1. COGNITION PowerPoint 3: Forgetting

2. What is forgetting?  Forgetting refers to the inability to retrieve information that has previously been stored in memory, despite efforts to do so.  Does not necessarily mean the info is lost!  Memory may still be storing it & there may in fact be a good reason why you can not recall it.

3. Why do we forget?  Why do we forget where we have placed the car keys, work we studied last week or the names of people we use to know?  Hermann Ebbinghaus – first person to study forgetting.  1870s applied scientific principles to studying his own memory. He memorized lists of 13 nonsense syllables (such as hez, ceh, min) and then attempted to recall them after different time intervals.

4.  He plotted his results in a graph that became know as the Forgetting Curve.  He concluded that the most forgetting occurs within an hour after we learn something.  After an hour, the rate of forgetting tends to be more gradual. The Forgetting Curve

6. Does this mean it is pointless trying to remember information, since it is lost so soon? As it turns out Ebbinghaus’ results were biased. More recent studies by psychologists have shown that meaningful information is lost more slowly and less is forgotten. The Forgetting Curve

7. HOW IS MEMORY LOST?  Memory loss occurs due to either: PSYCHOLOGICAL CAUSES OR BIOLOGICAL CAUSES

8. Psychological causes: Retrieval Failure  This theory suggests that forgetting is due to failure to use appropriate retrieval cues to recall information, rather than the information being lost.  Retrieval cues are a prompt, clue or signal that assists the process of locating + recovering info stored in memory.  Learning Activity 7.4 on page 235 of textbook.

9. Psychological causes: Interference Theory  This theory says that people forget because of competition from other, similar information.  The more information we learn, that is of a similar type, the greater the possibility that some will be unable to be retrieved from the long term memory.  Retroactive interference - new info interferes with recalling old info. Example: Confusing concepts that you learnt last week in psychology with info from this week  Proactive interference - old info interferes with recalling new info. Example: Trying to remember a new pin number.

10. Psychological causes: Motivated Forgetting  This theory states that some memories are lost because the person derives some benefit from not remembering, avoiding memories that make us feel anxious or traumatised – Example: an assault  Suppression of memories is a conscious effort to forget something.

11. Biological causes of forgetting  Forgetting can also be caused by biological or physiological factors associated with some sort of damage to the brain.  Anterograde amnesia  Retrograde amnesia  Alzheimer’s disease

12. Biological causes: Anterograde amnesia  Anterograde = forward moving in time  Anterograde amnesia is the loss of memory for experiences occurring after the amnesia-causing event (such as brain injury due to trauma)  Memory of experiences prior to amnesia-causing event remain in tact  Suggests that only STM is affected

13. Biological causes: Retrograde amnesia  Retrograde = backwards moving in time  Retrograde amnesia is loss of memory for experiences occurring before the amnesia-causing event.  Suggests that LTM is affected  Time of memory loss may vary… days, months, years. So, what does this tell is about memory?

14. Biological causes: Alzheimer’s Disease  Alzheimer’s Disease is a disorder characterised by the progressive degeneration of brain neurons, resulting in the increasingly severe deterioration of cognitive abilities, behaviour and personal skills.  Plaques (slabs) and tangles of brain fibres develop and cause large numbers of brain fibres to die off at a greater rate than normal.  1 in 8 people over 65 + 1 in 4 people over people 80 are affected  No test to confirm the disease. Rather, skills + knowledge are assessed to determine the rate of deterioration.