What is Memory?
- Learning and memory involve the retention of information, but the study of memory focuses on cognitive processes and retrieval.
- Memory tests assess learning
- Psychologists distinguish between short-term memory in terms of:
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Short Term Memory
- The short term memory store is described as:
- having limited capacity of 7 +/- 2 chunks
- limited duration
- Using mainly acoustic coding
- Capacity: span measures indicate STM capacity 7 items but can be increased by chunking. Capacity for STM can also be seen in the recency effect (higher recall for last few items in list)
- Duration: Brown-Peterson technique is a means of showing STM duration. If rehearsal is prevented, there is little recall beyond 18 seconds.
- Encoding: differs from LTM which more semantically coded
- Evidence about different kinds of memory comes from studies of brain damaged individuals, also supports a distinction between STM and LTM. But hard to generalise case studies.
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Long Term Memory
- Described as
- having unlimited capacity
- Lasting forever
- Using mainly semantic coding
- Capacity: never reached upper limit of LTM storage capacity
- Duration:Shown in studies of very-long-term memories
- Encoding: differs from STM which acoustically coded
- Can be divided into:
- Declarative knowledge: knowing certain things are the case
- Producedural knowledge: knowing how to do certain things.
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Multi store model
- The multi-store model of memory supports distinction between separate stores and proposes that information is transferred from the STM to the LTM by rehearsal.
- Model criticised in that:
- Rehearsal much less important in forming LT memories than is assumed within this model
- Not correct that information always goes into STM before LTM
- The model is oversimplified in assuming there is only one short-term storage and 1 long-term store.
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Working Memory Model
- Consists of central executive, phonological loop and visuo-spatial sketchpad.
- 2 tasks can be performed together without disruption if they use different components of working memory, but not if they use the same ones
- Phonological loop used when learning new words, Visuo-spatial sketchpad when finding route or playing computer games, and the central executive for complex thinking and reasoning.
- 3 of functions of central executive are as follows:
- Inhibition function: used to reduce distraction effects
- Shifting function: this is used to shift attention from 1 task to another
- Updating function: update information in working memory
- Working memory is of fundamental importance in information processing and thinking, and working memory capacity is closely associated with intelligence.
- Criticised in that
- number + nature of functions of central executive remain unclear
- Don't know detail of how components in WM interact with each other
- Model concerned with STM but not LTM
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- Eyewitness testimony is often inaccurate but generally believed by jurors.
- Age important factor influencing accuracy of EWT- young kids and older adults generally less accurate
- High anxiety or stress level lead to reduced ability of eyewitnesses to make accurate face idenifications and to remember details of a crime
Relevance of lab findings
- Doubts have been expressed about value of lab findings for EWT in real world. But, most factors found to be important in lab also important in real world
- EW inaccuracies and distortions observed in lab underestimate memory problems experienced by EW to real crimes
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- EWT can be distorted by ML information presented before or after incidient.
- Evidence that ML information has less of negative impact with real-life crimes, and memory distortions occur mainly to minor details.
- Schema Theory describes memory retrieval as a process of active reconstruction based on schemas. Lead to people remembering events that didn't happen but consistent with their schemas.
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- Used to enhance EW memory. involves mental recreation of context at time of crime, reporting details and recall in various orders + from different perspectives
- CI is an effective technique, but enhanced CI (includes minimising distractions, avoidance of personal comments and review of what EW says) more effective.
- Limitations to CI
- Produces increased amount of incorrect information recalled compared to standard tech
- Less effective when used at long intervals after crime
- Not very clear which components of CI contribute most to success.
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Strategies for memory improvement part 1
- Very important for learners to make full use of their pre-existing knowledge when learning something new, makes it easier to organise new information. Various forms of organisation.
- Organisation often used at same time of learning and at time of retrieval
- Even lists of unrelated words can be organised- known as subjective organisation
- Mandler found that learners who sorted a list of words into several categories recalled much more than those who used only a few. Some problems:
- data from many PP's had to be excluded because didn't use meaningful categories or didn't sort words consistently into categories
- Generally didn't assign PP's random conditions varying in number or categories
- Wasn't clear how PP's organising the list of words
- Organsiation not always effective- sometimes lead to an increase in nom. of memory errors
- Method of loci on of best visual imagery techniques. Very effective when the to-be-info presented orally but not when presented visually. capitalises on learner's pre-existing knowledge. Some Limitations
- hard to use abstract material
- Doesn't produce integration of the to-be-learned material
- hard to recall any given item without working through list.
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Strategies for memory improvement part 2
- Pegword method is another visual imagery mnemonic, provides learners with knowledge needed to memorise successfully. Also effective, but suffers similar limitations to methods of loci.
- Various mnemoic techniques work cause involve:
- Meaningful encoding
- Retrieval structure
- Mind maps can be very effective at enhancing memory, in part cause they help to organise and integrate info that needs to be learnt. Plus learner is actively involved in process.
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Aims and Hypotheses
- 1st stage in designing study is to decide aims and hypothesis. Aim tells us why, hypothesis tells us what.
- Null Hypothesis:
- Statement of no effect
- Increases precision, one can prove (accept) experimental/alternative hypothesis by rejecting null hypothesis.
- Experimental/Alternative Hypothesis
- may be directional or one-tailed, or non-directional or two-tailed.
- Non-experimental research may also have aims and hypothesis
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- 3 types:
- Independent Groups- experimental and control group. With this, random allocation generally used to assign PP to group. Aim to ensure that both groups equal
- Repeated measures- experimental and control condition. With this avoid individual differences as PP's experience both conditions. Problem of order effects may be overcome by counter-balancing
- Matched pairs design, uses independent group design of PP's who are similar. Control groups provide a baseline measure.
- Several stages in developing behavioural categories for studies using naturalistic observations:
- Relevant categories identified
- Categories based on recording or interpretation need to be produced
- Observers need training in use of categories
- Behavioural categories must produce reliable measurement.
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Interviews and Questionnaires
- Interviews vary in terms of structure and type of Q. (closed vs Open).
- Non-directive interviews + open Q's
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