AS Memory

?
  • Created by: annasaira
  • Created on: 11-11-17 20:54

Coding

Definition: The format in which information is stored in the various memory stores.

Research: Baddeley (1966) gave 4 groups of participants lists of words to rememeber. Group 1: Acoustically similar, Group 2: Acoustically dissimilar, Group 3: Semantically similar,   Group 4: Semantically dissimilar. When asked to recall directly after (STM), acoustically similar did worse, when asked after 20 minutes (LTM), semantically similar did worse. Shows that STM is coded acoustically, LTM is coded semantically. 

Evaluation: The experiment used artificial stimuli. This means that we have to be careful when generalising the findings. This is because it may be different when processing more meaningful words.

1 of 28

Capacity

Definition: The amount of information that a memory store can hold

Research: Jacobs (1887) measured digit span. He would say one digit and ask the participant to recall the digit. If they were correct he would give 2 digits... He found that the mean digit span was 9.3 for numbers and 7.3 for letters.

Evaluation: The experiment took place a long time ago, early psychological resarch usually lacked addequate control. For example, some ppts may have been distracted- not all confounding variables were controlled. /H/ the results of the study have been confirmed by other research, thus supporting the validity.

2 of 28

Duration of STM

Research: Peterson and Peterson (1959). Tested 24 undergraduate students. Each student took part in 8 trials. On each trial the student was given a trigram (such as YCM) to remember but also a 3 digit number. The student was asked to count backwards from this number until they were told to stop. The counting prevented rehersal. On each trial they were asked to stop after a certain amount of time: 3 seconds, 6 seconds... This is known as the retention interval. Ppts remembered more after a shorter period of time,showing that STM has a short duration.

Evaluation: Meaningless stimuli- doesnt reflect real life situations- lacked external validity

3 of 28

Duration of LTM

Research: Bahrick studies 392 ppts from Ohio, America. The ppts were between 17 and 74. Yearbooks were obtained from the ppts or directly from schools. Recall was tested in various ways: 1) Photo recognition test consisting of 50 photographs, some from the participants high school yearbook; 2) free recall where participanst recalled the names of people in their class. Participants who were tested within 15 years of gradution had a 90% accuracy in photo recognition. After 48 years, recall declined to 70% for photo recognition. Free recall was worse than photo recognition: after 15 years, it was 60% accurate, this dropped to 30% after 48 years. This shows that LTM has a long duration.

Evaluation: This study has higher external validity. When similar studies were carried out with meaningless information, recall rates were lower. 

However, the down-side of the real-life reseaarch is that confounding variables cannot be controlled. For example, it is likely that the participants had looked back on their yearbooks, thus rehearsing their memory.

4 of 28

Short-term Memory

The limited-capacity memory store. Coding is mainly acoustic and the capacity is 7+/- 2. Information can last between 18 and 30 seconds unless it is rehearsed.

Maintenance rehersal occurs when we rehearse material to ourselves over and over again. We can keep information in our STM as long as we repeat it. If we rehearse information for long enough, it will go into our LTM.

Research: 

Spirling (1906) showed ppts a grid of numbers for 50 miliseconds. They were then asked to write down all 12 numbers or only a row if they heard a tone. 42% recall for the whole thing, 75% for one row. This shows STM has a small capacity. This research can be trusted as it has been repeated with similar results. It is therefore reliable.

Glanzor and Curtis (1966) gave a list of 20 words to ppts one at a time. They found that ppts tended to remember the words at the start (primary effect) and the words at the end of the list (recency effect).

Primary effect: first words are repeated and transfered to LTM. Recency effect: words at the end are still in STM.

Peterson and Peterson: see 'Duration of STM'.

5 of 28

Long-term Memory

The permanent memory store. Coding is mainly semantic. It has unlimited capacity and a possible life-long duration. 

When material is stored in the LTM, we can recall it by transferring information to our STM. This is known as retrival.

Research: Bahrick (see Duration of LTM)

6 of 28

The Multi-store model (MSM)

The multistore model of memory (also known as the modal model) was proposed by Atkinson and Shiffrin (1968) and is a structural model. They proposed that memory consisted of three stores: a sensory register, short-term memory (STM) and long-term memory (LTM).

Information is detected by the sense organs and enters the sensory memory. If attended to this information enters the short term memory.Information from the short-term memory is transferred to the long-term memory only if that information is rehearsed (i.e. repeated). If maintenance rehearsal (repition) does not occur, then information is forgotten, and lost from short term memory through the processes of displacement or decay.

Research: Glanzer and Cunitz

7 of 28

Strengths of MSM

  • There is a large base of research that supports the idea of distinct STM and LTM systems (e.g. brain-damaged case study patient KF’s STM was impaired following a motorcycle accident, but his LTM remained intact).
  • It makes sense that memories in the LTM are encoded semantically – i.e. you might recall the general message put across in a political speech, rather than all of the words as they were heard.
  • The MSM was a pioneering model of memory that inspired further research and consequently other influential models, such as the Working Memory Model. 
8 of 28

Weaknesses of MSM

  • Some research into STM duration has low ecological validity, as the stimuli participants were asked to remember bear little resemblance to items learned in real life, e.g. Peterson and Peterson (1959) used nonsense trigrams such as ‘XQF’ to investigate STM duration.
  • The model is arguably over-simplified, as evidence suggests that there are multiple short and long-term memory stores, e.g. ‘LTM’ can be split into Episodic, Procedural and Semantic memory.
  • It does not make much sense to think of procedural memory (a type of LTM) as being encoded semantically, i.e. knowing how to ride a bike through its meaning.
  • It is only assumed that LTM has an unlimited capacity, as research has been unable to measure this accurately.
9 of 28

Three Types of Long-term Memory

Tulving critisised the MSM. This is because he felt that it was too simplistic. For example, he believd that there were three types of LTM:

Episodic Memory: Episodic memory s a part of the long-term memory responsible for storing information about events (i.e. episodes) that we have experienced in our lives.  It involves conscious thought and is declarative.  An example would be a memory of our 1st day at school.

Semantic Memory: Semantic memory is a part of the long-term memory responsible for storing information about the world.  This includes knowledge about the meaning of words, as well as general knowledge. For example, London is the capital of England. It involves conscious thought and is declarative.

Procedural Memory: Procedural memory is a part of the long-term memory is responsible for knowing how to do things, i.e. memory of motor skills.  It does not involve conscious (i.e. it’s unconscious - automatic) thought and is not declarative.  For example, procedural memory would involve knowledge of how to ride a bicycle.

10 of 28

Evaluation of the Three Types of Long-term Memory

Research evidence supports the case for their being 3 different memory stores associated with the LTM. Brain scans have showered brain damage after the removal of a tumour found deficiencies in ability to create new episodic memories. However she was still able to create semantic memories supporting the theory that they are separate. 

Case studies such as HM (Milner 1962) support the case for procedural and declarative memory stores being distinctively different. HM could not form episodic or semantic memories due to the destruction of his hippocampus and temporal lobes however he was able to form procedural memory through learning how to draw figures by looking at their reflection (mirror drawing). 

Another major weakness into theories for long-term memory is the lack of research into brain areas that are involved in procedural memory. Case studies of individuals with brain damage that affects procedural memory but not declarative memory is needed to understand this better however such cases are extremely rare. Therefore we cannot conclusively say the procedural memory store is fully understood with any detail to generalise such a theory.

11 of 28

Working Memory Model (WMM)

(http://aspsychologyblackpoolsixth.weebly.com/uploads/5/4/2/8/5428408/3337730.png?629)

Working memory is short term memory. Instead of all information going into one single store, there are different systems for different types of information.

It includes: The central executive, phonological loop, visuo-spatial sketchpad and the episodic buffer.

12 of 28

Central Executive (WMM)

Drives the whole system (e.g. the boss of working memory) and allocates data to the subsystems: the phonological loop and the visuo-spatial sketch pad. It also deals with cognitive tasks such as mental arithmetic and problem solving. The central executive has a limited processing capacity. It receives information from the senses or from long-term memory. It is also involved in directing “attention” and resources towards particular tasks. 

13 of 28

Phonological Loop (WMM)

Part of working memory that deals with auditory information- both written and spocken (coding is acoustic). Preserves the order in which information arrives. 

  • Phonological Store (inner ear) – Linked to speech perception Holds information in speech-based form (i.e. spoken words) for 1-2 seconds. Holds the words you hear.
  • Articulatory control process (inner voice) – Used to rehearse and store verbal information from the phonological store.
14 of 28

Visuo- Spatial Sketchpad (WMM)

Stores and processes information in a visual or spatial form. The VSS is used for navigation.

Processes visual information through the senses (eyes) or longterm memory on what things look like, patterns of recognition and spacial information consisting of the relationship between things and perception of movement. Logie (1995) suggested the VSS could be further sub-divided into a visual cache (CV) which stores visual material on color and form and an inner-scribe (IS) which deals with spatial relationships, rehearsal and the transfer of information from the visual cache to the central executive. 

15 of 28

Episodic Buffer (WMM)

episodic buffer

The original model was updated by Baddeley (2000) after the model failed to explain the results of various experiments. An additional component was added called the episodic buffer. The episodic buffer acts as a 'backup' store which communicates with both long term memory and the components of working memory

16 of 28

Strengths of the Working Memory Model

Researchers today generally agree that short-term memory is made up of a number of components or subsystems. The working memory model has replaced the idea of a unitary (one part) STM as suggested by the multistore model.

The working memory model explains a lot more than the multistore model. It makes sense of a range of tasks - verbal reasoning, comprehension, reading, problem solving and visual and spatial processing. And the model is supported by considerable experimental evidence.

The working memory applies to real life tasksreading (phonological loop), problem solving (central executive), navigation (visual and spatial processing)

The KF Case Study supports the Working Memory Model. KF suffered brain damage from a motorcycle accident that damaged his short-term memory. KF's impairment was mainly for verbal information - his memory for visual information was largely unaffected. This shows that there are separate STM components for visual information (VSS) and verbal information (phonological loop).

Working memory is supported by dual task studies (Baddeley and Hitch, 1976).

The working memory model does not over emphasize the importance of rehearsal for STM retention, in contrast to the multi-store model.

17 of 28

Weaknesses of WMM

Lieberman (1980) criticizes the working memory model as the visuo-spatial sketch pad (VSS) implies that all spatial information was first visual (they are linked). However, Lieberman points out that blind people have excellent spatial awareness, although they have never had any visual information. Lieberman argues that the VSS should be separated into two different components: one for visual information and one for spatial.

There is little direct evidence for how the central executive works and what it does. The capacity of the central executive has never been measured.

Working memory only involves STM so it is not a comprehensive model of memory (as it does not include SM or LTM).

The working memory model does not explain changes in processing ability that occur as the result of practice or time.

18 of 28

Interference Theory

Interference theory states that forgetting occurs because memories interfere with and disrupt one another, in other words forgetting occurs because of interference from other memories (Baddeley, 1999).  There are two ways in which interference can cause forgetting:

1. Proactive interference (pro=forward) occurs when you cannot learn a new task because of an old task that had been learnt.  When what we already know interferes with what we are currently learning – where old memories disrupt new memories.

2. Retroactive interference (retro=backward) occurs when you forget a previously learnt task due to the learning of a new task. In other words, later learning interferes with earlier learning - where new memories disrupt old memories.

Research: McGeoch & McDonald (1931) Participants were asked to learn a list of words with 100% accuracy. Then they were given a new list of words to learn. The new material varied differention in comparison to the orignal. G1 - synonyms, G2 - antonyms, G3 - unrelated, G4 - Nonsense syllables, G5 - Three digit numbers, G6 -  No new list. Performance depended on the nature of the second list. Synonyms produced the worst recall. When participants were given different material to revise such as numbers recall increased. This shows that recall is worse if the memories are similar.

19 of 28

Evaluation of Interference Theory

Although proactive and retroactive interference are reliable and robust effects, there are a number of problems with interference theory as an explanation of forgetting. 

First, interference theory tells us little about the cognitive processes involved in forgetting.  Secondly, the majority of research into the role of interference in forgetting has been carried out in a laboratory using lists of words, a situation which is likely to occur fairly infrequently in everyday life (i.e. low ecological validity).  As a result, it may not be possible to generalize from the findings.

Baddeley (1990) states that the tasks given to subjects are too close to each other and, in real life; these kinds of events are more spaced out.  Nevertheless, recent research has attempted to address this by investigating 'real-life' events and has provided support for interference theory. However, there is no doubt that interference plays a role in forgetting, but how much forgetting can be attributed to interference remains unclear (Anderson, 2000).

Evidence from lab studies

Real-life evidence- Rugby players, remeber last match, some hadn't played for weeks but could remember the last team they played- no new infromation to interefere.

20 of 28

Retrieval Failure

Information is in the LTM, but cannot be accessed. The information is available, but not accessible. It cannot be accessed because the retrieval cues are not present. When we store a memory we also store information about the situation- these are known as retrieval cues. When we come into the same situation again, these retrieval cues can trigger the memory. The cues can be :

External/ Context: the environment- E.g. smell, place... Godden and Baddeley (1975) investigated this. They used two groups: one learnt a list of words on land and the other learnt a list of words underwater. The groups then ssplit in half. One half would go to the other location, the other would remain. They found that when people stayed in the same location, they did better. Accurate recall was 40% lower when in a different location.

Internal/ State: how we were feeling. Carter and Cassaday (1998) gave anti-histamine drugs to their participants. This medication made the participant feel slightly drowsy. This causes a change in psychological state. The ppts were then asked to learn a list of words and then recall it. Participants were either in the condition of: drug-drug, drug-no drug, no drug- drug, no drug- no drug. When there was a mis-match, the recall was worse

21 of 28

Evaluation of Retrieval Failure

According to retrieval-failure theory, forgetting occurs when information is available in LTM but is not accessible.  Accessibility depends in large part on retrieval cues.  Forgetting is greatest when context and state are very different at encoding and retrieval.  In this situation, retrieval cues are absent and the likely result is cue-dependent forgetting.

There is considerable evidence to support this theory of forgetting from laboratory experiments. The ecological validity of these experiments can be questioned, but their findings are supported by evidence from outside the laboratory. 

For example, many people say they can't remember much about their childhood or their school days.  But returning to the house in which they spent their childhood or attending a school reunion often provides retrieval cues which trigger a flood of memories.

22 of 28

Factors Affecting EWT: Leading Questions

A question which, because of the way it is phrased, suggests a certain answer. 

Loftus & Palmer (1974) aimed to investigate the effect of a leading question about a car accident on recall of speed and damage caused.

The students were shown a video clip of a car accident and asked the question 'How fast were the cars travelling when they contacted?' However, the verb was replaced by either: contacted bumped, hit or collided. The mean estimated speed was 31.8 mph for contacted but 40 mph when smashed. The leading question biased the ppts answer.

They conducted a second invetication where they asked the ppts if there was any glass after the accident (there was none). Those who heard smashed were more likely to say yes than those who heard hit.

23 of 28

Factors Affecting EWT: Post-event Discussion

Occurs when there is more than one witness to an event. Witnesses may discuss what they have seem. This may influence the accuracy of their recall.

Fiona Gabbert studied this. They studied people in pairs. Both people would watch a scenario but from differernt POVs. They would then discuss what they had seen. This meant that when asked to recall what they had seen, they were giving information that was not in their video. For example, they were able to give the title of a book which they had not personally seen. 

They called this memory conformity.

24 of 28

Strengths of research into misleading questions (E

- There is a large base of evidence suggesting that misleading information can lead to EWT inaccuracy, which has raised awareness that the criminal justice system cannot always rely on EWT as a basis for [sometimes incorrect] convictions.

- Highlighting misleading information as a negative factor in EWT has led to new techniques designed to improve memory retrieval, such as the cognitive interview developed by Geiselman and colleagues.

25 of 28

Weaknesses of research into misleading questions (

- Laboratory experiments may have low external validity (i.e. bear little relation to a real court scenario); participants in research may be more likely to anticipate truthful information from experimenters, whereas eye witnesses in court cases may anticipate being subject to leading arguments as guilt/innocence is advocated (and thus identify/attempt to avoid being misled).

- A further realism pitfall - watching a video is arguably less emotionally arousing than witnessing real incidents, and some evidence suggests that emotional arousal can increase can improve the accuracy of EWT.

- We cannot be certain whether or not misleading information actually influences the memory ‘trace’ itself; it could just be demand characteristics driving changes in recall (i.e. participants’ behaviour may be affected by how they perceive the purposes of the experiment).

26 of 28

Factors Affecting EWT: Anxiety

Anxiety is a state of apprehension, worry or fear.
Anxiety causes intense stress at the time of the incident.
This means that the eyewitness may have difficulty encoding the information during the acquisition stage of the memory process.

negative effect: Johnson & Scott (weapon focus): high anxiety knife condition led to reduced recall (tunnel theory)

positive effect: Yuille & Cutshall (shooting): high anxiety associated with better recall when witnessing real crime.

27 of 28

Cognitive Interview

cognitive interview report everything: Include even unimportant details

reinstate context: Picture scene and recall how you felt (contextdependent forgetting)

reverse order: Recall from the end backwards (disrupts expectations)

Change perspective: Put yourself in the role of someone else present (disrupts schema)

Positives:

Consistently produces more accurate recall

Some elements may be more effective (report everything + context = best recall)

Nagatives:

Time-consuming

Creates increase in inaccurate information

28 of 28

Comments

No comments have yet been made

Similar Psychology resources:

See all Psychology resources »See all Memory resources »