Download Ch24- Memory Systems

Bear: Neuroscience: Exploring the
Brain 3e
Chapter 24: Memory Systems
Slide 1
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 2
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 3
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
Types of Memory and Amnesia
Long-Term, Short-Term, and Working Memory
Sensory
information
Short-term
memory
Consolidation
Long-term
memory
Short-term memory
Sensory
information
Consolidation
Long-term
memory
Time
Working memory: Temporary information
storage
Slide 4
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 5
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 6
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
Engram:
memory trace
Slide 7
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 8
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Search for the Engram
Hebb’s Cell Assembly
and Memory Storage
Slide 9
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 10
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 11
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Temporal Lobes and Declarative
Memory
The Effects of Temporal Lobectomy
Slide 12
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Temporal Lobes and Declarative
Memory
The Medial Temporal Lobes and Memory
Processing
Slide 13
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Temporal Lobes and Declarative
Memory
The Medial Temporal Lobes and Memory
Processing (Cont’d)
DNMS: Delayed non-match to sample
Medial temporal structures: Important for
consolidation of memory
Slide 14
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 15
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 16
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
Declarative memory processing or
consolidation
Slide 17
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
Morris water
maze
Slide 18
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, Working Memory, and
Relational Memory
Relational memory
Highly processed sensory information
To hippocampus and nearby cortex
Slide 19
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Striatum and Procedural Memory
Two elements of basal ganglia Striatum
Caudate nucleus
Putamen
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 light task; Double dissociation
Slide 20
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Striatum and Procedural Memory
Habit Learning in Humans and Nonhuman
Primates
Striatum in humans plays a role in
procedural memory
Slide 21
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: selfawareness, capacity for planning and
problem solving
Slide 22
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 (Cont’d)
Imaging Working Memory
in the Human Brain
Numerous areas in
prefrontal cortex are
involved in working
memory
Slide 23
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
The Neocortex and Working Memory
Lateral Intraparietal Cortex (Area LIP) and
Working Memory
Area LIP: Guiding eye movements
Delayed-saccade task
Slide 24
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 25
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins
End of Presentation
Slide 26
Neuroscience: Exploring the Brain, 3rd Ed, Bear, Connors, and Paradiso Copyright © 2007 Lippincott Williams & Wilkins