Words here are still in STM.

·         Amnesiac case studies. 

Most people with memory problems have either impairment of their STM or LTM, not usually both.  This suggests that they are different systems.  H.M. who had his temporal lobes removed to cure epilepsy lost all memory for events since the operation, (LTM).  However, his STM was fine.  Clive Wearing had similar impairment.  KF who had brain damage following a motorcycle accident has an impaired STM (2 digits rather than the usual 7), but his LTM is fine. 

·         Working memory model

This is explained in later sections and argues that STM may not be just one store but a collection of components each with a different task.  This would be evidence for there being more than two stores.

·         Types of LTM

Suggests that LTM may also be more than one store.  Clive Wearing provides good evidence for this too.

·         Levels of processing model

Again discussed later, this model suggests there is no such thing as STM and LTM but instead believes we have one memory store.

Types of Long term memory

First a note of caution.  ‘Types of long term memory’ is not specifically mentioned in the specification, nor do some of the texts, e.g. Cardwell for AS cover the topic.  However, some texts, including ours, do and the wording in the specification is sufficiently woolly to allow a question on it.  To date no questions have been set on the topic, however, information contained in this section and covered in class will at the very least be useful in part c questions that deal with STM and LTM.

We saw in the videos on amnesia that many patients suffering memory loss still have vital aspects of their LTM intact.  It is very rare for amnesiacs to lose their memory for skills such as language (reading and writing) and for walking, swimming etc.  As we saw in the case of Clive Wearing his ability to play the piano and conduct choirs was still intact despite most other memories having been lost.  In the video his long suffering wife says that his episodic memory is severely impaired whilst his semantic memory is largely intact.  This is one way of distinguishing types of LTM, however, there are others:  What follows is a brief summary of these, with examples and similarities drawn between them.

Episodic and Semantic (Tulving 1972)

• Episodic memory contains the details of your life.  When Victoria Beckham gets someone to write her autobiography for her she would first sit down and tell them, presumably in words of not more than two syllables, all the interesting events that have happened to her.  For example the chive she had for dinner each day in August and the counselling she received on discovering she had a split end! 
• Semantic memory contains our memories of the World and how it works.  Continuing the theme, hubbie Dave would store here his vast knowledge of the English language, capital cities of the World (presumably so they can name their next son Ulan Bator), and most importantly his footballing skills, specifically how to bend it like… well Beckham! 

Research evidence: Tulving (1989) using radioactive gold, found different areas of the brain are active when the two memory types are being used.  Episodic engages the frontal lobes, semantic the posterior lobes.

Declarative and Procedural (Cohen and squire 1980)

• Declarative (knowing that).  For example knowing capital cities and other factual information and knowing about personal events in our life.  This is different to Tulving who believed that these two types of information were stored in different aspects of LTM.
• Procedural (knowing how).  This covers our knowledge or memory for skills such as walking, talking, driving, playing football etc.

Research evidence: Squire et al (1992) used PET scans to show that different areas of the brain were active during each memory type. 

Implicit and Explicit (Graf and Schacter 1985)

• Explicit: similar to declarative and being used for memories that we have to consciously recall, for example we need to think about personal memories and memories for trivia.
• Implicit: similar to procedural and being used for memories that we don’t have to consciously think about.  These are mostly skills such as walking and talking.  If we do consciously think about such activities e.g. driving, they can become more difficult.

Evaluation: Implicit/explicit is particularly useful in explaining amnesia in brain-damaged patients, typically these having damage to their explicit memory but retaining an intact implicit memory. (E.g. H.M. and Clive Wearing).

Models of Memory

Multi-store Model of Memory:  Atkinson & Shiffrin (1968)

This model builds on the idea of three memory stores and tries to explain how they work together.  The model sees memory as a flow of information through a system.  The model takes an information processing approach and as such it is usually represented in the form of a flow diagram.  Exam tip: in your exam it is advisable to describe the model in words.

So called since it sees memory as comprising three stores!

Components (see previous notes for more detail)

Sensory Memory stores the incoming information from the senses.  The model assumes that these are modality specific, that is there is a separate store for each of the five senses.  The store is very brief and the vast majority of information is lost here.  Only information that is relevant or important is attended to and passed on to STM.  Forgetting from the sensory store is by decay.

STM Atkinson & Shiffrin believed the store to be fragile and retains information for about 30 seconds.  Compare this to the 18 seconds of the Brown–Peterson technique.  Material that is rehearsed is passed on to LTM.  Forgetting from STM is by displacement or decay.

LTM can store this information for a lifetime.  Forgetting from LTM is by decay or interference.  (note: displacement is not an issue since capacity is limitless).

Processes

Attention: needed to transfer information from the senses to STM.  Most stimuli that reach the senses are ignored because they aren’t seen as important.  Only relevant or interesting information, or material that we choose to concentrate on is passed to the STM.  99% is lost at this stage.

Rehearsal: needed to transfer information from STM to LTM.  We can rehearse information out loud as a child would do learning times tables by rote, or we can rehearse sub-vocally, in our heads.  Either way it is seen as crucial and is one of the main criticisms of the theory, as we shall see.

Evaluation

·         The model has simplistic appeal and has been influential in stimulating research.  Other models such as the ‘working memory model’ take the multistore model as starting point and then add to it.

·         Various studies that suggest the existence of two separate stores support the theory.  For example Murdoch (1962) found evidence for a primacy and recency effect.  As already mentioned primacy effect due to information heard first being rehearsed and passed to LTM and recency effect because recently heard or seen information is still present in the STM. 

·         On the face of it, amnesiac case studies such as Clive Wearing, H.M. and K.F. also provide evidence for a distinction between two different stores, since usually amnesiacs have one aspect of memory such as STM intact whilst other aspects show impairment.

·         There appears to be a distinction between stores in terms of capacity, duration and encoding.

However

The model is too simplistic:

·         Given the multitude of different memories we store it is unlikely that LTM is a unitary store.  Others have distinguished between semantic memory (for skills) and episodic memory (for facts and events) as already mentioned.

·         When considered more closely case studies of amnesiacs suggest that both STM and LTM are far more complex than the multi-store model suggests, e.g. Clive Wearing has an intact memory for skills but a severely impaired memory of facts.  KF has a severely impaired STM but his LTM is intact.  According to the multi-store model this could not happen since the memories in LTM must pass through STM first.

·         Flow of information is assumed to be one way, but it seems likely that our LTM is able to assist our STM suggesting a ‘reverse flow.’

·         The role of rehearsal is probably over stated.  We often remember facts without conscious rehearsal.  Tulving (1967) got participants were asked to read a list of words over and over again.  Later participants were asked to remember another list of words containing a mixture of ‘old’ (ones read earlier that day), and ‘new’ words.  Tulving found that participants were just as likely to recall the new words as the old ones suggesting that rehearsal has little effect in transferring memories to LTM. 

·         Finally the multi-store model provides a passive explanation of memory.  Research suggests that memory is an active process, for example STM being involved in our ability to focus attention and guide our thinking and LTM being used to help STM in this process.

The working memory model seeks to explain the operation of ‘STM’ in more detail.

Working Memory Model:  Baddeley & Hitch (1974)

It seems that STM is far more complex than the multi-store model assumes.  Working model proposes an active, multi-component short term memory store with each sub-system having its own role to play in learning, problem solving and concentration.

The original model comprised three components

The central executive: is the control centre responsible for coordinating the other slave units.  It is able to process information from any of the senses and appears to have a minimal storage capacity.  We use the central executive when we are concentrating on a task and it is sometimes likened to ‘attention.’  If we are attempting to do two things at the same time, for example read and hold a conversation, it is the central executive that switches our attention between the two, deciding which other components of the working memory to use.  People attempting to drive whilst using a mobile phone are therefore dividing their attention and stretching their central executive. 

Slave systems:

Articulatory (phonological) loop: is sometimes called the inner voice.  It holds sounds for a few moments (one to two seconds), storing the sounds temporally, i.e. sounds we hear first are stored first.  This is important for example when we are replaying a sentence to check its meaning or when we are rehearsing a telephone number.  The clearest illustration of the loop in use is that situation we are all familiar with; you are sat reading and not switched on to events around you.  Someone asks a question and you realise that it is being directed at you.  You ask the person to repeat what they’ve just said with a polite ‘AYE?’  However, before the word is out you realise that you do know the question.  The words are stored in your loop and you area able to play them back as you would when rewinding and replaying a tape.  Baddeley et al (1975) found that the loop can hold about 2 seconds worth of sounds, so it can hold more short words than it can long ones.

Primary acoustic store: this was added later and not always included in the model.  It appears to store sounds but unlike the articulatory loop stores them in terms of pitch and volume.  Personally I find that it confuses the model and prefer to consider only the original three components!

Research evidence

This usually takes the form of getting participants to use different components of the model and examining their performance.  If the same component is used to carry out two tasks simultaneously then because capacity is limited performance is impaired on both tasks.  However, if participants perform two tasks together that rely on different components each task can be performed normally. 

Baddeley (1986) got participants to complete two tasks simultaneously:

1.       To remember a list of numbers (a so called digit span task)

2.       To answer true or false to a number of problems such as

                        BA                    A follows B (true or false)

If STM is a unitary (single store) as proposed by the multi-store model, and has a capacity of around 7, then as task 1 reached 7 digits there would be no capacity left to carry out task 2.  In fact this was not the case.  Both tasks could be performed at the same time.  However as the number of digits in task 1 was increased the speed at which task 2 could be completed slowed, but not appreciably. 

Evaluation

·         Active process: It sees memory as an active process and not merely a passive store

·         Multi-component: Evidence from a variety of studies suggests that STM does comprise a number of components that work side by side.

·         Rehearsal: It only considers rehearsal to be important in the phonological loop.  It is widely considered that the multi-store model does place too great an emphasis on rehearsal in transferring information to STM.

·         PET scans (Positron Emission Tomography), show that different parts of the brain are active when different parts of the system are in use.  This provides further evidence for distinct components.  The central executive seems to reside in the frontal cortex and the scratch pad in the right side of the occipital lobe, known to be associated with vision.

·         Amnesiac case studies: A single component STM is unable to explain the case of KF, who, following a motorbike accident suffered impairment of his STM.  Shallice & Warrington (1974) showed that although his memory for verbal material was poor his memory for visual information was unaffected.  In terms of the working memory model this can be explained by damage to the articulatory loop but with the sketchpad remaining intact.

·         Baddeley (1986) found that patients with damage to their frontal lobe had problems concentrating suggesting damage to the central executive.

However

Working memory only considers short term aspects of memory so is not a full memory of the function of memory.

Very little is known about the central executive, the main component, the central executive.  For example we have no idea of its capacity.  Richardson (1984) believes there are problems in defining the exact role of the central executive. 

Baddeley (2001) added an acoustic store making the model more complex.  This suggests again that the model is not complete and may need still further revision as more evidence is uncovered.

Overall the model has proved to be influential and has stimulated lots of research.  It is still being developed and expanded.

Levels of Processing: Craik and Lockhart

This is different to the other two theories as it does not consider different stores or physical components.  Basically it believes

1.       Depth of processing carried out on incoming information has a substantial effect on how well we remember it.

2.       Deeper levels of analysis produce longer lasting and stronger memory traces than shallow levels of analysis.

Shallow levels of processing include simply noticing the physical characteristics of the material to be memorised, e.g. the shape of the letters such as upper or lower case.  Learning by rote (or parrot fashion) is called maintenance rehearsal and is also seen as shallow.

Medium levels of processing include noticing the sound of the material to be learned, referred to as phonetic processing (e.g. does the word rhyme with…?).

Deep levels of processing are semantic since they consider the meaning of the material to be learned.

Research into LOP

1. Craik & Tulving (1975) presented participants with words via a tachistoscope.  After each word they were asked one of four questions:

1.       Is the word in upper case? (shallow processing)

2.       Does the word rhyme with chair? (phonetic or medium processing)

3.       Is the word a type of food? (semantic or deep processing)

4.       Would the word fit into the sentence ‘He kicked the …… into the tree. (semantic or deep processing).

Findings: Participants remembered more of the words that had been semantically processed.

2. Hyde & Jenkins (1973) got participants to listen to lists of 24 words and carry out one of a number of different tasks, for example:

1.       Estimate how often the word is used in the English language

2.       Spot the letters ‘e’ or ‘g’ in any of the words

3.       Decide whether the word is a noun, verb etc.

4.       Decide whether or not the word would fit into a particular sentence.

Half the participants were told in advance that they would be tested on the words afterwards, the other half were not.

Findings:  Whether the participants had been told to expect a test or not made little difference to their recall.  This is what Craik & Lockhart would predict since they consider intention to learn to be unimportant in the learning process.  Also, the words that were semantically processed were recalled better.

Evaluation

Influential when it first appeared particularly since it concentrates on steps we take to memorise information.

But

·         It is difficult to asses how deeply a word has been processed, this makes it difficult to test the theory.  Some psychologists believe the arguments are circular.  Effort rather than depth may be important.  Tyler et al (1979) gave participants easy or difficult anagrams e.g. DOCTRO or OCDRTO.  Later participants remembered the difficult anagrams better even though the type of processing was the same.  What had altered was the effort put in.

·         Elaboration and distinctiveness may also be important, as we saw with the lovely Kylie.

Forgetting

Forgetting can occur because of one of two basic reasons:

·         Availability: Material is forgotten because it has never been stored in the first place.  This is most likely to explain forgetting from STM. 

·         Accessibility: Material cannot be recalled because for whatever reason we are unable to gain access to it.  Most likely to explain forgetting in LTM.

Forgetting from STM

Trace decay

Believes forgetting occurs because of the passage of time.  STM has a limited duration.

Peterson & Peterson (1959) found that recall of trigrams was minimal after 18 seconds suggesting that STM does have a brief duration.  Hebb (1949) believed that learning leaves a physical trace in the brain.  During learning the trace is fragile.  Decay theory believes that if nothing is done within this 18 seconds, for example if information is not rehearsed, then the memory trace disappears and is lost forever!

Evaluation

1. Jenkins & Dallenbach (1924) argued that time alone was not the cause of forgetting.  Participants learned lists of nonsense syllables.  They were tested on their recall 1, 2, 4 or 8 hours later.  During this time some slept.

Findings: Those who slept during the interval between learning and recall remembered more than those who had stayed awake even though the amount of time was the same.

Conclusion: What happens between learning and recall is important in forgetting, not the passage of time. 

2. Waugh & Norman (1965) used a ‘serial position probe’ (don’t worry its not painful), to question how much forgetting in STM is due to decay.  Participants are presented with 16 numbers:

            7, 14, 6, 10, 9, 1, 3, 5, 12, 4, 13, 2, 16, 8, 15, 11

They are then given the ‘probe’ and asked to say what number follows.  So in this case if the probe is ‘9’ the correct answer is ‘1.’   If time is an issue then the faster the presentation of the numbers the less time there is for the trace to decay and the better should be the recall.  In fact the researchers did not find that speed of presentation made any difference so they concluded that forgetting was not due to decay.

Displacement

Believes forgetting occurs because of the limited capacity of STM.  Miller (1956) suggested a capacity of 7+/- 2 (just in case you’d forgotten).  The theory suggests that new material pushes out or replaces information already present.

Evidence for

Waugh & Norman (1965) used a serial probe to test the theory.  Participants are given a set of digits followed by one being repeated (the probe).  Just as above.

                        13  5  9  11  3  41  6  22  7  4  16  32  45  1  25  8 ……5 (the probe)

Participants have to say what digit followed the probe, in this case 9.

Findings: If the probe was towards the end of the list (e.g. 32), participants were far more likely to recall the correct digit.

Conclusion: Digits at the end of the list were still in STM, whereas those earlier in the list (e.g. 9), had been displaced by later digits.

Evaluation: Shallice (1967) found that if presentation of the words is speeded up recall is better.  This suggests that time is possibly a factor, i.e. DECAY.  Note this is obviously contradicted by Waugh & Norman’s research as described in ‘trace decay!’

Evaluation point: in practice it is very difficult to separate out the effects of displacement and decay since adding more material to create displacement also takes longer, creating time for decay!  However, generally displacement is seen as a better explanation of forgetting from STM.

Interference

This refers to the process by which old information may be confused with new information or new information with old.  Research suggests that interference is most common when the old and new material is similar, for example trying to remember a friend’s new mobile number and confusing it with their old. 

Loess 1968 asked participants to read the names of three animals (e.g. lion, deer, aadwark).  They then had to count backwards for 15 seconds, similar to Brown-Peterson technique.  This process was repeated six times with different animals each time.  Accurate recall of the animals decreased as the number of trials increased.  Loess believed that this was due to old animal names interfering with correct recall of later ones.

When the category was changed so for example the participants were than asked to recall the names of three vegetables performance returned to the original level.  A new category was avoiding confusion or interference from previous tasks. 

Availability or accessibility?

Trace decay and displacement are clearly cases of availability.  The information is pushed out of STM either by lack of time (duration) or lack of space (capacity).  As a result the memory disappears completely. 

Interference is not so clear cut.  Some researchers and texts explain interference in terms of availability whereas others see it more in terms of accessibility, believing that the information that has been interfered with is still present in memory.  More on this when we consider LTM.

Forgetting from LTM

Cue dependent forgetting or retrieval failure.

A problem with accessibility, the all too familiar case of tip of the tongue phenomenon; we know that we know, but can we get to the answer, can we heck as like, (town just outside Dewsbury in West Yorkshire!).  This theory argues that information in LTM is only accessible if the appropriate cues are present.  (Note the town is actually called ‘Heckmondwike’).

One aspect of the target word(s) we normally report knowing is the first letter.  We know for a fact that it begins with ‘G.’   Brown (1991), reviewed 25 years of research into tip of the tongue phenomena and found that we accurately remember the initial letter between 50 and 70% of the time.  More often than not we can also report the number of syllables in the word. 

Interlopers:

Words that sound alike are confused.  For example: 15 down in a crossword, ‘Band of the late 70s early 80s, had a hit with ‘Baby I love You’?’  You know its something like ‘Ronettes.’  Once that thought is in your head it drives you crackers ‘cos you know it’s not the right answer but you’re stuck with it (bit like the tune itself).  By the way the answer is the Ramones!  In fact both had a hit with ‘Baby I love you!’ the Ronettes version was in the 60s.

Tulving & Psotka (1971):  Participants were given lists of words to remember.  These lists were presented in category order for example:

            Pea, carrot, cabbage, turnip, cat, dog, fish, budgie, red, blue, white, green…etc.

Some participants were asked to free recall the words others were given cued recall (i.e. told the category names as cues, colour, pets etc.).

Findings:  Basically, they found that we are able to remember up to four times more if we are given clues in the form of categories.  Using the example above, recall would be cued by the words: vegetables, pets, colours etc.  In fact some psychologists believe that all forgetting is cue dependent.  That is, we never really forget anything form our LTM.  Provided some form of clue is given we could remember anything!  This is the basis of the cognitive interview technique (see notes on EWT) but is impossible to test!

Encoding specificity principle:

This sounds complex but is really about as simple as it gets!  Tulving (1979), found that the closer the cue to the target word the better our recall.  Not exactly rocket science!  For example in trying to recall ‘Ramones’ a clue like ‘Ram Jams’ or ‘Ramrods’ is more likely to trigger the correct response than ‘Abba’!

Context dependent and state dependent learning/forgetting

Godden & Baddeley (1975) gave deep sea divers lists of words to remember.  Some learned them on the beach the others under 15 feet (4.5 metres) of water.

State dependent

Our state of mind when learning can also act as a cue.  The classic example is not remembering what you did at the party the night before due to amount of alcohol consumed, but being able to remember all the embarrassing details the next time you’re in a similar state (of mind!).  By the way this is Goodwin et al (1969), not personal experience!  For example they found that participants who had hidden money or alcohol when drunk and were unable to remember where the next day, were able to find it the next time they were drunk.  Other studies have found similar results with the effects of marijuana and barbiturates.  In these cases the cues are internal reflecting psychological or physiological states.

There is some evidence for mood dependent learning; the idea that if you learn something when happy you are best able to recall it the next time you’re in that state of mind.  However, evidence for this is at best mixed.

Evaluation

Forgetting due to retrieval failure is the most obvious case of a problem due to accessibility.  The information is still present in memory but requires some sort of clue to get at it.  There appears to be plenty of support for cue dependent forgetting, but remember that this evidence mostly lacks ecological validity.  However, Eysenck (1998) claims that retrieval failure is probably the ‘main reason for forgetting in LTM.’

Interference

As mentioned in forgetting from STM, this is the idea that forgetting is due to one piece of information getting confused or mixed up with another piece of information.

Proactive interference

When previous learning interferes with later information for example an Essex man (let’s call him Kevin) is about to enjoy a moment of passion with his new girlfriend Tracey (Trace to her mates), and he calls out the name of Sharon, the young lady with the white stilettos he was dating last week. *

Retroactive interference

When new learning interferes with previous learning, for a boring example, learning your new postcode and then being unable to remember your old one.

Research evidence

Most research involves paired associate learning.  Participants are presented with pairs of words:

                        Cat-pear

                        Floor-badger

                        Window-glass…

They are then presented with a second list of paired words in which the first words are repeated but the second word is changed:

                        Cat-radio

                        Floor-jelly

                        Window-spanner…

*having the same ‘pet name’ like ‘babe’ for all of your partners gets around this particular problem!

Proactive interference

Experimental group are given both lists to remember, control group just remember the second list.  The experimental group are then asked to recall the second list and do less well than the control since the first list has interfered with their recall.

Retroactive interference

Experimental group are given both lists to remember, control group just remember the first list.  Both groups are then asked to recall the first list and the experimental group do less well since the second list is interfering with their recall.

Underwood (1957) reported an accidental case of proactive interference.  He got participants to remember a list of nonsense syllables.  Twenty four hours later their recall was far worse than he would have expected.  Since the students had not learned any other nonsense syllables in that 24 hours their poor recall could not be put down to retroactive interference.  However, these students had taken part in lots of other similar experiments so Underwood concluded that earlier memory tasks were causing confusion with later recall.

Evaluation

Interference almost certainly occurs but most psychologists agree that it is unlikely to occur often in everyday life since it is unusual that two different responses are attached to the same stimulus.

Tulving & Psotka (1971) found that interference disappears when participants are given cued recall i.e. given clues such as category names.  They concluded that the words had not actually been replaced as interference suggest, but had been forgotten due to retrieval failure (accessibility).

The issue of ecological validity is a particular problem for research in this area. 

·         The lists of words are trivial and not typical of the material we are normally expected to remember.

·