Topic 4: Neural Basis of Behaviour

Question 1

What are Fixed Action Patterns (FAP’s)?

Answer 1

• a series of actions that are triggered by a fixed stimuli, in which the action will come to completion, even if the stimuli is removed.
• coined by Lorenze and Tinbergen

Question 2

What are the 3 key characteristics of a fixed action pattern?

Answer 2

1. Species specific. All members of the species will engage in the behavior if the stimuli is present.
2. No learning is needed for the action. It is an innate action.
3. The pattern is fixed, from start to end. Even if the stimuli is removed, the action pattern will come to completion.

Question 3

Explain Tinbergen’s experiments with herring gull chicks.

Answer 3

• Experiment done to explain fixed action patterns (FAP’s) and supranormal stimuli.
• chicks engaged in a specific behaviour that got a specific response from the parents. Chick will reach up and beg/peck at the red dot on the parents beak (which is characteristic of herring gulls), until the parent fed the chick.
• Tinbergen made 4 models/dolls to present to the chicks (one realistic gull head, one less realistic, one with no red dot, and one was just a red stick with white strips)
• The chicks were most attracted to the red stick, even more than the realistic gull head. The contrasting effect of the red/white colour had high contrast, and so was the most identifiable to the chicks.

Question 4

How does a fixed action pattern occur?

Answer 4

• Sign stimulus (releaser) is presented, which engages innate releasing mechanism in the brain, which then causes the fixed action patter/behaviour.

Question 5

What is a supranormal stimuli? examples?

Answer 5

• Stimuli that is outside the normal realm of stimuli, so an organism may be extra attracted to it
• ex. Tinbergens gull experiment (chicks were most attracted to the red stick)
• ex. Male beetles being attracted to/trying to copulate with large yellow signs, beer bottles, cause the colours are the same as their female counterparts

Question 6

Why does misidentifying sign stimulus occur (fixed action patterns)? examples?

Answer 6

• typically it is better to act upon a stimulus, even if the stimulus is wrong, rather than not do the behaviour, and miss the correct stimulus.
• it is a question of energy and output- is the energy put into the behaviour worth the output of the outcome?
• ex. Geese have a FAP where if their egg ends up outside their nest, they will roll it back in. The sign stimulus ended up being the object outside of the nest, and not the actual egg. Even if the object didnt look like an egg, the goose would roll it in. It is better to grab something that might not be an egg and protect it, than accidentally loose your egg because it doesn’t look like the exact simuli your brain ‘needs’

Question 7

How does neural information relay? What are some examples?

Answer 7

• Simple cues can trigger general responses in neurons, resulting in specific behaviour
• bat/moth example. Bats use echolocation to hunt moths, and moths are able to hear these calls. Depending on what side/if bat is below or above, the moth will hear it on that side or in a specific pattern which tells the moth where the bat is, and they will fly in the opposite direction. This all occurs within their A1 sensory neuron.

Question 8

What is an example of how neurons can detect particular sensory information?

Answer 8

• neurons can detect particular sensory information and filter unwanted stimulus
• Crickets! Crickets can hear many decibels, however they have sensitivities at 2 specific decibels, (5, 40). The lower decibel is intraspecies communication, and at this decibel, their body will swing towards where it is coming from. The louder decibel is from a common predator they have, and if they hear this decibel they will move away from the sound.
• the filtering can also be sex specific.

Question 9

How can neuron stimulus filtering be sex specific?

Answer 9

• neurons can detect particular sensory information and filter unwanted stimulus. The filtering can be sex specific, as males and females of a species may pay attention to different things
• ex. Parasitoid flies that lay eggs in bush crickets. Female flies are the ones that lay the eggs, so they are specifically attracted to a specific decibel in the cricket song, while the male flies are not sensitive to that decibel

Question 10

can there be learning differences in organisms depending on sex and sexual systems? (example)

Answer 10

• Yes! It was found that there can be differences in spatial learning in voles dependent on sex and sexual systems.
• meadow voles are polygynous. A single male will mate with multiple females. Males will need to go to multiple nests/holes to find their females, while the females just wait at home for the males. In this species, the males were better at spatial problems (because they were used to navigating them) than the females.
• Additionally, Prairie voles are monogamous. So, based on the previous thinking, males and females should not have any difference in spatial prediction. Both are the same at figuring out spatial problems.
• However, in both vole species, it was found that males tended to have larger hippocampus’ then females. So they ‘remember’ more.

Question 11

How can proximate neural mechanisms and function be different across species? (examples)

Answer 11

• Similar proximate neural mechanisms but the functional attributes are different across species.
• same perception, different function
• ex. The perception of UV light. Bees use this as a feeding adaptation, to be able to better see where pollen is on a flower. However, some butterflies use it as a mating adaptation to tell males and female apart. Even different, some small birds will use it as a mating adaptation as well, but more to judge a male based on his health (higher reflectance of UV light - preference for females)