Memory (Paper 1) Flashcards
Cognitive Psychology
Cognitive psychology is concerned with people’s thought processes and how these affect the way in which they behave.
Memory
Memory is the process of retaining learned information, and accessing this information when it is needed. Memory is an important factor in how human beings process information.
Processes in Memory
Coding, Storage and Retrieval
Coding
The way information is changed so that it can be stored in memory.
Storage
Keeping information within the memory system until it is needed.
Retrieval
Recovering information stored in the memory system when it is required.
Memory Stores
Sensory Register, Short-Term Memory and Long-Term Memory
Sensory Register
The Sensory Register (SR) contains unprocessed impressions of information received through the senses. It has a separate sensory store for each sensory input. There is an iconic store for visual information and the echoic store for auditory information.
Short-Term Memory
Short-Term Memory (STM) is a temporary store for information received from the SR.
Long-Term Memory
Long-Term Memory (LTM) is a permanent store holding limitless amounts of information for long periods of time, potentially a lifetime.
Capacity
The amount of information that can be held in memory before new incoming information displaces it. This means the information is ‘pushed out’.
Duration
The amount of time information can be held in a memory store before it is lost due to decay. This means the information ‘fades away’.
Coding - Sensory Register
Coding in the Sensory Register (SR) is modality specific. This means that each sensory store (e.g. iconic for visual information) codes information differently.
Coding - Short-Term Memory
Baddeley (1966) investigated coding in Short-Term Memory (STM); he gave participants four lists of words to recall. List A contained words that sounded similar and list B had words that sounded dissimilar. Lost C contained words that had similar meanings; list D had words with dissimilar meanings. Baddeley (1966) argued that STM is coded acoustically because when tested participants performed worse with list A than list B, but there was no difference between list C and D. Baddeley (1966) theorised that because STM organises information according to how it sounds, similar sounding words can become muddled.
Coding - Long-Term Memory
Baddeley (1966) repeated this experiment to test the coding of Long-Term Memory (LTM). He tested participant’s recall of the lists after a 20 minute delay in order to ensure the information had passed into LTM. Participant’s recall of list C was worse than their recall of list D. There was no difference between list A and list B. Baddeley (1966) concluded that LTM is coded semantically. LTM organises information according to its meaning, so words with similar meaning can become confused.
Strengths of Baddeley (1966)
This study is a laboratory experiment and so it is easy to replicate as variables have been closely controlled. This means that reliability can be assessed.
Weaknesses of Baddeley (1966)
The findings of this study have low ecological validity. The material (lists of unconnected words) which participants needed to recall was artificial (unlike the types of information which people need to recall in their everyday life) as was the laboratory setting.
Capacity - Sensory Register
The capacity of the SR is unlimited
Capacity - Short-Term Memory
Jacobs (1887) used a digit span test to determine the capacity of STM. He gave participants several sequences of digits or letters, asking them to repeat each sequence immediately after he had given it, in the correct order. The sequences got longer by one item each time. Jacobs (1887) found that on average we can hold 9.3 digits and 7.3 letters. Miller (1956) reviewed psychological research studies and concluded that the span of STM is 7 (+/) 2. If we try to recall more information than we have the capacity for then new incoming information displaces old information. He also found that people can recall five words as easily as five letters, and so chunking (grouping large amounts of information into smaller groups) can help us remember more.
Strengths of Jacobs (1887)
Jacob’s (1887) research was the first to acknowledge that STM capacity gradually improves with age.
Weaknesses of Jacobs (1887)
This study was conducted a long time ago, so may not have been done to the same scientifically rigorous standard as research today, therefore the validity of the findings is in question.
Capacity - Long-Term Memory
The capacity of LTM is unlimited.
Duration - Sensory Register
The duration of the SR is 250 milliseconds.
Duration - Short-Term Memory
Peterson & Peterson (1959) used nonsense trigram’s (random 3 consonants) to test STM duration. To prevent participants keeping the information in STM using maintenance rehearsal they were asked to count backwards from 100 in threes. After 3 seconds recall was accurate 90% of the time, after 9 seconds they were accurate 20% of the time, but after 18 seconds it was only accurate 2% of the time. They concluded that information in STM lasts for 18-30 seconds without rehearsal, before it is lost due to decay.
Strengths of Peterson & Peterson (1959)
In this study, the researchers used fixed timings for participants to count backwards from. They also eliminated noise and other factors that could have had an influence on memory. The research can therefore be said to have a high level of control, using standardised procedures to make sure all participants experienced the same process
Weaknesses of Peterson & Peterson (1959)
The findings of this study may have been caused by interference rather than by STM having a short duration. It is possible that earlier learnt trigrams became confused with later ones.
Duration - Long-Term Memory
Bahrick (1979) tested 400 people of various ages (17-74) on their memory of their classmates. A photo recognition test consisted of participants being shown 50 photos and deciding if they belonged to their classmates or not. In a free recall test participants were asked to list the names they could remember from their graduating class. They found 90% accuracy at identifying faces of school friends within 15 years of leaving school. After 48 years this declined to 70%. Free recall of names of classmates was 60% accurate within 15 years of leaving school, dropping to 30% after 48 years. Bahrick et al. (1979) concluded that the duration of LTM is potentially a lifetime but sometimes we have retrieval failure and need retrieval cues in order to access this information.
Strengths of Bahrick (1979)
This study has higher ecological validity than Peterson and Peterson (1959) as the material used was more meaningful and relevant to everyday life.
Weaknesses of Bahrick (1979)
It is problematic to control for extraneous variables, such as people staying in touch after they left school or how many participants have looked in their yearbook since leaving school.
Multi-Store Model of Memory
The multi-store model of memory (MSM) was developed by Atkinson and Shiffrin (1968). It attempts to explain how information flows from one memory store to another. There are three permanent structures in the memory system: the sensory register (SR), short-term memory (STM) and long-term memory (LTM). Each of these memory stores differ in terms of their capacity, duration, coding and how information is lost from them.
Neurobiological Strengths of The Multi-Store Model of Memory
Scoville (1957) attempted to treat a patient he referred to as HM’s epilepsy by removing several brain areas, including his hippocampus. This resulted in the patient being unable to code new long-term memories (LTM), although his short-term memory (STM) was unaffected. This supports the idea of separate and distinct STM and LTM.
Shallice and Warrington (1970) reported the case study of KF who as a result of a motorbike accident had reduced STM capacity of only one or two digits, yet his LTM was normal. This supports the idea of a separate STM and LTM stores.
However, KF had poor STM for verbal tasks but not visual tasks and this suggests that there is more than one type of STM, which contradicts the Multi-Store Model (MSM) of memory. Also, according to the MSM, LTM are retrieved by STM so if STM is damaged it should be difficult to retrieve LTM. However, KF was able to access LTM without any difficulty.
Laboratory Strengths of The Multi-Store Model of Memory
Murdock (1962) presented participants with a long list of words to be recalled in any order, this was referred to as the free recall experiment. Words at the beginning and the end of the lists were recalled better than those in the middle. This is called the serial position effect. Words at the beginning of the list are recalled because they have been constantly rehearsed and transferred to LTM (the primacy effect), while words at the end of the list are recalled because they are still in STM (the recency effect). This supports the idea of separate and distinct STM and LTM
Weaknesses of The Multi-Store Model of Memory
The MSM is over simplified in assuming that there is only one type of STM and one type of LTM. Research studies indicate that there are several types of STM, such as one for verbal information (phonological loop) and another for non-verbal information (visuo-spatial sketchpad). Research also suggests that there are several types of LTM, we have episodic memory for life events, semantic memory for knowledge and facts and procedural memory for motor skills.
Baddeley and Hitch (1974) claimed that the MSM could not explain the ability to multi-task; if there is only one type of STM then multi-tasking would not be possible. However, people multi-task all the time, for example listening to the radio while driving.
The Working Memory Model
Baddeley and Hitch (1974) questioned the idea promoted by the multi-store model (MSM) of memory that people only have one type of short-term memory (STM). They also argued that STM is far more complex than simply being a temporary store for information before it is transferred to long-term memory (LTM). They instead saw STM as an active store holding several pieces of information while they are being worked on, that is why they referred to their model as the working memory model (WMM). They argued that LTM is the passive store that only holds previously learned material to be used by STM when needed.