models of memory

• Multi store memory model:

  Information firstly is briefly stored in sensory memory ( less than a second ). If information is attended to it flows into the STM which has a duration of up to 30 seconds and can hold 7 plus or minus 2 pieces of information . If it is rehearsed it is encoded in LTM which has an unlimited duration. Information can be retrieved from the LTM back to STM.
• Supporting evidence for the Multi store model:

  • Miller found that STM has a capacity of 7 items of information and struggles to hold more than 9. Bits of information can be grouped together into chunks and STM can hold more information in chunks but can loose accuracy.
• Applying the multi store model :

  • Eyewitnesses- if they are distracted key details might not reach the STM and others not reach LTM if not rehearsed. If the victim refuses to think about or mention the crime due to it being truistic they won't rehearsed the information. Which makes misidentification more likely to happen if important characteristics are forgotten about.
• Conflicting evidence of multi store model:

  • Shallice and Warrington- case study of KF who was left with amnesia after brain injury. He could still add memories to LTM even though his STM was so damaged, he couldn't repeat back more than two digits. Thus, suggesting that memory is far too complex than the model suggests
• Working memory model:

  STM is arranged into four main components. The central executive has a 'supervisory role' by allocating memories to salve systems. The phonological loop deals with auditory information (sounds) whilst preserving the order that it arrives; is split into phonological store and the articulatory process. The visuo-spatial sketchpad that can temporality store visual/spatial information, subdivided into; viodual cache and inner scribe. The third slave system is the episodic buffer which was added later on which integrates the acoustic, visual and spatial information
• Supporting evidence for Working memory model:

  • Baddeley 1966- participants found it hard to generate lists of random number whilst simultaneously pressing numbers, suggesting that two tasks were competing for CE resources. Supports the idea that the central executive has limited capacity
  • The KF Case Study supports Working Memory. KF suffered brain damage from a motorcycle accident that damaged his short-term memory. KF struggled to process verbal information but his visual memory  was unaffected. This shows that visual information (VSSP) is processed separately from verbal information (phonological loop).
• Applying working memory model :

  • Can be applied to dementia and alzheimers- have partial trouble with dual tasks, fault with central executive explains lost of dementia symptoms. Dual load can be reused by creating a white environment for dementia sufferers
• Conflicting evidence for the working memory model:

  • introduction of the episodic buffer in 2000 to expand on the understanding of STM due to criticism- suggest that the model was inaccurate in its original form and so addressed the shortcomings of the model
  • based on lab experiments involving dual tasks- artificial. Lacks to explain how memory works in real life situations when you may use your other senses
• Multi store memory Model:

  
• Working memory model :

  
• Episodic and semantic memory - Tulving

  States that LTM is made up of semantic and episodic memory which are both types of declarative memory. Procedural memory is another type but is non declarative.
• what is episodic memory?

  Knowing when something happened

  Considered to be autobiographical- relating to dates, times and events relevant to the individual. Episodes in a persons life can be encoded visually, acoustically and spatially so they are perceptually encoded.
• What is semantic memory?

  Knowing something is factual

  Stand as simple knowledge, semantic memory is derived from episodic memory in that we learn new facts or concepts from our experiences and episodic memory is considered to underpin and support semantic memory. Episodic memories may reduce in their association transferring to semantic where essentially information is simply 'known'
• What is procedural memory?

  Knowing how something is done

  Procedural memory is knowing how to perform a series of related tasks to achieve an outcome such as baking a cake
• Encoding, storage and retrieval- episodic and semantic memories

  • The capacity of LTM is considered to be limitless where episodic and semantic memories may last forever
  • Studies suggest that we store memories into our LTM using meaning
  • LTM is therefore said to use 'semantic representation'
• Encoding, storage and retrieval- episodic and semantic memories

  • Episodic memories are store according to how they are experienced as they are stored with information relating to where the person was when an event occurred
  • semantic memories are not usually stored with information that tells us what the person was doling at the time and so are said to be organised according to time and space.
  • retrieval from semantic memory doesn't change the original memory but it may cause a new memory to be stored
• In support of semantic and episodic memory- Tulving

  KC sufferer brain damage after a motorbike accident and this left him unable to form or recall memories of personal events in his life (episodic). However he was able to recall factual information (sematic) This supports Tulving's idea of separate LTM stores, where one can be affected without disrupting the other
• Problems with episodic and semantic memory explanation:

  The extent to which episodic and semantic memory systems are different is unclear as there is lots of overlap as semantic memory often clearly originating in episodic memory. Therefore the gradual transformation of an episodic into a semantic LTM means a change in memory systems cannot be certain.
• what are schemas ?

  an organised package of information that stores our knowledge about the world.We each have many schemas, one for each aspect of our lives.

  for example the process of getting transport
• what problems may occur with schemas ?

  may contain sterotypes and gemerlised information. Schemas rely on out expectations therefore can cause us to make errors,seeing what we expect to be there instead of what is actually there
• Brewer and Tyrens 1981: schema memory

  • Aimed to study the role of schema in encoding and retrieval of episodic memory
  • procedure involved participants being seated in a room made to look like an office, consisting of typical office objects. Also some atypical itemsd such as a skull. Participants were asked to recall what was in the office
  • Found that participants were more likely to recall items in the office congruent with their schema of an office
  • Therefore suggesting we rely on our schemas that predicts items effecting both encoding and retrieval
• reconstructive memory - bartlett


  Reconstruction is an active process in which are memories are reconstructed to fill in gaps that we are not even aware of influenced by how we encode, store and retrieve information.

  Gaps are filled using information from schemas, stereotyping and what we ‘expect’ in a given situation this is called confabulation, putting pressure on our mind to remembers things in a way that fits with the schema.

  Sometimes we accommodate new information, changing our memories to keep our schemas intact and we do this by levelling and sharpening.

  He suggested that our previous knowledge of the world widely affects the way our memories are stored and recalled
• War of the ghosts- Bartlett

  • Bartlett showed 20 students a Native American ghost story (the war of the ghosts) which had unusual features. He asked them to read it then recall it on several occasions after a few hours, days, weeks or even years- serial reproduction
  • Bartlett compared how the recalled versions of the story differed from the original.
• War of ghosts - Bartlett findings

  • Participants shortened the story when they reproduced it, from 330 words to 180 words
  • Participants also confabulated details, changing unfamiliar parts of the story to familiar ideas in line with their schemas- paddles became boats and oars
  • Participants rationalised the story, coming up with explanations for baffling parts of the story making it more familiar with own culture
• Supporting evidence for reconstructive memory:

  • Loftus and Palmer 1974- investigated the effect of leading questions on recall- found that information supplied to us after the event has the ability to reconstruct our original memory.
  • A strength of the theory is that the research conducted by Bartlett shows how our memory is reconstructed to be more coherent and culturally familiar. The war of the ghost procedure is not conducted in an artificial environment so is useful in explaining how our memories can be reconstruct
• Applying reconstructive memory:

  • unreliable EWT-Eyewitnesses to crimes and accidents often have to reproduce their testimony many times to journalists, the police or a court – this is rather like the serial reproduction in Bartlett’s study. You would expect levelling and sharpening of memories to happen.
  • Police ask leading questions- as seen in Loftus this make eyewitness testimony very unreliable, since the memories change when we learn more information.
• Testability of reconstructive memory:

  War of the ghosts is not a scientific study- no internal or extenral validity or standardisation. Therefore cannot replicate the study to test its reliability and credibility.
• conflicting evidence to reconstructive memory

  Wynn and Logie 1998 replicated bartlett students to recall events from their first week at university and found a small reduction in amount of information recalled after 6 months, therefore real-life situations may be less susceptible to reconstruction than what bartlett suggested.