L2 Causation and Development

The Body’s Response to Stimuli

The nervous system detects things, this includes the CNS, PNS, and ANS.
The nervous system (fast short reaction) is linked to the endocrine system (slow long reaction) and together they create a neuroendocrine response.
Stimuli create learned and cognitive responses which create experiential responses which are often heightenings/wanings of innate responses.
E.g. cats kneading is due to kittens kneading their mothers for milk, but they continue it as adults by changing the instinctive behaviour’s reason to being a self soothing mechanism instead of one for feeding.
Behaviour: “All observable processes by which an animal responds to perceived changes in the internal state of its body or in the external world.”

Deer have antlers which are covered in velvet which provides blood flow and nutrients but once velvet sheds the deer go into rut and become behaviourally more aggressive.
Changed environmental interaction: a deer is using a stick to push the velvet off his antlers, more interaction with objects like sticks will make him stronger and therefore a better mate during breeding season.
Another deer sprays urine over itself to increase his odour and acts aggressively towards the zoo barriers around him, while outside of breeding/rutting season he would be more placid.
- Internal factors = hormone changes.
- External abiotic factors = other stags.
- External biotic factors = sticks or weather.
- Context dependent = time of year and social grouping of deer.

Biological rhythms.
- Daily time schedules are reset by zeitgebers.
- Annual movements are usually in tube with seasonal change.
Motivations are either homeostatic (putting on condition ready for rut) or non-homeostatic (rutting which puts life in danger).

They’re the mechanism which link the outside world with the internal to create a response, they can each take different functions.
Sensory: These nerves carry sensory information to the brain and are responsible for the special senses of smell, sight, and hearing/balance.
- CN I (Olfactory)
- CN II (Optic)
- CN VIII (Vestibulocochlear)
Motor: These nerves carry motor commands from the brain to where they need to be effective.
- CN III (Oculomotor)
- CN IV (Trochlear)
- CN VI (Abducens)
- CN XI (Accessory)
- CN XII (Hypoglossal)
Mixed: These nerves contain both sensory and motor fibers, performing a variety of functions.
- CN V (Trigeminal)
- CN VII (Facial)
- CN IX (Glossopharyngeal)
- CN X (Vagus)

Sensory input → behavioural response
Carry sensory information (vision, smell, taste, hearing, balance, touch) to the brain. These inputs are critical for an animal’s perception of their environment, as well as to recognise threats, find food, and engage in social interactions.
Motor output → expression of behaviour
Control muscles of the eyes, face, tongue, pharynx, and larynx. These allow animals to orient toward stimuli, vocalise, feed, groom, display emotions, or defend themselves.
Autonomic regulation → motivation & arousal
Influence visceral states such as heart rate, digestion, breathing, which in turn affect motivation, stress, and readiness to act.

Biological rhythms.
- Daily time schedules are reset by zeitgebers (‘time givers’)
- Annual movements are normally in-tune with seasonal change.
- Circadian rhythms; synchronised to a 24-hour cycle.
Motivations; either homeostatic or non-homeostatic.
- Homeostasis is in a dynamic equilibrium and has a very important regulatory role over behaviour including hunger, thirst, and temperature regulation. Normal homeostatic mechanisms may be over-ridden if changes to behaviour increase overall fitness
- Animals can quickly evolve their behaviour to best fit the environment their in.
- Specific alterations to, or cues from, physiological state.

Abiotic.
- Light.
- Temperature.
- Tide.
- Landmarks/habitat features.
Biotic.
- Population density, e.g. locusts usually jump around but when they become too crowded they bump into eachother a lot and then start flying and swarm.
- Sex ratio.

Alteration of a reaction to a stimuli with time.
The animal is able to differentiate between stimuli to produce the most appropriate response, save energy and increase survival.

Misconception or misidentification of a stimuli.
- (more!) swans and motorways.
- Hatchling turtles make errors in navigation if they don’t see the moon when they first hatch to guide them on where to swim, so if people help them into the water in the daytime they may not finding their hatching beach.
- Newly-emerged mayflies.

Learning from others permits spread of behaviour(s) faster than genetic inheritance.
Learning from others permits horizontal, as well as vertical transmission of behaviour(s).
May be especially useful for common behaviour(s) in a changing environment.
Development and change of behaviour occurs due to copying errors.

Innate behaviour: Seminal work by Lorenz (commencing 1931) placed behaviour within the context of the entire species (a move away from the lab-based approach of the comparative psychology movement in the USA).
Maturation, practice and experience overtime, e.g. hunting badly and not getting food then developing better hunting behaviour.
Chance.
Self-learning, repetition and practice.
Learning from others.
Insight learning, an individual learning to perform a behaviour with no prior knowledge about it.

An instinctive behavioural sequence that is highly stereotyped and species-characteristic.
Fixed action patterns are most likely produced by the innate releasing mechanism (releaser).
Once released, a fixed action pattern runs to completion.
E.g. squeezing a babies cheeks makes it start suckling as they’re very sensitive and it’s the motion babies commence to feed.

Stereotyped Complex Species-characteristic Released Triggered Independent of experience

Sign stimulus or releaser
- The essential cues needed to allow a fixed-action pattern to be performed.
- Presence of a specific characteristic, identified by the animal = behaviour.
Supernormal stimulus
- Elicits an exaggerated response.

Male bowerbirds developing plumage too early means they don’t get time to watch other males creating bowers as they get chased away.

Behaviour is determined by a single (or few) specific environmental event experienced at a crucial stage in life.
For example:
- Temperature.
- Diet.
- Almost all reptiles put their eggs in a nest which is incubated by the sand around them, depending on egg placement the temperature is different and this determines the gender of offspring.