Chapter 5- Learning

Question 1

Why do males usually have better spatial memory?

Answer 1

Generally, males of many species have a larger hippocampus and are better at spatial memory tasks. This is likely due to natural selection, as males generally have larger territories than females and a better spatial memory is required. In cowbirds, females have a larger hippocampus and females face more challenging spatial memory tasks. In meadow voles, natural selection favors spatial memory more strongly in the sex with more difficult spatial memory tasks (males).

Question 2

Spatial learning in female cowbirds

Answer 2

Female cowbirds face more difficult spatial tasks because female cowbirds lay their eggs in the nests of other species. They have to search for a host nest and flush out the female resident of the nest. Researchers tested cowbirds on a memory task. Birds were given 25 cups, with one cup containing food. They were able to feed at the cup, then were removed from the site and brought back to search for the cup again. While males and females spent the same amount of time searching in the second test, females made fewer errors as they searched for the correct cup.

Question 3

Learning

Answer 3

A relatively permanent change in behavior as a result of experience. It is a mechanism by which individuals show adaptive plasticity. This does not specify how long of a time period behavior will change for.

Question 4

Phenotype

Answer 4

The observable characteristics of an organism

Question 5

Phenotypic plasticity

Answer 5

The ability of an organism to produce different phenotypes depending on environmental conditions. Learning can be describes as phenotypic plasticity if behavior is replaced with phenotype. Therefore, all learning is a type of phenotypic plasticity, but not all phenotypic plasticity involves learning.

Question 6

Flushing behavior in foraging birds (Jablonski)

Answer 6

*Goal- to determine whether flushing is a learned behavior or if it is fixed genetically.
*Background- birds may move their tails and wings to flush insects out from under the cover of leaves as they are searching for food.
*Results- birds in nature increase their wing flapping behavior while under branches, even when they get no reward (food) for doing so.
*Explanation- this represents phenotypic plasticity, because animals are producing different phenotypes (behaviors) depending on environmental conditions (whether they are under a branch). However, it is not a case of learning.

Question 7

3 types of experience that can lead to learning

Answer 7

1. Single stimulus
2. Stimulus-stimulus
3. Response reinforcer

Question 8

Sensitization

Answer 8

Becoming more sensitive to a stimulus over time

Question 9

Habituation

Answer 9

Becoming less sensitive to a stimulus over time

Question 10

Single stimulus forms of learning

Answer 10

This type of stimulus can take almost any form. Sensitization and habituation are examples. The rat and blue stick are an example- when exposed to the blue stick in its cage, the rat may respond more frequently with repeated exposures or begin to ignore it.

Question 11

Pavlovian/classical conditioning

Answer 11

Stimuli are paired. One is neutral (conditioned), the other is designed to elicit a response (unconditioned stimulus). Eventually the animal will respond to the neutral stimulus like it would the conditioned stimulus. This response to the conditioned stimulus is called the conditioned response

Question 12

Conditioned stimulus

Answer 12

Classical conditioning- a stimulus that initially fails to elicit a particular response but comes to do so once it’s associated with the second (unconditioned) stimulus. For example, a blue stick being paired with cat odor will eventually cause a fear response in rats.

Question 13

Unconditioned stimulus

Answer 13

A stimulus that elicits a response in the absence of training, like fear.

Question 14

Appetitive stimulus

Answer 14

Any stimulus that can be considered positive, pleasant, or rewarding. Includes food, a mate, or a safe habitat

Question 15

Aversive stimulus

Answer 15

Any stimulus that is unpleasant, includes shock, bad smells, etc

Question 16

Positive vs negative relationships

Answer 16

When one event predicts the occurrence of a second event, there is a positive relationship between the events. When one event predicts the second event will not occur, that is a negative relationship. Positive relationships produce excitatory conditioning while negative relationships produce inhibitory conditioning

Question 17

Second order conditioning

Answer 17

Once a conditioned response has been learned by pairing the unconditioned stimulus and conditioned stimulus 1, a new stimulus is presented before CS1. If the new stimulus eventually elicits the conditioned response, the new stimulus becomes a conditioned stimulus (CS2).

Question 18

Learnability

Answer 18

The ability to learn under certain conditions. Includes overshadowing, blocking, and latent inhibition.

Question 19

Overshadowing

Answer 19

When, during classical conditioning, a second conditioned stimulus is presented simultaneously with the first conditioned stimulus (like a yellow light and blue stick in the rat example). If rats respond less strongly to the blue stick when it’s presented alone, then the yellow light is overshadowing the blue stick. The new stimulus makes pairing the old stimulus more difficult

Question 20

Blocking

Answer 20

When rats respond less strongly to the yellow light when it is presented alone. Initially training to respond to the blue stick alone blocked the ability of the rats to pair it with cat odor.

Question 21

Latent inhibition

Answer 21

A group of rats is exposed to a blue stick, but no cat odor, for a long time. The blue stick is then paired with a cat odor. If these rats have more difficulty learning than the rats in the standard classical conditioning group, then latent inhibition has occurred- when CS1 is first learned alone, there is difficulty learning about CS2.

Question 22

Operant/instrumental conditioning

Answer 22

Occurs when the response that is made by an animal is reinforced (increased) by the presentation of a reward or the termination of an aversive stimulus. Or the response can be suppressed (decreased) by the presentation of aversive stimulus or termination of reward.

Question 23

What is the main difference between pavlovian and operant conditioning?

Answer 23

In operant conditioning, an animal must take some sort of action or response for learning to occur.

Question 24

Thorndike puzzle boxes

Answer 24

Early research in operant conditioning to determine how quickly cats could escape from puzzle boxes. The cats were able to discover behaviors that allowed them to escape from the box by chance, and they were then more likely to use those behaviors to escape (the reward).

Question 25

Law of effect

Answer 25

Thorndike- states that if a response in the presence of a stimulus is followed by a positive event, the association between the stimulus and the response will be strengthened. If the response is followed by an aversive event, the association will be weakened.

Question 26

Skinner box

Answer 26

A box where a rat can press down on a lever to receive food. This is called an operant response because the action changes the rat’s environment by adding food to it

Question 27

Ecological learning/cognitive ecology model of learning

Answer 27

The idea that the ability to learn is under strong selective pressure, so individuals will learn information that is helpful in their environment

Question 28

Garcia rat study

Answer 28

Tried to get rats to form an association between a series of cues. He used water paired with bright light and a noise or water paired with a gustatory cue (tasty water). Each type of water was paired with a negative stimuli (radiation, toxins, or shocks). The tasty water was easily paired with negative cues, but not the audiovisual cues in the toxin condition. Rats did not learn to avoid bright-noisy water easily. In the shock condition, the reverse was true- rats did not learn to avoid the tasty water. This is likely due to adaptation- natural selection would favor the ability to pair gustatory cues with discomfort (getting sick), since internal discomfort is usually due to something the animals ate. Peripheral pain is likely to be associated with audiovisual cues. Garcia also found that learning occurred in rats without immediate reinforcement, contrary to the beliefs of many psychologists at the time. In nature, there is usually a delay between the rat eating and then getting sick.

Question 29

Associative learning in fruit flies

Answer 29

One location where eggs were laid had quinine added to it- a chemical that fruit flies are averse to. The quinine location had either a color or odor cue associated with it. Then, when the females were ready to lay eggs, the quinine was removed but the cue was still present. In one treatment group, the color cue was always a reliable indicator of quinine, but odor was unreliable. In the other treatment, odor was reliable and color was not. In each subsequent generation, only eggs laid in the location with the reliable cue were selected. When the offspring were tested, it was found that more individuals learned to pair color with quinine than odor. Flies from treatment 2 showed the opposite pattern. This suggests that selection pressures can change the nature of associative learning

Question 30

Group living in doves

Answer 30

It was hypothesized that individuals living in groups must compete for resources and therefore must learn more quickly. Researchers used both solitary and group living dove populations, and all subjects learned how to operate an apparatus to obtain food. Birds in the group living group learned the task more quickly than birds from the territorial population did. Also, the more difficult the task, the more pronounced the differences were between the populations

Question 31

What causes differences in learning abilities between territorial populations and populations that live in groups? (2)

Answer 31

1. Animals might have had differences in foraging experience before the experiment and therefore have had prior learning
2. Natural selection might have operated on learning ability across populations, beyond the experiences in the experiment

Question 32

3-spined sticklebacks (Huntingford & Wright)

Answer 32

*Goal- to circumvent the confounding effects of learning vs natural selection
*Background- different populations of sticklebacks face different predation pressures, with some sticklebacks facing almost no pressure from predators
*Methods- sticklebacks were trained to associate one side of their tank with food, then they were subjected to a simulated attack from a heron predator on the side of the tank that contained food. Examined between population differences in terms of how long it took the fish to learn to avoid the side of the tank associated with heron predation.
*Results- fish from high predation areas learned the task more quickly than did fish from predator-free populations.

Question 33

In the Huntingford & Wright study, what evidence supported the hypothesis that natural selection operated on learning and antipredator behavior in sticklebacks? (2)

Answer 33

1. The laboratory protocol minimized the probability that individual experiences differed across populations
2. Researchers did not find between-population differences in all learning contexts. Differences were only found when the learning task was to avoid feeding in areas associated with danger

Question 34

Trade-off between learning and life span in fruit flies

Answer 34

Flies were subjected to a learning test where they were trained to associate an odor with a mechanical shock. Flies in the learning treatment died sooner than flies from the same line that had been selected for better learning abilities but not shocked or exposed to learning trials. The difference could be due to the cost of learning, being shocked, or both. Another trial compared flies in a learning treatment to flies that were exposed to shock but did not learn. Flies in the learning treatment died sooner than those that were just exposed to the shock

Question 35

Constitutive costs

Answer 35

Costs paid by good learners regardless of whether they learn a task

Question 36

Induced costs

Answer 36

Costs paid only when learning has occurred

Question 37

Costs of learning in the cabbage white butterfly

Answer 37

Cabbage white butterflies lay their eggs in green plants, but there is some genetic variation in the extent to which they can be trained to search for red items. It was found that females from families with individuals who learned to forage for red items produced fewer and less well developed eggs, even when given no learning tasks. This is a constitutive cost, probably due to the investment of larger brain sizes that occur in these individuals. Also, butterflies selected for the ability to learn to forage on red items showed a greater decrease in reproductive success after learning trials for red items. This is an induced cost.

Question 38

How does natural selection select for learning ability based on changes in the environment?

Answer 38

When the environment rarely changes, information is best passed on genetically. This avoids the cost of learning, and parents and offspring share a common environment. If the environment constantly changes, learning isn’t really worth it, so genetic transmission of a response is also favored in this situation. If the environment is in the middle of these two extremes, learning becomes worth the cost

Question 39

Model for the evolution of learning (Stephens)

Answer 39

Takes into account both within-lifetime predictability of the environment, and between generation predictability. Learning is favored when within lifetime predictability is high, but environmental predictability between generations is low.

Question 40

Reintroduction programs

Answer 40

Involve managers that raise individuals of a threatened or endangered species in capacity and then release them into the area the species previously occupied. One issue is that the animals are not exposed to predators in captivity, so researchers try to expose them to some aspect of the environment before they’re released

Question 41

Damselflies learning about predation through chemical cues

Answer 41

Damselflies may learn about pikes (predators) through chemical cues. The damselflies were fed different foods that pikes eat. When they were exposed to the water of a tank where pikes can eaten minnows, their foraging behavior was reduced. This was not true of damselflies who were exposed to water treated with a pike that had eaten mealworms (a control). These results suggest that damselflies innately associate the scent of pike plus minnow with danger, but not pikes and other foods like mealworms. However, when damselflies were exposed to water treated with pikes and mealworms multiple times, they did decrease the foraging behavior. This means that the flies were able to associate pike plus the scent of any potential prey with danger

Question 42

Mate choice in Mongolian gerbils

Answer 42

Mongolian gerbils rely on chemical communication during the formation of pair bonds. Researchers allowed pair bonds to form between a male and female Mongolian gerbil. One group of males was exposed to an olfactory cue, and the other group was exposed to a cue but not given access to females. Males paired with an odor and then a female learned to approach an area where access to the female was signaled by an odor. Next, it was tested whether females learned to associate an odor with the presence of their mates. Females did learn to approach the area associated with the cue, and the differences between males and females disappeared over time.

Question 43

Sex differences in linking cues with selecting a mate

Answer 43

It has been hypothesized that in species where there are sex differences in learning abilities when selecting a mate, there should be linked differences in male and female parental involvement. The more equally parental involvement is shared, the more the sexes should be similar in terms of learning the location of partners. If both parents are providing resources, one individual should invest in learning where their partner is. In many species, only females provide resources for the offspring. Therefore, males should be better at learning their location, so that they know their offspring are being taken care of.

Question 44

Learning who is kin in long tailed tits

Answer 44

Experiments focused on the “churr” call given by both males and females in the context of short range communications (like nest building and aggression). Researchers set up a playback experiment- an individual heard the tapes call of either a close genetic relative or a nonrelative. The birds showed a preference for the calls given by their kin. Researchers then ran a cross fostering experiment, and found that the churr call is learned. The calls of foster siblings raised together were as similar as the calls of biological siblings raised together, the calls of biological siblings raised apart were dissimilar, and the songs of foster parents and their offspring were similar

Question 45

Facial learning in wasps

Answer 45

Reproduction in paper wasp colonies is linked to the position a wasp holds in a dominance hierarchy, so knowing who is dominant in the hierarchy in important. Wasps have facial marks that could allow for recognition. The wasps were shown facial images of two other stimulus wasps. One image was paired with an electric shock and the other was not. The wasps were able to pair a scientific facial image with an electric shock. In addition, the wasps were only capable of pairing intact faces with an electric shock- not pictures where wasps lacked antennae or their faces were rearranged. The wasps also were not able to pair geometric patterns with an electric shock, suggesting facial learning.

Question 46

Which selective forces have shaped facial learning in wasps?

Answer 46

It was hypothesized that facial learning allows wasps to recognize individuals in their colony, and that other wasp species that live a solitary lifestyle and lack specific facial markings would not be able to recognize faces. Researchers ran another facial recognition experiment using a wasp species where individuals usually nest alone and have less facial pattern variability. Facial learning was not observed in this species.

Question 47

Molecular genetics of learning in rats (Zhang)

Answer 47

Used 2 lines of rats that had been selectively bred- called the Syracuse high avoidance (SHA) line and Syracuse low avoidance (SLA) line. Researchers examined gene expression patterns in the hippocampus- this area of the brain is important in both avoidance learning and anxiety. After rats had been selected through learning trials, researchers removed the hippocampus and measured gene expression in each rat. They found 8 candidate genes. 4 were expressed more frequently in SHA rats, and the other 4 were expressed in SLA rats. It seems that complex traits like avoidance learning are controlled by many genes, each of which contributes a small amount to phenotypic expression.

Question 48

In the molecular genetics of learning in rats study, how were SHA and SLA rats identified?

Answer 48

The rats were tested on their tendency to avoid auditory and visual cues associated with a foot shock. The rat was placed in a cage with two compartments. A light and a tone were set off before foot shocks were delivered to a cage the rat was in. It was tested in avoidance trials to determine how well it was able to move to the other compartment and avoid the shock. The rats that were best at avoiding shock (SHA) were bred with each other. The two lines of rats differed in fearlessness- SLA rats showed higher levels of anxiety. SLA rats were both anxious and poor at learning to avoid unpleasant cues, while the opposite was true for SHA rats.

Question 49

Glucocorticoids

Answer 49

Hormones that play a role in the stress response and learning in animals. They can cross the blood brain barrier and enter the brain, where they can influence cognitive abilities and an individual’s emotional state. Glucocorticoid levels rise in female rats when stressed, and if they are pregnant, their offspring are anxious and have difficulty learning. Corticosterone is an example.

Question 50

Where do glucocorticoids act in the brain?

Answer 50

They bind to receptors in the hippocampus, including the mineralocorticoid receptor (MR)

Question 51

Relationship between glucocorticoids, stress, and learning in rats (Herrero)

Answer 51

Researchers administered behavioral tests to a group of rats and then measured the level of various hormones. One group of tests measured the fear response- it used mazes and measured how rats respond to large open fields (an environment they fear). After fear testing, rats were classified as either high or low anxiety. Rats were then tested on their spatial learning skills- they were placed in a water maze and their ability to find and remember the location of a submerged escape platform was measured. Researchers measured the rats’ corticosterone levels and number of MR receptors. High anxiety rats took significantly longer to learn to swim to the submerged platform because they spent more time swimming near the edge of the tank. These rats also had higher corticosterone levels, and they had fewer MR receptors in their hippocampus. A reduced ability to bind corticosterone indirectly leads to an increase in circulating stress hormones.

Question 52

What are the implications of Herrero’s relationship between glucocorticoids, stress, and learning in rats study?

Answer 52

The cause and effect relationship between the variables is not clear. It could be that rats with few MR receptors and high circulating corticosterone became anxious in the open environment tests and scored poorly on the water maze test. Or, it could be that the open environment tests caused changes in the number of MR receptors and circulating corticosterone, and animals with increased corticosterone and less MR receptors did poorly on the water maze test.

Question 53

Plasticity

Answer 53

Neurons in the brain rewire each other to learn a new behavior

Question 54

Sensitive periods

Answer 54

Periods of onset, offset of sensitivity. Children are able to learn faster because their brains have greater plasticity

Question 55

Imprinting

Answer 55

In some species, they will imprint on the first animal they encounter or the first animal that brings them food. They will then imitate that animal’s behavior.

Question 56

How does an organism recognize relevant cues of important discriminations?

Answer 56

Genetic predispositions and sensitive periods

Question 57

Why do animals learn? (3)

Answer 57

1. To find food
2. To find a mate
3. To avoid predators

Question 58

Assumptions about the value of learning (3)

Answer 58

1. Learning is a trait
2. Learning often comes at a cost, even if small.
3. Learning occurs relatively rapidly

Question 59

What do animals learn about? (4)

Answer 59

1. Distinguish predatory from nonpredatory species
2. Mate
3. Aggression
4. Food

Question 60

Prairie dogs learning about predators study

Answer 60

*Question: How do young prairie dogs learn about predators (black footed ferrets)?
*Methods- For five weeks, young in one group were paired
with a predator-experienced adult, the other not. Post-training test measured juvenile activity level, frequency
of fleeing, antipredator vocalizations and vigilance behavior.
*Results- young prairie dogs learned better about predators when learning from an experienced adult.

Question 61

Mate choice in female quails study

Answer 61

*Question- Can social factors influence the mate choices of
female quail? Females choose a mate in this species.
*Methods- A female was given a pretest to affiliate with two males held in the end chambers of an apparatus. Then, the female was held (10 min) in the center of the apparatus, while a model female mated with her nonpreferred male. There was a posttest during which she could once again
affiliate with the two males.
*Results- female quails consistently showed a significant increase in the time they spent affiliating with non-
preferred males seen mating with model females
*Conclusion- female quails learn to favor males that are favored by other females. Social factors can influence female quails’ choice

Question 62

Blue gourami learning

Answer 62

Males were trained to associate a light cue with an intruder. When the light cue was present, the average number of aggressive displays when the light cue was present increased.

Question 63

Which hormones can influence learning? (2)

Answer 63

1. Estrogen is associated with improved cognition
2. Glucocorticoids are associated with learning and anxiety