---

AO1

Interference is an explanation for forgetting from long term memory – two sets of information become confused.

1. Proactive interference (pro=forward) is where old learning prevents recall of more recent information. When what we already know interferes with what we are currently learning – where old memories disrupt new memories.

2. Retroactive interference (retro=backward) is where new learning prevents recall of previously learned information. In other words, later learning interferes with earlier learning - where new memories disrupt old memories.

Proactive and retroactive Interference is thought to be more likely to occur where the memories are similar, for example: confusing old and new telephone numbers. Chandler (1989) stated that students who study similar subjects at the same time often experience interference. French and Spanish are similar types of material which makes interference more likely.

AO3

Semantic memory is more resistant to interference than other types of memory.

Postman (1960) provides evidence to support the interference theory of forgetting. A lab experiment was used, and participants were split into two groups. Both groups had to remember a list of paired words – e.g. cat - tree, jelly - moss, book - tractor. The experimental group also had to learn another list of words where the second paired word if different – e.g. cat – glass, jelly- time, book – revolver. The control group were not given the second list.

All participants were asked to recall the words on the first list. The recall of the control group was more accurate than that of the experimental group. This suggests that learning items in the second list interfered with participants’ ability to recall the list. This is an example of retroactive interference.

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 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.

AO1

Retrieval failure is where information is available in long term memory but cannot be recalled because of the absence of appropriate cues.

When we store a new memory we also store information about the situation and these are known as retrieval cues. When we come into the same situation again, these retrieval cues can trigger the memory of the situation.

Types of cues that have been studied by psychologists include context, state and organisation.

• Context - external cues in the environment, e.g. smell, place etc. Evidence indicates that retrieval is more likely when the context at encoding matches the context at retrieval.

• State - bodily cues inside of us, e.g. physical, emotional, mood, drunk etc. The basic idea behind state-dependent retrieval is that memory will be best when a person's physical or psychological state is similar at encoding and retrieval.

  For example, if someone tells you a joke on Saturday night after a few drinks, you'll be more likely to remember it when you're in a similar state - at a later date after a few more drinks. Stone cold sober on Monday morning, you'll be more likely to forget the joke.

• Organisation - Recall is improved if the organisation gives a structure which provides triggers, eg categories.

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.

Evaluation (AO3)

People tend to remember material better when there is a match between their mood at learning and at retrieval. The effects are stronger when the participants are in a positive mood than a negative mood. They are also greater when people try to remember events having personal relevance.

A number of experiments have indicated the importance of context-based (i.e. external) cues for retrieval. An interesting experiment conducted by Baddeley indicates the importance of context setting for retrieval.

Baddeley (1975) asked deep-sea divers to memorize a list of words. One group did this on the beach and the other group underwater. When they were asked to remember the words half of the beach learners remained on the beach, the rest had to recall underwater.

Half of the underwater group remained there and the others had to recall on the beach. The results show that those who had recalled in the same environment (i.e. context) which that had learned recalled 40% more words than those recalling in a different environment. This suggests that the retrieval of information is improved if it occurs in the context in which it was learned.

A study by Goodwin investigated the effect of alcohol on state-dependent (internal) retrieval. They found that when people encoded information when drunk, they were more likely to recall it in the same state.

For example, when they hid money and alcohol when drunk, they were unlikely to find them when sober. However, when they were drunk again, they often discovered the hiding place. Other studies found similar state-dependent effects when participants were given drugs such as marijuana.

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.

---

Eyewitness Testimony

→ Misleading Information | Anxiety

AO1

Loftus and Palmer investigated how misleading information could distort eyewitness testimony accounts.

Procedure: Forty-five American students formed an opportunity sample. This was a laboratory experiment with five conditions, only one of which was experienced by each participant (an independent measures experimental design).

Participants were shown slides of a car accident involving a number of cars and asked to describe what had happened as if they were eyewitnesses. They were then asked specific questions, including the question “About how fast were the cars going when they (hit/smashed/collided/bumped/contacted ) each other?”

Findings: The estimated speed was affected by the verb used. The verb implied information about the speed, which systematically affected the participants’ memory of the accident.

Participants who were asked the “smashed” question thought the cars were going faster than those who were asked the “hit” question. The participants in the “smashed” condition reported the highest speeds, followed by “collided”, “bumped”, “hit”, and “contacted” in descending order.

AO3

The research lacks mundane realism, as the video clip does not have the same emotional impact as witnessing a real-life accident and so the research lacks ecological validity.

A further problem with the study was the use of students as participants. Students are not representative of the general population in a number of ways. Importantly they may be less experienced drivers and therefore less confident in their ability to estimate speeds. This may have influenced them to be more swayed by the verb in the question.

A strength of the study is it's easy to replicate (i.e. copy). This is because the method was a laboratory experiment which followed a standardised procedure.

AO1

The Yerkes Dodson effect states that when anxiety is at low and high levels, EWT is less accurate than if anxiety is at a medium level. Recall improves as anxiety increases up to an optimal point and then declines.

When we are in a state of anxiety, we tend to focus on whatever is making us feel anxious or fearful, and we exclude other information about the situation. If a weapon is used to threaten a victim, their attention is likely to focus on it. Consequently, their recall of other information is likely to be poor.

Clifford and Scott (1978) found that people who saw a film of a violent attack remembered fewer of the 40 items of information about the event than a control group who saw a less stressful version. As witnessing a real crime is probably more stressful than taking part in an experiment, memory accuracy may well be even more affected in real life.

However, a study by Yuille and Cutshall (1986) contradicts the importance of stress in influencing eyewitness memory. 21 witnesses observed a shooting incident in Canada outside a gun shop in which 1 person was killed and a 2nd seriously wounded. The incident took place on a major thoroughfare in mid-afternoon.

All of the witnesses were interviewed by the investigating police, and 13 witnesses (aged 15-32 yrs) agreed to a research interview 4-5 months after the event. The witnesses were also asked to rate how stressed they had felt at the time of the incident, using a 7 point scale. The eyewitness accounts provided in both the police and research interviews were analysed and compared.

The results of the study showed the witnesses were highly accurate in their accounts, and there was little change in amount or accuracy of recall after 5 months. The study also showed that stress levels did not have an effect on memory, contrary to lab findings.

All participants showed high levels of accuracy, indicating that stress had little effect on accuracy. However, very high anxiety was linked to better accuracy. Participants who reported the highest levels of stress were most accurate (about 88% accurate compared to 75% for the less-stressed group).

AO3

One strength of this study is that it had high ecological validity compared with lab studies which tend to control variables and use student populations as research participants.

One weakness of this study was that there was an extraneous variable. The witnesses who experienced the highest levels of stress where actually closer to the event (the shooting) and this may have helped with the accuracy of their memory recall.

Reduced accuracy of information may be due to surprise rather than anxiety – Pickel found that identification was least accurate in high surprise conditions rather than high threat conditions – The weapon focus effect may be related to surprise rather than anxiety therefore research may lack internal validity.

Real wordl application: We can apply the Yerkes Dodson effect to predict that stressful incidents will lead to witnesses having relatively inaccurate memories as their anxiety levels would be above the optimum – We can avoid an over-reliance on eyewitness testimony that may have been impacted by anxiety.

---

The Cognitive Interview

The cognitive interview is a police technique for interviewing witnesses to a crime which encourages them to recreate the original context in order to increase the accessibility of stored information.

AO1

The cognitive interview involves a number of techniques:

The main additional features are:-

• Encourage the witness to relax and speak slowly.

• Offer comments to help clarify witness statements.

• Adapt questions to suit the understanding of individual witnesses.

AO3

One limitation is the cognitive interview is that it's time consuming to conduct and takes much longer than a standard police interview. It is also time consuming to train police officers to use this method. This means that it is unlikely that the 'proper' version of the cognitive interview is used.

Another limitation is that some elements of the cognitive interview may be more valuable than others. For example, research has shown that using a combination of 'report everything' and 'context reinstatement' produced better recall than any of the conditions individually.

A final criticism is that police personnel have to be trained and this can be expensive and time consuming.

Geiselman (1985) set out to investigate the effectiveness of the cognitive interview. Participants viewed a film of a violent crime and, after 48 hours, were interviewed by a policeman using one of three methods: the cognitive interview; a standard interview used by the Los Angeles Police; or an interview using hypnosis.

The number of facts accurately recalled and the number of errors made were recorded. The average number of correctly recalled facts for the cognitive interview was 41.2, for hypnosis it was 38.0 and for the standard interview it was 29.4.

Exam Question Guides

Revision Notes