Download Lects 22,24,25 Chap 31 (Bear 24) Tu,Tu

CSE511 Brain & Memory Modeling
Lect 22,24,25: Memory Systems
Compare Chap 31 of Purves et al., 5e
Chap 24 of Bear et al., 3e Larry Wittie
Computer Science, StonyBrook University
http://www.cs.sunysb.edu/~cse511 and ~lw
11/12,19,21/13
Lect22,24,25 Memory Systems
1
Neuroscience: Exploring the Brain 3e
Chapter 24: Memory Systems
Slide 2
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Introduction
  Learning and remembering distinguishes naïve
from mature brain
  Relationship between visual development and
learning
 Similar mechanisms in different cortical areas
  Memories range from stated facts to ingrained
motor patterns
  Anatomy: Several memory systems
 Evident from brain lesions
Slide 3
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Types of Memory and Amnesia
  Learning
  Acquisition of new information
  Memory
  Retention of learned information
  The way information is stored may change over time
  Declarative memory (explicit)
  Facts and events
  Nondeclarative memory (implicit)
  Procedural memory- skills, habits, behaviors
Slide 4
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Types of Long-Term Memory
Slide 5
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Types of Memory and Amnesia
  Amnesia
 Amnesia: Serious loss of memory and/or
ability to learn
 Causes: Concussion, chronic alcoholism,
encephalitis, brain tumor, or stroke
 Common amnesia: Limited amnesia
 Dissociated amnesia: Amnesia, no other
cognitive deficit (rare)
Slide 6
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Types of Memory and Amnesia
  Amnesia (Cont’d)
 Memory loss related to time
 Retrograde amnesia
 Forget things you already knew
 Anterograde amnesia
 Inability to form new memories
 Transient global amnesia: Shorter period
 Symptoms: Disoriented, ask same questions
repeatedly; Attacks subside in couple of
hours; Permanent memory gap
Slide 7
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Search for the Engram
Lashley’s Studies of Maze Learning in Rats
Figure 24.4
Engram: memory trace
Slide 8
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Search for the Engram
  Hebb and the Cell Assembly
  External events are represented by cortical cells
  Cells reciprocally interconnected reverberation
  Active neurons—cell assembly
 Consolidation by “growth process”
 “Fire together, wire together”
  Hebb and the engram
 Widely distributed among linked cells in the
assembly
 Could involve neurons involved in sensation and
perception
Slide 9
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The
Search
for the
Engram
Slide 10
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Search for the Engram
  Localization of Declarative Memories in the
Neocortex
 Experiments—macaque monkeys
 Differentiate objects
based on shapes
 Lesion made in area IT
 Cannot discriminate
 Does not remember
stimulus
 Studies in humans
Slide 11
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Slide 12
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Search for the Engram
  Electrical Stimulation of the Human Temporal
Lobes
 Penfield’s experiments
 Electrical stimulation of the temporal
lobe Complex sensations
 Penfield’s patients: Sensations like
hallucinations, recall past experiences
 Temporal lobe: Role in memory storage
 Temporal lobe stimulation
 Different from stimulation of other areas
of neocortex
Slide 13
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Temporal Lobes and Declarative Memory
Temporal Lobectomy => Retrograde Amnesia
Slide 14
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Temporal Lobes and Declarative Memory
Medial Temporal Lobes and Memory Processing
Slide 15
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Temporal Lobes and Declarative Memory
Medial Temporal Lobes and Memory Processing
 DNMS:
Delayed
non-match
to sample
 Medial
temporal
structures:
Important for
consolidation
of memory
to form
long-term
memories
Slide 16
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Temporal Lobes and Declarative Memory
Medial Temporal Lobes and Memory Processing
 Medial temporal structures: Important for
consolidation of memory
Slide 17
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Temporal Lobes and Declarative Memory
The Diencephalon and Memory Processing
 Diencephalon:
Brain regions
associated
with memory
and amnesia
(outside the
temporal
lobe)
Slide 18
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Temporal Lobes and Declarative Memory
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
Slide 19
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Temporal Lobes and Declarative Memory
Memory Functions of the Hippocampus
 Declarative
memory
processing or
consolidation
 Long-term
memory
consolidation
=> recognition
Slide 20
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Temporal Lobes and Declarative Memory
Memory Functions of the Hippocampus
 Role of the medial temporal lobes (rhinal cortex)
 Declarative memory processing or consolidation
 Hippocampal lesions: hard to learn efficient path
Slide 21
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Temporal Lobes and Declarative Memory
Memory Functions of the Hippocampus
 Morris Water Maze: Learn Where Platform Is
 Bilateral hippocampal lesions block learning
Slide 22
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Temporal Lobes and Declarative Memory
Memory Functions of the Hippocampus
 Spatial Memory and Place Cells
Slide 23
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Temporal Lobes and Declarative Memory
Memory Functions of the Hippocampus
 Spatial
Navigation
in Humans
Slide 24
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Temporal Lobes and Declarative Memory
Memory Functions of the Hippocampus
 Spatial, Working, and Relational Memories
 Relational memory
 Highly processed sensory information
 Comes into hippocampus and nearby cortex
Figure 24.19 Spatial Navigation Alternative theories of navigation by
(a) a spatial map or (b) a series of overlapping relations.
Slide 25
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Striatum and Procedural (Habit) Memory
Two elements of basal ganglia Striatum
 Caudate nucleus
 Putamen
Figure 14.11
Rodent Recordings and Lesions in the Striatum
 Lesions to striatum: Disrupts procedural memory
 Damaged hippocampal system: Degraded
performance on standard maze task
 Lesion in striatum: Impaired performance of the
lighted maze arms task; Double dissociation Slide 26
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Striatum and Procedural (Habit) Memory
Habit Learning in Rodent Striatum
Slide 27
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Striatum and Procedural (Habit) Memory
  Habit Learning in Humans and Nonhuman Primates
 Human striatum plays role in procedural memory
 Parkinson’s destroys substantia nigra, the main
input to the striatum
Slide 28
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Neocortex and Working Memory
The Prefrontal Cortex and Working Memory
 Primates have a large frontal lobe
 Function of prefrontal cortex: self-awareness,
capacity for planning and problem solving
Slide 29
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Neocortex and Working Memory
The Prefrontal Cortex and Working Memory II
 MRI: Imaging Working Memory in the Human Brain
 Many areas in prefrontal cortex are involved
Slide 30
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Neocortex and Working Memory
The Prefrontal Cortex and Working Memory III
 Humans with prefontal cortex (PFC) damage very
slowly discover a newly changed card sorting rule
Figure 24.25 The Wisconsin card-sorting test. Subjects must sort cards with
symbols of various shapes, colors, and numbers, but are not told the sorting rule.
They are told only when they do not sort a card properly. They must discover the
sorting rule. When they do, the rule is changed. Subjects with PFC injuries keep
Slide 31
using a previously correct rule long after the sorting rule has changed.
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Neocortex and Working Memory
Lateral Intraparietal Cortex (LIP) and Working Memory
 Area LIP: Guiding eye movements
 Delayed-saccade task
Slide 32
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Concluding Remarks
  Learning and memory
  Occur throughout the brain
  Memories
  Duration, kind of information stored, and brain
structures involved
  Distinct types of memory
  Different types of amnesia
 Multiple brain systems for memory storage
  Engrams in temporal lobe neocortex
  Physiological basis?
  Long-term memories: structural basis?
Slide 33
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins