Prof. Greg Francis 8/16/11 PSY 200: Intro. to Cognitive Psychology 1 Purdue University Amnesia PSY 200 Greg Francis Lecture 21 What is wrong with my wife? Purdue University Fundamental fact  There is no method other than object physical evidence to verify the accuracy of a memory  Memory is a cognitive experience  Confidence in the memory is another cognitive experience  You can be very confident and still be wrong  Of course, we must be correct fairly often, or our lives would be a total mess! Purdue University Amnesia  Loss of memory or memory abilities  retrograde: forgetting events prior to the injury  anterograde: forgetting events after the injury  In most cases amnesia is limited in scope and duration  like when my brother Joe slipped while playing frisbee Purdue University Amnesia  Scope and duration  Retrograde amnesia for one patient coma 5 months to infancy 2 years coma 8 months to infancy 1 year 4 years coma 16 months to infancy 2 weeks Time of accident Purdue University What’s wrong with my wife?  Nothing!  But she cannot remember anything before her senior year in high school  motor cycle accident  complete retrograde amnesia Purdue University An unusual case  Side issues  Sense of smell  Mild anomia  Odd aphasia (language deficit)  She is able to learn and remember new information  Remarkably unaffected by the loss of memories  Personality  Parents  college  makes study of retrograde amnesia difficultProf. Greg Francis 8/16/11 PSY 200: Intro. to Cognitive Psychology 2 Purdue University What is lost?  How can someone who loses their childhood memories go to college the next year?  memories cannot be “wiped clean”  perhaps they are just not directly accessible  forgetting = recall problem? Purdue University What is lost?  More generally,  while patients with retrograde amnesia forget their names, parents, addresses,…  they do not generally forget how to walk, talk, solve problems » Although they may have problems…  Different types of memory systems » controversial! Purdue University Memory systems  There are many different types of memory  Amnesia seems to affect declarative more than nondeclarative memory Purdue University Anterograde amnesia  Some patients have amnesia that preserves past memories but prevents formation of new memories  many are long-time alcoholics who did not eat properly » which leads to a thiamine deficiency » which leads to Korsakoff’s syndrome  Leonard in Memento Purdue University Patient HM  Surgery on hippocampus (to control epilepsy)  anterograde amnesia  unable to learn anything new  Thought it was 1953  shocked by age of face in his mirror  Could not stand to read newspapers  reintroduced himself to doctors, nurses,…  Could carry on a conversation! Purdue University Anterograde amnesics  Fairly normal STM digit span (~7 items)  But very difficult to extend digit span  how many trials to repeat back list correctly? 0510152025300 5 10 15 20 25Number of digits to rememberMean trials to criterionControlsPatientsProf. Greg Francis 8/16/11 PSY 200: Intro. to Cognitive Psychology 3 Purdue University Serial position curve  Normal recency  Abnormal primacy  Consistent with STM-LTM dichotomy 01020304050607080901000 5 10 15Item numberPercent correctControlsAmnesicsPurdue University Patient HM  Could learn some things!  E.g., location of hospital cafeteria  E.g. mirror drawing task Purdue University Patient HM  Mirror drawing task (Milner, 1968)  HM had no knowledge of doing the task before! Purdue University Amnesia-like memory  Some aspects of memory seem very much like amnesia  infantile “amnesia”  repressed memories  Careful studies are difficult to come by because the memories (and absence thereof) must be verified  remember the “fundamental fact” at the start of today’s lecture Purdue University Infantile amnesia  Most people report that they cannot remember anything that happened to them before age 4 years 051015200 2 4 6 8Age at time of eventNumber of memories reportedPurdue University Infantile amnesia  Reason is unknown, but the best theory goes like this…  children younger than 4-years-old view the world differently from adults  by encoding specificity, one needs to be in a similar state as study to best recall something  adults are very different from children, and this prevents recall of early memoriesProf. Greg Francis 8/16/11 PSY 200: Intro. to Cognitive Psychology 4 Purdue University Repression  Psychotherapists (e.g. Freud) suggested that infantile amnesia occurred because much of childhood is filled with painful events and memory of the pain is prevented by psychological defense mechanisms (repression)  This is very unlikely  people do remember painful events well  laboratory studies find no evidence of repressed memories Purdue University Repression  In a laboratory, showing evidence of repression requires  being unable to remember something  being able to recover the memory through therapy  proving that the recovered memory is accurate Purdue University Repression  In therapy, clinicians often claim evidence of repression with  dream interpretation  patterns in symptoms  recovering a memory through hypnosis  None of these techniques demonstrate a verified memory  Among carefully controlled memory research, there is no evidence of repression! Purdue University Conclusions  Retrograde amnesia  Anterograde amnesia  Learning in anterograde amnesics  Infantile amnesia  Repression Purdue University Next time  Study schedules  Levels of processing  Mnemonics  Sleep  How to improve your memory without spending