Memory Flashcards
Epileptic seizures involve two concurrent processes. What are they?
- EXCITATION in groups of neurones
2. loss of INHIBITory potential
Of GABA and glutamate, which is inhibitory?
GABA
What form of epilepsy is responsible for informing us the most about the operation of memory?
Temporal lobe epilepsy (TLE)
What is distinctive about ‘simple partial seizures’, as distinct from ‘complex partial seizures’
In the former case, the patent does NOT lose awareness
What is the most common form/location of Temporal Lobe Epilepsy (TLE)?
Hippocampal sclerosis (HS)
What is gliosis?
Excessive growth in glial cells after neuronal loss occurs)
What is occurring in hippocampal sclerosis?
- Neuronal loss
2. Gliosis
Does Temporal Lobe Epilepsy (TLE) typically occur early or late in life?
EARLY
What three aetiologies were mentioend for Temporal Lobe Epilepsy (TLE)?
I T V
- Infections
- Tumours
- Vascular malformations
In the case of Temporal Lobe Epilepsy (TLE), what steps can be taken to cure or reduce seizure?
Surgical removal of the lesioned hippocampus
What is the name of the operation that Henry Molaison (HM) underwent?
Bilateral resection (of medial temporal tissue)
Which parts of brain were removed when Henry Molaison (HM) underwent his bilateral resection?
- Amygdala
- (most of) hippcampi
- (part of) parahippocampal gyrus
After his bilateral resection, what was the state of Henry Molaison’s (HM) attention span?
Normal
After his bilateral resection, what was the state of Henry Molaison’s (HM) intelligence?
Normal
After his bilateral resection, what was the state of Henry Molaison’s (HM) retrograde memory?
Recovered over time
Amnesia can be retrograde and/or anterograde. Which one relates to impairment in the formation of new memories?
Anterograde
What type of amnesia did Henry Molaison (HM) have after his bilateral resection?
Anterograde amnesia
What is declarative memory?
Access to information
What is procedural memory?
Remembering how to ‘do’ things (ie playing piano)
After Henry Molaison’s (HM) bilateral resection, which type of memory was impaired, declarative or procedural?
Declarative
Based on the case of Henry Molaison (HM), which brain lobe is essential for memory function?
Medial temporal lobe
Based on the case of Henry Molaison (HM), which from of memory is the medial temporal lobe essential for? (two terms)
Declarative, anterograde
Taking into account what we learned from the case of Henry Molaison (HM) and everything we’ve learned since…
do we now assume that memory relies on a specific module in the brain, or a wider network of regions?
A wider network
neuroanatomical network
Taking into account what we learned from the case of Henry Molaison (HM) and everything we’ve learned since…
are memory functions anatomically symmetric or asymmetric?
Asymmetric
Which region of the brain was described in lectures as the ‘engine’ of memory?
Temporal lobes
What does it mean for someone to have ‘material specific’ memory impairments?
The impairment only affects some types/forms of memory (like verbal or visual)
What form of ‘material specific’ memory impairment results from legions in the LEFT of the medial temporal lobe (MTL)?
Verbal memory
What form of ‘material specific’ memory impairment results from legions in the RIGHT of the medial temporal lobe (MTL)?
Visual/non-verbal memory
In which brain region (lobe) is the hippocampus located?
Medial temporal lobe (MTL)
What is the other name for the hippocampus?
Cornu ammonis
Ammon’s horn
What are the code letters or the hippocampus/Cornu ammonis
CA1 to CA3
What are the three bits of the hippocampal formation?
D C S
D C C S
- Dentate gyrus
- CA3 - CA1
- Subiculum
Where would you find the ‘subiculum’?
In the hippocampal formation
What does the ‘subiculum’ do?
Nobody knows
When it comes to memory function, information is integrated in which systems, and sent to which formation for long term storage?
Sensory … and … hippocampal
Memory is access via reciprocal connections between which two brain formations/regions?
Hippocampal formation and temporal neocortex
Surgical case studies show that hippocampal formation is not necessary for consolidation of over information, T/F
FALSE!
Hippocampal formation and surrounding structures are essential for learning and consolidating novel information
Who is associated with ‘Consolidation Theory’, and what is it?
Squire (2004)
After a period of consolidation, information can be retrieved independently of hippocampal formation
Who is associated with Multiple Trace Theory (MTT), and what is it?
Moscovitch (2005)
Retrieval of episodic memory ALWAYS involved hippocampal formation
What type of memory task is the hippocampal formation particularly necessary for?
Paired/relational learning
What neurological condition is particularly useful for studying memory?
Temporal Lobe Epilepsy (TLE)
What are the 3 regions outside the temporal lobe (the ‘extra temporal brain’) that our particularly involved in memory?
P F D
P F D
- Papez’s circuit
- Frontal lobes
- Diencephalon
P F D
What constitutes the limbic system? (2)
Papez circuit + amygdala
Together, what do the amygdala and paper’s circuit constitute?
The limbic system
The slides mention two ways in which the amygdala supports memory of emotionally arousing experiences. Name them
- Classical fear conditioning
2. Rich representations of emotional experiences
What can lesions in the amygdala result in? (2)
- Loss of fear conditioning and fear learning
2. Reduced memory for emotionally laden events
What are the 5 things comprising Papez’s circuit?
M F A C H
M F A C H
- Mamillary bodies
- Fornix
- Anterior thalamic nuclei (ATN)
- Cingulate gyrus
- Hippcampus
M F A C H
What type of memory is impaired by lesions on Papez circuit?
Declarative memory
If you’re going to have legions anywhere on the Papez circuit, where would you want them if you wanted to retain as much declarative memory as possible?
Hippocampus or Anterior thalamic nuclei (ATN)
How are the frontal lobes involved in memory?
Developing strategies for encoding and retrieval
What brain bits comprise the Diencephalon?
Thalamus and hypothalamus
What brain bit is comprised by the thalamus and the hypothalamus
The Diencephalon
the ‘interbrain’
Is the thalamus contain mini bits of brain that are connected to all the other bits of the brain?
Yes, actually it does
Having legions in which regions of the thalamus is more likely to cause memory deficits? (2)
A M
A M
Anterior and medial
A M
If you have legions in the posterior region of the thalamus, are you more or less likely to have memory deficits than if the lesion was in the medial region?
Less
Anterior and medial lesions more likely to cause memory deficits than posterior or lateral lesions.
Dense amnesic syndrome is associated with damage to which tract?
Mammillo-thalamic tract (MTT)
Which two brain regions does the mammillo-thalamic tract (MTT) connect?
AT & H
AT & H
Anterior thalamus and hippocampus
AT & H
If you have damage to the Medio Dorsal Nucleus (MDN) and/or the Internal Medullary Lamina (IML)…
but your Mammillo-thalamic tract (MTT) is okay
are you likely to have difficulties with memory retrieval?
Yes!
But… not recognition
amazing
Of the following brain bits, which appears most associated with recognition (as opposed to retrieval)?
- Medio Dorsal Nucleus (MDN)
- Mammillo-thalamic tract (MTT)
- Internal Medullary Lamina (IML)
Mammillo-thalamic tract (MTT)
If you have damage to the dorsal medial nuclei (DMN) region of the thalamus, what type of memory is likely to be impaired?
Active retrieval
Petrides 1996
If you have damage to the intralaminar/midline nuclei region of the thalamus, what type of memory is likely to be impaired?
Semantic memory + memory retrieval
You see a patient who can remember past experiences but cannot remember which year Obama was elected. In which brain region is he likely to have damage?
In the intralaminar/midline region of the thalamus
What type of memory impairment is associated with lesions on Papez’s circuit?
Impaired relational memory/encoding (hippocampal type of amnesia)
What type of memory impairment is associated with lesions on frontal lobes?
Impaired ability to organise the encoding, retrieval and maintenance of memories
What type of memory impairment is associated with lesions on dorsal medial nuclei (DMN), intralaminar nuclei or the midline nuclei regions of the thalamus?
Retrieval
Mental flexibility
Long term potentiation (LTP) is an example of what?
Synaptic plasticity
What is the name for the following process:
‘A long-term increase in the excitability of a neuron to a particular synaptic input caused by repeated high frequency activity of that input’
Long term potentiation
What is the name given to the following process?
“When an axon of cell A…excites cell B and repeatedly or persistently takes part in firing it, some growth process or metabolic change takes place in one or both cells so that A’s efficiency as one of the cell’s firing B is increased”
Hebb’s rule
What’s the name of the rule associated with long term potentiation?
Hebb’s rule
During long term potentiation (LTP), what is happening to the membrane of the post-synaptic neutron?
New receptors are getting inserted…
Of the Glutamates and GABA, which was inhibitory and which is listed in the slides alongside the discussion of long term potentiation?
GABA is inhibitory
but it is Glutamate that is listed on that slide
What are the three synaptic changes that LTP causes?
- Increased SENSITIVITY of receptors to glutamate
- increased AMOUNT of glutamate released by pre-synaptic terminal
- Protein synthesis in post-synaptic dendrites
What are the sit4s of long term potentiation (LTP) that are mentioned in the slides? (7)
H E P M T A V
H E P M T A V
- Hippocampus
- Entorhinal cortex
- Prefrontal cortex
- Motor cortex
- Thalamus
- Amygdala
- Visual cortex
H E P M T A V
The slides mentioned three other forms of synaptic plasticity, beyond long term potentiation (LTP). What were they?
LTD H S
LTD H S
- Long term depression
- Habituation
- Sensitisation
LTD H S
What type of thing is Long term depression, and what actually is it?
It’s an example of synaptic plasticity
It is actually..
Low frequency stimulation at synapse can decrease synaptic strength
What type of thing is Habituation, and what actually is it?
It’s an example of synaptic plasticity
It is actually..
Repeated stimulation reduces strength of synaptic response (reduced
neurotransmitter release)
What type of thing is Sensitization, and what actually is it?
It’s an example of synaptic plasticity
It is actually..
Single noxious stimulus causes exaggerated synaptic response to repeat presentation of noxious stimulus
If we were to say that learning in memory is caused by main a specific thing at the level of neurons, what would that thing be?
Long term potentiation
What was Matlin’s (1998) definition of memory?
‘Maintaining information over time’
What was Ashcroft’s (1994) definition of memory?
‘The mental processes of acquiring and retaining information for later retrieval’
We learned about two different ways of thinking about memory:
- the implicit/explicit way, and
- the procedural/declarative way
They can be related, but do not completely map onto each other.
Which one was derived from dissociable cognitive theories?
The procedural/declarative one
The hippocampal formation is essential for PROCEDURAL memory formation, T/F
FALSE!
Procedural memory formation is supported by memory systems that are independent of the hippocampal formation
Is declarative memory relational?
Yup
We learned about 4 models of memory. What were they?
A L T P
A L T P
- Atkinson-Shiffrin (1968)
- Levels of processing
- Tulvings
- Parallel distributed processing model
A L T P
Of the models of memory we learned, three were serial models and one was parallel. Which one was parallel
The Parallel Distributed Processing Model
Tell me all about the Atkinson-Shiffrin model of memory
> > SENSORY MEMORY»_space; attention»_space; WORKING MEMORY»_space; encoding/retrieval»_space; LONG TERM MEMORY
Who came up with this model of memory?
> > SENSORY MEMORY»_space; attention»_space; WORKING MEMORY»_space; encoding/retrieval»_space; LONG TERM MEMORY
Atkinson-Shiffrin (1968)
Tell me all about the Levels of Processing model of memory
Information is retained according to the depth of processing it has undergone…
leading to
- Shallow to deep continuum, and
- Maintenance vs elaborative rehearsal distinction
Who do we associate with the Levels of Processing mode of memory?
Craik & Lockhart (1972)
If I told you about a model of memory that focused on depth of processing, and levels of rehearsal, what type of model might it be… and who would we associated with it?
Levels of processing model
Craik & Lockhart (1972)
What was same same and what was special about Tulving’s model of memory (1972, 1983, 2001)
The pathway from STM to LTM was same same like the Atkinson-Shifrrin model
I think the new bit was that he divvied LTM up into procedural/episodic/semantic
Tell me all about the Parallel Distributed Processing model of memory
Well, basically…
Memory = activation of a whole network of distributed areas
Knowledge is basically the pattern of activation
Learning, therefore, becomes about strengthening connections between relevant locations
Of the two types of models of memory, which is mot useful for studying amnesia
Serial
Which form of memory is autonoetic awareness related to?
Episodic memory
WTF is autonoetic awareness?
Highly personalized feeling of (re)experiencing oneself in the autobiographical past or present
According to Tulving’s model, episodic memory was entirely independent of semantic memory, T/F
FALSE!
Tulving believed episodic memory depended on semantic and other forms of memory
Some people argue that episodic and declarative memory are entirely parallel. Name a couple of them
Squire and Zola
These guys made the case that
What is Tulving’s view on whether episodic and semantic memory are parallel systems?
He recons they are not parallel
Tulving recoded one memory system (of episodic and semantic) was dependent on the other? Which way around was it?
He believed that episodic relied on semantic
That is, if you damaged your episodic memory you can keep your semantic memory. But if you damage your semantic memory, both your semantic and episodic memory are fucked
What is Vargha-Khadem et al (1997) associated with?
The study of the kids that showed semantic memory could be encoded without episodic memory
Who is associated with the (1997) study that showed semantic memory could be encoded without episodic memory
Vargha-Khadem (1997)
In Vargha-Khadem’s (1997) study, what did neuroimaging work reveal about the brains of the three subjects? (2 things)
All three had:
- abnormally small bilateral hippocampi
2 relatively intact extra-hippocampal temporal lobes
So after the Vargha-Khadem’s (1997), what might we conclude about the dissociability of episodic and semantic memory?
They must be functionality dissociable… but there is still much to learn
Declarative memory allows 3 types of memory processing. What are they?`
- recall
- recognition
- manipulate memory internally
Of all dementing illnesses, how common is Alzheimer’s?
The most common of them all…
Probably 50% of all dementias are AD
If you live to 80, what are the chances of you getting Alzheimer’s
1 in 5, buddy
Can you diagnose a living person with Alzheimer’s?
No
In relation to Alzheimer’s, What is the fancy name for the only diagnosis you can actually give a living person
Demential of the Alzheimer Type
What is the most common aetiology of AD?
Sporadic
What is going on with the early onset autosomal dominant cases?
– Mutations in 3 genes: amyloid precursor protein (APP), presinilin 1 (PSEN1), presenilin 2 (PSEN2)
– All alter production of amyloid β (Aβ) peptide – principal component of senile plaques
What is the mean number of years to death after onset?
- 5 years
range: 2-20 years
How many phases doesAD have?
3
What happens in phase 1 of AD, and how long does it last?
- Failing memory (amnestic presentation)
- Muddled inefficiency in Activities of Daily Living (ADL)s
- Spatial disorientation
- Mood disturbance can
occur (agitated or apathetic)
(lasts 2-3 years)
What happens in phase 2 of AD?
- Intellect and personality deteriorate
- Focal symptoms appear (dysphasia, dyspraxia, agnosia and acalculia)
- Disturbance of posture and gait, increased muscle tone
- Delusions/hallucinations can occur
What happens in phase 3 of AD
- Profound apathy, become bed ridden
- Eventually lose neurological function
- Bodily wasting occurs
What are the three diagnoses relevant to AD (McKhann)
- Probable AD
- Possible AD
- Definite AD
What are the diagnostic criteria for PROBABLE AD
- Deficits in 2 or more areas of cognition
– Amnestic presentation: most common
– Nonamnestic presentations: Language, Visuospatial, Executive dysfunction - Progressive worsening of memory and/or other cog. functions
- No disturbance of consciousness
- Onset between 40 and 90
- In the absence of other causes
- Biomarkers
What are the diagnostic criteria for POSSIBLE AD
- Made on the basis of dementia syndrome if have variations in onset, presentation or clinical course
- Can be made in the presence of another disorder, which is not considered to be the cause of the dementia
What is the diagnostic criteria for DEFINITE AD
- Histopathological evidence of AD obtained from biopsy or autopsy
In AD, what is occurring at a pathology level?
- Grossly atrophied brain
– Affects frontal and temporal lobes > parieto- occipital regions - Extensive degeneration of neurons
- Accompanying glial cell proliferation
- Extensive amounts of senile plaques
- Extensive amounts of neurofibrillary tangles
- Intensity of neuropathological features correlates closely with severity of dementia
One of the diseases we learned about is associated with senile plaque. What is it?
Alzheimer’s Disease (AD)
One of the diseases we learned about is associated with excessive neurofibrillary tangles. What is it?
Alzheimer’s Disease (AD)
In terms of brain regions, where does Alzheimer’s Disease (AD) start?
Hippocampus / MTL
In terms of brain regions, to where does Alzheimer’s Disease (AD) spread after it starts in the hippocampus?
- Posteriorly to the parietal cortex
1. Also the frontal cortex
What are the first markers of cognitive impairment in the progression of Alzheimer’s Disease (AD)?
MTL type impairment
- Anterograde memory deficits
- can’t learn - Retrograde memory deficits
- recent memories for first
What are the second markers of cognitive impairment in the progression of Alzheimer’s Disease (AD)?
- Wernicke-type aphasia (spread into posterior temporal lobe)
- word finding difficulties
- fluent - Visuospatial deficits/topographical disorientation (spread into parietal lobes)
- Dyspraxia (movement/coordination), agnosia (can’t process sensory info), acalculia
What are the third markers of cognitive impairment in the progression of Alzheimer’s Disease (AD)?
- Behaviour change (into fontal lobes)
- Apathy (more common)
- Agitation - Generalised impairment (into neocortex)
What is the brain chemical that is out of balance during Alzheimer’s Disease (AD)?
Acetylcholine
Acetylcholine imbalance is associated with what disease?
Alzheimer’s Disease (AD)
What prevents Alzheimer’s Disease (AD)?
So far, nothing… - not diet, physical cognitive or social activity
