Photographic Memory

• Also known as eidetic memory

• 5% of preschool children show evidence of eidetic memory

• Images persist

Savant Syndrome (previously Idiot Savant)

• Autistic Savants account for half of Savants

• Other developmental disorder & brain injury account for remainder

• About 10% of autistics exhibit savant skills

• Can normal people exhibit savant skills?

Kim Peek, Mega-Savant, Rainman

Savant Syndrome

• Right hemisphere skills, very narrow range

• Calendar calculation

• Music performance

• Mathematical (primes, multiplication)

• Artistic creation

• Spatial skills, map memorization

PHENOMENAL MEMORY BUT NARROW

Causes of Savant Syndrome

• Social deprivation or isolation – Kim Peek story

• Compensation

• Undistractibility

• Concrete reasoning

• Right hemisphere dominance

• Pre-verbal coding scheme survives

Transcranial Magnetic Stimulation (TMS)

To test Adult Eidetics

Infant Amnesia

• Little to no recall first few years of life

• Girls generally show earlier recall than boys

• Why?

Temporal Lobe

TL=MAROON

SAF 1402- “Don’t Forget” (2003)

• “Don’t Forget” - Meet "E.P.," a spry, affable 82-year-old retiree. Don't be surprised, though, if E.P. doesn't remember your name, or if he tells you the same story six times in 10 minutes. About 10 years ago an acute virus infection destroyed E.P.'s hippocampus, a part of the brain that is critical to memory. Today, Larry Squire and Jen Frascino of the University of California, San Diego work with E.P. to learn more about why he cannot form new memories.

• E.P. lives in a state of "permanent present." Because his hippocampus is effectively "dead," anything new that happens to him simply doesn't get recorded. But, although he can't record new memories, old ones from before his hippocampus was destroyed -- some going back decades -- remain remarkably intact. As Alan sees firsthand, E.P. can mentally map a route from his boyhood home to the town library but cannot name any of the streets in his current neighborhood.

• • Mieke Verfaellie works with victims of memory loss to learn more about the role of the hippocampus in

processing and recalling memories.  • At the VA Hospital in Boston, Mieke Verfaellie conducts similar research with "Mr. O," an amnesiac whose

hippocampus was badly injured as a result of a heart attack five years ago. Verfaellie asks Mr. O to look at photos from the September 11 terrorist attacks and tell her what happened that day. Though he knows that something bad happened to the towers in New York City, he can't remember where he was that day and mistakenly believes that his son lived in New York at the time. Later on, when asked about the photos, Mr. O cannot recall what he saw.

• The effects of E.P.'s and Mr. O's hippocampus injuries provide valuable insight into the role of the hippocampus in processing and recalling memories. Researchers believe that the hippocampus works not to store memories but to organize details of an experience -- sights, sounds, smells and feelings -- so when recalled, an event can be remembered as a complete memory.

• http://www.pbs.org/saf/1402/index.html

Memory and Forgetting

Memory System

Extent Duration

Sensory Register

10 Megs milliseconds

STM 7 +/- 2 < 30 seconds

LTM Infinite lifetime

STM DEMO

Primacy & Recency Effects

• Candle• Maple• Subway• Tiger• Ceiling• Ocean• Paper• Thunder• Sofa• Dollar• Wagon• Doorbell

Retrieval Types

• Free recall _______

• Cued recall M _ _ _ _ or ____ LEAF

• Recognition CHAIR TABLE SOFA

• Implicit Asked to name a piece of furniture after having seen

one in unrelated task or test

Animal Research in Memory

Delayed nonmatch to sample test

1. Perirhinal cortex lesion

a. severe memory deficit

2. Hippocampal lesion

a. mild amnesia

3. Amygdala lesion

a. no effect

4. Medial temporal lobe (bilateral) lesion

a. normal test with short delay

b. increasing errors with increasing delay

Hippocampi

Patient H.M.

• Bilateral temporal lobe resection for treatment of epilepsy.• Included removal of hippocampus and amygdala from both sides.• Various etiologies lead to symptoms like H.M.'S, including stroke and herpes

Case of Patient H. M.• Age 9, knocked over by a bicycle rider,

sustained brain damage• Age 16, suffered bilateral temporal lobe

seizures which became uncontrollable– Unable to work and lead a normal life

• Age 27, underwent bilateral removal of hippocampal formation, amygdala, parts of multimodal association areas of temporal cortex (1953)

Consequences of Psychosurgery for H.M.

• Positive - seizures better controlled- IQ unaffected; bright- good long term memory for events before the surgery- good command of language including vocabulary- remembered his name and job he held

• Negative • suffered anterograde amnesia -

unable to transfer new short-term memory into long term memory– unable to retain for more than a

minute new people, places or objects

– unable to recognize people he met during surgery including his neurosurgeons

– took a year to learn his way around a new house

- suffered retrograde amnesia for information acquired a few years before surgery

• Retrograde amnesia – loss of memory prior

to trauma

• Anterograde amnesia– loss of ability to form

new memories after trauma

Retrograde Amnesia Test: Famous Faces of the Past

Patient HM• Revealed declarative/ nondeclarative distinction

– Declarative memories (explicit memories) involve conscious recollection of events and information.

• H.M. Lost this ability.

– Nondeclarative memories (implicit memories) involve ability to acquire and perform new behaviors or associations.

• H.M. Retained this ability. – could perform mirror-tracing after training but could not

remember doing the task before

Memory by Content

• (23.1)

Brain regions in Learning and Memory

Explicit Implicit• Declarative• Recalled consciously• Requires deliberate

effort • Factual knowledge of

people, places and things• Concerned with what

these facts mean• Highly flexible, involving

association of bits and pieces of information

• Non declarative; procedural• Recalled unconsciously• Training reflexive and

perceptual skills;procedures and rules

• builds up slowly over time• Concerned with how to

perform something• Rigid and tightly connected

to the original stimulus condition

Forms of Nonassociative implicit memory:• Habituation – decreased response to a stimulus

presented repeatedly

• Sensitization – enhanced response to a variety of stimuli after an intense or noxious stimulus

• Skill training – performing a task– sensorimotor, perceptual, and/or cognitive skills

• Priming – change in the processing of information as a result of prior exposure to such, word or picture – perceptual – form of stimulus– conceptual – meaning of stimulus

Case of H. M. cont’d.• Now:

- isolated from the past- doesn’t know his age or current date- doesn’t know his parents (with whom he lived) died years ago- sometimes guesses where he is (MIT) where he had been tested & interviewed for 40 years- recognized something is wrong with him but has no memory of what he did earlier in the day

Corkin, S. (2002) What's new with the amnesic patient H.M.? Nature Reviews Neuroscience, 3, 153-160.

Evidence of episodic memory

Wilder Penfield found that stimulation of the temporal lobe produced experiential response – recall of earlier experience

Hippocampus

• Important in spatial representation (rat research)

• Mediates initial steps of long-term memory storage

• Neuroimaging shows intense activity in RH for spatial memories, in LH for memories of words, objects, people

• Active avoidance

• Directed escape

• Undirected escape

• Passive avoidance

• Discriminated avoidance

• Depression

Amygdala – “circuit breaker” to cognition, when quick response needed

Famous people with TLE

• Alexander the Great

• Aristotle

• Napoleon Bonaparte

• Buddha

• Julius Caesar

• Lewis Carroll

• Agatha Christie

• Dante

• Leonardo da Vinci

• Charles Dickens

• Fyodor Dostoyevsky

• Moses

• Hannibal of Carthage

• Margaux Hemingway • Joan of Arc • Vladimir Ilyich Lenin • Abraham Lincoln • Michelangelo • Mohammed • Sir Isaac Newton • Alfred Nobel • Saint Paul • Edgar Allan Poe • Pythagoras • Socrates • P. Tchaikovsky • Harriet Tubman • Vincent van Gogh

TLE and Psychopathology

•William James arguing against what he called ‘medical materialism’:

“whatever be our organism’s peculiarities, our mental states have their substantive value as revelations of the living truth”.

•R.D. Laing:

‘the mystic swims in the same water in which the schizophrenic drowns’

Mystical experience linked to temporal lobe structures, including subcortical ones (amygdala & hippocampus).

Temporal Lobe Personality

• hyperreligiosity

• excessive concern with details– hypergraphia

• altered sexuality

• altered mood (particularly aggressive)

• hypersociability or stickiness, clinginess

Temporal Lobe Epilepsy & Hyperreligiosity• On the road to Damascus Saul/St.Paul saw a bright light, fell to

ground, temporarily blinded and unable to eat or drink. Resembles an ecstatic seizure; some NT evidence of tonic-clonic attacks.

• Mohammed had seizures since 3y, said, "This is a common affliction of prophets, of whom I wish to be counted as one.“

• Joan of Arc, a farmer's daughter, drove England out of France through her military victories as a teenager. She reported ecstatic moments -- flashes of light, voices of saints visions of angels, often triggered by ringing of church bells (musicogenic epilepsy –trigger is emotional significant music). Burned at stake as a heretic at 19 years of age in 1431; canonized 1920s.

• Soren Kierkegaard, father of existentialism and religious philosopher, suffered from epilepsy.

Links with TLTs

•Persinger: seizure like activation called temporal lobe transients in the temporal lobes are related to:

»anomalous beliefs and experiences such as sensed presences, time dilation, out of body experiences, auditory hallucinations

»paranormal beliefs

»hyperreligiosity

Temporal Lobe Readings

•Transcendental Meditation session.

subject reported experience as especially meaningful -- being very close to the ‘cosmic whole’

Alpha wave activity

Alpha wave activity

“Delta frequencies with an aberrant spike

and slow wave profile”

emporal

ccipital

rontal

Temporal Lobe Readings

•EEG during glossolalia (speaking in tongues). Subject reported “contact with the Spirit”

pike events

•Persinger: seizure like activation called temporal lobe transients in the temporal lobes are related to:

»anomalous beliefs and experiences such as sensed presences, time dilation, out of body experiences, auditory hallucinations

»paranormal beliefs

»hyperreligiosity

Temporal Lobe Stimulation

•Induce weak complex magnetic fields over the temporal lobes.

•Right temporal, or bilateral stimulation produced sensations of fear and ‘sensed presences’.

Misidentification & Reduplication Syndromes

• Capgras – hypoidentification– identify people close to them as being imposters, replicas.

• Fregoli – hyperidentification– Possibly an excess of connections between the facial recognition

centers and the amygdala

• BOTH are alteration in relatedness to people, objects, events, experiences

• Possible brain mechanisms:– Intact ventral route for explicit recognition– Disturbed dorsal route for implicit (emotional) recognition

Fregoli Syndrome(Italy’s Lon Chaney)

• Dual-route model of visual recognition– prosopagnosia =

interruption of overt route

– Capgras delusion = interruption of covert route

GSR

Nonconscious (Implicit) Recognition

– Blindsight– Agnosia/prosopagnosia/alexia– Neglect

• Proper hand grasp or slot insertion in apperceptive

• Dorsal visual pathway – no conscious awareness

Conscious awareness may be required for certain perceptual processes to be engaged

Kluver-Bucy Syndrome• Bilateral destruction of amygdaloid body and inferior

temporal cortex - emotive behavioral changes

• Emotional Blunting: flat affect and may not respond appropriately to stimuli. – Following bilateral amygdala lesions, previously fierce monkeys will approach

fear-inducing stimuli with no display of anger or fear.

• Visual Agnosia or "psychic blindness," i. e. an inability to visually recognize objects. Oral compulsions may provide an alternate means of object identification.

• Hyperorality: strong tendency to compulsively place inedible objects in their mouths (leads to hyperphagia and extreme weight gain).

• Inappropriate Sexual Behavior: fail to publicly observe social sexual morays with increase in sexual activity. – Monkeys show atypical sex behaviors, mounting inanimate objects, members

of the same sex.

Kluver-Bucy Syndrome

• As Ramachandran says, "they are not hypersexual, just indiscriminate. [Monkeys with surgically modified temporal lobes] have great difficulty in knowing what prey is, what a mate is, what food is and in general what the significance of any object might be."

•  

INTERFERENCELEARN LEARN TEST

RETROACTIVE

(eg., early tel.no.)

OLD NEW OLD

PROACTIVE

(eg., parked car)

OLD NEW NEW

Proactive Interference Exercise

List 1

• Cheetah• Falcon• Sparrow• Caribou• Crab• Catfish• Coyote

List 2

• Bison• Raccoon• Duck• Mole• Turtle• Ferret• Trout

List 3

• Goose• Leopard• Shrew• Hawk• Deer• Fox• Hammerhead

List 4

• Canary• Weasel• Buffalo• Cougae• Turkey• Lizard• Goldfish

List 5

• Hedgehog• Eagle• Elk• Lobster• Panther• Moose• Groundhog

List 6

• Hummingbird• Crocodile• Cow• Jackal• Chicken• Squid• Eel

List 7

• Mink• Owl• Lion• Salmon• Wolverine• Quail• Ox

List 8

• Alligator• Condor• Wolf• Antelope• Pheasant• Tiger• Sea horse

List 9

• Hyena• Vulture• Tuna• Mongoose• Muskrat• Yak• Gazelle

T List 1

• Waterfall• Cavern• River• Lawn• Forest• Valley• Channel

Medial Temporal Lobe vs. Korsakoff’s The role of the diencephelon in memory: N.A.

1960, 22yrs old US Air force radar tech.

• miniature fencing foil through nostril

• damaged diencephelon– Retrograde amnesia– Anterograde amnesia

• MRI study also implicate mammillary bodies

mainly in chronic alcoholics

• damage to diencephalon

• vitamin B1 (thiamine) deficiency

• (but famine induced B1 deficiency does not usually lead to Korsakoff’s)

Other source of amnesia: Korsakoff Syndrome

Medial Temporal Lobe vs. Korsakoff’s

Cognitive Functions

Medial Temporal Lobe

Korsakoff’s

Anterograde severe severe

Retrograde 3 mths–10 yrs Hard to tell

Confabulation no yes

STM intact intact

LTM old memories old memories

Procedural Learning

intact Intact

Implicit Learning intact intact