Animal learning

This part of the syllabus

• Simple learning (classical and operant conditioning) and its role in the behaviour of non-human animals.• What do you know

What is going to be covered

• Acquisition • Extinction • Spontaneous Recovery• Disinhibition • Generalization & Discrimination • Higher-order conditioning & Preconditioning

Acquisition

• Acquisition: The gradual development and strengthening of a CR. • The S-R association requires a number of pairings of the CS and US before an CR develops. • The more times the CS and US are paired, the stronger the CR. • The stronger the US is and the stronger the NS is, the stronger and faster conditioning will be. • The strength of the CR will increase up to a certain point, and will then level off. – For example, as a dog is repeatedly presented with a tone and food, the amount of salivation increases until it reaches a certain peak, at which point it will remain at that level.

Extinction

• Continually presenting a CS without a US, will result in the elimination of the CR. • When the CS no longer elicits a CR, experimental extinction is said to have occurred. – Situations where it is useful to extinguish the CR?

Factors Affecting Extinction

• 1. The strength of the CR. The stronger the CSCR bond, the slower the extinction of the CR. • 2. Influence of Predictiveness: If the CS is occasionally presented alone during acquisition, resistance to extinction is increased. • 3. Exposure to Cs: As the duration of the CS exposure in extinction increases, the strength of the CR weakens.

• Is the CR completely extinct? How can we tell?

Spontaneous Recovery

• The reappearance of the CR after a rest period following extinction. • Becomes weaker each time it occurs after extinction

Does this remind you of anything?

Spontaneous Recovery

To Pavlov, extinction is not a matter of “unlearning”, but of inhibiting (suppressing) the CR. (still exists on some underlying level)

– Example: Imagine that you have a problem with test anxiety. Part way through taking a test, your anxiety level starts to die down. Then, someone walks into the test late and you experience a fresh wave of anxiety.

Evidence for Pavlov’s View

• What causes this? Perhaps the process of disinhibition (the sudden recovery of a response during an extinction procedure when a novel stimulus is introduced).

• This shows that the CR is still right there, ready to return once your “guard” is down – It also provides evidence for Pavlov’s view that extinction is caused by inhibition rather than unlearning.

Classical Conditioning: A Refinement

• It is not very efficient to have to learn a separate conditioned response to every single conditioned stimulus that is similar. • At other times, it is important only to make the conditioned response to a very particular stimulus.

• What are these processes called?

Generalization and Discrimination

• Examples of Stimulus Generalization • Example: someone frightened at the sight of blood may transfer their fear to other red objects. • Little Albert -- conditioned fear of white rat that generalized to other white fuzzy things • Can lead to the onset of Phobias- Overgeneralization of fears to inappropriate stimuli

Stimulus Discrimination

• Stimulus Discrimination: The tendency for a response to be elicited by one stimulus and not another – – Example: baby learns that food comes from its Mum (CS=Mum’s face) but not from any other person.

Second order conditioning

• Drill (US) - Whirring sound (NS) –- fear (UR)• Haridryer NS2 - Whirring sound (CS) –- fear (CR)• Haridryer CS2 –- fear (CR)

Outline key features of classical conditioning. (8 marks)

Mark Scheme

• Features of Pavlovian classical conditioning include reflexive unconditioned responses, such as salivation, to unconditioned stimuli such as food; paired presentation of unconditioned neutral stimulus (eg bell) with the unconditioned stimulus; development of the conditioned response to the neutral stimulus. Other features such as forwards/backwards conditioning, extinction, stimulus generalisation and discrimination, and spontaneous recovery would also be relevant. Note that for marks in the top band answers should be accurate and well detailed. To move beyond Basic, in addition to an accurate outline of the basic Pavlovian paradigm there should be reference to one or more additional features.

Operant Conditioning

• What do you know!

Operant Conditoning

• Key Word is reinforcement• There are four possible outcomes to behaviour:• Positive reinforcement • Negative reinforcement

• Positive Punishment• Negative punishment

Positive reinforcement

• Positive reinforcement can also be called rewards. Rewards take on many forms. For animals, one of the most common rewards is food. Indeed, many behaviors animals do in the wild are for getting food. If certain behaviors allow an animal to get food successfully, the animal will repeat these behaviors the next time it is hungry.• Food is an example of a primary reinforcer. Primary reinforcers are

reinforcers that are automatically positive. An animal does not have to learn to "like" them. Other examples of primary reinforcers include water, shelter, and mating opportunities. Several types of primary reinforcers provide tactile stimulation, like a good back scratch. For people, a hug can be very reinforcing.

Negative reinforcement

• Negative reinforcement is not punishment. Punishment involves giving an unfavourable consequence. Punishment decreases the likelihood of a behavior repeating. Both positive and negative reinforcement increase the likelihood that a behaviour will be repeated.

• Almost all traditional animal training consists of the applied use of negative reinforces. The horse learns to turn left when the left rein is pulled, because by doing so it can ameliorate the tugging feeling in the left corner of it's mouth. Elephants, oxen, camels, and other beasts of burden learn to move forward, halt, pull loads, and so on to avoid the tug of a halter, the poke or blow of a prod, goad, or whip.

• People use spontaneous negative reinforcers on each other all the time: The warning glance, the frown, the disapproving remark. Some children's lives, and some spouses' lives too, are filled with constant daily effort to behave in such a way as to avoid disapproval.

• If this is not good enough use baby crying - parents remove crying.

Positive Punishment

• Positive punishment is something that is applied to reduce a behaviour. The term "positive" often confuses people, because in common terms "positive" means something good, upbeat, happy, pleasant, rewarding. Remember, this is technical terminology we're using, though, so here "positive" means "added" or "started". Also keep in mind that in these terms, it is not the animal that is "punished" (treated badly to pay for some moral wrong), but the behaviour that is "punished" (in other words, reduced). Positive punishment, when applied correctly, is the most effective way to stop unwanted behaviours. Its main flaw is that it does not teach specific alternative behaviours.

Examples• Our society seems to have a great fondness for positive punishment, in spite of all the problems

associated with it. The peeing on the rug (by a puppy) is punished with a swat of the newspaper. A dog's barking is punished with a startling squirt of citronella. The driver's speeding results in a ticket and a fine. The baby's hand is burned when she touches the hot stove. Walking straight through low doorways is punished with a bonk on the head. In all of these cases, the consequence (the positive punishment) reduces the behaviour's future occurrences.

Negative punishment

• Negative punishment is reducing behaviour by taking away Something Good. If the animal was enjoying or depending on Something Good she will work to avoid it getting taken away. They are less likely to repeat a behaviour that results in the loss of a Good Thing. This type of consequence is a little harder to control.

Examples

• The child has his crayons taken away for fighting with his sister. The window looking into the other monkey's enclosure is shut when the first monkey bites the trainer. "This car isn't getting any closer to Disneyland while you kids are fighting!" The dog is put on leash and taken from the park for coming to the owner when the owner called (this causes the unintentional result of the dog being less likely to respond to the recall). The teenager is grounded for misbehaviour. The dolphin trainer walks away with the fish bucket when the dolphin acts aggressive. "I'm not talking to you after what you did!" Xena The Warrior Princess cuts off the air of an opponent who refuses to tell her what she wants.

In short

• Positive reinforcement: receiving something pleasant.• Negative reinforcement: not receiving something unpleasant.

• Positive Punishment: receiving something unpleasant.• Negative punishment: not receiving something pleasant.

Primary and secondary

• Primary occur naturally and directly satisfy biological needs. Eg: food• Secondary where they have to be learned and indirectly satisfy

biological need eg: money.

Behaviour Shaping

• Using operant conditioning to gain a desired outcome through reinforcement.

• B. F. Skinner used shaping—a method of training by which successive approximations toward a target behaviour are reinforced—to test his theories of behavioural psychology.

• Shaping involves a calculated reinforcement of a "target behaviour": it uses operant conditioning principles to train a subject by rewarding proper behaviour and discouraging improper behaviour.

• The method requires that the subject perform behaviours that at first merely resemble the target behaviour; through reinforcement, these behaviours are gradually changed or "shaped" to encourage the target behaviour itself.

• Skinner's early experiments in operant conditioning involved the shaping of rats' behaviour so they learned to press a lever and receive a food reward.

• Shaping is commonly used to train animals, such as dogs, to perform difficult tasks; it is also a useful learning tool for modifying human behaviour.

Source: Boundless. “Shaping.” Boundless Psychology. Boundless, 20 Aug. 2015. Retrieved 15 Sep. 2015 from https://www.boundless.com/psychology/textbooks/boundless-psychology-textbook/learning-7/operant-conditioning-47/shaping-198-12733/

Reinforcement Schedules

• Fixed Ratio• Fixed Interval• Variable ratio• Variable interval

• Watch this

Role of learning in Non-human animals• Learn whether food sources are safe.

• Biological Preparedness: Is the animal predisposition to learn.

• Trial and error is used often with operant conditioning

Research

• Skinner: rats and doves• Baker trial and error learning by pigeons to discover navigational aids.• Fisher and Hinde showed that animals learn behaviours similar to

innate ones. Blue tits stripping the tops off milk similar to stripping bark off trees.

Evaluation

• Social learning also occurs through observation and imitation• Does not account for innate influences such as biological

preparedness or instinctive drift.• Behaviourism sees no role for free will.• Unethical training animals for warfare.• Emotional and cognitive factors eg: insight learning by chimps

The Ecological Perspective

• Skinner’s view was that virtually any response can be conditioned in any stimulus situation—this is known as equipotentiality. In fact, this is not true. Some behaviours are harder to learn than others and even harder to maintain because of “instinctive drift”, i.e. the preference for a behaviour that is instinctive may replace or modify the conditioned behaviour. This is shown in research by Gaffan, Hansel, and Smith (1983) in which rats in a T-shaped maze had to decide whether to turn left or right. According to conditioning, if the rat was rewarded for turning left it should turn left on the following trial. However, in the natural environment the rat would not return to where it had just removed food. Gaffan et al. found that early in training rats tended to avoid the arm of the maze in which they had previously found food, as predicted from the ecological perspective. This shows the influence of their instinctive behaviour.

EVALUATION OF OPERANT CONDITIONING

Applications. The principles of operant conditioning (OC) have been used effectively in the training of animals and this has generated many positive applications. For example, OC has been used to teach language to chimps, and the learning process involved has informed understanding of children who have learning difficulties. Thus, OC has made significant contributions both theoretically and in applied psychology.Equipotentiality lacks validity. Skinner’s concept of equipotentiality is incorrect, as is his assumption that operant conditioning is uninfluenced by instinctive behaviour, as instinctive drift shows animals have a preference for instinctive behaviour. Circularity. We only know that a stimulus is a reinforcer because it reinforces! It is not a scientific statement, because there is no way that it can be tested. This means the concept of reinforcement is circular and lacks scientific validity.

Individual differences. Food is a fairly universal source of reinforcement for animals—all animals need food! However, other forms of reinforcement may have a less consistent effect, as whether the reinforcement is rewarding or punishing is open to interpretation. Ignores other forms of learning. Other forms of learning are possible. Humans often engage in observational learning—they learn simply by observing someone else being rewarded for behaving in a certain way. Operant conditioning does not account for the more sophisticated social learning. Ignores nature. Skinner exaggerated the importance of external or environmental factors as influences on behaviour and minimised the role of internal factors. For example, apes have innate personalities and instinctive behaviours.Difficult to distinguish between CC and OC. A key problem is that it can be difficult to distinguish between CC and OC in the learning process. For example, if we take Pavlov’s research, was the food the UCS or was it a source of positive reinforcement?

Scientific validity. The research on OC is conducted in the controlled conditions of the laboratory and so it can be replicated to check reliability and has greater control of confounding variables and so higher internal validity.External validity. Research in the laboratory is artificial, e.g. rats pressing a lever, dogs salivating to a bell, and so it is difficult to know how well the theory generalises to real-life animal behaviour. The simple conditioning researched in the laboratory is much more complex in real life.Ignores cognitive factors. The rejection of the influence of cognition (because this is not observable or measurable) is a key limitation of OC as animals are capable of developing expectancies that a particular form of reinforcement will follow a behaviour. This is a significant omission since cognitive factors are an important part of the learning process.

Instinctive drift

Instinctive drift or instinctual drift is the tendency of an animal to revert to instinctive behaviours that interfere with a conditioned response. The concept originated with B.F. Skinner's former students Keller Breland and Marian Breland when they tried to teach a raccoon to put tokens into a piggy bank. Instead, the raccoon drifted to its instinctive behaviour of putting the tokens on the ground or turning them over in its paws, as they often do with food.

Notes handout and essay question.