Cognitive Psychology

• Atkinson and Shiffrin (1968) proposed the MSM as a way of understanding memory.
• Atkinson and Shiffrin described memory as having 3 basic stores - the sensory register, the short term memory and the long term memory.
• Environmental stimuli causes information to enter the sensory register. The SR has a register for each sensory modality, and is capable of holding large amounts of information at any given time. It's duration is limited - approximately up to a few seconds. Information is forgotten quickly due to decay.
• Information enters the STM when it is paid attention to. The STM prefers acoustic encoding (Baddeley), and has a capacity of 7+-2 items (Miller). The duration is up to 30 seconds (Peterson and Peterson) and information can be forgotten due to decay or displacement. To keep information in the STM store, maintenance rehearsal is required.
• Elaborative rehearsal passes information from the STM to the LTM. LTM prefers semantic encoding (Baddeley) and is thought to have a limitless capacity and duration. Information can be forgotten due to decay or retrieval cue failure. Information retrieval passes information back to STM.
• A strength of the MSM is there is evidence to support it - lots of lab research and case studies, such as Baddeley and Henry Molaison, support the existence of seperate memory stores with different encoding styles, durations and capacities.
• A weakness of the MSM is that the lab research in support of it lacks ecological validity - Baddeley's study, for example, took place in an artificial setting and this may have affected the results. Furthermore, it is difficult to generalise case studies of brain damaged individuals, such as HM, to the wider population.
• A strength of the MSM is that it is scientific - because the model itself is testable and allows for predictions to be made, further research can be done to expand it and improve it.
• A weakness of the MSM is that it is reductionist - the simplicity of the model makes it more so descriptive than explanatory. It does not explain why some things are easier to remember than others, and it does not account for flashbulb memories.
• In conclusion, the MSM proposed by Atkinson and Shiffrin (1968) has lots of evidence and research to support the existence of seperate memory stores, and this effectively supports the model. However, the model could be expanded to reflect the more detailed aspects of memory.
• The Classic study for Cognitive Psychology is Baddeley 1966b.
• The aim of Baddeley 1966b was to test whether LTM and STM were seperate memory stores. He thought that if information encoded differently in the STM and LTM, that would suggest they are seperate stores.
• The participants in Baddeley's study were 20 males and females from Cambridge University. It was a volunteer sample.
• Baddeley used an independent groups design - participants were assigned either word list A, B, C or D.
• Baddeley's word list A consisted of acoustically similar words such as man, cab, can.
• Baddeley's word list B consisted of acoustically dissimilar words such as pit, few, cow.
• Baddeley's word list C consisted of semantically similar words such as great, large, big.
• Baddeley's word list D consisted of semantically dissimilar words such as good, huge, hot.
• Baddeley's word lists were standardised - he only used monosyllabic words and the lists were controlled for word frequency.
• The first stage of Baddeley's study was the learning stage - this consisted of participants being shown the word list and having 40 seconds to recall the words in the correct sequence. They had a list of the words in a random order, as it was not about learning the words, it was about learning the sequence. This happened 4 times.
• The final stage of Baddeley's study was the suprise re-test - participants were given a distraction task (recalling 8-digit sequences) before being asked to recall their word list again.
• Baddeley found that the acoustically dissimilar list was better remembered in the learning stage than the acoustically similar list, however there was no significant difference in the suprise re-test. This is because in the learning stage they were recalling the words from their STM, where encoding is acoustic, and in the suprise re-test they were recalling from LTM, where encoding is semantic.
• Baddeley found there was not a significant difference in the semantically similar and dissimilar list in the learning stage, as encoding is acoustic, but in the suprise re-test the semantically dissimilar words were better remembered.
• A strength of Baddeley 1966b is that it is a controlled lab experiment so any possible effects of confounding variables can be eliminated, which means a cause and effect relationship can be established. This gives the study good internal validity.
• A weakness of Baddeley 1966b is that it lacks ecological validity and mundane realism - the setting was highly artificial and the task of learning random lists of words is not an everyday task, so this could effect the findings.
• A strength of Baddeley is that he used male and female participants, so findings are not gender specific and this therefore increases the generalisability of the findings.
• A weakness of Baddeley 1966b is that the sample is arguably not random and representative of the population and certain sub groups are likely under-represented such as elderly people, children, those with disabilities.
• In conclusion, Baddeley 1966b is a highly controlled experiment where each individual was subjected to the same procedure, which gives the study good internal reliability. Furthermore, the fact that findings have been replicated shows good external reliability.
• The working memory model was proposed by Baddeley and Hitch in 1974 as a 3 component short-term memory system.
• In the original WMM, Baddeley and Hitch proposed 3 components for working memory - a central executive, a phonological loop and a visuospatial sketchpad. The episodic buffer was added at a later date.
• The central executive in the WMM decides how attention is directed. It drives the system and allocates information to either itself or the slave systems.
• The phonological loop within the WMM has 2 components which deal with auditory information - the phonological store deals with phonological information, such as pitch and amplitude, and the articulatory store organsises verbal material as it is spoken.