long term memory function = organizes and stores info. more passive form of storage than working...

Long Term Memory• Function = organizes and stores info. More passive form of storage than

working memory• Capacity = unlimited. Average adult = 100 billion neurons, each of which

can make perhaps 5,000 to 10,000 synaptic connections with other neurons five hundred trillion to a thousand trillion synapses

• Duration = thought be some to be permanent

Long-term memory

Working orShort-term

Memory

Sensory

Input

Sensory Memory

Attention Encoding

Retrieval

Maintenance Rehearsal

History Channel: The Brain

• Start at scene 12 or 58:00 of DVD 71• What is the function of memory?• Describe Lashly’s rat maze experiment in the 1920s. What

did he discover?• What is the capacity of long-term memory? • Who is Stephen Wiltshire? What is unique about his

memory? How is his brain different from a “normal” brain?

• Who is Clive Wearing? What type of memory loss does he suffer from and why? How has he changed over time? Why?

SemanticFacts/General

Knowledge

EpisodicExperienced

events

ProceduralSkills

Motor/Cognitive

Classical Conditioning

Explicit (Declarative)knowing you know something

conscious recall

Implicit (Non-declarative)knowing how to do something

(but not know you know)without conscious recall

Types of Long-Term Memory

Medial Temporal Lobe / Hippocampus / Frontal Lobe

Cerebellum

http://ngm.nationalgeographic.com/2007/11/memory/brain-interactive

Memory Loss• Anterograde amnesia – means forward; can’t form new memories.

– Effects of the accident are working forward in time and patient is unable to remember things that have happened since the accident

• Retrograde amnesia – means backward; can’t remember old memories . • Hit by a car at noon on Tuesday. Patient regained consciousness

Tuesday night and it is now Wednesday. Patient can’t remember the accident or anything that happened Tuesday morning before the accident.

Famous Amnesic Patients• EP – herpes simplex virus chewed its way though his brain, destroying his medial temporal

lobe (which contains hippocampus and amygdala)• HM – surgery destroyed hippocampus to stop epileptic seizures

– Surgery was effective in reducing seizures BUT, had other side effects as well– Can remember explicit memories acquired before the surgery

• e.g., old addresses, normal vocabulary – Cannot form NEW explicit memories

• e.g., remembering the name of someone he met 30 minutes prior• cannot name new world leaders or performers• can recognize a picture of himself from before his surgery but not from after and

doesn’t recognize himself in a mirror• Clive Wearing - renowned European conductor; viral encephalitis (inflammation of the

brain tissue) destroyed his hippocampus. – While brain damage has totally obliterated Clive's explicit memory--his ability to

remember new facts or events--his implicit memory remains intact; he still has language and musical skills, although he is not consciously aware of his ability to play music.

• All suffer deficits in explicit, but not implicit memory• All suffer from anterograde and retrograde amnesia

Explicit Memory Memories are those of which

one is consciously aware. EX: I may have an explicit memory of playing a particular golf course

1. Episodic = memories are those for personally experienced events

2. Semantic = memories are for general factual knowledge

Medial Temporal Lobe Hippocampus (left – trouble

remembering verbal info / right – trouble recalling visual designs and locations)

Frontal Lobe

Implicit Memory

Memories are those of which one is not conscious. EX: one may have implicit memories of how to tie one’s shoe but not be able to describe to another how to do it1. Procedural = memories are those

that relate to skills or habits. Learn how to do something, often through classical conditioning, but cannot know or declare they know.

2. Classical Conditioning Cerebellum

Synaptic Changes

• Release more serotonin at certain synapses when learning occurs

• Glutamate enhances long-term potentiation = an increase in the release of neurotransmitters or increase in receptors sites on receiving neuron. Rapidly stimulating memory-circuit connections causes those synapses to become more efficient at transmitting signals; takes less of a signal to recall a memory.

Review! Pieces of Mind: Remembering What Matters

• What is the role of adrenaline in the formation of memory? How do we know? Describe the experiments with the rats and people.

• What is the role of the amygdala in the formation of memory?

Stress Hormones and Memory Formation• Prolonged stress

disrupts LTP • Moderate stress

enhances LTP• When subjects are given

a beta blocker to stall the activation of the SNS, the experimental group did not remember the livelier story any better than the controls remembered theirs. The drug disrupts stress-enhanced memory formation and the experimental subjects did not get a boost in memory for the emotional section.

• Flashbulb Memories - Where you when????

Emotion Charged Event

Sympathetic Nervous System releases epinephrine

(adrenaline) and norepinephrine (noradrenaline)

Amygdala

Hippocampus into a more alert, activated

state. Something important is happening…

Focus! Focus! Focus!

Memory Consolidation