memory

The Multi-Store Model (MSM)

• Definition: A representation of how memory works in three stores: sensory register, short-term memory (STM), and long-term memory (LTM).

• Process: Information flows through these stores linked by processing.

• Sensory Register: Receives stimuli from the environment (e.g., iconic for visual, echoic for sound); it has high capacity but duration is less than half a second.

• STM: Limited-capacity store; information is coded mainly acoustically and lasts about 18 seconds unless rehearsed.

• LTM: Potentially permanent store for information rehearsed for a prolonged time; coding is mainly semantic.

Evaluation of the MSM

• Strength: Research Support: Strength: Studies show STM and LTM are separate; for example, Baddeley found we mix up words that sound similar in STM but those with similar meanings in LTM. Evidence: This supports the MSM's claim that these are distinct, independent stores. Explanation: It shows coding is different in each store. Link: Therefore, the model's structure is empirically supported.

• Weakness: More than one STM store: Weakness: The MSM portrays STM as a single unitary store, but clinical evidence suggests otherwise. Evidence: Patient KF, who had amnesia, had poor STM for verbal information but good STM for visual information. Explanation: This suggests there are separate stores for different types of information. Link: This limits the MSM as an oversimplified model of memory.

• Weakness: Elaborative Rehearsal: Weakness: Prolonged rehearsal is not always necessary for LTM transfer. Evidence: Craik and Watkins found that the type of rehearsal (elaborative, linking info to existing knowledge) is more important than the amount (maintenance). Explanation: Information can transfer to LTM without long-term repetition. Link: Thus, the MSM does not fully explain how LTM storage is achieved.

Features of Memory (Coding, Capacity, Duration)

• Coding: The format in which information is stored. Baddeley found STM is coded acoustically and LTM semantically.

• Capacity: The amount of information held. Jacobs measured digit span, finding a mean of 9.3 items for digits. Miller noted the capacity of STM is "7 plus or minus 2".

• Duration: The length of time information can be held. Peterson and Peterson found STM lasts about 18 seconds without rehearsal. Bahrick et al. found LTM can last a lifetime, with 90% accuracy in photo-recognition after 15 years.

AO1:Retrieval Failure due to Absence of Cues

• Definition: Forgetting occurs when we lack the necessary 'triggers' or cues to access a memory, even though the memory is available.

• Encoding Specificity Principle (ESP): Tulving suggested cues must be present at both encoding and retrieval for recall to be successful.

• Context-Dependent Forgetting: Recall relies on external environmental cues. Godden and Baddeley (1975) found deep-sea divers had 40% lower recall when learning and recall environments did not match.

• State-Dependent Forgetting: Recall relies on internal cues (e.g., mood). Carter and Cassaday (1998) found worse recall when there was a mismatch between internal states (e.g., on vs. off antihistamines).

AO3 : Retrieval Failure due to Absence of Cues

• Strength: Real-world application. Retrieval failure theory explains common experiences, such as returning to the room where you first had a thought to remember it. This demonstrates that the theory has practical value for improving recall in everyday life.

• Strength: Research support. A large range of studies, such as those by Godden and Baddeley and Carter and Cassaday, support the theory. This evidence shows that retrieval failure occurs in real-world situations and controlled lab settings, increasing the validity of the explanation.

• Weakness: Recall vs. recognition. Godden and Baddeley (1980) found that when divers used a recognition test instead of recall, there was no context-dependent effect. This implies the theory is limited as it only applies when a person has to recall information rather than simply identify it.

AO1:Interference Theory

• Definition: Forgetting occurs because one memory blocks another, especially when the memories are similar.

• Proactive Interference (PI): Occurs when older memories disrupt the recall of newer ones.

• Retroactive Interference (RI): Occurs when newer memories disrupt the recall of older ones.

• Effects of Similarity: McGeoch and McDonald (1931) showed that interference is strongest when memories are similar (e.g., synonyms produced the worst recall).

AO3:Interference Theory

• Strength: Real-world interference. Baddeley and Hitch (1977) found rugby players’ recall of teams played depended on the number of intervening games, not the time passed. This shows interference operates in real-life situations, increasing the ecological validity of the theory.

• Strength: Support from drug studies. Coenen and van Luijtelaar (1997) found that drugs like diazepam, which prevent new information from being processed, improved recall of older information (retrograde facilitation). This provides physiological evidence that reducing retroactive interference helps consolidate memory.

• Weakness: Validity issues. Most research is lab-based using artificial materials like lists of nonsense syllables. In the real world, we learn meaningful information which is harder to interfere with, suggesting the theory may overemphasize the frequency of interference in daily life.

AO1:Misleading Information (Leading Questions & PED)

• Leading Questions: Questions phrased to suggest a certain answer. Loftus and Palmer (1974) found the verb used (e.g., 'smashed' vs. 'contacted') influenced speed estimates of a car crash.

• Substitution Explanation: Wording of a question actually alters the participant's memory (e.g., reporting broken glass that wasn't there).

• Post-Event Discussion (PED): Occurs when co-witnesses discuss an event, leading to memory contamination or memory conformity. Gabbert et al. (2003) found 71% of participants mistakenly recalled aspects of an event they hadn't seen but heard from a partner.

AO3:Misleading Information (Leading Questions & PED)

• Strength: Real-world application. Research into EWT has led to important changes in the legal system, such as how police officers phrase questions. This shows psychologists can help improve the way the legal system works by protecting innocent people from faulty testimony.

• Weakness: Evidence against substitution. Sutherland and Hayne (2001) found participants were more accurate for central details than peripheral ones even when asked misleading questions. This suggests original memories for central events are resistant to substitution, limiting the theory.

• Weakness: Demand characteristics. Lab studies of EWT may suffer from participants trying to be helpful and guessing answers they don't know. This means the results may be a product of participant behavior rather than actual memory change, questioning the internal validity of the studies.

AO1:Effects of Anxiety on EWT

• Negative Effect (Weapon Focus): Anxiety creates physiological arousal that prevents attention to details. Johnson and Scott (1976) found lower recall when a person held a bloody knife (high anxiety) compared to a pen.

• Positive Effect: Stress triggers 'fight or flight', increasing alertness. Yuille and Cutshall (1986) found real-life shooting witnesses were highly accurate even 5 months later.

• Yerkes-Dodson Law: The inverted-U theory suggests memory performance is best at moderate levels of anxiety.

AO3:Effects of Anxiety on EWT

• Weakness: Unusualness not anxiety. Pickel (1998) found recall was equally poor when seeing a raw chicken as when seeing a gun in a salon. This suggests 'weapon focus' is due to surprise rather than anxiety, meaning the theory may not accurately explain the role of anxiety.

• Strength: Support for positive effects. Real-life studies, like Yuille and Cutshall, confirm that high stress can lead to very accurate long-term recall. This challenges laboratory-based findings that anxiety always has a negative effect on memory.

• Weakness: Ethical issues. Purposely inducing high anxiety in participants, such as the 'bloody knife' condition, raises concerns regarding psychological harm. This makes it difficult and ethically questionable to replicate these findings in controlled settings.

AO1:Improving EWT: Cognitive Interview (CI)

• 1. Report everything: Witnesses include every detail, even if it seems irrelevant.

• 2. Reinstate the context: Mentally returning to the crime scene.

• 3. Reverse the order: Recalling events in a different chronological order to prevent schema.

• 4. Change perspective: Recalling the event from the viewpoint of others.

• Enhanced CI (ECI): Includes social dynamics like eye contact and reducing anxiety.

AO3:Improving EWT: Cognitive Interview (CI)

• Strength: Support for effectiveness. A meta-analysis found the CI produced a 41% increase in correct information compared to standard interviews. This provides strong evidence that CI is an effective technique for accessing stored memories.

• Weakness: The CI is time-consuming. It takes much longer than standard interviews and requires specialist training that many forces lack the resources for. This means the complete CI is often not a realistic method for officers to use in everyday tasks.

• Weakness: Increase in incorrect information. While CI increases correct info, studies like Köhnken et al. (1999) also found an increase in incorrect information recalled. This indicates that police must treat CI-obtained evidence with caution as it may lead to more errors.