Psychology memory studies and evaluations

Duration of STM (Peterson and Peterson)Procedure: 24 students were given a consonant syllable and a three digit number e.g DTC 491. After, they had to count backwards in threes to stop rehearsal, then asked to recall the syllable. They had different times to spend counting backwards such as 3,6,9,12,15,18 seconds. Results: Participants remembered 90% with a 3 second interval and only 2% with an 18 second interval. Conclusion: Without rehearsal, STM lasts 20 seconds at most.Evaluation: Participants were relying on more than their STM because they were aware that they had to recall the syllable after the interval Other research has shown that without warning, the information can be forgotten after 2 seconds Lacks validity - only studies memory of syllables, whereas much of our time is concerned with other things

Duration of LTM (Bahrick et al)Procedure: Asked people to put names to faces from their school yearbook. Results: 48 years later, they were 70% accuracy.Evaluation: Longitudinal study so it accurately measures LTM Real life situation, instead of repeating nonsense syllables, high in ecological validity

Capacity of STM (Jacobs)Procedure: Digit span techniqueResults: Participants recalled an average of 9 digits, but 7 for lettersEvaluation: Individual differences - Capacity of STM is different for everyone, Jacobs found digit span recall gradually increased with age Real world application - Chunking (Miller)

Chunking (Miller)Procedure: Meta-analysis.Results: People can recall 5 words, just as well as they can recall 5 letters.Conclusion: We chunk things together so we can remember more.Evaluation: Other research has found that 4 chunks was the maximum for STM Baddeley found that postcodes being made up of meaningful letters, were more memorable as we find them easier to chunk

Acoustic and semantic encoding (Baddeley)Procedure: Gave participants lists of words which were acoustically similar or dissimilar and words that were semantically similar or dissimilar.Results: Difficulty with acoustically similar words in STM but not LTM. Dfficulty recalling semantically similar words in LTM.Evaluation:Research has shown that STM is not exclusively semantic and LTM is not exclusively acoustic

Sensory store (Sperling)Procedure: Grid of numbers and letters for a blink of an eye, asked to write them immediately or wait for a tone and only write a row. Results: Recall of the whole thing was poorer, than when giving a rowConclusion: Info decays rapidly in the sensory storeEvaluation:Lacks validity - lab experiment, not an everyday task

Serial position effect (Glanzir and Cunitz)Procedure: List of words, presented one at a time, asked to recall in any order.Results: Remembered words from the start (primacy effect) and the end of the list (recency effect).Conclusion: Words at the start are in LTM, words at the end are in STMEvaluation:Validity - lab experiment, not everyday task to recall words

Separate stores for STM and LTM (case study HM)Brain damage after operation to reduce his epilepsy (Dr Scoville removed hippocampus). Personality and intelligence were the same but he could not form long term memories, but could remember things before surgery.Conclusion: Information passes through hippocampus before entering permanent storage.

Evaluation of Multi-store model Strong supporting evidence Oversimplifies memory KF showed that STM is not a single store - brain damage meant he struggled with verbal info but not visual Logie - STM relies on LTM so does not always come first as the model by Atkinson and Shiffrin suggest - to chunk a list of letters, you need to give them meaning which comes from LTM

Working memory model (Baddeley and Hitch) STM is not a unitary store Components of working memory are the Central Executive, the Phonological Loop (Phonological Store and Articulatory Process), the visuo-spatial sketchpad and the episodic buffer Central executive - directs attention to particular tasks, allocates resources to the other slave systems and has limited capacity Phonological loop - deals with auditory information Phonological store - holds words you hear Articulatory process - holds words that are heard or seen, these words are repeated like an inner voice which is a form of maintenance rehearsal Visuo-spatial sketchpad - Visual and spatial (relationship between things) Episodic buffer - added in 2000, holds visual AND acoustic information, is an extra storage system but still has limited capacity

Evaluation of working memory model Strengths: Considerable amount of supporting evidence for the model Offers better explanation of STM than Multi-store model Weaknesses: Central executive is too vague Evidence from brain damaged patients

Accuracy of eyewitness testimony (Loftus and Palmer)Procedure: Students were shown films of traffic accidents and given a questionnaire. The critical question was 'how fast were the cars going when they hit each other?' but sometimes the verb was changed to bumped, smashed, collided or contacted instead of hit.Results: The estimated mean speed was calculated for each group. The group with the word smashed gave the highest speed estimate (41mph) and the group with contacted gave the lowest.Conclusion: Misleading information can affect the accuracy of eyewitness testimonyEvaluation Students may not have paid attention to the verb Small sample of students (45) Lab experiment - not like real life, not aroused, knew the task

Anxiety has negative effect on EWT (Deffenbacher et al)Procedure: Meta-analysis of 18 studies, looking at the effects of anxiety on accuracy of eyewitness testimony.Results: High levels of anxiety negatively impacts eye witness memory

Anxiety enhances recall (Christianson and Hubinette)Procedure: Questioned real witnesses of bank robberies Results: The witnesses who had been threatened in some way were more accurate in their recall, this was true even 15 months laterEvaluation: Repeating the study 15 months later makes the results more accurate The witnesses were real so the researchers didn't try to create an unethical situation, and it means that the study has high ecological validity Fairly small sample of 58 but is understandable as there are not many bank robbers available for a sample

Age of witness - children (Parker and Carranza)Procedure: Compared primary school children and college students in their ability to identify an individual from a mock crimeResults: Child witnesses had a higher rate of choosing than adult witnesses but they were more likely to make errors than the college studentsEvaluation:Most studies use college students for example, and they identify photographs of people their own age but it may be that participants have a better memory for remembering faces of people who are a similar age to them

The Cognitive Interview1. Report everything - even if it seems irrelevant 2. Mental reinstatement - recreate the environment 3. Changing the order - reversing the events 4. Changing perspective - imagining how it would appear to other witnessesEvaluation: Milne and Bull found that when students were interviewed using different components of CI. When using 'report everything' and 'mental reinstatement' their recall was significantly higher than other conditions where they were told to 'try again' Negative stereotypes could make older witnesses cautious but CI stresses that recalling every detail which may overcome this Police have reported they don't have enough time to work through CI so they have other techniques in place which gives them as much information as they see necessary

Strategies for memory improvement Method of Loci - Imagining a journey through a familiar location and placing information in each room or object e.g. house Verbal mnemonics - Focus on words e.g rhyming or chunking Visual imagery mnemonics - mind maps Evaluation: Verbal mnemonics have been found to be effective in children with learning disabilities Method of Loci has long term benefits for older adults Most research is conducted in labs, real life research shows more mixed results