Anti-associationistic positions
Not all psychologists have accepted the general validity of association theories; many have suggested that considerations other than association are crucial to learning.
Organization
Major critics of association theory included such Gestalt psychologists as Wolfgang Köhler (1887–1967), who held that learning often entails a perceptual restructuring of environmental relationships. Köhler cited his own studies of insightful learning by a chimpanzee. The animal learned to join two sticks (akin to a jointed fishing pole) as a tool to pull in a banana that was out of arm’s reach and of either short stick alone. The ape was described as sitting quietly (as if in thought), and then suddenly fitting the sticks together to rake in the fruit. It was argued that the ability to perceive new ways of relating the sticks to the banana was essential in solving the problem.
Similar organizational processes in perceiving can be demonstrated in serial verbal learning. Memorizing the list thick, wall, it, tea, of, myrrh, seize, knots, trained should demand some rehearsal. Yet, notice the phonetic resemblance to Shakespeare’s famous line from The Merchant of Venice: “The quality of mercy is not strained. . . .” With that kind of perceptual organization, learning can become quick and easy.
A powerful argument also was made by psycholinguists who criticized what they took to be the associationistic account of language learning. Even assuming one-trial acquisition, it was held that such individually learned associations could not account for all combinations of words people use; there are simply too many. They suggested that learning a language requires some general organizing structure on which words are hung. Some proponents of this position hold that this structure does not depend on learning, being transmitted genetically from parent to child.
Inhibition
Gestalt interpretations often reject the associationistic hypothesis wholesale. Other theorists endorse the notion of association, but hold it to be less important than is a process of inhibition through which errors in learning are eliminated. Such theorists find support in evidence for the development of learning sets (what is called learning to learn).
For example, a monkey may learn a long series of discriminations; e.g., red versus green, black versus white, round versus square, large versus small, triangle versus ellipse. After solving several hundred such problems, some monkeys learn to master each new one in a single trial, as if insightfully. The animal is said to have learned to learn such discriminations.
Evidence clearly shows that the monkey gradually abandons erroneous tendencies as learning proceeds. At first it might be prone to choose stimuli that are red, black, round, large, or triangular. Correct choices do not always correspond to the animal’s initial biases, and their suppression (inhibition, extinction) eventually permits single-trial learning. Theoretically, organisms learn to learn by inhibiting erroneous behaviour; thus, Harry F. Harlow, a proponent of this view, called it an error-factor theory.
Motivation in learning
Motivation popularly is thought to be essential to learning. Yet many theorists suggest that motives make little or no direct contribution—that they simply tend to promote practice.
Motivation and performance
Learning was defined above as a change in a behavioral potentiality. Realization of such potential seems to be related to the learner’s level of motivation. A pupil who has learned the names of all members of the British Commonwealth of Nations would be expected to recite them with particular energy under some sort of incentive (reward or punishment). The incentive is said to raise his level of motivation.
Incentives do seem to invigorate performance up to a point; however, when motivation seems particularly intense, some studies show performance to deteriorate. From such data some theorists conclude that the effect of drive intensity on performance follows a U-shaped course, first helping and later hindering.
Greatly increased motivation also may change performance qualitatively by introducing new inefficient modes of behaviour. A student may be so tautly driven to do well on an examination that his tension, fear of failure, and his visceral and muscular discomfort interfere with performance.
Motivation and learning
To show that motivation affects performance of what has been learned is not the same as demonstrating its effect on the process of learning itself. This would require that individuals learn under various levels of motivation and be tested under the same incentive levels. (This is to control for the effects of motivation on performance alone.) And, indeed, the best-controlled experiments of this design indicate learning effects to be the same under different levels of motivation.
Varieties of learning
It is debated whether all forms of learning represent the same process. This question applies even to relatively primitive phenomena such as classical and instrumental conditioning.
In instrumental conditioning reinforcement is contingent on the learner’s response; a rat receives food only if it presses the lever. In classical conditioning there is no such contingency; a dog is fed whether or not it salivates. But this is a distinction in experimental procedure. Whether the underlying process of learning is the same for both is quite another question.
Classical conditioning usually has been reported for glandular, autonomically mediated, involuntary responses (e.g., salivation, heart rate). By contrast, voluntary movements of skeletal muscles more typically have been found to be conditionable instrumentally. However, to theorize that classical conditioning is exclusively effective for one class of responses while instrumental conditioning is uniquely applicable to others seems to be a mistake.
Evidence that seems to demolish such theorizing comes from a series of experiments directed by Neal E. Miller at the Rockefeller University in New York City. Rats were immobilized with curare; this drug blocks the junction between muscle and nerve to paralyze the skeletal muscles. However, a curarized individual still can show autonomic, involuntary signs of emotional activity such as a rapidly beating heart.
Electrical stimulation of selected parts of the brain seems to be rewarding; animals behave as if they seek such stimulation and will learn to press a switch for it (voluntary muscle function). Using curarized animals, Miller and others made the rewarding stimulation contingent on such typically involuntary responses as changes in heart rate, blood pressure, contractions of the bowel, and salivation. Their research has shown such instrumental conditioning to be effective for all these responses. The evidence appears to destroy the once-popular hypothesis that involuntary autonomic reactions are subject only to classical conditioning. In this sense the two primitive forms of learning seem to be the same.
Stages of learning
Should the basic process prove to be the same for all varieties of learning, there would still be reason to believe that it operates differently from one stage of practice to another. For example, in coping with painful stimuli (e.g., electric shocks) laboratory animals seem to learn in two successive, distinguishable phases. Apparently they first learn to fear the situation, then to avoid it.
For example, when an animal learns to avoid painful shock (by turning a paddle wheel or by running away), a warning signal can be given; e.g., with a flash of light or a buzzer. The two stages of learning then can be studied separately. The animal first is subjected to pairings of signal and unavoidable shock to establish (by classical conditioning) signs of fear in response to the signal. In the second stage it is allowed to stop the frightening signal by making an appropriate response. Preconditioned members of the many animal species have learned to avoid the signal itself, even though shock never was presented again.
Theoretically, the classically conditioned signs of fright in response to the initially neutral signal have a motivating function. Termination of that stimulus is seen as instrumental—that is, as rewarding the animal by reducing learned experiences of fear.
Classical conditioning
A two-stage process has been suggested even for classical conditioning. One theory is that in the first stage the subject learns that a neutral stimulus (a ringing bell) is to be presented along with another stimulus (food) whether or not it exhibits a reaction (salivation). Conditioning of any reaction is held to constitute the second stage of learning. The skimpy supporting evidence points to the first stage as a prerequisite, suggesting that responses can only be conditioned after the sensory conditions are recognized.
Verbal learning
Theories that interpret verbal learning as a process that develops in stages also have been worked out. In one variety of rote learning the subject is to respond with a specific word whenever another word with which it has been paired is presented. In learning lists that include such paired-associates as house–girl, table–happy, and parcel–chair, the correct responses would be girl (for house), happy (for table), and chair (for parcel). By convention the first word in each pair is called the stimulus term and the second the response term. Paired-associate learning is theorized to require subprocesses: one to discriminate among stimulus terms, another to select the second terms as the set of responses, and a third to associate or link each response term with its stimulus term. Although these posited phases seem to overlap, there is evidence indicating that the first two (stimulus discrimination and response selection) precede the associative stage.
Remembering and forgetting
Learning, remembering, and forgetting often have been considered separate processes. Yet these distinctions seem to blur in the face of contemporary research and theory.
Transient and enduring memory
Evidence for stages of learning comes from observations of learners over relatively extended series of trials (or comparatively long periods). The empirical data suggest that several alterations in memory function occur even during a single trial. The process that commits information to memory also seems to have several stages.
Most theorists attribute at least three stages to memory function: immediate, short-term, and long-term. Immediate memory seems to last little more than a second or so. For example, subjects may be asked to remember where specific objects are located within a complex array they have just seen. Their performance shows that considerable information is retained only briefly, rapidly fading unless it is given special attention.
Short-term memory lasts about 15–30 seconds, as after looking up a telephone number. One makes the call, discovers he has forgotten the number (perhaps in the midst of dialing), and has to look it up again. Nevertheless, such short-term retention does make information available long enough to be rehearsed; if the learner repeats it to himself, the number can be transferred to some sort of longer term storage.
Thus, rehearsal seems to facilitate transfer of data from short-term to long-term memory. Once committed to long-term memory, the results of learning tend to endure but can be abruptly abolished when specific parts of the brain are injured or removed; they also are vulnerable to interference from other learning. Nevertheless, conditioned responses may undergo little or no forgetting over periods of months or years. And electrical stimulation of the surgically exposed brain while a person is awake can make him remember experiences long thought forgotten. Recall is reported to be similarly enhanced during hypnosis.
Retrieval
The amount of information one readily can retrieve from what is stored in memory is prodigious. In locating an item in memory, he apparently activates a system that stores a set of related data; then he searches for the item within that system. For example, a person is shown a long, randomly mixed list of words that belong to different categories (e.g., names of animals, plants, professions, tools). When asked to remember as many words as he can, he spontaneously will tend to group them by category; this is called clustering of recall. Thus, names of animals (spread throughout the original list) are likely to be remembered one after the other.
Studies of the familiar tip-of-the-tongue experience yield analogous results. College students who heard definitions (of this sort: a small, open Chinese boat) were asked to supply the right word (in this case it would be sampan). Those who said they might have it somewhere on the tip of the tongue were significantly accurate in guessing the first letter and the number of syllables. Their tendency also to recall words that sounded the same or that had similar meanings is reminiscent of clustering.
Considerable evidence of this kind supports the theory that the process of retrieval first locates stored data in some sort of associative network and then selects an item with specific characteristics.
Forgetting
Whether immediate and short-term data simply decay or are lost through interference is a matter of controversy. However, evidence is clearer that interference affects retention of information in long-term storage. Retention of the word happy (learned as a paired associate of table) seems to be subject to the interference of a strong tendency to associate table with chair. Thus, the paired associate table–happy becomes more readily forgotten when followed by parcel–chair as the very next item in a list; this seems to help chair reassert its old tendency to be associated with table. In general, it is found that associations tend to interfere with or to inhibit one another. Interference deriving from earlier (and later) associations is called proactive inhibition (and retroactive inhibition). These two forms of inhibition commonly are accepted as major processes in forgetting, proactive inhibition being assigned greater importance.
