Lecture 7 (final) Flashcards
(46 cards)
what is a modern misleading metaphor of the brain
BRAIN AS A COMPUTER
Information-processing perspective: “Brain (and so memory) is like a digital computer.”
Processes (how are memories created, maintained, revived?) Encoding, Storage, Retrieval, Recall
Representations: What is stored, retrieved, recalled?
A memory representation (memory trace, memory record) is a unit of information, that can be processed.
Structures: Where are memories stored, retrieved from/to, recalled from/to?
Short-term store: like RAM of computer – restricted capacity; holds information for a short time.
Long-term store: like the hard disk of a computer – nearly infinite capacity; holds information almost forever.
what is the POINT OF ORIGIN OF MODERN MEMORY RESEARCH
HENRY MOLAISON (HM)
who was HM
had hippocampus removed to stop seizures and this resulted in a big case study on the hippocampus and its use
what was concluded from the HM hippocampy
Bilateral hippocampectomy to treat epilepsy led to temporally graded retrograde and dense anterograde amnesia for episodic memory (memory for events). Other forms of memory, however, remained unaffected (e.g., semantic memory [memory for facts], procedural memory [memory for motor sequences]).
what was impaired from the hippocampy
Episodic memory
Recognition Memory for recent objects/places Explicit memory tasks
what was sparred from the hippocampy
Semantic memory Priming
Procedural memories Conditioning
Implicit memory tasks
what are the two types of memory
declarative and nondeclaritive
what is under declarative memory
episodic and semantic
where is episodic and semantic memory
hippocampus– medial temporal lobe
what is under non declarative memory
procedural, priming, classical conditioning, non-associative learning
what is the WORKING DEFINITION OF MEMORY
Memory is the ability to use or revive information that was previously encoded or processed
is memory directly observed
Memory is never directly observed. In humans, awareness of its influence on behavior probably not always present
how is memory indirectly observed
Memory is indirectly observed (problem of measurement): its existence is inferred from behavior (e.g., a change in level of performance).
what counts as memory
No agreement as to what counts as memory. From a biological perspective, every change in neural connectivity reflects memory. Chronic pain, for example, is memory in the sense as it depends on long-lasting changes in synaptic morphology.
Some classification systems attempt to assign memory types to discrete brain areas (e.g., spatial memory and hippocampus
does memory exist physically
Memory does not exist physically. It is an experience arising from brain activity patterns
what is the great challenge with understanding memory
MEMORY AS A FUNDAMENTALLY DYNAMIC PROCESS
Understanding memory requires a holistic perspective that integrates molecular- cellular, circuit, brain/memory systems, cognitive and behavioral phenomena and their interactions into a comprehensive, systemic perspective based on the idea that dynamic, well-regulated biological processes underpin all memory phenomena.
Understanding memory remains one of the great human challenges.
Memory
Understanding memory will provide the basis for finding answers to the really big questions, such as about the nature of consciousness, or, more philosophically speaking, about the human condition
what is the Law of Regression
“The progressive destruction of the memory […] descends progressively from the instable to the stable. It begins with the recent recollections which, being but faintly impressed on the nerve elements, seldom repeated, and consequently but feebly associated with other recollections […].
[…] the progress of amnesia […] follows the line of least resistance, that is, of least organization.”
aka memory is meant to be forgotten
what is the CONSOLIDATION HYPOTHESIS
preservation-Consolidation hypothesis: the tendency to preserve might serve to consolidate the associations among (the syllables)
what is the Current consolidation “dogma”
Memories are labile after acquisition and are fixed, i.e., permanently stored (consolidated) over time.
Consolidated memories are stable and can persist long-term
Consolidation is a transient, unidirectional process that occurs after acquisition.
Disrupting consolidation impairs memory retention
what PROMOTES LONG-TERM MEMORY STORAGE
consolidation (basically, the memory gets stronger with time)
what is the first postulate in HEBB’S DUAL PROCESS MEMORY MODEL
principle of associative learning:
“Whenever an axon of cell A is near enough to excite a cell B and repeatedly or persistently takes part in firing it, some growth process or metabolic change takes place in one or both cells such that A’s efficiency, as one of the cells firing B, is increased.”
‣ After a while, recurrent activity leads to changes in the synapses of the cell assembly. As a consequence, the pattern can be recreated at a later time. These structural modification support “long-term memory”.
Experience is represented in a pattern of activity in a set of connected neurons (cell assembly).
This pattern can stay active on its own for a while after the experience. Recurrent connections among neurons of the cell assembly keep the pattern activated. This supports “short term memory”.
“Neurons that fire together, wire together
what are DENDRITIC SPINES
Small membranous compartments protruding from dendrites that house the essential postsynaptic components (post-synaptic density, cytoskeleton and supporting organelles) and receive synaptic contacts from glutamate-releasing axons
is there physical evidence of learning
yes, the spines on dendrites appear/become larger with learning
What are LTP ad LTD considered
LTP and LTD are experimental phenomena which can be used to demonstrate the repertoire of long-lasting modifications of which individual
synapses are capable.
