Wk 6 - Attention and Memory Pt. 2 Flashcards
What is the multiple-trace hypothesis of memory and what are the classifications
The multiple-trace hypothesis classifies different types of memory by time.
- Iconic memories are the shortest
- Then STM
- Then LTM
How can LTM be conceptualised/divided
Long Term Memory can be sorted in to
- Declarative memory
and
- Nondeclarative (Procedural) Memory
What is Nondeclarative memory
Nondeclarative or procedural memory is the LTM we have for things that we inherently know but can’t say we know and can only show by doing.
- E.g. We know how to touch type but would never be able to tell where the individual keys are on a keyboard.
- Other examples include, grammar, motor skills and problem solving.
- Shown by performance rather than conscious recollection. Also called “Implicit memory”
What is Declarative memory and its subcategories?
Declarative memory is the part of LTM for information one knows and can tell others about.
- E.g Facts and events.
This can be split into 2 subcategories
- Semantic memory and Episodic memory
“Explicit” or “conscious memory”
What is semantic memory and how is categorised amongst the memory processes
Semantic memory refers to memories for generalised knowledge.
It is located as such LTM > Declarative Memory > Semantic memory
What is Episodic memory and how is it categorised amongst the memory processes?
Episodic memory is ones memory for autobiographical details.
- LTM > Declarative memory > Episodic memory
What are some “side effects” of Nondeclarative memory
- Skill learning
- Priming (i.e being more likely to use words that you heard recently)
- Conditioning (salivating and fiending chocolate when Dad comes home)
What was removed when H.M had a bilateral temporal lobectomy
The bilateral medial temporal lobectomy removed the medial portions of both temporal lobes.
- This included majority of the hippocampus, the amygdala and the rhinal cortex.
What did H.M experience after his surgery
After his bilateral medial temporal lobectomy H.M experience the following
- The same perception and motor abilities
- The same STM
- Some retrograde amnesia
- Quite severe anterograde amnesia
What is retrograde amnesia
Loss of memory from before an injury event
What is anterograde amnesia
Loss of memory of after an injury event
How was H.M’s memory affected during two tests and what did they show
H.M improved in the mirror drawing test and the incomplete pictures test despite not remembering doing them. This showed that his declarative memory was affected.
What happens when the perirhinal cortex is bilaterally removed
Permanent and severe deficits in object recognition tests.
- The perirhinal cortex is important for both categories of Declarative memory.
What is the Hippocampus’s role in memory
The hippocampus is important in:
- Memory formation and consolidation. Reorganises memories over time and forms new ones.
- Temporary storage. its has a transitory role in memory storage. Damage to it affects recent not remote memories.
- Spatial representation. It is involved in representing spatial information and navigation.
- Memory retrieval. Supports LTM storage by working with the cortex. Its role in LTM storage slowly declines as memories become more stable in cortex.
What are the two hypotheses surrounding the neural mechanisms of learning and memory?
The two hypotheses centre around
- Structural changes at the synapse
- Physiological change at the synapse
What are examples of structural changes of synapses and to what function/hypothesis do they belong
Structural changes of the synapse are one hypothesis for the neural mechanism of memory.
Examples include:
- Formation of new synapses
- Rearrangement of synapses
- Neurogenesis
What is the physiological hypothesis for the Synaptic mechanism of ________
Long Term Potentiation (LTP)
- The stable and enduring increase in the effectiveness of synapses
How many stages are in LTP and what are their characteristics
The three stages of Long term potentiation are:
- Stage 1 (pre-change): Pre-synaptic neuron fires at a normal rate. Post-synaptic neuron fires at a certain normal strength in response.
Stage 2 (induction): Pre-synaptic neuron fires a lot. Post-synpatic neuron then fires a lot.
Stage 3 (expression, after change): Pre-synaptic neurpn fires at normal rate. Post-synaptic neuron now fires more strongly than at stage 1 (aka before any change.)
What are the neurological mechanisms of LTP (not stages)
- NMDA receptors work in tandem with AMPA receptors.
- AMPA’s are open, NMDA’s are blocked by Mg+ ions.
- When Glutamate fires, it binds to AMPA and NMDA receptors.
- When it binds to AMPA recep. Na+ ions travel through, depolarising the Post-synaptic neuron. (This causes action potentials to fire).
- This depolarisation unblocks the NMDA’s Mg+ ion (because of charge) which allows more Na+ and importantly Ca+ to travel through.
- The more of these there are, the more the A.P’s fire. Thus, more (greater) LTP.
Side note: The more Ca+ in the neuron the more excited the neuron is and thus more AMPA receptors appear.
What happens in LTP stage 2
Stage 2 (induction): Pre-synaptic neuron fires a lot. Post-synpatic neuron then fires a lot.
- This examples is at synapses where the NMDA receptor is most prominent (receptor for the excitatory neurotransmitter called glutamate).
- NMDA doesn’t to respond maximally unless two events occur at the same time: Glutamate binds to it and the post-synaptic neuron is already partially depolarised.
- This dual requirement happens because the calcium channels that are associated with NMDA receptors allow only small amounts of Ca2+ in unless the neuron is already depolarised.
- the influx of Ca2+ triggers the A.P (action potentials) and the events that happen in the post-synaptic neuron which induces LTP.
