Flashcards in 17 Comparative Cognition 2: Animal Models of Memory Deck (26)
Why is the Morris water maze thought to be a good model of declarative memory?
When rats were released from a different starting point, they performed well - swimming almost directly to the target. This indicates the rat has used the distal/spatial cues, evidence of learning.
Why are tests that involve spontaneous preference for novelty good models of short-term memory?
Exploits rats' natural tendency to explore the new. Familiarity implies memory.
What is the radial arm maze, and what types of memory does it test? What happens to performance after a delay?
Rats placed in eight-arms radial maze. Trial starts with food at end of all arms. Rats must go to a new arm each time and remember which arms already visited. With experience, number of arms re-visited decreases.
Over delays, memory is forgotten, especially if there is a hippocampus lesion.
Working memory - memory for within-trial changes, which arms already visited in current trial.
Reference memory - memory for stable properties of the environment (e.g. spatial cues), which arms baited.
What is implicit memory?
Unconscious learning, which aids in the performance of a task, e.g. procedural memory or Classical Conditioning. It can be tested observing the effects of unconscious priming on performance.
What is the difference between learning and memory?
Learning is the acquisition of knowledge and memory relates to the structure, nature and use of knowledge - how it is retained and retrieved.
How do we test memory and what some confounding factors in testing memory?
We can infer the presence of memory from changes in behaviour.
-Behaviour can change without memory
What is latent learning?
Acquiring memory that can be acted on later.
How did Tolman and Hoznik (1930) test latent learning?
Rats placed in a maze, learned about environment passively, without reward motivation. Rats developed a map to utilise when necessary. For rats, exploration more important than food.
What happened when Tolman and Hoznik placed detours in the maze?
No detour: rats took shortest route
One detour: rats took next shortest route.
Two detours: rats took only available route.
What is face validity?
The extent of phenotypical similarity between animals and humans
What is predictive validity?
The extent to which the effect of a pharmacological agent on an animal will translate to humans.
What is construct validity?
The extent of which association between behaviour and material cause can be translated from animal to human.
What happened to H.M., in terms of memory functions lost and retained. Why were animal models inappropriate for studying H.M.'s case?
H.M. suffered from a hippocampal lesion, losing the ability to form long-term memories. However, his working memory and procedural memory were intact.
Animal models had no FV, CV, PV.
What is working memory?
Working memory will last for as long as you keep rehearsing it or it is relevant. It can then be forgotten or observed in behaviour, or be consolidated and stored as LTM.
E.g. remembering where you parked your car is working memory, even a week later. Once car is retrieved, memory no longer serves a purpose.
How can long-term memory be tested in rats?
Fear conditioning in rats observed in licking after an electric shock. The same pattern of licking responses was observed in rats given a 1-day delay in shocks and rats given a 60-day delay --> evidence for LTM
What effect does a delay have on generalisation gradients?
Time delays flatten the generalisation gradients (stimulus intensity vs. response), suggesting a loss of information about specific details of learned event.
E.g. pigeons peck at light at 550nm, memory fades, pigeon more likely to generalises)
What is special about the marsh tit, compared to the blue tit?
A) What does this difference suggest about relationship between morphology and memory capacity?
Marsh tits cache their food and blue tit do not, which means marsh tits need a greater memory capacity. The marsh tit has a larger brain than the blue tit. The marsh tit's brain gets bigger as it develops.
There is a linear relationship between memory and hippocampus size.
What are place cells and where are they located in the brain?
Place cells are located in the hippocampus and are involved in spatial learning. The hippocampus will only fire if environment is familiar. If landmarks moved, cells will stop firing.
What happens if NMDA receptors in the hippocampus are blocked?
Inhibits rat's ability for spatial learning.
How do delayed response tasks work? What is a potential confounding factor to testing memory?
Present subject with a sample condition (T1). Test T1 after a delay and measure accuracy. Non-memory strategies are a confounding factor when attempting to test memory.
What happens if eight-arm radial maze tasks are run in succession?
Performance deteriorates, more and more errors on successive trials. Evidence of proactive interference.
What is proactive interference? How can one reduce proactive interference?
Errors in memory from juggling information from many successive trials, due to limited STM capacity. Proactive interference can be reduced if trials are spaced apart.
How does a sample matching test work? What is the difference between sample matching test that train procedural memory and ones that test working memory?
Subject is given sample to memorise, then choose the object that matches the sample or does not match the sample( choose B, which does not match A).
Procedural memory training - training with same object over repeated trials.
Working memory training - features change from trial to trial
What are the differences between novel object recognition and novel location recognition, in terms of area of brain and the type of information that is stored.
NOR: parahippocampal cortices, semantic/object identity information
NLR: hippocampus, spatial/egocentric
What is episodic memory? Do animals have it?
The ability to recall the 'what', 'where' and 'when' of a unique event experienced.