Memory

• Coding in memory:

  • Acoustic coding in short-term memory
  • Semantic coding in long-term memory
• Capacity of memory stores:

  • Short-term memory capacity is 7 +/- 2 items
  • Long-term memory capacity is unlimited
• Duration of memory stores:

  • Short-term memory duration is 18-30 seconds
  • Long-term memory duration is unlimited
• Multi-Store Model of Memory:

  • 3 stores: sensory register, short-term memory, long-term memory
  • Sensory register has a huge capacity but duration of less than half a second
  • Short-term memory is acoustically encoded, has a capacity of 7+/- 2 items, and a duration of 18-30 seconds
  • Long-term memory is semantically encoded, has unlimited capacity, and very long duration
• Types of Long-Term Memory:

  • Episodic, semantic, procedural memories
  • Episodic and semantic memories are recalled consciously, procedural memories are recalled unconsciously
• Working Memory Model:

  • STM consists of central executive, phonological loop, visuo-spatial sketchpad, and episodic buffer
  • Central executive allocates tasks to slave systems
  • Phonological loop processes auditory information
  • Visuo-spatial sketchpad combines visual and spatial information
  • Episodic buffer integrates all types of data processed by other stores
• Explanations for Forgetting - Interference:

  • Interference can be retroactive or proactive
  • Retroactive interference demonstrated by McGeoch and McDonald (1931)
  • Extent of forgetting is larger when memories/materials are very similar
• Retrieval failure suggests that forgetting occurs when the 'cues' present at encoding are not present at recall
• This describes Tulving's 'encoding specificity principle' (ESP)
• There are two types of forgetting associated with retrieval failure: context-dependent and state-dependent
• Context-dependent forgetting occurs when external cues at encoding do not match those at recall
• State-dependent forgetting occurs when internal cues at encoding do not match those at recall
• Godden and Baddeley (1975) demonstrated context-dependent forgetting with deep-water divers
• Carter and Cassaday (1998) demonstrated state-dependent forgetting using anti-histamines
• Eysenck suggested that retrieval failure may be a main reason for forgetting from the LTM
• Retrieval failure is supported by lab experiments with strictly-controlled conditions
• Findings from studies of retrieval failure may lack ecological validity
• Godden and Baddeley found no significant difference in recognition between matched and non-matched conditions
• The encoding specificity principle suffers from cyclical reasoning
• Factors affecting the accuracy of Eyewitness Testimony: Misleading Information
• Eyewitness testimony can be influenced by misleading information like leading questions and post-event discussions
• Loftus and Palmer (1974) showed the effects of leading questions on EWT accuracy
• Response bias and substitution explanation are used to explain the effects of leading questions
• Gabbert et al (2003) demonstrated the impact of post-event discussions on EWT accuracy
• Anastasi and Rhodes criticized the use of young targets in EWT studies
• Zaragosa and McCloskey highlighted demand characteristics affecting EWT reliability
• Artificial tasks and stimuli - watching film clips - reduce the ecological validity of EWT findings - not like real life
• Factors affecting the accuracy of Eyewitness Testimony: Anxiety
• Anxiety can have a positive or negative effect on EWT accuracy
• Johnson and Scott (1976) demonstrated the negative effect of anxiety on EWT accuracy
• Yuille and Cutshall (1986) showed the positive effect of anxiety on EWT accuracy
• The Yerkes-Dodson Law explains the relationship between arousal and performance
• The weapon focus effect may test for the effects of surprise rather than anxiety
• Ethical issues are associated with exposing participants to distressing images in EWT studies
• Improving the Accuracy of Eyewitness Testimony: Cognitive Interviews
• The cognitive interview aims to increase accurate recall in eyewitnesses
• Stages of the cognitive interview include: report everything, reinstate the context, change the perspective, and reverse the order
• The cognitive interview may be time-consuming and require specialist skills
• Kohnken et al (1999) found that the CI increased recall of both correct and incorrect information
• Milne and Bull (2002) suggested that context reinstatement and report everything produced the greatest accuracy of recall