17 Comparative Cognition 2: Animal Models of Memory_FM

Question 1

What is implicit memory?

Answer 1

Memory that can be observed from behaviour but which cannot be verbalised - they can’t tell you what experience guided their behaviour

Question 2

What is explicit memory?

Answer 2

Declarative memories that can be verbalised

Question 3

What is difference between learning and memory?

Answer 3

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.

Question 4

Can memory be measured directly?

Answer 4

No, it can only be inferred from behaviour which changes through experience.

Question 5

What is latent memory?

Answer 5

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.

Question 6

What is face validity in animal models of memory?

Answer 6

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

Question 7

What is predictive validity?

Answer 7

Can you predict that the effects of a drug will have the same effect on a human as it does on an animal

Question 8

What is construct validity?

Answer 8

Is the underlying theoretical rationale the same across species - are the nervous system process the same across species

Question 9

How did animal studies initially contradict the HM hypothesis that memory depends on the hippocampus?

Answer 9

Because hippocampal lesions in some cases enhanced performance on learning and memory tests

Question 10

What are the three parts of Atkinson and Shifrin model of memory?

Answer 10

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

Question 11

How do generalisation gradients of pigeons, conditioned to peck certain colour for reward, change over time?

Answer 11

They flatten out over time - exact details of colour gradually forgotten

Question 12

What do marsh tits (caching) and blue tits (non-caching) tell us about hippocampal volume?

Answer 12

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.

Question 13

How is hippocampus of London cab drivers different?

Answer 13

Posterior part of hippocampus is larger.

Question 14

How do hippocampal place cells work?

Answer 14

They fire in response to certain configurations of spatial cues.

Question 15

Why is the Morris Water Maze a good test of declarative memory?

Answer 15

Because there are no cues telling where the platform is other than distal configurations of objects the rats must learn to know platform location

Question 16

How does blocking NMDA receptors in hippocampus affect performance on Morris Water Maze?

Answer 16

Impairs performance - induces retrograde amnesia.

Question 17

What type of memory is tested by the radial arm maze?

Answer 17

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.

Question 18

What happens over multiple successive trials of radial arm maze?

Answer 18

Performance decreases. Proactive interference. This gives evidence for a limited capacity short-term memory system.

Question 19

Whyare tests that involve spontaneous preference for novelty for novelty good models of short-term memory?

Answer 19

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

Question 20

What is the difference in types of memory employed for novel object and novel location memory?

Answer 20

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

Question 21

Why did early animal studies of memory fail to support HM hypothesis of hippocampus-memory association?

Answer 21

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.

Question 22

Does Clayton and Dickinson’s 1998 food caching study reveal whether non-humans have episodic-like memory?

Answer 22

Scrub jays cache meal worms (preferred) and peanuts (not-preferred). Half locations had peanuts, other half had meal worms. Then they devalued meal worms - gave rotten ones. Birds selectively uncached peanuts - spatial context for memory.

Then birds were trained that mealworms decayed faster than peanuts, that after 120 hours mealworms decayed. If birds uncached after 124 hours, they would uncache peanuts - birds remembered not only WHAT they buried and WHERE they buried it, but also WHEN (or how long since – so different from humans) they buried it.