Memory Flashcards
what is memory?
the process by which we retain information about events that have happened in the past.
what are the two types of memory?
short-term memory (STM) and long-term memory (LTM).
what is long-term memory (LTM)?
the permanent memory store, lasts up to a lifetime. (semantic coding)
what is short-term memory (STM)?
the limited capacity memory store, lasts approximately 18-30 seconds. (acoustic coding)
how do the STM and LTM differ?
coding, capacity and duration.
what is coding?
the way in which information is changed and stored in memory: acoustically (sound) - dominant method for STM, visually (image) and semantically (meaning) - dominant method for LTM
what is capacity?
how much information can be held in a memory store.
what is duration?
how long information can be held in a memory store.
who conducted research on coding and when?
baddeley (1966)
what did baddeley (1966) do in his study and what were the findings / conclusions?
researched coding in STM and LTM - word recall of similar / dissimilar words and found that words were coded acoustically in STM and semantically in LTM.
what is a strength of baddeley’s coding research?
supports separate memory stores for LTM and STM.
what is a weakness of baddeley’s coding research?
use of artificial and meaningless stimuli - the word lists had no personal meaning and do not reflect how memory works in everyday life so the findings lack external validity and real life application.
who conducted research on capacity and when?
jacobs (1887) and miller (1956)
what is digit span?
a way of measuring capacity of STM in terms of maximum no. of digits that can be recalled in the correct order
what did jacobs (1887) do in his study and what were the findings / conclusions?
developed digit span, he asked participants how many number they could recall in a row and found that the mean = 9.3 items and 7.3 letters
what is a strength of jacobs’ digit span research?
the study has been replicated which proves that is it a valid test of digit span in STM.
what are weaknesses of jacobs’ digit span research?
the research is outdated (1887), so may not have been done to the same scientifically rigorous standard as research today, therefore low in validity.
not representative of STM tasks performed in real life situations (lacks generalisability).
what did miller (1956) do in his study and what were the findings / conclusions?
investigated the span of memory and chunking in STM, concluded 7 plus or minus 2 ‘bits’ of information to describe capacity and that putting items together (chunking) extends STM capacity, the capacity of LTM is thought to be potentially unlimited.
what is a weakness of miller’s capacity research?
overestimated STM capacity - cowan established only 4 chunks which suggests that miller’s research is flawed.
who conducted research on duration and when?
bahrick et al (1975) and peterson and peterson (1959)
what did peterson and peterson (1959) do in their study and what were the findings / conclusions?
researched duration of STM, used consonant syllables and counting backwards as a means of preventing rehearsal and found that STM lasts about 18 seconds.
what is a weakness of peterson and peterson’s duration research?
use of artificial stimuli - lacks external validity.
what did bahrick et al (1975) do in their study and what were the findings / conclusions?
research duration of LTM, used recall tests of yearbooks (photos and names) and found that after 15 years = 90% facial recognition and 60% free recall, after 48 years = 70% facial recognition and 30% free recall which he then councluded that LTM lasts up to a lifetime for some material but over time memories are lost.
what is a strength of bahrick et al’s duration research?
used meaningful materials which lead to better recall than other studies - high external validity.
what is the multi-store model of memory (MSM)?
information comes through stimuli into sensory register - irrelevant info is lost and decays, attention is payed to important info from sensory register and transferred to STM - info not lost in STM: this is through maintenance rehearsal so forgetting does not occur and moved to LTM where stays and retrieved back to STM.
what are the strengths of the MSM?
there is research support, patient HM - STM intact but could not form new LTMs while old LTMs were still there which supports STM and LTM stored separately; MSM true & accurate.
baddeley (1966) - found that we tend to mix up words that sound similar when using our STMs and have similar meanings when using LTMs which shows STM and LTM as separate and independent memory stores.
what are the weaknesses of the MSM?
there is conflicting evidence, patient KF - visual STM undamaged but verbal STM damaged, can store LTMs without passing through damaged STM - suggests STM isn’t a unitary store: different parts processing different information.
lack of RWA - memories relate to peoples’ faces, names, places etc. but studies use artificial stimuli (digits, letters, words etc) which suggests that MSM is not reliable or valid.
prolonged rehearsal is not needed for LTM - information can be transferred without rehearsal which suggests that MSM doesn’t fully explain how long-term storage is achieved.
what are the three types of LTM?
episodic memory, semantic memory and procedural memory.
what is tulving’s theory on the types of LTM?
tulving makes a distinction between different types of LTM: procedural memory and declarative memory and he splits declarative memory into two sub-types: episodic memory and semantic memory.
what is declarative memory?
the memory of meaningful events, it is recalled consciously and is explicit.
what is episodic memory?
the ability to recall events and specific information (declarative - explicit, timestamped).
what is semantic memory?
the ability to recall facts that have meaning (declarative - explicit, not timestamped).
what is procedural memory?
the ability to recall actions and skills and it is recalled subconsciously (non-declarative - implicit, not usually timestamped).
what was the case study on clive wearing like?
- he suffered severe memory loss but he can still walk, talk, read, write, play piano, doesn’t remember children’s names, recognises his wife and greets her sweetly.
- he had a 7 second STM, no new LTMs formed but still knew his old LTMs, reduced memory for personal events (damaged STM, no new LTMs), his case supports the MSM as it shows that in order for LTMs to be formed, the STM is needed.
what are the strengths of tulving’s theory on the types of LTM?
there is clinical evidence:
- the case study of clive wearing supports tulving’s theory as clive was severely impaired due to brain damage but his semantic memories were unaffected and his procedural memories were intact.
- miner (1962) studied the case of patient HM and showed that he could learn procedural tasks even though he had poor episodic or semantic memory.
both these studies support tulving’s theory of there being more than one type of LTM - one store can be damaged and the others unaffected.
brain scanning studies show that different areas of the brain are active when performing tasks involving different types of LTM, this supports that types of LTM are physically different.
what are the weaknesses of tulving’s theory on the types of LTM?
however, there are issues in case studies, clive wearing and patient HM’s illnesses before are unknown so they cannot be compared to the rest of the population, this lack of control limits what clinical studies can say about different types of LTMs, therefore lacking generalisability.
what is a dual-task performance?
using two different parts of the STM - so not interfering with each other.
what is the working memory model (WMM)?
the WMM suggests that the STM does not exist as unitary stores and it is an account of how short-term memory functions when working on a task, it is made up of the central executive, the visuospatial sketchpad (VSS), the phonological loop and the episodic buffer.
what is the central executive?
the supervisory role - monitors incoming data, allocates ‘slave’ systems (subsystems) to tasks, has a very limited processing capacity and doesn’t store information.
what is the visuospatial sketchpad?
a subsystem for the inner eye - it stores visual data (images) in visual cache and manipulates / arranges images in visual field (inner scribe), it has a limited capacity (3-4 objects) and it is coded visually.