Learning and Memory

1. Learning and Memory • Can they be understood separately? • Learning is the process of acquiring new information, while memory refers to the persistence of learning in a state that can be revealed at a later time • Memoryis any indication that learning has persisted over time. It is our ability to store and retrieve information; to remember (recognize or recall) things we have experienced, imagined, or learned

2. Memory • The Atkinson-Shiffrininformation-processing or multi-store memory model sees memory as comprised of three processes • Encoding • Storage • Retrieval

3. The Multi-Store Memory Model

4. Atkinson and Shiffrin’s Multi-Store Memory Model (1968) • Memory consists of three stages based on how long memory is retained (duration) and how much can be stored (capacity). Three “stages” of memory • Sensory register • Short-term memory (working memory) • Long-term memory

5. Sensory Register (aka Sensory Storage aka Sensory Memory) • A sensory-based, temporary representation of input. The first stop for all sensory information • Iconic (visual) Less than .5 seconds • Echoic (auditory) Two to three seconds • Decays quickly • Immense capacity limited only by our sensory system’s abilities

6. Sensory memory: Iconic store • Sperling(1960) determined the capacity and duration of the iconic (visual) store with a series of ingenious experiments • Full versus partial report method

7. Sensory memory: Iconic memory • The partial report technique demonstrated that the capacity of iconic memory is quite large • Participants could perceive much more than they could verbally report • Information was being read out from a rapidly decaying icon

8. Observations about Sensory Register/Storage/Memory • Sensory memory holds briefly presented stimuli to increase the chance that they will be present long enough to be attended to… • …when this happens the stimuli enters short term/working memory • Allows for “stream of consciousness”, rather than a series of disconnected images and sounds (e.g. film)

9. Short-term Memory (often also referred to as Working Memory) • The part of memory where information from sensory memory and long-term memory are made conscious • Information is maintained in STM via maintenance rehearsal. Without rehearsal there is a rapid decay, e.g., repeating an unfamiliar phone number until you dial it • Primarily a process of acoustic encoding

10. Short-term Memory and Acoustic Coding (and interference) • Experiments prove phenomena known as phonological similarity effect • Which list is most difficult to recall? (Conrad) • E, F, M, P N • D, P, T, Z, V • W, L, C, S, R • Which of these lists is most difficult to recall? (Baddeley,et.al) • large, big, immense, huge, obese • fish, door, awkward, map, love • fan, can, plan, ran, tan

11. ST/Working Memory - Capacity and Chunking • George Miller (1956) demonstrated that short- term memory capacity is about seven(plus or minus two) units of information (phone #) • This can be extended through a process known as chunking (e.g. telephone numbers). Example of chunking • Recall the following sequence of letters…. • F D R T V F B I J F K C I A • The sequence when chunked into meaningful units… • FDR TV FBI JFK CIA

12. ST/Working Memory - Capacity • Word-length effect A set of monosyllabic words are recalled more easily than a set of polysyllabic words • wit • sum • harm • bag • top • university • opportunity • aluminum • constitutional • auditorium

13. ST/Working Memory - Duration • Information in STM decays rapidly without rehearsal (Peterson,1959), between 15-20 seconds • Ability to report novel consonant strings (TFDHG) decreases if subjects are prevented from rehearsing (e.g., count backwards by 3 from 309) • Correct responses reduced to below 10% after 18 seconds

14. Working Memory v. Atkinson and Shiffrin’s Short Term Memory • Baddeley and Hitch, 1974 • A limited capacity store for retaining information over a period of seconds to minutes, and used for performing mental operations.Information can be acted on and processed, not merely maintained by rehearsal • Sentence perception and comprehension • Mental arithmetic • Visual-spatial sketchpad and phonological loop

15. Long-term Memory • In long-term memory • Vast amounts of information may be stored for many years. No known limits to capacity or duration of LTM • Most information in LTM is encoded on the basis of elaborative rehearsal • Process of relating new information to information already stored in memory • Meaning (semantic encoding) is assigned to new information and then linked to as much existing knowledge as possible

16. Types of Long-Term Memory • Explicit (declarative) v. Implicit memory • Semantic memory Memory for general facts and concepts not linked to a specific time • Episodic memory Memory for personal events in a specific time and place • Proceduralmemory&conditioned response

17. Types of Long-Term Memory Explicit (declarative) v. Implicit memory

18. Rehearsal: Memory and Forgetting Curves • Learning usually requires rehearsal(overlearning) or conscious repetition • Ebbinghausstudied rehearsal by using nonsense syllables: TUV YOF GEK XOZ. Introduced learning and forgetting curves • Concept ofmassed v. distributed practice (spacing effect)

19. Memory Phenomena • Serial Position Effect – Primacy and recency the first and last items learned are most easily remembered (Ebbinghaus)

20. More Memory Phenomena • Autobiographical memory (Self-reference effect) • Recollection of events in our life • More recent events are easier to recall • Extraordinary memory (super-memorists) • Includes eidetic imagery (photographic memory) • Usually due to well-developed memory techniques • Resource: The Brain: Teaching Modules • Tip of the Tongue phenomena

21. Mood and Memory • Context dependent memory • Recall of information is better if environment is the same as when information was learned. Examples? • State-dependent memory • Recall of information is better if person is in the same physiological state as when information was learned • Mood congruent memory • Network theory

22. Biology of Memory • Flashbulb memory Heightened emotions (stress-related or otherwise) make for stronger memories, e.g. 9/11 • Early memories. Examples? • Role of limbic system - amygdala • However, continued stress may disrupt memory • Scientific American Frontiers . Don't Forget. Watch Online | PBS

23. Biology of Memory (and Learning) • In Aplysia,Kandel (1982) showed that serotonin release from neurons increased after conditioning • Long-Term Potentiation (LTP) = enhancement of synapses after learning (Lynch, 2002). Increases in neurotransmitter release leads to strengthening of synapses • Where are memories stored? • Different parts of the brain are specialized for different types of memory information • Primary role of hippocampus in forming

24. Where are Memories Stored?

25. Memory and Forgetting • Decay Theory • Memories deteriorate because of the passage of time • Amnesia • Memory loss caused by accidents, surgery, poor diet, or disease (dementia/Alzheimer’s) • Retrograde andanterograde • Psychogenic (v. organic) amnesia • Scientific American Frontiers . Don't Forget. Resource: The Brain: Teaching Modules

26. Memory and Forgetting • After losing his hippocampus in surgery, patient Henry M. (HM) remembered events before the operation but could not make new memories. Types of amnesia? Causes? • UnkownWhite Male • Scientific American Frontiers . Don't Forget. • Resource: The Brain: Teaching Modules

27. Memory The Story of Clive Wearing • Accomplished musician suffered a viral infection and subsequent damage to his brain • His capacity to recall autobiographic details as well as general knowledge is severely limited Resource: The Mind: Teaching Modules

28. The Story of Clive Wearing • The hippocampus, the structure we use for recall and laying down new thoughts, was profoundly damaged due to infection • Clive lost episodic memory, that is, memory for events • He can remember some general information (semantic memory)

29. Memory and Forgetting • Infantile and Childhood Amnesia • Generally poor memory for events prior to age 2-3 • Due to underdevelopment of brain structures (hippocampus) and lack of cognitive abilities • Role of language in memory?

30. Forgetting: Retroactive and Proactive Interference • Retroactive Interference occurs when new information interferes with information already in memory • Proactive interference occurs when information already in memory interferes with new information

31. Memory and Forgetting • Alzheimer’s Disease and Dementia • Scientific American Frontiers . Don't Forget. Resource: The Brain: Teaching Modules

32. (Re)Constructive Memory • Reconstructive memory (Loftus) • Memories can be altered with each retrieval • Memory levelling and sharpening • Memory is affected by one’s schema, prejudices, experiences, suggestion, new information and/or context • Misinformation effect (confabulation) • Misattribution (source amnesia) • Elizabeth Loftus’ car crash and implanted memories research • Don't Forget. • Loftus’ Curriculum Vitae

33. (Re)Constructive Memory and Eyewitness Testimony • Eyewitness testimony (Loftus) • Shown to be unreliable • People’s recall for events may be influenced by what they heard or imagined (e.g. post-event information) • Role of schema

34. Repressed Memory • Recovered memories (Repressed memory or Motivated Forgetting) • Involves the recall of long-forgotten dramatic events • May also be the result of suggestion, post-event information, imagination inflation (False Repressed Memory Syndrome) • More recent research supports that some memories can be repressed and recalled later. It remains controversial