Storage Chapter 8, Lecture 3

1. StorageChapter 8, Lecture 3 “So, despite the brain’s vast storage capacity, we do not store information as libraries store their books, in discrete, precise locations.” - David Myers

2. Storage: Retaining Information Storage is at the heart of memory. Three stores of memory are shown below: Sensory Memory Working Memory Long-term Memory Encoding Events Encoding Retrieval Retrieval

3. Sensory Memory Sensory Memory Working Memory Long-term Memory Encoding Events Encoding Retrieval Retrieval

4. Whole Report Sperling (1960) R G TF M QL Z S “Recall” R T M Z (44% recall) 50 ms (1/20 second) The exposure time for the stimulus is so small that items cannot be rehearsed.

5. Partial Report S X TJ R SP K Y Low Tone Medium Tone High Tone “Recall” J R S (100% recall) 50 ms (1/20 second) Sperling (1960) argued that sensory memory capacity was larger than what was originally thought.

6. Time Delay A D IN L VO G H Low Tone Medium Tone High Tone “Recall” N _ _ (33% recall) Time Delay 50 ms (1/20 second)

7. 80 60 Percent Recognized 40 20 0.15 0.30 0.50 1.00 Time (Seconds) Sensory Memory The longer the delay, the greater the memory loss.

8. Iconic 0.5 sec. long Echoic 3-4 sec. long Hepatic < 1 sec. long Sensory Memories The duration of sensory memory varies for the different senses.

9. Working Memory Sensory Memory Working Memory Long-term Memory Encoding Events Encoding Retrieval Retrieval

10. Working Memory Working memory, the new name for short-term memory, has a limited capacity (7±2) and a short duration (20 seconds). Sir George Hamilton observed that he could accurately remember up to 7 beans thrown on the floor. If there were more beans, he guessed.

11. Capacity The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information (1956). Ready? M U T G I K T L R S Y P You should be able to recall 7±2 letters. George Miller

12. Chunking The capacity of the working memory may be increased by “chunking.” F-B-I-T-W-A-C-I-A-I-B-M FBI TWA CIA IBM 4 chunks

13. Duration Peterson and Peterson (1959) measured the duration of working memory by manipulating rehearsal. CHJ MKT HIJ 547 547 544 541 … CH?? The duration of the working memory is about 20 sec.

14. Working Memory Duration

15. Long-Term Memory Sensory Memory Working Memory Long-term Memory Encoding Events Encoding Retrieval Retrieval

16. Long-Term Memory Essentially unlimited capacity store. R.J. Erwin/ Photo Researchers The Clark’s nutcracker can locate 6,000 caches of buried pine seeds during winter and spring.

17. Memory Feats

18. Memory Stores

19. Storing Memories in the Brain • Loftus and Loftus (1980) reviewed previous research data showing, through brain stimulation, that memories were etched into the brain and found that only a handful of brain stimulated patients reported flashbacks. • Using rats, Lashley (1950) suggested that even after removing parts of the brain, the animals retain partial memory of the maze.

20. Synaptic Changes In Aplysia, Kandel and Schwartz (1982) showed that serotonin release from neurons increased after conditioning. Photo: Scientific American

21. Synaptic Changes Long-Term Potentiation (LTP)refers to synaptic enhancement after learning (Lynch, 2002). An increase in neurotransmitter release or receptors on the receiving neuron indicates strengthening of synapses. Both Photos: From N. Toni et al., Nature, 402, Nov. 25 1999. Courtesy of Dominique Muller

22. Stress Hormones & Memory Heightened emotions (stress-related or otherwise) make for stronger memories. Flashbulb memoriesare clear memories of emotionally significant moments or events Scott Barbour/ Getty Images

23. Beryl Benderly has described “flashbulb” memories this way: “It’s as if our nervous system takes a multimedia snapshot of the sounds, sights, smells, weather, emotional climate, even the body postures we experience at certain moments.” In a sentence or two, write down your three most vivid memories…

24. The percentage of Duke students who had flashbulb recollections of each event: A car accident you were in or witnessed (85) When you first met your college roommate (82) Your high school graduation (81) Your senior prom (78) An early romantic experience (77) A time you had to speak in front of an audience (72) When you got your admissions letter from college (65) The day President Reagan was shot in Washington (52) Your first flight (40) The moment you opened your SAT scores (33) Your seventeenth birthday (30) The last time you ate a holiday dinner at home (23) Your first college class (21) The first time your parents left you alone at home (19) Your thirteenth birthday (12)

25. Storing Implicit & Explicit Memories Explicit Memoryrefers to facts and experiences that one can consciously know and declare. Implicit memoryinvolves learning an action while the individual does not know or declare what she knows. p. 343

26. Hippocampus Hippocampus– a neural center in the limbic system that processes explicit memories. Weidenfield & Nicolson archives

27. Anterograde Amnesia After losing his hippocampus in surgery, patient Henry M. (HM) remembered everything before the operation but cannot make new memories. We call this anterograde amnesia. Anterograde Amnesia (HM) No New Memories Memory Intact Surgery Different from retrograde amnesia, which is loss of memory from before an event or injury.

28. A C B Implicit Memory HM is unable to make new memories that are declarative (explicit), but he can form new memories that are procedural (implicit). HM learned the Tower of Hanoi (game) after his surgery. Each time he plays it, he is unable to remember the fact that he has already played the game.

29. Cerebellum Cerebellum – a neural center in the hindbrain that processes implicit memories.

30. Homework Read p.345-349 “At any given moment, we can consciously process only a very limited amount of information.” - David Myers