Memory Evaluation Flashcards
Capacity evaluation. STM.
Capacity of STM maybe even more limited. Cowan reviewed a variety of studies on the capacity of STM and concluded it was limited to about four chunks. This means the lower end of Miller’s range is more appropriate.
The size of the chunk matters as it affects how many chance you can remember. Simon found that people had a shorter memory span for larger chunks.
Individual differences. STM capacity is not same for everyone. Eight-year-olds can remember an average of 6.6 digits where as 19-year-olds can remember 8.6 as found by Jacobs.
Duration evaluation. STM.
Testing STM was artificial. Trying to memorise consonant syllables does not reflect everyday activities.
STM results may be due to displacement. In Peterson study forgetting may have been due to displacement rather than decay so was not measuring the duration of short term memory.
Coding evaluation. STM and LTM.
Badly may not have tested long-term memory. In the study long-term memory was tested by waiting 20 minutes. So it is questionable whether this was actually testing long-term memory.
STM may not be exclusively acoustic.
LTM may not be exclusively semantic.
They can both vary under circumstance.
Multi store model evaluation.
Strengths.
Supporting evidence- controlled lab studies on capacity, duration and coding support the existence of a separate short-term and long-term store which is the basis of the MSM. Studies using brain scanning techniques have also demonstrated that there is the difference between STM and LTM.
Case studies such as HM also support the MSM. His brain damage was caused by an operation to remove the hippocampus to reduce the epilepsy he suffered. His personality and intellect remained intact but he could not form new LTMs, although he remember things before surgery.
Limitations.
Too simple- it suggests that both STM and LTM are single unitary stores. However research doesn’t support this. Research shows both STM and LTM subdivide into separate stores, as shown in the WMM.
LTM involves more than maintenance rehearsal it is about how deeply you process it. Craik and Lockheart, suggested this.
Working memory model evaluation.
Strengths.
Dual task performance - many research studies show dual task performance work better when different parts of the working memory model are being used eg. One task is visual and the other is sound there is no interference so you perform both well. If both are visual tasks you perform them less well them if you do them separately.
Evidence from brain damaged patients - KF, would forget auditory but not visual information. In addition his auditory problems were limited to verbal materials such as letters but not meaningful sounds. So his brain damage seemed to be restricted to the PL.
Limitations.
The central executive - some believe it is too vague and doesn’t really explain what it is. Also believe it probably subdivides as well, so is probably more complex than currently represented.
The key evidence for the WMM comes from brain damaged patients, this has a number of problems. Firstly, brain injury is traumatic which may itself change a behaviour so an individual performs worse on a certain task. Secondly, they may have other difficulties such as difficulty paying attention and therefore underperform on tasks.
Types of LTM evaluation.
Brain scans support the idea of different types of LTM, as different parts of the brain are used for each type.
Episodic - hippocampus, temporal and frontal lobe.
Semantic- temporal lobe.
Procedural - cerebellum and motor cortex.
Distinguishing between procedural and declarative studies. HM could still form procedural LTMs, eg. could draw a figure using a reflection in a mirror.
Distinguishing between episodic and semantic memories. Episodic memories may be a gateway to forming semantic memories or semantic memories may be able to form separately. Alzheimer’s study.
Interference evaluation.
Research is quite artificial, usually lab based studies and using artificial lists. However interference has been seen in real life situations.
Interference only explains some types of forgetting. The memories have to be similar for interference to appear. Therefore it is considered to be a relatively unimportant explanation for everyday forgetting.
Real world application to advertising.
Individual differences - some ppl less affected than others.
Retrieval failure evaluation.
There is a lot of research support. Such research includes lab, field and natural experiments as well as anecdotal evidence and thus has relevance to everyday memory experiences.
Real world applications - cognitive interview, exams etc.
Retrieval cues do not always work, as information is related to more than just the cues. Contextual effects are largely eliminated when learning meaningful material.
Retrieval failure explains interference. Tulving demonstrated that apparent interference effects are actually due to an absence of cues. Word lists- multiple or one. Tulving found evidence of retroactive interference. But once given cues ppts remembered around 70% of the words regardless of how many lists they had been given. So the information is there but cannot be retrieved. Therefore retrieval failure is more important than interference as an explanation for forgetting.
Misleading information evaluation. EWT.
Supporting evidence- Loftus Disneyland study. Bugs bunny and Ariel. Misleading info creating false memory.
EWT in real life. Yuille and Cutshall found evidence of greater EWT in real life. Witnesses to an armed robbery in Canada gave very accurate reports of the crime, even after being given 2 misleading questions. Therefore misleading info may have less influence on real life EWT.
Real world application- criminal justice system. Recent DNA exoneration cases, the largest single contributing factor to these innocents people’s arrests were mistaken eyewitness testimony.
Individual differences- age. A number of studies have found that, compared to younger subjects, elderly ppl have problems R.E.M. Bering the source of their information, as a result they are more prone to the effect of misleading information.
Anxiety evaluation. EWT.
Weapon focus effect may not be caused by anxiety. Pickel suggested it may be due to surprise not anxiety. She had ppts watch a thief enter a salon with either a pair of scissors, a handgun, a wallet or a whole raw chicken. Identification was lowest in the high surprise conditions rather than the high threat.
Real life studies vs Lab. Christianson and Hubinette found high levels of anxiety helped EWT. Maybe lab studies do not create the same level of anxiety experienced by an eyewitness at an actual crime.
No simple answer- find violent crimes are often more accurate for EWT than non violent crimes but this was not a definite rule.
Individual differences - Bothwell. Neuroticism vs stable. Stable = more accurate under stress whereas neurotic = less accurate under stress.
Cognitive interview evaluation. EWT.
Meta-analysis of 53 studies found an average of a 34% increase of correct info generated by the CI compared with standard techniques.
Quantity vs quality. Kohnken et al found an increase of 81% of correct information, but also a 61% increase of incorrect information. Therefore information needs to be treated with caution.
However it takes a lot of time, and is sometimes impractical. Also it requires special training and many forces have not been able to provide this.
Difficulties in establishing effectiveness. Many police forces do not do it the same way as it is a collection of techniques rather than one procedure, so it is hard to compare and evaluate effectiveness.
