375: Remembering Events Pt 3

1. Capacity & Forgetting Rates
1. Sensory memory
1. Relatively large capacity 
2. Immediate decay
2. STM
1. 7 or so chunkcs
2. ~30 seconds or longer
3. LTM
1. Infinite?
2. Lifetime?
2. Geneology
1. Ebbinghaus (1885)
1. He was an introspectionist
1. Served as his own subject
2. Had someone come up with a list of nonsense, one syllable words.
3. He would study them then test himself at different time intervals (immediately, a few hours later, a few days later, etc.)
1. He found that his memory would have a very rapid decay rate but then would bottom out
1. The difference between one week and four weeks was very negligible
2. This became known as the Ebbinghaus Forgetting Curve
4. Following this curved seemed to suggest that forgetting is really just decay
1. This raised a problem...
1. McGoech (1932): Time itself doesn't cause anything, it is the processes occurring in that time that make things happen.
2. So what is the process that is going on during this decay period
3. Decay
1. What process is causing decay?
1. Thinking
1. We are constantly thinking about other things and this overlap can cause some interference 
2. Sleep
1. Sometimes we sleep which would create a time gap for decay
3. If it is just decay then have the same time lapse between a person being awake and a person being asleep then people would have the same rate of decay in either situation
1. What they actually found is that people remember better when they sleep as opposed to when they are awake with normal daily activities.
2. Sleep seems to help with consolidation
4. Consolidation
1. Takes memories from a malleable state and makes it fairly impervious (LTM)
2. Systems Consolidation
1. Going from hippocampal dependent to hippocampal independent
3. Ribot's Law
1. Found that the older a memory is the more impervious it is to forgetting from brain damage
2. a.k.a. "last in, first out" or "first in, last out" principle
5. Why do we forget?
1. Decay
2. Occlusion
1. Example: remembering your old phone number now that you have a new one can be very difficult
1. Tip-of-the-tongue phenomenon
1. This is where you feel like you remember but it's just on the tip-of-your-tongue.  This could be what is happening but most of the time it is not
3. Unlearning
1. Not a very big difference between this and occlusion
2. Works for recall, not for recognition
4. Interference
1. This accounts for most forgetting
2. AB-AC design
1. This is where you have two lists of word pairs and the second pairs have one of the same words from the first pairs but paired with a novel word.  Usually the second list will cause interference on the recall of the first list
2. This type of interference is quite bad when it comes to two word lists but if you have one word list and the next the pairing is with a picture then memory interference is much less.
3. Muller & Pilzecker (1900)
4. The best time to study is right before you sleep or before you drink alcohol
5. Why does timing matter?
1. If you have time to consolidate information then it is much less susceptible to interference.  Specifically it protects from retroactive interference
6. Retroactive Interference
1. The new things that you learn interfere with the old things that you learned
7. Proactive Interference
1. The old things that you learned can interfere with consolidation of new information
5. We Never Forget
1. Another theory is that nothing is lost from LTM but this is not a falsifiable theory so it is not a very good theory
6. Summary
1. LTM is not infinite
2. Forgetting happens along a curve