A4 Innate and learned behaviour Flashcards
What is innate behaviour?
Innate behaviour is inherited from parents and so develops independently of the environment. An example of innate behaviour is, if an object touches the skin in the palm of a baby’s hand, the baby grips the object by closing its fingers around it. This innate behaviour pattern, called the palmar grasp reflex, is seen in babies from birth until they are about 6 months old no matter what experiences the baby has. Innate behaviour is genetically programmed, so it is inherited. It can change through evolution if there is genetically determined variation in behaviour and natural selection favours one behaviour pattern over others, but the rate of change is much slower than with learned behaviour.
What are the two types of research methods in animal behaviour?
- laboratory experiments, the variables can be highly controlled, but the disadvantage is that animal behaviour is an adaptation to the natural environment of the species and animals often do not behave normally when removed from that environment, especially with learned behaviour.
- field investigations
What is the disadvantage of laboratory experiments to look at animal’s behaviour?
the disadvantage is that animal behaviour is an adaptation to the natural environment of the species and animals often do not behave normally when removed from that environment, especially with learned behaviour.
How else can we study innate behaviour?
We can study behaviour by looking at invertebrates, they have relatively simple behaviour patterns and so they can be studied more easily than mammals, birds or other vertebrates. A stimulus can be given and the response to it observed. Repeating the stimulus with a number of individuals allows quantitative data to be obtained and tests of statistical significance to be done. Once the response to a stimulus has been discovered, it may be possible to deduce how the response improves animals chances of survival and reproduction and thus how it evolved by natural selection as an innate behaviour pattern.
Many different invertebrates can be used in experiments. Planarian flatworms, woodlice, blowfly larvae, snails, beetles.
Two types of behaviour can be studied:
- Taxis is the movement towards or away from a directional stimulus. An example is movement of a woodlouse or slater away from light.
- Kinesis also involves movement as a response, but the direction of movement is not influenced by a stimulus. Instead, the speed of movements or the number of times the animal turns is varied. An example is slower movement, with more frequent turning, when woodlice are transferred from drier to more damp conditions.
What are reflexes?
Autonomic and involuntary responses are referred to as reflexes.
A stimulus is a change of environment, either internal or external, that is detected by a receptor and elicits a response. A response is a change in an organism, often carried out by a muscle or a gland. Some responses happen without conscious thought and are therefore called involuntary responses. Many of these are controlled by the autonomic nervous system. These autonomic and involuntary responses are known as reflexes.
A reflex is a rapid unconscious response to a stimulus. The pupil reflex is an example: in response to the stimulus of bright light, the radial muscles in the iris of the eye contract, constricting the pupil. This involuntary response is carried out by the autonomic nervous system.
What is a stimulus?
A change in the environment
What are reflex arcs?
A reflex arc is the system of neurones linking the receptor to the effector. The simplest one just has 2 neurones, a sensory neurone to take the impulse from the receptor to a synapse with a motor neurone in the spinal chord, and then the motor neurone to carry impulses on to the effector.
Explain the withdrawal reflex?
The pain withdrawal reflex is an innate response to a pain stimulus. For example dropping a hot pan. The pain receptors in the skin detect the heat and activate sensory neurones which carry impulses from the fingers to the spinal chord via the dorsal route of the spinal nerve. The impulses travel to the end of the sensory neurone in the grey matter of the spinal chord where there are synapses with relay neurones. The relay neurones have synapses with motor neurones, which carry impulses out of the spinal chord via the ventral root and to muscles in the arm. Then the muscle contracts and pulls the hand away from the hot object.
Draw a reflect arc?
PAGE 536 STILL NEEDS TO BE DONE
What is learned behaviour?
Learned behaviour develops as a result of experience. For example, human offspring inherit the capacity to learn a language.
How are innate behaviours and learned behaviours exhibited in birds?
All members of a bird species share innate aspects of song, allowing each individual to recognise other members of the species. In many species males also learn mating calls from their father. The learned aspects introduce differences, allowing males to be recognised by their song and in some species to be chosen by the quality of singing.
What is reflex conditioning?
Reflex conditioning involves forming new associations by establishing new neural pathways in the brain. Conditioned reflexes are used extensively in animal behaviour and can greatly increase survival chances.
For example, birds have an innate reflex to avoid foods with a bitter taste - this is an unconditioned reflex, but they have to learn which insects are likely to have that taste. If a bird eats a black and white insect and finds that it tastes unpleasant it develops an association between black and yellow stripes and bitter taste and therefore avoids them in the future.
What were Pavlov’s experiments and what did they demonstrate?
The 19th century Russian physiologist Pavlov developed apparatus to collect saliva from the mouth of his experimental dogs. He found that saliva was secreted in response to the sight or smell of food. These types of stimulus, to which all dogs respond without learning, are called unconditional stimuli and the secretion of saliva that results is the unconditioned response.
While doing this he noticed that the dogs also started to secrete saliva before the stimulus arrived and therefore something else must be acting as a stimulus. He found that the dogs could learn to use a variety of signals this way, including the ringing of a bell, the flashing of a light, a metronome ticking or a musical box playing. These are examples of conditioned stimuli and the secretion of saliva that these stimuli elicit is the conditioned response. Pet dogs and children also quickly learn indicators that they will soon be fed.
What is imprinting?
Imprinting is learning occurring at a particular life stage and is independent of the consequences of behaviour.
Imprinting can only occur at a particular stage of life and is the indelible (making marks that cannot be removed) establishment of a preference or stimulus that elicits behaviour patterns, often but not always of trust recognition. An example is greylag geese.
The greylag goose will incubate her eggs so that she is the first large object that they will see. The young birds then follow their mother around during the first few weeks of life. She leads them to food and protects them.
Young geese that are incubated away from their mother will still attach themselves to another large moving object. This can be a bird of another species or a boot, or an inanimate moving object. This is called imprinting and was discovered by Lorenz.
The critical period in greylag geese when imprinting occurs is 13-16 hours after hatching. A distinctive feature of imprinting is that it is independent of the consequences of the behaviour - in experiments animals remain imprinted on something even if it does not increase their chance of survival.
What is operant conditioning?
Operant conditioning is a form of learning which consists of trial and error experiences.
It is different to reflex conditioning, whereas reflect conditioning is initiated by the environment imposing a stimulus on an animal, operant conditioning is initiated by an animal spontaneously testing out a behaviour pattern and finding out what its consequences are. Depending on whether the consequences are positive or negative for the animal or its environment, this behaviour pattern is either reinforced or inhibited.
Lambs learn not to touch electric fences by operant conditioning.
