Lecture 3

Question 1

What organism has 4 olsin genes and is therefore tetrachromatic?

Answer 1

European starlings - can perceive UV light

Question 2

Sensory optimisation

Answer 2

Environments vary in signal transmission (Endler, 1993)

Perception mechanisms are underpaid by genes, which are affected by natural selection

Question 3

Genes underlying vision

Answer 3

1000 opsin genes in 7 subfamilies

Terakita 2005

Question 4

Perception

Answer 4

The process by which an organism detects and interprets information from the external world by means of the sensory receptors

Question 5

Methods to study perception

Answer 5

1. Electrophysiology
2. Behaviour changes
3. Psychophysical experiments

Question 6

Electrophysiology - how to use this method

Answer 6

Direct testing of the nervous system

Give stimulus and see if signal is perceived by neurones

Question 7

Behaviour changes - how to use this to study perception

Answer 7

Give a stimulus and see if an animal responds to it

Question 8

Psychophysical experiments - how to use this to study behaviour

Answer 8

Train an animal first then carry out experience by

Based on learned behaviour

Question 9

5 basic principles in tests of perception

Answer 9

1. Species differ in what they perceive
2. Species differ in their ability to perceive stimuli of different intensities
3. Sensory neurones respond more to stimuli of greater intensities
4. Senses habituate to prolonged unchanged stimuli
5. Responses depend on contrast to the environment

Question 10

Why is perception so important?

Answer 10

For choosing the right species to mate with
For selecting safe prey
Threshold for when rival attacks

Question 11

Costs of making perception mistakes

Answer 11

Wasted energy
Injury
Mating opportunity lost
Death

Question 12

Signal detection theory

Answer 12

• Way of testing and answering questions on how perception of useful signals evolve
• Helps to design experiments and interpret results

Question 13

Psychophysics

Answer 13

Method to explore relationship between stimulus and sensation

Question 14

Iridescence

Answer 14

Property of certain surfaces that appear to change colour as the angle or view changes e.g. iris
Could be an example of co-evolution between plant signals and an insect pollinator

Question 15

Sensory bias

Answer 15

The innate ability to detect a signal, typically referring to sexually selected traits

Question 16

Two predictions of sensory bias

Answer 16

1. The preference can evolve before the sensory trait ‘function’
2. The preference may have another function in another context

Question 17

Attention

Answer 17

Act of concentrating on any one of a set of objects or thoughts

Question 18

How is attention studied?

Answer 18

Using visual searches
Can be simple feature target where objects differ by just one feature
Or more complex where object differs in 2+ features eg. colour and shape

Question 19

Who said ‘reaction times are a good method of working out the attention needed to discover visual items’

Answer 19

Treisman and Gelade, 1980

Question 20

Bumblebee discrimination experiment

Answer 20

Trade-off between speed and accuracy
Bees who spent more time making a decision were more successful
Dyer and Chittka 2004