Learning is a relatively permanent change in an organism’s behavior due to experience. In associative learning, we learn to associate two stimuli (as in classical conditioning) or a response and its consequences (as in operant conditioning). In observational learning, we learn by watching others’ experiences and examples. Learned associations also feed our habitual behaviors.

As we repeat behaviors in a given context—the sleeping posture we associate with bed, our walking routes on campus, our eating popcorn in a movie theater—the behaviors become associated with the contexts.

Conditioning is not the only form of learning. Through observational learning, we learn from others’ experiences. Chimpanzees, too, may learn behaviors merely by watching others perform them. If one sees another solve a puzzle and gain a food reward, the observer may perform the trick more quickly.

By conditioning and by observation we humans learn and adapt to our environments. We learn to expect and prepare for significant events such as food or pain (classical conditioning). We also learn to repeat acts that bring good results and to avoid acts that bring bad results (operant conditioning).

In classical conditioning, a unconditional reflex (UR) is an event that occurs naturally (such as salivation), in response to some stimulus. A unconditional stimulus (US) is something that naturally and automatically (without learning) triggers the unlearned response (as food in the mouth triggers salivation).

A conditional stimulus (CS) is a previously irrelevant stimulus (such as a bell) that, through learning, comes to be associated with some unlearned response (salivating). A conditional reflex (CR) is the learned response (salivating) to the originally irrelevant but now conditioned stimulus.

Pavlov repeatedly presented a neutral stimulus (such as a tone) just before an unconditioned stimulus (UCS, food) that triggered an unconditioned response (UCR, salivation). After several repetitions, the tone alone (now the conditioned stimulus, CS) triggered a conditioned response (CR, salivation).

Salivation in response to the tone was conditional upon the dog’s learning the association between the tone and the food. Today we call this learned response the conditioned response (CR). The previously neutral (in this context) tone stimulus that now triggered the conditional salivation we call the conditioned stimulus (CS). Distinguishing these two kinds of stimuli and responses is easy: Conditioned =learned; unconditioned = unlearned.

Our educational, cultural, and life experiences shape what we perceive. As a simple example, consider airplane cockpits.

If your knowledge of the instruments contained in an airplane cockpit is limited, as is the case with your author Sandy, an airplane cockpit looks like a confusing, meaningless jumble of dials.

It agrees when giving experimental researches, two neuron classes take part in formation of conditioned reflexes: command neurons which realize specific behavioral acts and modulating neurons, which adjust a condition of command neurons. Before the first appearance of stimulus and supporting reflex neurons were mainly monotouch. In process of the further development of a conditioned reflex neurons get ability to answer different stimulus, that is become polytouch. After the conditioned reflex is produced, again it is observed selective reaction of neurons - they answer only stimulus, which became conditional irritant.

The synaptic hypothesis considers that the mechanism of formation of a conditioned reflex is caused by change of an overall performance of synapses.

The membrane hypothesis asserts that in a basis of the mechanism of formation of a conditioned reflex change of excitability of postsyneptic membrane lays.

For development of a conditioned reflex it is necessary, that any factor of an environment, which may be perceived by one of analyzer systems of an organism, occur repeatedly and acted on an organism of the person or an animal. If at each occurrence this irritant outstrips a little or takes place simultaneously with performance of any unconditioned reflex in an organism, probability of development of a conditioned reflex very high. But for formation of a conditioned reflex still it is necessary, that the brain cortex be in an active, awake condition.

For development of a conditioned reflex the important value has optimum force of irritant, which may become conditional irritant. Small force irritant does not cause a sufficient level of activity in neurons of appropriate analyzer system. In this case the conditioned reflex is formed slowly. Such conditioned reflex exists the short period of time and then is fast inhibited.

In real conditions irritants from the environment do not occur as isolated factor. There are a set of similar irritants and such irritants, which operate simultaneously

The opportunity spreading excitation in the central nervous system is caused by presence in it of numerous branches of shoots of nervous cells - axons and dendrites. Shoots connect neurons and the nervous centres in a uniform network. Strengthening of irritation neurons stimulates distribution of excitation on nervous circuits. Due to existence of such communications excitation long time may circulate on closed neuronal to circuits, till opportunities of synapses to transfer impulses will be exhausted or there will be a braking process in any of neurons, so the circuit will be opened.

The centre of excitation, which arises in a brain cortex under action of conditional stimulus may be spread on neuronal circuits in all directions. But if simultaneously in an organism the unconditioned reflex is carried out, in a zone of cortical representations of this reflex the prepotent centre varying a direction spreading of excitation develops. In such a case distribution of the excitation caused by a conditional irritant, will be directed aside dominants.

Dominanta (from Latin dominare - to dominate) - is the centres of excitation prevailing in the central nervous system, which change and subordinate to themselves activity of other nervous centres at present. The principle of a dominant is one of main principles of activity of the central nervous system. The Russian scientist O.O. Ukhtomsky was formulated these principles.

The prepotent centre of excitation is characterized by such properties:

1) Increase of excitability; 2) Stability of excitation; 3) Ability to summarize excitation - to accumulation of

excitation from stranger irritants; 4) Ability to inhibit function of other nervous centres and

reflex reactions; 5) Ability long time to keep excitation after the termination

(ending) of irritation, which has caused it (inertia of a dominant).

I. On a way of formation: 1. Classical conditioned reflexes - are formed in natural

conditions. 2. Tool conditioned reflexes - are developed artificially.

More often they represent purposeful motor reactions. As supporting stimulus for their development the unconditioned reflex causing in a laboratory animal feeling of pleasure (effect of "award") or painful irritant, causing avoidance reaction usually serves.

II. Under the relation of conditional irritant to unconditional:

1. Natural conditioned reflexes - conditional irritant it is related to an unconditioned reflex. For example, a smell and how a food looks have the direct relation to irritation by food of tongue receptors, which starts unconditional salivatory discharge reaction.

2. Artificial conditioned reflexes - conditional irritant has no the direct relation to an unconditioned reflex which serves as a reinforcement. For example, the bell or a light signal in natural conditions have no the relation to unconditional salivatory discharge reflex.

III. On biological importance: 1. Food conditioned reflexes - provide getting food and

digestion. 2. Sexual conditioned reflexes - provide sexual behavior. 3. Protective conditioned reflexes - provide defensive reactions. 4. Statokinetic conditioned reflexes - provide motor behavioral

reactions and impellent skills. 5. Homeostatic conditioned reflexes - are directed on

maintenance of a constancy of the inner environment of an organism.

III. On a degree of complexity: 1. Conditioned reflexes of the first order - the conditioned reflex

is developed on the basis of a unconditioned reflex. 2. Conditioned reflexes of the second order - the conditioned

reflex is developed on the basis of other conditioned reflex of the first order.

3. Conditioned reflexes of the third order - the conditioned reflex is developed on the basis of a conditioned reflex of the second order.

4. Conditioned reflexes of the higher order - are formed only at the high organization of nervous system. In human formation of conditioned reflexes of the second - twentieth order is probably.

B. F. Skinner (1904–1990) was a college English major and an aspiring writer who, seeking a new direction, entered graduate school in psychology. He went on to become modern behaviorism’s most influential and controversial figure.

Skinner’s work elaborated what psychologist Edward L. Thorndike called the law of effect: Rewarded behavior is likely to recur. Using Thorndike’s law of effect as a starting point, Skinner developed a behavioral technology that revealed principles of behavior control. These principles also enabled him to teach pigeons such unpigeonlike behaviors as walking in a figure 8, playing Ping-Pong, and keeping a missile on course by pecking at a screen target.

Skinner showed that when placed in an operant chamber, rats or pigeons can be shaped to display successively closer approximations of a desired behavior. Researchers have also studied the effects of primary and secondary reinforcers, and of immediate and delayed reinforcers. Partial reinforcement schedules (fixed-ratio, variable-ratio, fixed-interval, and variable-interval) produce slower acquisition of the target behavior than does continuous reinforcement, but they also create more resistance to extinction.

Punishment is most effective when it is strong, immediate, and consistent. However, it can have undesirable side effects.

Fixed-ratio schedules reinforce behavior after a set number of responses. Just as coffee shops reward us with a free drink after every 10 purchased, laboratory animals may be reinforced on a fixed ratio of, say, one reinforcer for every 30 responses.

Once conditioned, the animal will pause only briefly after a reinforcer and will then return to a high rate of responding.

Variable-ratio schedules provide reinforcers after an unpredictable number of responses. This is what slot-machine players and fly-casting anglers experience—unpredictable reinforcement—and what makes gambling and fly fishing so hard to extinguish even when both are getting nothing for something.

Like the fixed-ratio schedule, the variable-ratio schedule produces high rates of responding, because reinforcers increase as the number of responses increases.

Fixed-interval schedules reinforce the first response after a fixed time period.

Like people checking more frequently for the mail as the delivery time approaches, or checking to see if the Jell-O has set, pigeons on a fixed-interval schedule peck a key more frequently as the anticipated time for reward draws near, producing a choppy stop-start pattern rather than a steady rate of response.

Variable-interval schedules reinforce the first response after varying time intervals. Like the “You’ve got mail” that finally rewards persistence in rechecking for e-mail, variable-interval schedules tend to produce slow, steady responding. This makes sense, because there is no knowing when the waiting will be over.

Animal behaviors differ, yet Skinner contended that the reinforcement principles of operant conditioning are universal. It matters little, he said, what response, what reinforcer, or what species you use. The effect of a given reinforcement schedule is pretty much the same: “Pigeon, rat, monkey, which is which? It doesn’t matter. Behavior shows astonishingly similar properties.”

Learning by Observation

• In observational learning, we observe and imitate others. Mirror neurons, located in the brain’s frontal lobes, demonstrate a neural basis for observational learning.

• Another important type of learning, especially among humans, is what Albert Bandura and others call observational learning.

Mirror Neurons in the Brain• PET scans of different brain areas reveal that humans, like

monkeys, have a mirror neuron system that supports empathy and imitation.

• Mirror neurons help give rise to children’s empathy and to their ability to infer another’s mental state, an ability known as theory of mind. People with autism display reduced imitative yawning and mirror neuron activity—“broken mirrors,” some have said.

Bandura’s Experiments• Albert Bandura is the

pioneering researcher of observational learning. A preschool child works on a drawing. An adult in another part of the room is building with Tinkertoys.

• As the child watches, the adult gets up and for nearly 10 minutes pounds, kicks, and throws around the room a large inflated Bobo doll, yelling, “Sock him in the nose. . . . Hit him down. . . . Kick him.”

Experienced and imagined pain in the brain

• Brain activity related to actual pain (left) is mirrored in the brain of an observing loved one (right).

• Empathy in the brain shows up in emotional brain areas, but not in the somatosensory cortex, which receives the physical pain input.

Children tend to imitate what a model does and says, whether the behavior being modeled is prosocial (positive, constructive, and helpful) or antisocial. If a model’s actions and words are inconsistent, children may imitate the hypocrisy they observe.

The big news from Bandura’s studies is that we look and we learn. Models—in one’s family or neighborhood, or on TV—may have effects—good or bad.