Memory

Memory

1. Know the taxonomy of memory

   • Explicit vs Implicit
   • Declarative vs Non-declarative
   • Long-term vs Short-term
   • Episodic vs semantic

2. Semantic memory

   • Basic-level fastest to categorise
   • Attributes model (Collins and Quillian, 1969)
     • Hierarchy of attributes e.g. is an animal, has wings etc...
   • Prototype and Exemplar theories (Rosch, 1973, 1975)
     • Focus on typicality and similarity
   • Parallel Distributed Processing (PDP) models
     • Neurobiologically plausible connectionist models
     • Explains typicality and generalisation
     • Semantic memory as a distributed network of modality-specific regions AND a hub (Rogers and Paterson, 2007)
     • Basic-level effect = semantic space has dfifferent groupings.
       • General level names = less support from similarity-based generalisation
       • Specific-level = too much interference from similar representations

3. Semantic dementia

   • Progressive loss of semantic knowledge
     • Impaired in any modality thus damage to hub
     • General > Basic, rather than Basic> General in healthy
   • Other types of memory usually preserved e.g. episodic/prospective
     • Suggests distinct memory systems
     • Double dissociation with Alzheimer's
       • Damage in semantic dementia: inferior and anterior temporal lobe
         • Semantic hub for generalisation
       • Damage in Alzheimer's: medial temporal lobe
         • Episodic hub for integrating time/place
   • Practising/rehearsing words benefited performance in the short-term
     • Still declined in the end

4. Long and Short-term memory

   • Early models
     • STM = Limited capacity - around 7 items (Miller, 1956)
     • James (1890) - Primary memory = conscious information; Secondary memory = ALL accumulated information
     • Waugh + Norman (1965) - rehearsing information moves to LT store
     • Patient HM = impaired LTM, spared STM; Patient KF = impaired STM, spared LTM
       • Double dissociation implicates independent systems
     • Atkinson + Shiffrin (1965) - Sensory ==> (attention) ==> ST ==> (rehearsal) ==> LT
   • Working memory and STM often used interchangeably
     • WM = ST store AND manipulation
   • WM = (1) actively holds info for short time, (2) ST storage function and manipulation/control function
     • LTM = (1) Info encoded and stored as traces (2) not held in active state, (3) retrieval mechanisms required to reactivate traces
   • Multistore models: WM and LTM are different systems that interact
     • Unitary models: One set of representations, with active LTM representations forming content of WM
   • Novel stimuli engage hippocampus in WM task (Ranganath et al., 2005)
     • Hippocampus active without LTM requirements (Lee et al., 2005)
   • LTM and WM may be interrelated systems with shared representations (Slotnick, 2004)
     • Category-selective brain regions activated in WM retention and LTM retrieval (Ranganath et al., 2004)
     • Pattern classifiers trained on LTM activity show good predictive ability for WM patterns
     • Sustained WM activity enhances LTM encoding and retrieval (Schon et al., 2004)

5. Working memory

   • Baddeley and Hitch(1974) - tripartite model
     • Two slave systems - visuospatial sketchpad + phonological loop
       • Dual-task deficit when both tasks performed use same slave systems compared to when they use different slave systems
         • Phonological loop explains: acoustic similarity effect, irrelevant speech effect, word length effect and articulatory suppression
     • Central executive = attention
       • Activates LT memory using episodic buffer
         • Linked to frontoparietal netweork
   • Cowan's Embedded process model (1988)
     • Believes WM is a part of STM
       • Hierarchically organised faculties: 1) LTM, 2) activated memory, 3) focus of attention
         • Novel stimuli automatically attract FOA; Unchanged stimuli related to controlled processes (central executive) for transfer of FOA
       • Cowan et al. (199) - attention changes perceptual encoding: used as support for model

6. Source memory

   • Recognition vs recall dual process account
     • Typically look at hits vs misses
   • Source monitoring framework: multiple cues to source can be retrieved automatically or strategically
     • External/Internal/Reality
   • Thought to be impaired in schizophrenia
     • Recollection impaired, familiarity not (van Erp et al., 2008)
     • Misattribution of performed and imagined actions in SCZ (Gaweda et al., 2012)
     • Mixed evidence of relationship to symptoms
       • Positive symptoms (Anselmetti et al., 2007; Brebion et al., 2000, 2002; Startup et al., 2008)
       • Negative Symptoms (Brebion et al., 2002; Moritz et al., 2003)
       • Unrelated (Vinogradov et al., 1997)

7. Factors affecting encoding and retrieval

   • Levels of processing (Craik and Lockhart , 1972)
     • Deeper processing => better memory
       • Not related to speed of processing (manipulated using difficulty)
       • More elaboration/more distinctive
   • Mandler (1967) - Knowledge of a test does not affect memory
   • Transfer appropriate processing: encode materials in the way they will be tested (Morris et al., 1977)
   • Encoding specificity principle: memory improves when the same cues at encoding are available at retrieval (Tulving & Osler, 1968)
   • Context dependency: memory is better when retrieval environment and encoding environment are the same (Godden & Baddeley, 1975 - divers on land and in water)
     • Also state-dependency e.g. mood, alcohol, exercising
   • Retrieval depends on cues therefore attention to cues, number of cues and relevance of cues are all important
   • Retrieval in reverse order improves memory (Whitten & Leonard, 1981)
   • Change in perspective: (Anderson & Pritchert, 1978)

8. Learning techniques

   • Elaborative interrogation (Pressley et al., 1987)
     • Supports integration of information (Woloshyn et al., 1992)
     • Moderate utility, little training required, consistent prompting
   • Highlighting did little to improve memory (Fowler and Baker, 1974)
     • Differences between active vs passive
     • Quality/Quantity of highlighting important
   • Practice testing improves recall (Roediger & Karpicke, 2006)
     • Robust effect, high utility
   • Distributed practise improves memory retention over a longer period of time (Bude et al., 2011)
     • Do not have to work as hard, reminded of previous learning, consolidate learning better
     • Cepeda et al. (2008) - lag between intervals should be 10-20% of desired retention period
     • High utility

9. Forgetting

   • Ebbinghaus (1913) - Logarithmic relationship between time and forgetting
   • Meeter et al. (2005) replicated Ebinghaus and found recall worse than recognition memory
   • Availability vs accesibility
   • Trace decay
   • Interference
     • Competition assumption + cue-overload principle
     • Retroactive interference (Barnes + Underwood, 1959)
       • Baddeley & Hitch (1977) - recall names of rugby teammates better predicted by number of intervening games NOT by time
     • Proactive interference (Underwood, 1957)
     • Retrieval induced forgetting (Anderson et al., 1994)
       • Associative blocking: leads to repeatedly stronger competitor
       • Inhibition: contextually inappropriate responses prevented
         • Cue independence supports
   • Amnesia
     • Anterograde vs retrograde
       • Ribot's Law
     • Damage from AD, Korsakoff's, Herpes or surgery
     • Explanations of retrograde amnesia
       • Standard models = gradual transfer between systems
         • Ribot's Law explained by damage to not-fully-consolidate
       • Multiple Trace Hypothesis
         • Hippocampus also required for LT retrieval
         • Older memories have more traces therefore more robust, producing Ribot's Law
       • Difficulties acquiring semantic information highly contentious

10. 7 Sins (Schacter, 1999)

    • Transience
      • Forgetting e.g. Ebbinghaus
    • Absent-mindedness
      • Change-blindness/Shallow encoding
    • Blocking
      • Retrieval induced forgetting/ Tip-of-the-tongue
    • Misattribution
      • Source memory
    • Suggestibility
      • Eyewitness testimony (Loftus & Palmer, 1974)
    • Bias
      • Bartlett (1932)
    • Persistence
      • PTSD