Memory and Cognition Flashcards
Cognition relates to
the highest order of brain function and to behaviour that deals with thought processing
Cognition describes the integration of
all sensory information to make sense of a situation
What is neuronal plasticity?
The ability of central neurons to adapt their neuronal connections in response to learning experiences
Where are memories stored and formed?
Stored in cortex
Formed in limbic system
What are the distinct areas of the limbic system?
Hypothalamus
Hippocampus
Cingulate gyrus
Amygdala
Functions of the ares of the limbic system
Responsible for instinctive behaviour e.g. drive for thirst, hunger etc.
Important in emotive behaviours
Motivation to learn comes from
gaining a reward or avoiding punishment
Memory recall depends on
the significance of the event
The limbic system is responsible for
selecting what experiences are stored in the memory
Almost all sensory information goes through
the hippocampus, which in turn relays information to other limbic systems
The hippocampus is central to
learning and the formation of memories
Consequence of bilateral hippocampal damage
Immediate sensory memory and long-term memory intact, but unable to form new long-term memories
Reflexive memory stays intact
Memory can be divided into
Immediate (sensory) memory
Short-term memory
Immediate long-term memory
Long-term memory
Describe immediate/sensory memory
Ability to hold experiences in the mind for a few seconds
Based on different sensory modalities
Visual memories decay fastest, auditory ones slowest
Describe short-term memory
Lasts seconds-hours
Used for short-term tasks e.g. dialling phone number, mental arithmetic
Associated with reverberating circuits
Describe immediate long-term memory
Lasts hours-weeks
Associated with chemical adaptation at the presynaptic terminal
e.g. what you did last weekend
Describe long-term memory
Lasts hours-lifetime
Associated with structural changes in synaptic connections
e.g. where you grew up, childhood friends
Two types of long-term memory
Declarative/Explicit
Procedural/Reflexive/Implicit
Describe declarative/explicit memory
Abstract memory for events, words, rules and language
Based mainly in the hippocampus
Describe procedural memory
Acquired slowly through repetition
Includes motor memory for acquired motor skills and rule-based learning
Mainly based in cerebellum
Short-term memory depends on
maintained excitation from reverberating circuits
What occurs if a short-term memory is determined to be significant in the reverberating circuit?
Consolidation into long-term memory storage
What occurs if a short-term memory is determined to be insignificant in the reverberating circuit?
Reverbation fades, no consolidation occurs
Presentation of the refreshing effect of reverberation being interrupted e.g. due to a head injury
Amnesia
What is retrograde amnesia?
The inability to remember events leading up to the injury
Recall of events that happened a long time ago usually unaffected
How does retrograde amnesia usually present?
With anterograde amnesia
Occurs only with retrograde amnesia if only the thalamus is damages and hippocampus is spared
Memory requires the ability to
store and search memories
What is anterograde amnesia?
Inability to recall events following an injury
Can be short lived or permanent
Destruction of the hippocampus results in
permanent inability to form new memories
Structural changes at the synapses involved in long-term memory
Increase in number of neurotransmitter release sites on presynaptic membrane
Increase in number of neurotransmitter vesicles stored and released
Increase in number of presynaptic terminals
What is often observed in the post-synaptic cell in long-term memory formation
Greater change in graded membrane potential
Strengthens the synapse - long-term potentiation
Forms basis of learning and memory
Short-term memory is converted to long-term memory through
consolidation
Consolidation involves
selective strengthening of synaptic connection through repetition
During consolidation, memory exists as
electrical activity, so is vulnerable to being wiped
What part of the brain assesses the significance of an event in short-term memory?
The frontal cortex and its association with the reward/punishment centres in the limbic system
New memories are coded and stored in
the sensory and association areas of the cortex
Coding results in memories being stored where?
Alongside other existing memories that the brain deems similar
Subjects deprived of REM sleep show impairment of
memory consolidation for complex cognitive tasks
