The Limbic System: Part 2 Flashcards
what is working memory and give 2 scenarios when it is used
think conscious ability for part 1 of question
- Conscious ability to manipulate information held in short-term memory
- Used in:
- Problem solving and reasoning
- awareness of emotional and social cues during conversation
what is short term memory
- recalled minutes or hours after a stimulus
What is working memory controlled by?
- Controlled by lateral prefrontal cortex (frontal lobe) and association areas of temporal and parietal lobes.
What is long-term memory
- Events recalled weeks, months or years after a stimulus with structural changes in neurons (i.e protein synthesis, increased synaptic strength, increased neuronal excitability)
What is declarative (explicit) memory and define the 2 types of it
think words
- Means it can be put into words
- Two types:
- semantic memory: common knowledge (i.e: who is the prime minister)
- episodic memory: personal experiences (eg: a party you attended)
What is non-declarative memory and what is a type of non-declarative memory and define it
think muscle memory
- semi-automatic learning
- Type of non-declarative memory:
- procedural memory: learning and performing motor skills (muscle memory)
What is amnesia and what are the 2 types of it.
- Loss of declarative memory
- Two types:
- retrograde amnesia: unable to remember events from before an injury
- Anterograde amnesia: unable to remember new events after an injury
What is unaffected and what is affected in amnesia
think tasks, and muscle memory
- Unaffected: procedural memory
- Affected: ability to recall practicing tasks or skills
What are the 3 stages of declarative memory
1.Encoding
2. Consolidation
3. Retrieval
What is encoding in declarative memory and how is it improved
thing information processing and what this does to memory for first part
think drawing connections for second part
- Processing information into a representation of a memory
- Improved by: paying attention, mood, drawing connections between information
What is consolidation in declarative memory and how does it happen
thinks stabilization, synapses and medial temporal lobe
*It is stabilizing of memories
- Happens by synaptic connections become stronger with repeated activation (long-term potentiation)
- Medial temporal lobe directs storage of memories across large networks of neurones elsewhere
what is an engram
an engram is a group/network of neurones that all fire at the same time when you think of a memory
What is Retrieval in declarative memory and how is it important?
think usage of memories for part 1
for part 2 think spaced retrieval practice
- Accessing and using memories in different ways (recall, recognition)
- important for learning (spaced retrieval practice)
What does the lateral prefrontal cortex do in memory and what is it involved in?
think working memory for first part
think what lateral prefrontal cortex does for declarative memory for second part
- Keeps working memory “focused”
- Involved in processing and retrieving declarative memory
What are association areas in temporal, parietal and occipital lobes involved in
think types of memory and sensory perceptions
- Involved in declarative memory and integrating sensory perceptions
What can bilateral lesions of anterior hippocampus cause?
Can cause anterograde amnesia
What does the posterior hippocampus help with
think type of storage and what it DOESNT help with
Helps to encode memories for long-term storage elsewhere but does NOT help with recall
what does the left hippocampus help with
Helps to encode verbal memories
What does the right hippocampus help with
Helps to encode spatial memories
What artery supplies the hippocampus
Anterior choroidal artery branches
What expands in the brain in Alzheimer’s disease?
Lateral ventricle expands
Where does the cingulate cortex receive information
think position of this nucleus in thalamus and also fibres
Receives information from anterior nucleus of thalamus via projecting fibres
What 7 things is the cingulate cortex involved in?
think insular cortex, pain and emotions, memory, Auto something, bladder, CEOs (like the business man), mood
- linking to insular cortex - self awareness and interoception
- pain perception and emotional regulation
- learning and memory
- autonomic areas
- bladder control
- speech
- executive function
- mood disorders (Most important one) like depression
What blood vessel supplies the cingulate cortex?
anterior cerebral artery
Where is amygdala located
think lobes
More anteriorly in medial temporal lobe
what 4 things is amygdala involved in
think fear, pathways, food and sex
- Processing fear or stressful stimuli
- autonomic and endocrine pathways
- appetite
- regulating sexual restraint
What 2 things is the nucleus accubens involved in?
think types of behaviors and types of learning it encourages
- Role in addictive behaviours (eg gambling)
- Encourages motivation, reward-based learning
What is septal nuclei involved in and what can lesions here cause?
think type of behavior for second part
- Roles in pleasure, social connection and empathy
- Patients with lesions can display antisocial behaviour
What is Wernicke-Korsakoff Syndrome and what does it lead to?
think inflammation of tissues around brain for first part
for second part think vision, discumbobulation and coordination
- It is a syndrome caused by Wernicke’s encephalopathy (chronic inflammation of tissues around the brain),
- leads to acute confusion, loss of coordination and gaze paralysis (ophthalmoplegia)
What can cause Wernicke-Korsakoff syndrome and what environmental factors can increase the risk of this?
think mammillary bodies and hippocampi for first part
think alcohol and what specific vitamin deficiency this causes for part 2
- Small haemorrhages in mammillary bodies and damage to connections with hippocampi
- These haemorrhages can be increased in risk by environmental factors like chronic alcoholism as this causes vitamin B1 (thiamine) deficiency
What can repeated episodes of wenicke-Korsakoff syndrome cause and what are 2 symptoms of this?
- Can cause Korsakoff’s psychosis
- Symptoms:
- anterograde amnesia
- confabulation (patient creates fictional memories believing they are real)
What is kluver-Bucy syndrome
think lesions of lobes and destruction
- Bilateral (both sides) temporal lobe lesions E.g bilateral stroke, traumatic brain injury, neurodegenerative disorders
- Also bilateral destruction of amygdala
What are 4 symptoms of Kluver-Bucy syndrome?
think objects in mouth, abscense of fear/aggression, loss of restraint of something and difficulty recognizing certain things
- Hyperorality (compulsioni to put objects in mouth)
- Placidity – fear and aggression may be absent
- Hypersexuality – loss of restraint
- Visual agnosia - difficulty recognizing familiar objects/faces
