Lecture 5
Page 1: Biological Psychology 2
The Neuroscience of Memory Processes
Page 2: Key Concepts in Memory
The Engram
Long-Term Potentiation
Neural Replay
Page 3: The Substrate of Memory
Where Are Memories Located?
Early theories suggested memories were linked to an immaterial soul.
Aristotle compared memories to notes on a wax tablet, indicating a physical aspect to memory.
Page 4: Brain as Memory Store
How the Brain Stores Impressions
The brain is the physical substrate for memories.
Memory formation can be explained through associations, which are relationships between impressions.
Page 5: The Engram
Concept of the Engram
Richard Semon introduced psycho-physiological parallelism where every psychological state corresponds to nervous system changes.
The mneme represents the memory of an experience.
A mnemic trace or engram is revisited when a related stimulus is encountered.
Page 6: Distributed Engram
Lashley's Experiments
Karl S. Lashley studied memory locations in the brain by removing parts of rodent brains.
Memory degradation increased with more tissue removal; however, the specific area removed did not affect memory retrieval.
Page 7: Hebb’s Rule
Neural Processes of Memory
Donald O. Hebb's work emphasized synaptic weight changes associated with forming associations.
Hebb's rule or Hebbian learning describes how synaptic strength increases with concurrent activation of neurons.
Page 8: Key Memory Concepts
The Engram
Long-Term Potentiation
Neural Replay
Page 9: Non-Associative Learning
Habituation and Sensitization
Eric Kandel’s research focused on changes in membrane potential in relation to presynaptic signals.
Page 10: Gill Withdrawal Reflex
Habituation and Sensitization
Illustration of tactile and tail stimuli affecting sensory neurons and motor neurons in the Gill withdrawal reflex model.
Page 11: Role of the Hippocampus
Hippocampus and Long-Term Memory
Case study of H.M. highlighted the hippocampus's central role in long-term memory encoding.
Distinction observed between declarative and procedural memories.
Page 12: Morris Water Maze Experiment
Significance of the Hippocampus
Experiment demonstrated that rodents with hippocampal damage struggled with spatial navigation compared to healthy rodents.
Page 13: Long-Term Potentiation (LTP) in the Hippocampus
Bliss and Lømo's Study
Research revealed synaptic changes in the hippocampus's perforant pathway, showing lasting potentiation effects.
Page 14: Molecular Basis of LTP
Components of Synaptic Transmission
Overview of synaptic transmission activities involving NMDA and AMPA receptors, calcium ions, and magnesium ions.
Page 15: Induction of LTP
Process Overview
Detailed sequence of events leading to the induction of long-term potentiation in synapses.
Page 16: Expression of LTP
Enhanced Transmitter Release
Explanation of how LTP leads to an enhanced release of neurotransmitters and the insertion of new AMPA receptors.
Page 17: Summary of Molecular Basis of LTP
Key Mechanisms
Role of NMDA and AMPA receptors in glutamatergic synapses and the details of molecular signaling leading to synaptic changes.
Page 18: Behavioral Studies in LTP
Morris Water Maze Results
Experimental data comparing wild-type and mutant responses in the Morris water maze, highlighting discrepancies in memory performance.
Page 19: NMDA Receptors and Memory
Impairment Studies
Findings from Tsien et al. (1996) showing genetic deletions affecting performance in memory tasks, supporting the vital role of NMDA receptors in LTP.
Page 20: Key Memory Concepts
The Engram
Long-Term Potentiation
Neural Replay
Page 21: Place Cells in the Hippocampus
Cognitive Mapping
Identification of place cells in the hippocampus firing in relation to specific locations, connecting to memory consolidation theories.
Page 22: Reactivation of Place Cells
Memory Recall during Sleep
Place cells exhibit sequential activation correlated with physical travel and reactivation during sleep periods.
Page 23: Electrophysiological Patterns during Sleep
Sharp-Wave Ripples
Synchronous patterns in place cell activity noted during sleep, associated with sleep spindles and slow-wave features.
Page 24: Active System Consolidation Hypothesis
Hippocampal-Cortical Communication
The coordinated activity across brain regions suggests a mechanism for memory consolidation through communication between the hippocampus and cortex during sleep.
Page 25: Synaptic Homeostasis
Strength Changes
Overview of synaptic strength adjustment during sleep, promoting overall memory functions.
Page 26: Sequential Consolidation
Behavioral Memory Manifestation
Changes in synaptic and system consolidation processes lead to observable memory consolidation behaviors.
Page 27: Memory Consolidation and Creativity
Evolution of Memory
Sleep is linked with memory strengthening and evolving ideas; processes may lead to novel neural patterns and creative insights (e.g., creative dreams).