Memory

• Memory is the process of maintaining information over time
• Capacity is the amount of information that can be held in a memory store, represented as "bits" of information
• Coding is the way information is changed so it can be stored in memory.
• Information enters via the senses, and is then stored as visual, acoustic or semantic codes
• Duration is the length of time information can be held in memory until it is no longer available
• Baddeley (1966) - Coding; Aim + Procedure


  Aim - to investigate what type of coding is used in STM and LTM

  Method - Laboratory Experiments

  Procedure - 4 conditions; 1 is acoustically similar, 2 is acoustically dissimilar, 3 is semantically similar, and 4 is semantically dissimilar. words presented one at a time, each participant completed four trials. participants recall a set of words in the correct order immediately + after 20 mins
• Baddeley (1966) - Coding; Findings + Conclusion


  Findings - difficulty remembering acoustically similar words when recalling immediately (acoustic confusion). after 20 mins, difficulty recalling semantically similar words (semantic confusion)

  Conclusion - short term memory prefers to code acoustically, long term memory prefers to code semantically
• Chunking is grouping information into parts. It enables us to recall more info
• External validity is the extent to which findings can be generalised to people, different situations and settings etc
• Ecological validity refers to the setting - can results be generalised to the real world or across different settings?
• Mundane realism refers to the task - was the task something participants would do in their everyday life?
• Miller (1956) - Capacity; Aim + Procedure

  Aim - to investigate the capacity of STM

  Method - Laboratory experiments

  Procedure - each tested individually in a quiet room. participants recall sequence of digits immediately after presented. length was systematically increased, starting with 4, ending with 10
• Miller (1956) - Capacity; Findings + Conclusion


  Findings - participants could remember approx. between 5-9 items before their accuracy significantly declined

  Conclusion - capacity of STM is limited. limit is "magical number seven, plus or minus two"
• Peterson & Peterson (1959) - Duration(STM); Aim + Procedure


  Aim - Duration of STM

  Method - Laboratory experiments, 24 undergrads, 8 trials

  Procedure - participants presented with constant syllables/nonsense trigrams + three digits. asked to recall letters after intervals of 3, 6, 9, 12 or 15 seconds (retention interval). participants count backwards from number given to prevent maintenance rehearsal
• Peterson & Peterson (1959) - Duration(STM); Findings + Conclusion


  Findings - 3 secs = 90% correct, 9 secs = 20% correct, 18 secs = 2% correct

  Conclusion - duration increased, recall decreased. suggests STM has a duration of 18-30 secs before it disappears
• Bahrick et al (1975) - Duration(LTM); Aim + Procedure


  Aim - investigate duration of LTM

  Method - field experiment, 400 participants aged 17-74

  procedure - participants tested on memory of classmates from their year. tested through two ways: 1 is recognise photos from year book, 2 is free recall
• Bahrick et al (1975) - Duration(LTM); Findings + Conclusion 


  Findings (photo recognition) - participants tested within 15 years of grad had 90% accurate recall

  Findings (free recall) - 15 years = 60% recall, 48 years = 30% recall

  Conclusion - LTM could potentially last forever
• Multi-Store Model is a representation of how memory works. Consists of three stores; sensory register, STM and LTM. Explains how info is transferred between each of them.
• Sensory Register is the memory store for each of our five senses. Coding is visual in the iconic store and acoustic in the echoic store. Capacity is huge and duration is limited to half a sec
• STM is memory for immediate events. Has a limited capacity of 5-9 items, and a limited duration of approx. 18 seconds and coding is mainly acoustic
• LTM is memory for past events. Has an unlimited capacity and unlimited duration. Coding is mainly semantic.
• Episodic memory is the long-term memories consisting of personal experiences of events. Characterised by time, context including emotions, and a conscious effort required to recall
• Semantic memory is long term memories consisting of shared knowledge including language, general facts, and appropriate behaviour. requires conscious effort to recall
• Procedural memory is long-term memories consisting of knowledge of how to do things, i.e. learned skills. Conscious effort is required for recall as they become automatic after practice
• The Working Memory Model is an active representation of STM when working on a task. it suggests that STM processes different types of info simultaneously using different stores all co-ordinated by a central decision-making system
• The central executive is the component of the WMM that coordinates the activities of the subsystems. It allocates processing resources for those activities to each subsystem. Its capacity is very limited. Coding is modality-free
• Multi-Store Model of Memory Diagram

  Diagram:

  
• The phonological loop processes auditory info. Consists of the phonological store and the articulatory control process which allows for maintenance rehearsal. Preserves the order info arrives in. Capacity is 2 seconds. Coding is acoustic.
• Visuospatial sketchpad processes visual and spatial info. consists of the visual cache (visual data i.e. colour) and the inner scribe (arrangement of objects in visual field). Capacity is ~3-4 objects. Coding is visual
• Episodic buffer is a temporary store that integrates info from all subsystems to produce a single memory. provides a bridge between working memory and long-term memory. Capacity is ~4 chunks. coding is modality-free.
• Interference is when forgetting occurs due to two pieces of info disrupting each other, resulting in forgetting or distortion of one or both memories. most likely to happen when memories are similar to each other.
• Proactive interference is when forgetting occurs when previous memories disrupt the recall of newer memories
• Retroactive interference is when forgetting occurs when newer memories disrupt the recall of older memories
• Retrieval failure is when forgetting occurs in the absence of cues. suggests that memories are inaccessible not unavailable and can be accessed using suitable cues
• Cues are triggers that serve as reminders that help memories be accessed. Can be meaningfully linked or indirectly linked by being encoded at the time of learning. indirect cues may be external or internal.
• The Encoding Specificity Principle is the idea that for a cue to be helpful for memory recall, it has to be present at both learning and recall
• Context-dependent forgetting occurs when the environment during recall is different from the environment where the info is learnt. There's a lack of environmental cues.
• State-dependent forgetting occurs when the internal state during recall is different from the internal state when the info is learnt.
• Eye Witness Testimony is the account given by an individual of an event they themselves have observed.
• Misleading information is incorrect info given to an eyewitness that may result in the distortion of their memory affecting the accuracy of the EWT Usually given after the event has occurred and can be in the form of leading questions or post-event discussion