memory

• Sensory register


  The first store which holds the sensory information received through all the senses for a brief period of time. Examples include iconic (visual) and echoic (sound) memory.
• Short-term memory


  The memory for immediate events. These memories tend not to last for more than a minute or two, usually shorter, and disappear unless they are rehearsed. Capacity is limited to 7 plus or minus 2 individual items.

  
• Long-term memory


  The memory for past events that can last for the life-time of a person. Its capacity is most probably unlimited
• Multi-store model of memory


  • Information flows through a number of storage systems in a linear fashion
  • There are three main storage systems which are unitary
  • Each store differs in terms of coding, capacity and duration
  • Information can remain in short-term memory by maintenance rehearsal, and prolonged rehearsal will create a long term memory
  • The more information is rehearsed, the better it is remembered
  • Information can be lost from each store, but in different ways

  
• When describing or outlining the multi-store model, you need to include detail on the key features of the model as well as information on coding, capacity and duration of each store
• Example of detail for a 6 mark answer on the multi-store model


  • The multi store model consists of three unitary stores; the sensory register, short term memory (STM), and long term memory (LTM). Information flows through these stores in a linear way.
  • Information from the environment will pass into the sensory register along with other sights, sounds, smells etc. The two main stores in the sensory register are echoic, which is sound or auditory information and iconic which is visual information.
  • Material in the sensory register only lasts very briefly, less than 3 seconds, but has a high capacity.
  • Information from the sensory register only passes through into STM if we pay attention to it.
  • STM has a limited capacity, 7 +/- 2 item, and information in STM has a duration of up to 30 seconds. If information is rehearsed it will be kept in STM, if not it will be lost. Information is usually encoded acoustically in STM.
  • Repeating information over and over again is called maintenance rehearsal. If we rehearse the information for long enough it will pass to LTM and remain for a life time although loss is possible. Encoding here is semantic, and the capacity is unlimited with information lasting for a very long time.
  • Although the information is stored in LTM when we want to recall it, it has to be transferred back to STM by a process called retrieval.

  
• Sensory register


  • Capacity is very large, with the information contained being in an unprocessed, highly detailed and ever-changing format
  • Duration is very limited, up to 0.5 seconds for iconic memory (visual) and up to 3 seconds for echoic memory (auditory)
  • Encoding is in raw sensory form, with little coding

  
• Short-term memory


  • Capacity is limited to 7 plus or minus 2 individual items
  • Duration ranges from a few seconds up to a minute, but for most is 15-30 seconds
  • Coding is mainly acoustic, but some visual and semantic coding also occurs

  
• Long-term memory


  • Capacity is unlimited
  • Duration can last a lifetime
  • Encoding is mainly semantic

  
• The multi-store model can be criticised for failing to explain why in our day to day lives a lot of information can transfer to long-term memory without prolonged rehearsal
• Craik and Lockhart suggested that enduring memories are created by the processing that you do, rather than through maintenance rehearsal, things that are processed more deeply are more memorable just because of the way they are processed

  
• Craik and Tulving (1975) found that participants remembered more words in a task involving deep processing rather than shallow processing

  
• Evidence from a case study of Clive Wearing challenges the idea that long-term memory is a unitary store, as he had very little long term memory for events but could still remember skills

  
• Sperling's research on the sensory register demonstrated its large capacity and very brief duration
• Baddeley's research on short-term memory showed that it relies more on acoustic coding than semantic coding

  
• Konkle's research demonstrated the vast capacity of long-term memory, with participants able to accurately recognise 96% of 2912 pictures of scenes

  
• Capacity of LTM


  Generally accepted to be unlimited. Therefore, no matter how much information is stored long-term, the store never becomes full.
• Duration of LTM


  Dependent on the person's life span, as memories can last up to a lifetime. Information processed at a deep level is likely to be remembered for longer, and memories based on skills rather than facts tend to be remembered better.
• Coding in LTM


  It is widely acknowledged that information is coded semantically in LTM, especially for verbal information. This means that information is stored in LTM when it has meaning or relevance to us. However, there is some evidence for both visual and acoustic encoding in LTM.
• As semantically dissimilar words were recalled more accurately than semantically similar words, there must be some semantic confusion in LTM during recall, which suggests that coding is semantic.

  
• As there was little difference in recall for the acoustically similar and dissimilar words, this would suggest that the sound of the words is not the coding used in LTM.

  
• Working Memory Model (WMM)


  Developed by Baddeley and Hitch (1974) to demonstrate what is happening to information when we are consciously thinking about it. It is more complex than the multi-store model, with separate components for processing and temporarily storing information.

  
• Central Executive


  • Directs attention to particular tasks, determining how the brain's resources are allocated. It has very little capacity and cannot attend to too many things at once.
• Phonological Loop


  • Has a limited capacity and its function is to store speech-based sounds for brief periods. It has two components: the phonological store (allows acoustically coded items to be stored) and the articulatory control process (allows sub vocal repetitions).

  
• Visuo-Spatial Sketchpad


  • Processes and stores mental images in terms of what they look like and their place in the visual field. It is independent from the phonological loop and has a limited capacity.
• Episodic Buffer


  • Added in 2000, it is a general store that allows both sound and visual information to be bound together. It integrates information from the other systems and also offers a sense of time sequencing.
• Episodic Memory


  The type of long-term memory that gives individuals an autobiographical record of things that have happened to them. It contains information about what happened, where it happened, and when it happened.
• Semantic Memory


  A structured record of facts, meanings, concepts and knowledge about the external world that we have acquired. It refers to general factual knowledge, shared with others and independent of personal experience.
• Procedural Memory


  The unconscious memory of skills and how to do things, particularly the use of objects or movements of the body, such as tying a shoelace or riding a bike. These memories are typically acquired through repetition and practice.

  
• Semantic memory


  Factual knowledge that we have about the world, but without any personal context. It includes types of food, capital cities, social customs, historical dates, functions of objects, vocabulary, understanding of mathematics, etc.

  
• There is an enormous amount of information available in semantic memory, and it is continually being added to
• Procedural memory


  The unconscious memory of skills and how to do things, particularly the use of objects or movements of the body, such as tying a shoelace, playing a guitar or riding a bike

  
• Procedural memories are typically acquired through repetition and practice, and are composed of automatic sensorimotor behaviours that are so deeply embedded that we are no longer aware of them
• Once learned, these "body memories" allow us to carry out ordinary motor actions more or less automatically
• Biological evidence for different types of long-term memory


  • When a person uses episodic memory, they use a different region in the brain compared with when they use semantic memory
  • Tulving (1989) found that in 3/6 participants, blood flow increased at the back of the brain when thinking about historical facts, whereas it increased at the front of the brain when thinking about childhood experiences

  
• Case studies supporting different types of long-term memory


  • Clive Wearing had near total destruction of his hippocampus, leaving him unable to store new episodic or semantic information, but he was perfectly able to read, write, speak and play piano
  • Huntingdon's Disease patients had no problems learning new facts and knowledge, but had severe problems learning new motor skills
• Critics challenge the need of distinguishing between types of long-term memory, suggesting semantic and episodic memory should be understood as the same type of memory called 'declarative memory'

  
• Research by Kan et al (2009) found that there was interdependence between episodic and semantic memory

  
• Being able to identify different aspects of long-term memory has led to psychologists targeting specific kinds of memory to make people's lives better, such as improving episodic memories in older patients with mild cognitive impairment
• Proactive interference


  Memory impairment for something we have learned by other learning that had occurred previously. Old information interferes with the new information.