Chapter 7: Memory
7.1 What is Memory?
LEARNING OBJECTIVES:
Define memory.
Describe the three phases of memory.
Identify brain regions involved in learning and memory.
Describe the processes of consolidation and reconsolidation.
(Example about Henry Molaison)
Memory Is the Nervous System’s Capacity to Retain and Retrieve Skills and Knowledge
Memory: the nervous system’s capacity to retain and retrieve skills and knowledge.
Each person perceives events differently.
Some events are more likely to be remembered than others.
Memory Is the Processing of Information
Three stages of memory:
Encoding: the processing of information so that it can be stored.
Storage: the retention of encoded representations over time.
Consolidation: the neural process by which encoded information becomes
stored in memory; neural connections become stronger and new synapses
are constructed.
Retrieval: the act of recalling or remembering stored information when it is needed.
Memory Is the Result of Brain Activity
Equipotentiality: Karly Lashley’s theory that memory is distributed throughout the brain
rather than in a certain region.
Memory involves the creation of neural circuits.
Long-Term Potentiation
Potentiate: to strengthen, to make something more potent.
, Long-Term Potentiation (LTP): strengthening of a synaptic connection, making the
post-synaptic neurons more easily activated by presynaptic neurons.
NMDA Receptor: glutamate receptor that opens only if a nearby neuron fires
at the same time; required for LTP.
- Firing neuron releases glutamate into synapse, which binds with the
NMDA receptor on the postsynaptic neuron
Genes that make NMDA receptors more efficient result in better learning.
Epigenetics of Memory
HDAC (histone deacetylases): enzyme that inhibits gene expression
Evidence that blocking HDAC leads to increased memory
Unless something critical happens in the environment, memory is blocked
Memory’s Physical Locations
Memory involves multiple regions of the brain, but not all brain regions are equally involved.
A lot of neural specialization occurs different brain regions are responsible from storing
different aspects of information.
Regions within the temporal lobe, such as the hippocampus, play a role in memory
storage.
Medial Temporal Lobe: middle section of the temporal lobe, responsible for the
formation of new memories.
- Form connections between the storage sites and strengthen these
- Once connections are formed, they are less important for memory
Actual memory storage takes place in the regions engaged during perception,
processing, and analysis of material being learned.
Reconsolidation of Memories
Reconsolidation: neural processes involved when memories are recalled and then
stored again for retrieval.