Flashcards in 17 Comparative Cognition 2: Animal Models of Memory_FM Deck (22):
What is implicit memory?
Memory that can be observed from behaviour but which cannot be verbalised - they can't tell you what experience guided their behaviour
What is explicit memory?
Declarative memories that can be verbalised
What is difference between learning and memory?
Learning refers to acquisition - how things are acquired.
Memory is how information is kept among patterns of neurons - and how it is retrieved and acted upon.
Can memory be measured directly?
No, it can only be inferred from behaviour which changes through experience.
What is latent memory?
Information acquired through experiences – such as in Tolman and Honzik's 1930 rat study – which only shows up when use of this information becomes motivationally significant.
What is face validity in animal models of memory?
The model is phenotypically similar and implies that the response observed in the animal model should be identical to the behavioural and physiological responses observed in humans
Behavioural responses of animals are different from humans, whose ethogram includes verbal aspect
What is predictive validity?
Can you predict that the effects of a drug will have the same effect on a human as it does on an animal
What is construct validity?
Is the underlying theoretical rationale the same across species - are the nervous system process the same across species
How did animal studies initially contradict the HM hypothesis that memory depends on the hippocampus?
Because hippocampal lesions in some cases enhanced performance on learning and memory tests
What are the three parts of Atkinson and Shifrin model of memory?
Sensory buffer – sense data, very short retention
Working memory - information goes here from SB and stays as long as is rehearsed, limited volume - data competes to be here
Long-term memory - no limit on storage
How do generalisation gradients of pigeons, conditioned to peck certain colour for reward, change over time?
They flatten out over time - exact details of colour gradually forgotten
What do marsh tits (caching) and blue tits (non-caching) tell us about hippocampal volume?
As adolescents, the birds have similar hippocampal volume relative to brain size. In adulthood, when they start caching, the marsh tits have relatively larger hippocampus. Evolutionary difference in the morphology of the brain related to the use of the brain.
How is hippocampus of London cab drivers different?
Posterior part of hippocampus is larger.
How do hippocampal place cells work?
They fire in response to certain configurations of spatial cues.
Why is the Morris Water Maze a good test of declarative memory?
Because there are no cues telling where the platform is other than distal configurations of objects the rats must learn to know platform location
How does blocking NMDA receptors in hippocampus affect performance on Morris Water Maze?
Impairs performance - induces retrograde amnesia.
What type of memory is tested by the radial arm maze?
Working memory - must keep in memory which arms they have visited. Important to note that this is not ‘short-term’ memory as performance can be good for up to 4 hours. Seems to be working memory – as it indicates a memory for within-trial/within-problem changes in conditions.
What happens over multiple successive trials of radial arm maze?
Performance decreases. Proactive interference. This gives evidence for a limited capacity short-term memory system.
Why are tests that involve spontaneous preference for novelty for novelty good models of short-term memory?
The degree to which the animal explores the new object rather than the familiar one tests whether it has a memory of the familiar object
What is the difference in types of memory employed for novel object and novel location memory?
For novel object animal must remember identity of object - cortical functioning
For object location animal must remember location of object - spatial memory for cues outside the maze - hippocampal functioning
Why did early animal studies of memory fail to support HM hypothesis of hippocampus-memory association?
Animal trained with same set of stimuli - eg. lights in predictable locations - over lots of trials. This activates implicit memory system - procedural memory, associated with cerebellum. If animals given choice of targets in testing phase - change in stimuli from trial to trial - then hippocampus lesions blocks learning.