Presentation on theme: "Susie Wang XSAC Lecture 17/5/12. Outline How memory works: What is Memory? Types of Memory & Amnesia Memory Formation When memory breaks: False Memories."— Presentation transcript:
Susie Wang XSAC Lecture 17/5/12
Outline How memory works: What is Memory? Types of Memory & Amnesia Memory Formation When memory breaks: False Memories Memory Erasure Conclusion
What is memory? “The retention of learned information” – p726, Bear, Connors & Paradiso. “The internal repository of stored information” – p193, Smith & Kosslyn.
What is memory? Memory is not a videorecording Different aspects of memory are stored and processed in different regions We remember the gist of things
Types of Memory Amnesia: partial or total loss of memory due to brain damage There are two main types: Retrograde amnesia Anterograde amnesia
Retrograde Amnesia Memory loss of events before brain damage [Clip: Bourne Identity] Things you forget: Your name, your age, family, events from your childhood. Things you may not forget: Skills, such as how to punch people Facts, such as that French is spoken in France
Anterograde Amnesia The inability to form new memories [Clip: Clive Wearing] Things you forget: Events that just happened to you New facts learned after acquiring amnesia Things you may not forget How to punch people, drive, etc. Your name, your family members, childhood
Anterograde Amnesia [Clip: Memento 1] Short term memory Long term memory Brain damage in: temporal lobe and hippocampus
Patient H. M. Surgical operation removed medial temporal lobe and hippocampus To some extent, H.M. has retrograde and anterograde amnesia. “Right now I’m wondering, have I done or said anything amiss? You see at this moment everything looks clear to me, but what happened just before? That’s what worries me. It’s like waking up from a dream. I just don’t remember”. (Smith & Kosslyn, 2009)
Long Term Memory “The kind of knowledge that persists so that it can be retrieved long after the experience is past” – p193, Smith & Kosslyn Used to make judgements regarding the future
Long Term Memory [Clip: Sammy Jankis] Types: Non-declarative Priming Skills Habituation and conditioning Declarative Semantic: facts Episodic: first-person memory
Encoding The process in which information is transformed into memory Regions of importance: Medial temporal lobe and hippocampus The temporal lobe The temples Tempus: Latin for time Memory of past events
Consolidation When memories become more stable over time, and are stored in long-term memory In structures other than the medial temporal region
Storage Long term memory for events is widely represented. Multiple areas are involved. May exist in synapses (electrical communication between cells in the brain) Regions of the brain?
Retrieval Cues! Encoding specificity Returning to the scene of the crime Remembering whilst underwater Remembering whilst drunk Cue-dependent forgetting Childhood amnesia: cues to retrieving early memories are inaccessible because they were stored differently (without language)
Retrieval “Each item [in memory] cannot be retrieved in precisely the same form as it was initially stored; it is better to think of a representation as being recreated or evoked than as being searched for. ” - Smith 1996 When you retrieve a memory, you are actually recreating it.
False Memories Repeated prompting for information Incorrectly remembering having seen objects that look similar or are conceptually related “Lost in the shopping mall” Imagination inflation
Imagination Inflation Check the Pepsi machine for change OR get down on one knee and propose marriage to the machine Wave from the top of the steps OR recite the balcony scene lines from Romeo and Juliet Look up a word in the dictionary OR pat the dictionary and ask how it’s doing Lie down on the couch and relax OR lie down on the couch and talk to Freud
Limitations Most psychology studies rely on statistical analyses Significance refers to when we can rule out that the result happened by chance or accident Ethical limitations on the strength of manipulations Most people did not believe false memories Plausibility, relevance and memorability are important factors in whether false memories are adopted
Extreme False Memories There are extreme cases that people have called “false memory syndrome”, where events described are not plausible and are highly memorable. Sexual abuse, Alien abductions, Satanic rituals Therapy for recovering repressed memories
Memory Erasure [Clip: Eternal Sunshine of the Spotless Mind] Selective removal Neural map of memories Cues again!
Memory Erasure “Rapid erasure of long-term memory associations in the cortex by an inhibitor of PKMz” Shema, Sactor & Dudai 2007 PKMz: Protein kinase M zeta, a type of biological molecule that increases the rate of chemical reactions (called an enzyme) Involved in maintaining long-term memories in many areas of the brain The inhibitor is called ZIP. ZIP blocks or decreases the activity of PKMz.
Memory Erasure Taste aversion in rats Findings: 1) Memories can be altered long after they are formed and consolidated in the cortex 2) Rats given ZIP had weaker memories for the bad taste Removal of the memory of the event, or just memory of the bad taste?
Memory Erasure PKMz alters the structure of synapses But synapses are not the end of the story! Constant enzymatic activity
Memory Erasure “On par with a heavy night of drinking…” - Eternal Sunshine of the Spotless Mind The state of intoxication mimics the brain activity found in people who have lesions in the temporal lobe Decrease in amount of information remembered Information encoded in a qualitatively different way Korsakoff’s Syndrome
War of the Ghosts If we have time, story-time! Listen to the story Try and write down what happens, step by step.
Conclusion Memories are fragile Complicated brain system, still a lot unknown Memory and the self