Lecture 6

Question 1

Importance of discrimination

Answer 1

-Important to select edible food instead of poisonous food
-Distinguish predators
Recognise mate, parents or which group an individual belongs to

Question 2

Discriminating dog

Answer 2

Pavlov 1917

Dog can discriminate between a tone+shape (which causes salivation) and just a tone (no salivation)

Question 3

What are sign stimuli

Answer 3

Important single stimulus that elicits a particular innate behaviour

Question 4

What is a supernormal stimulus?

Answer 4

An exaggerated stimulus that elicits a greater than normal innate response from an individual
E.g. mouths of cuckoo chicks mimic those of host chicks, but they have a much larger area, potentially stimulating the host ‘parents’ to feed more often

Question 5

Multiple stimuli

Answer 5

Environment has multiple stimuli that act additively to generate a response (= heterogeneous summation)
Effects are relative, not absolute
Not all stimuli control behaviour equally

Question 6

Costs of multiple stimuli

Answer 6

• Signal expensive to produce
• Extra signals mean extra stimulation
• More signals mean greater potential for error in any one signal
• Costs to signaller and receiver

Question 7

Benefits of multiple stimuli

Answer 7

• Communicate subtle differences in behaviour
• Reduces the need to rely on any one signal
• Better discrimination and better categorisation
• Different signals can communicate in different ways
• Draws attention in crowded niches

Question 8

Discrimination

Answer 8

The process by which animals learn to make different responses to different stimuli
Use a range of discrete and continuous variables

Question 9

How can discrimination be acquired?

Answer 9

-Associative learning (conditioning)
and/or
-Non-associative learning (habituation and imprinting)

Question 10

Influences on discrimination

Answer 10

• Depends on the relative validity of a cue
• Discrimination is faster with fewer cues
• Discrimination is faster if cues are physically dissimilar
• Memory
• Timing

Question 11

Generalisation

Answer 11

A reaction to similarities
Complementary process to discrimination (a reaction to differences)
Allows animals to deal with things they have never experienced before

Question 12

‘Learned biases’

Answer 12

Individuals have learned biases based on experience of similar stimuli
Responses to new objects will differ between individuals and this can change over time (a peak shift)

Question 13

Peak shifting

Answer 13

Responses to new stimuli depend on the similarity to past S+ (rewarded) and S- (punishment) stimuli
Birds who were punished for pecking at too high a wavelength pecked at much lower wavelengths than those that were not

Question 14

What 2 factors does discrimination depend on?

Answer 14

Reinforcement and inhibition
Generalisation is dependent on the contrast between S+ (reinforcement) and S- (inhibition), with S- being actively avoided

Question 15

Peak shifting and evolution

Answer 15

a) When populations are on their own, signals often match responses
b) In sympatry, populations may differ in the responses to sensory stimuli

Question 16

Peak shifts and mimicry

Answer 16

• Predators peak shift when learning which species are toxic

- Peak shifts may explain even how imperfect mimics benefit as predators avoid anything that looks remotely toxic

Question 17

Categorisation

Answer 17

Objects or individuals are grouped into categories
Can use range of discrete or continuous variables
Acquired through associative and non-associative learning
Assigning and object to a concept

Question 18

Categorising complex stimuli

Answer 18

Individuals able to respond differently to calls of different species
Species respond faster to the calls of their own species
Dooling et al. 1992

Question 19

Benefits of categorisation

Answer 19

Categorisation can significantly reduce the time needed to complete tasks
E.g. bees allowed to use associative learning to categorise flowers learnt which flowers were good to visit, saving energy visiting less rewarding flowers

Question 20

What are the three categories that make up a sense of number?

Answer 20

1. Relative number
2. Absolute number
3. Counting

Question 21

Relative number

Answer 21

More or less

Means being aware that 6 items are more than 2 items

Question 22

Absolute number

Answer 22

The recognition that all quantities of the same number have something in common

Question 23

Counting

Answer 23

Using number names in an order
Recognising the last item in a counter group is the total number if items
Arithmetical operations

Question 24

Relative number and ratios

Answer 24

Many species show reduced precision in determining which group is larger as the ratio increases

Question 25

What competencies define the ability to count?

Answer 25

Sense of relative and absolute number required firstly, with two further qualities

1. Tagging: certain number name ‘tag’ goes with a certain quantity of items. Tags must be applied in same order
2. Cardinality: tag applied to last item of a set is the name for the number of items in a set

Question 26

Periodic timing

Answer 26

Ability to respond at regular periods

Question 27

Sensitivity to time

Answer 27

Sensitivity to rhythm of the day

E.g. fiddler crabs change their body colour from day to night

Question 28

Interval timing

Answer 28

Ability to respond on the basis of specific durations

E.g. hummingbirds return to flowers within a few minutes of the time required for the flower to refill with nectar

Question 29

Circadian rhythm

Answer 29

Repeated occurrence of activity once every 24 hours
Ability to accurately gauge the time of day
Day-night cycle of 24 hours
Internal clock to regulate daily activities

Question 30

Why are circadian rhythms important?

Answer 30

• Enables animals to forage effectively
• Ensures animal is suited to the environment in which it lives
• Useful to animals that have to navigate

Question 31

How are circadian rhythms tested for?

Answer 31

‘Time and place’ learning experiments

Question 32

What does entrainable mean?

Answer 32

Brought into a specific rhythm

Question 33

Signals that animals use to entrain their circadian rhythm?

Answer 33

1. Light (photoperiod - day length)
2. Temperature
3. Social factors
4. Feeding

Question 34

Limitations of circadian clock

Answer 34

1. Unable to adapt to large changes of length of day
2. Restricted to time periods of 24 hours
3. Can only be used to place events within a daily cycle

Question 35

What are the mechanisms behind short-interval timing?

Answer 35

Internal clock (dominant theory, Church (1978), animals possess an internal clock)
vs
Alternative:
1. Behavioural theory of timing (Killeen and Fetterman (1988), in timing procedure animals pass through a series of stages, and when the interval is smaller the animals move through the states faster)
(Staddon and Higa (1999), timed behaviour is controlled by steadily decaying memory traces)

Question 36

Comparing circadian and short-interval timing

Answer 36

Interval timing more flexible than circadian timing
Events of daily frequency can be timed to 99.5% accuracy
Accuracy of timing decreases with the length of interval being timed