9/5/2012 Drs S & C Hanson 1

Learning & memory

9/11/2001

Where were you on the following day?

Your 10th birthday? What did you do?

Do you remember when you had an accident? How did it happen?

Can you remember a Skill you used to do well that you don't anymore?

Phenomenon:

9/5/2012 Drs S & C Hanson 2

Learning & memory

“Knowing that”

Vs.

“Knowing how”

Gilbert Ryle, Oxford philosopher of mind, 1949

9/5/2012 Drs S & C Hanson 3

The four “C”sEichenbaum's themes

Connectivity—memory in the dynamics

Cognition—Representation vs process

Compartmentalization-local vs distributed

Consolidation- fragile memory to permanent

9/5/2012 Drs S & C Hanson 4

Themes of the course(tensions)

(1) Involuntary vs voluntary (unconscious - conscious, procedural - declarative, implicit - explicit , incidental - intentional, automatic- controlled)

(2) functional mapping to neurophysiological processes

(3) representation (i.e., content) in the brain (MEMORY)

(4) relation between acquiring and accessing information (encoding-retrieval) LEARNING

(5) constraints on memory (e.g., duration, capacity/size, physiological) costs.

(6) memory system or systems?

9/5/2012

● Using process to classify memories (e.g., observational, associative,rational)

● Using content to classify memory (e.g., sensory vs motor memory)● Immediate vs permanent retention

(STM / LTM) –W. James reports Ebbinghaus's resultsas reflecting a short-term and long-term memories

Ebbinghaus: The Psychology of Learning (1913) Chapter II

http://www.us.archive.org/GnuBook/?id=psychologyoflear00meumrich#61

9/5/2012

● Elements comprising memory

● Constructive character of remembering

● Consciousness in memory (beyond behaviorism)

Bartlett: Remembering (1932) http://www.ppsis.cam.ac.uk/bartlett/TheoryOfRemembering.htm

9/5/2012 Drs S & C Hanson 7

MEMORY MODEL – ATKINSON & SHIFFRIN (1968)

9/5/2012 Drs S & C Hanson 8

Rapid consolidation: synaptic mechanisms

Three overlapping time courses for consolidation proposed by McGaugh

9/5/2012 Drs S & C Hanson 9

Multiple memory systems

9/5/2012 Drs S & C Hanson 13

Baddeley and Hitch model“Working memory”

Visualspatial sketchpad

Phonological Loop

Central Executive

9/5/2012 Drs S & C Hanson 20

Central executive

• Attentional control – Making changes to practiced routine. (Example:

Altering driving to work routine when there is a traffic accident)

• Dividing attention– Multitasking

• Switching attention from one task to another

9/5/2012 Drs S & C Hanson 21

Baddeley-- 2000

9/5/2012

9/5/2012

9/5/2012

Why is the brain made of GOO?

Best Computer technology at present has efficiency

.0000007 JOULES work for 10 MILLION OPERATIONS in 1

SEC!

The brain cost us almost nothing to run...

The BRAIN .000000000000000016 JOULES of work for 10

MILLION OPERATIONS in 1 SEC!

The brain is ~100 MILLION times more efficient then

the best computer technology

9/5/2012

Evolution and the Brain

From the inside out... from the simplest most

primitive responses

9/5/2012

9/5/2012

Scientific American

9/5/2012

9/5/2012

9/5/2012

9/5/2012

9/5/2012

Networks: AssociationismJames, 1890

9/5/2012

Actual Neural Networks

9/5/2012

9/5/2012

Semantic Network: Neural Networks

9/5/2012 Drs S & C Hanson 37

Core concepts• Modularity assumption

• Localisation of function– Transparency assumption about interpreting brain lesions.--tube radio– Lashley (1950) - misleading concepts of ‘mass-action’ and ‘equipotentiality’.

• Representation– How do neurons of a particular bit of the brain ‘represent’ something?– object recognition--categorization

• Single-cells and neural networks– ‘Grandmother cells’– Emergent properties of networks (e.g. distributed associative memories).

• Plasticity– Brain circuits show varying degrees of hard-wiring and susceptibility to

change.

9/5/2012

Face Recognition

Fusiform Face Area(FFA) ...bilateral.. butRH FFA seems more “active”.

9/5/2012 Drs S & C Hanson 41

FACE RECOGNITION: Uncanny Valley

Object Recognition Areas throughout the Brain?

9/5/2012 Drs S & C Hanson 43

Memory and Learning

Memory can be defined as a lasting representation that is reflected in thought, experience, or behavior.

Learning is the acquisition of such representations -- involving a wide range of brain areas and activities.

Memory storage is believed to involve widespread synaptic alterations in cortex.

9/5/2012 Drs S & C Hanson 44

Prefrontal cortex, consciousness and working memory

Different types of working memory

In his seminal work on working memory, Baddeley proposed that there were differing types of working memory: a visuospatial sketchpad for visual inputs and a phonological loop for sound-based inputs.

Neuroimaging studies have shown differing brain areas for visual and verbal working memory processes, with the DL-PFC (D) interacting with Broca’s area (B), a phonological loop (P) and with the frontal eye fields (F).

9/5/2012 Drs S & C Hanson 46

The MTL encodes information across sensory domains such as smell, vision, and touch.

The MTL is a highly interactive crossroads, well-placed for integrating multiple brain inputs, and for coordinating learning and retrieval in many parts of the cortex. It is a ‘hub of hubs’.

H. M. B.Milner1960s, M.N.I.

Important brain structures in the study of memory are the cortex and the medial temporal lobes (MTL), which contain the two hippocampi and their surrounding tissue.

9/5/2012 Drs S & C Hanson 49

Penfield and Olds 1940s

Electrically evoked autobiographical memories

For more than 50 years, neurosurgeons have reported that awake patients report vivid, specific conscious recollections during temporal lobe stimulation.

Electrode grids are typically placed on the surface of the temporal lobe and areas are systematically stimulated and the patient’s reported memories are noted.

9/5/2012 Drs S & C Hanson 50

Learning & memory: Single Events

Brewer J, Science 1998; Wagner A, Science 1998

During scanning of medial temporal lobe and frontal lobe regions, subjects viewed complex, color photographs. Subjects later received a test of memory for the photos. The magnitudes of focal activations in right prefrontal cortex and in bilateral parahippocampal cortex predicted

which photographs were later remembered well, remembered less

well, or forgotten.

9/5/2012 Drs S & C Hanson 51

The limbic system:Memory & emotion

9/5/2012 Drs S & C Hanson 60

Varieties of memory

Memory is not unitary: the Schacter-Tulving classification of memory types

9/5/2012 Drs S & C Hanson 61

StriatumThe grouping formed by thecaudate nucleus (orange) and the putamen (green)is called the striatum. It constitutes the major target for the cortical afferents of the basal ganglia. The efferents from the basal ganglia to the thalamus arise in the globus pallidus. The part of the ventrolateral nucleus of the thalamus that then projects to Area 6 is called "pars oralis" and usually designated by the symbol VLo.

The other structures of the basal ganglia form various internal loops that modulate the activity of the main loop, in which information passes through the following brain structures in succession: cortex – striatum – globus pallidus – VLo – cortex (supplementary motor area, or SMA).

9/5/2012 Drs S & C Hanson 63

The Striatum and Implicit Memory

• Two elements of basal ganglia Striatum– Caudate nucleus – Putamen

• Rodent Recordings and Lesions in the Striatum– Lesions to striatum: Disrupts procedural memory (classical

conditioning/implicit) – Damaged hippocampal system: Degraded performance on

standard maze task-spatial memory.. (Operant conditioning/explicit)

9/5/2012 Drs S & C Hanson 64

Temporal Difference Learning

• Sutton (1988).. predicting the weather..

Action

environment

Reward (Rt)

State (St) agent

9/5/2012 Drs S & C Hanson 65

9/5/2012 Drs S & C Hanson 66

Systems for LearningMost of what has been presented has been cortical processes for memory, but there are other kinds of memory and brain areas that have not been discussed:

9/5/2012 Drs S & C Hanson 67

Lets stop here for now...

Format of class:

White papers due at class time. This should be 1 pageof your view of the issues in the papers you read.

Papers will be assigned for student presentation and Discussion.

Papers will available on the course website:http://nwkpsych.rutgers.edu/~jose/course

Final paper and presentation due in the last session (12/5).

9/5/2012 Drs S & C Hanson 68

Discussion Points

1890: What was Ebbinhaus's concept of Memory?What is it now?

Learning and Memory? Same ? Are these different processes?Same process different phases?

Is a habit memory? Is a reflex memory? How do we reconcile Associative learning with other implicit memory?

Ebbinghaus seems to be investigating Eichenbaum's "Consolidation" feature of memory and Bartlett Eichenbaum's "Cognition". What, if anything do Ebbinghaus and Bartlett have to say about Eichenbaum's "Connection" and "Compartmentalization"?

Can Bartlett's idea of memory be reconciled wtih that of Ebbinghaus?

How does the biological basis of memory (Squire and Kandel) relate to something like Ebbinghaus' traces or Bartlett's "schema"?

Can memory be both localized and distributed?

9/5/2012 Drs S & C Hanson 69

Complexity— and the threshold for implicit learning..

Categorization and Learning

Depending on how complex the rulesAre to learn.. the more the memory system tends towards implicit encoding/learning.

Bruner Goodnow & Austin (1956) RULE Learning

Concepts & Categories: Bruner Goodnow & Austin, (1956)

9/5/2012 Drs S & C Hanson 72

Spared functions in amnesia: implicit / procedural learning and memory

A way to investigate implicit and explicit learning was developed by Knowlton and colleagues. The patterns on the cards ‘predict’ either rainy or sunny weather with an 80% probability. Healthy individuals implicitly extract the rules in this weather task before they are aware of them explicitly.

9/5/2012 Drs S & C Hanson 73

Spared functions in amnesia: implicit / procedural learning and memorySpared functions in PD: Explicit Learning

Amnesia patients perform as well as the controls in the early trials that involve implicit rule extraction, but perform worse in the later trials when explicit rule learning is involved.

PD patients perform poorly implicit—early trials, but eventually learn “rule”.

9/5/2012 Drs S & C Hanson 74

The Striatum and Procedural Memory

• Amnesic-- poor in Explicit memory

• PD-- poor in Implicit memory

9/5/2012 Drs S & C Hanson 75

How does (explicit) memory work?

• MTL-- both episodic and semantic information—whats the relationship?

9/5/2012 Drs S & C Hanson 76

The sight of a coffee cup activates visual cortex up to the level of object perception

9/5/2012 Drs S & C Hanson 77

Memory storage: MTL coordinates widespread memory traces throughout cortex

9/5/2012 Drs S & C Hanson 78

When the episodic memory -- the sight of the coffee cup -- is cued the following day, MTL is once again involved in retrieving and organizing widespread memory traces

9/5/2012 Drs S & C Hanson 79

Varieties of memory

Episodic and semantic memory: ‘Remembering’ versus ‘knowing’

Remembering autobiographical episodes involves an active reconstruction of the original (conscious) episode

9/5/2012 Drs S & C Hanson 80

Varieties of memory

Episodic and semantic memory: ‘Remembering’ versus ‘knowing’

Knowing semantic memories does not require active reconstruction of the original episode, it is assessed by a ‘feeling of knowing’.

9/5/2012 Drs S & C Hanson 81

Varieties of memory

Episodic memories may turn into semantic memories over time

A model for how semantic and episodic memories may be related: semantic memories may be the cortical residue of many episodic memories.

9/5/2012 Drs S & C Hanson 82

Consolidation: interaction between the medial temporal lobes and cortex

Two kinds of consolidation are through to exist: cellular and systems consolidation. Both are evoked by activation of the MTL and cortex.

9/5/2012 Drs S & C Hanson 83

LTM modulating factors

• Long term memory modulating factors improves all performance except for recency (eg Sumby 1963)– Slower list presentation– More familiar words

9/5/2012 Drs S & C Hanson 84

Atkinson and Shiffrin (1968)

9/5/2012 Drs S & C Hanson 85

Problems with Atkinson and Shiffrin

• Model says STS required for entry into LTS– A neurological patient with defective short term memory

(as measured by digit span) showed normal long term learning. (Shallice and Warrington 1970)

• Model says length of time in STS determines likelihood of LTM storage– Length of time in STM does not necessarily result in

transfer to LTM. Depth of processing is more important (Craik and Tulving 1975)

9/5/2012 Drs S & C Hanson 86

The Temporal Lobes and Deficits

• The Diencephalon and Memory Processing

– Korsakoff’s Syndrome• Symptoms: Confusion, confabulations, severe memory

impairment, and apathy

– Alcoholics: Develop thiamin deficiency • Leads to symptoms: Abnormal eye movements, loss of

coordination, tremors

– Treatment: Supplemental thiamin • Thiamin deficiency: Structural brain damage

9/5/2012 Drs S & C Hanson 87

Prefrontal InteractionsShort Term/Working Memory

9/5/2012 Drs S & C Hanson 88

Prefrontal cortex, consciousness and working memory

The delayed-match-to-sample task is widely used in studies investigating the role of the PFC in working memory.

In the classic experiment, a monkey is trained to delay responding to a stimulus (‘sample’, typically a red, blue, or white light). The monkey shows recognition of the stimulus after the delay by correctly pressing the light that matched the sample.

Neurons active during the delay period are shown in red at the bottom of the panel.

9/5/2012 Drs S & C Hanson 89

Prefrontal cortex, consciousness and working memory

Working with memory: the frontal lobe works purposefully with memory

The prefrontal cortex (PFC) plays a critical role in working memory. The macaque monkey has been the primary experimental animal if many studies of working memory.

PFC in monkeys (top) and humans (bottom). The most common division is between upper and lower halves of the PFC, called the dorsolateral prefrontal cortex (DL-PFC, purple shading) and the ventrolateral prefrontal cortex (VL-PFC, green shading).

9/5/2012 Drs S & C Hanson 90

Retrieval and metacognition

Metacognition is the ability to know our own cognitive functions, and to be able to use that knowledge. Many neurological patients who are severely impaired have no metacognitive insight that anything is wrong.

Healthy individuals use metacognition in memory retrieval. For example, semantic memories may be retrieved by using episodic cues and vice versa

9/5/2012 Drs S & C Hanson 91

Retrieval and metacognition

Theta rhythms may coordinate memory retrieval: theta oscillations may coordinate MTL and the prefrontal lobe during retrieval

9/5/2012 Drs S & C Hanson 92

Retrieval and metacognition

Hemispheric lateralization in retrieval

Do the two hemispheres play differing roles in memory encoding and retrieval?

Tulving and colleagues found that the left hemisphere showed greater activity in episodic learning (encoding), while the right hemisphere showed more activity in episodic retrieval.

9/5/2012 Drs S & C Hanson 93

Learning & memory:Working memory & sleep deprivation

Drummond SP, Nature 2004

After full night sleep After sleep deprivation

N-back task

9/5/2012 Drs S & C Hanson 94

Memories are made of this

Long-term potentiation and long-term depression: excitatory and inhibitory memory traces

These two processes are thought to occur in long-term potentiation (LTP) for excitatory cells and long-term depression (LTD) for inhibitory cells.

Recording from a cell in the hippocampus showing long lasting (90 minutes) activity in an excitatory cell (center).

9/5/2012 Drs S & C Hanson 95

Coordination of the Brain FunctionsCoordination of the Brain Functions

Figure 9-19: The diffuse modulatory systems modulate brain function