Memory and cognition Flashcards
(24 cards)
Define the term engram [2]
- physical substrate of memory
- brain cells and connections that store memory
Describe the Hebbian theory for memory function [6]
- set of neurones are excited by stimulus
- they form cell assembly for that stimulus
- activity of neurones can continue even when stimuli has ceased
- synaptic plasticity strengthen between neurones of this cell assembly
- this lasting representation of stimulus is an engram
- if a weakened stimulus cue appears the assembly will be activated
- Label the areas of the medial temporal lobe
see diagram
Draw a diagram show the flow of information on cortico-hippocampus areas
see diagram Q3
What areas in the medial temporal lobe are invovled on item detection [2]
- perihinal cortex
- lateral entorhinal cortex
What areas are invovled in item context [2]
- parahippocmapal cortex
- medial entorhinal cortex
Where item detection and context integrated
hippocampus
Where of the LEC and MEC send info to
dentate gyrus
What type of memory is spatial memory
declarative
How did scientists determine the brain regions involved in spatial memory [3]
- MWM
- lesions in brain areas
- saw decline in success
What are place cells
cells in the hippocampus involved in telling us where we are
Describe the experiment done to discover place cells [3]
- record individual neurones
- while mouse runs around table
- found individual neurones fired at specific location
Describe the experiment that showed place cells work together [4]
- mouse with electrode implant
- ran around maze
- individual neurones colour coded
- showed single neurones fire for specific place
What did heat map in place cell mouse study show? [3]
- some neurones fire at very specific locations on table
- others didn’t fire at all
- some were always firing
Describe the study procedure done to show place cells are substrate for spatial memories [6]
- mouse placed on ball
- can explore VR maze
- with aim of finding target
- running trajectory to rewards mapped by firing sequence of place cells
- changed so that ball does not move
- mouse could navigate imagining direct movement
What ere the results of the study showing place cells are substrate for spatial memories [2]
- found that same place cells fired when ball moved and when mouse was imagining where to go
- shows cognitive maps used to imagine places, independent of physical location
How waasnthe substrate spatial memory altered to study hippocampus memory independent of space? [5]
- rats has lever to change tone
- rat aims to reach tone to get reward
- HPC activity recorded
- specific cells for septic tones
- firing neurones becomes earlier as rat improves at task
What does the dorsal striatum consist of [2]
- caudate nucleus
- putamen
what does the ventral striatum consist of [2]
- nucleus accumbens
- olfactory tubercle
What is the function of the striatum [3]
- motor planning
- generation of movements
- procedural memory
Describe how the won-stay task was used to study procedural [5]
- rats learn simple procedure
- lit arms contain food reward
- lesions to some rats hippocampus or striatum
- lesions to hippocmapus: rats could learn task still
- lesion to striatum: rets failed to learn task
What study showed dorsal striatum neurones encode action sequences [4]
- rat learnt task requiring 5 lever presses for reward
- electrodes used to record neurones in striatum
- found that different levers were encoded by different neuronal sequences
- and there ere more task responsive neurones encoding behaviour start and end point
Explain how Parkinson’s disease is associated with impaired procedural memory [2]
- in PD there is degeneration of DA inputs into striatum
- disrupt movement and procedural memory
- Label diagrams
see diagram
