Non associative and associative memory I (3/12) Flashcards
What was found after removing the medial temporal lobe and hippocampus of a paitent suffering with epilepsy?
(3 marks)
- Found epilpesy was cured, but suffered from anterograde amnesia - couldn’t perform basic human activities
- Shows hippocampus v important for episodic memories
- Had procedural memory
What is episodic memory?
Recall things from past e.g. hearing a song from a few months ago
What is semantic memory?
Learn meanings of new words/ concepts
What is retrograde amnesia?
Memory loss for things prior to brain trauma - common in alzheimers and degenerative diseases
What is anterograde amnesia?
Inability to form new memories after brain trauma
Where do the parahippocampus and rhinal cortical areas project to?
The hippocampus - which then projects to the thalamus and hypothalamus
What is the radial arm maze?
- Test for memory where animals travel down one of multiple arms to pick up food
What was seen in the radial arm maze in rodents without a hippocampus?
(2 marks)
- Travelled down one arm multiple times those with a normal hippocampus did not
- Kept going down arm even after food retrieved - deficit i spatial refernce working memory
What does the morris water maze test for?
(4 marks)
- Long term memory
- A big pool of water with hidden platform
- Animals learn where hidden platform and swim towards it by using stimuli in the room
- If you remove hippocampus for animals show no form of learning pathway
What are place cells?
(2 marks)
- Cells that develop firing overtime of exploring the environment
- Reflect topography of environment - once place is established, it’s stable for long epriods of time
What are place cells firing dependent on?
Visual cues in the environment
Are place cells present in humans?
- PET imaging showed that when asked people to navigate themselves to particular point get large signal in hippocampus and NOT when directed by arrow
What are grid cells?
(4 marks)
- In entorhinal cortex - cells fire when animal in particular places
- Connecting centres of firing fields give triangular grid
- Allows it to understand position in space by integrating informtion on location, distance and direction
- Animal in motion, activates different grids so particular cells fire at certain place and therefore can integrate this information
What are time cells?
(2 marks)
Neurons that fire at particular times after neuron has been put inot environment
In hippocampus, encode temporal information and support episodic memory
What task was carried out to measure odour discrimination in hippocampus?
(2 marks)
- Pair certain odours together ad reward would be received in either pot A or B
- Found that cells in hippocampus responded to complex information and would fire at odours but if they are in the right pot
What important physiological functions in the hippocampus implicated in?
(3 marks)
- Declarative memory
- Spatial memory, spatial reference working memory and long term emory
- Odour discrimination linked to spatial location
What are engrams?
Cognitive unit in hte brain theorized to be the means by which memories are stored
What is the standard model of memory consolidation?
(4 marks)
- Info from neocortex sent to temporal lobe and stored in the hippocampus
- Interaction between the hippocampus and neocortex strengthen connection between neurons
- get System consolidation: formation of engrams in cortex over time and eventually becoming independent of hippocampus
- Memories move from hippocampus and into cortex
How may the neocortex be involved in establishing engrams?
(3 marks)
- With every memory recall get strengthening of engram
- Always invovles interaction with hippocampus and neocortex
- Develop lots of memory traces overtime
What are implicit memories?
- Formed from associative learning - behaviours altered by formation of association between events
What is instrumental conditioning?
- Associate a response with a meaningful stimulus
What is implicit instrumental learning?
(3 marks)
- Learnt o do a response to receive a particular outcome
- Operant conditioning and positive reinforcement required
- Predictive nature of stimuli involves learning a motor response ni reaction to sensory input
