A BRIEF HISTORY OF COGNITIVE PSYCHOLOGY

A brief history of cognitive psychology Cognitive psychology did not begin at any one defining moment, and there are many antecedents to its evolution as a branch of enquiry.

 In this section we will briefly sketch some of those antecedents and try to indicate how and why they resulted in the development of what today we call cognitive psychology. However, all written history is necessarily selective and simplified, and a historical account as brief as the one we are about to give must be especially so. We start with introspectionism.

INTROSPECTIONISM:

Modern experimental psychology has its roots in the work conducted in Europe in the mid nineteenth century by such people as Donders, Fechner, Helmholtz and Mach. When Wundt established the first dedicated psychology laboratory in Liepzig in 1879, he sought to build upon the efforts of these pioneers. He took consciousness to be the proper subject matter of psychology. According to Wundt, physical scientists study the objects of the physical world either directly or, more often, through observation of the readings on instruments. In either case, observation is mediated by conscious.

FOUNDATIONS OF COGNITIVE PSYCHOLOGY:

Conscious experience that preceded the response. For example, if one condition in an experiment yielded longer RTs than another, he wanted to know how the two preceding conscious experiences differed. Wundt was not concerned with the unconscious processes involved in responding to a simple stimulus – the rapid information-processing operations that, as you will find in the following chapters, form much of the subject matter of modern cognitive psychology. He considered these to lie in the realm of physiology rather than of psychology. 

In opposition to Wundt’s Liepzig school was the Wu¨ rzburg  school of introspection. Its leader, Ku¨lpe, was a former student of Wundt’s, who with his colleagues and students developed an alternative view of conscious experience and what could be revealed by introspection. in relation to the topic of perception, although the protagonists would not have used these exact terms themselves.

 Put simply, the Liepzig school held that the contents of consciousness are constructed ‘bottom-up’ from simple sensations combined in accordance with the strength of association between them .

 The Wu¨ rzburg school, on the other hand, held that the contents of consciousness are determined in a much more ‘top-down’ fashion by the nature of the task that one is engaged upon. Ku¨lpe and his colleagues sometimes studied simple tasks, but tended to favour more complex ones in which mental acts such as attending, recognizing, discriminating and willing played a larger role. 

Introspectionism went into a terminal decline during the first two decades of the twentieth century. The details of the many unresolved disagreements between the two schools of introspectionism need not detain us here, but it is worth noting two things. First, the introspectionists developed elaborate classifications of conscious experience, a topic that has quite recently begun to attract the attention of psychologists once again.

 Second, although psychologists began to lose interest in consciousness during those two decades, the exploration of consciousness still remained central to developments in the visual and literary arts (e.g. cubism and expressionism in painting, and James Joyce, Virginia Woolf and Gertrude Stein in literature).

GESTALT PSYCHOLOGY :

The perceived failures of introspectionism provoked a number of intellectual reactions. In Europe, the gestalt psychologists built upon the work of the Wu¨ rzburg school and argued that the contents of consciousness cannot be analysed into simple component sensations. 

According to Wundt, the perception of movement results from a sequence of sensations corresponding to an object occupying successive locations over time. However, Wertheimer argued in 1912 that ‘pure movement’ can be perceived directly; it does not have to be ‘inferred’ from changesin the location of an object. A good example is when we see the wind gust through grass. Blades of grass bend in succession but no blade changes location. What we perceive is pure motion (of the invisible wind) without a moving object. (Modern studies show that motion perception can, in fact, arise either on the basis of the changing location of an object or from successive changes across space without a moving object.) Gestalt psychologists also emphasized the importance of the perception of stimulus Patterning to our conscious experience. 

A tune played in one key on one sort of instrument remains the same tune when played in another key or on a different instrument. Since the notes, or the sounds making up the notes, have changed in each case, there must be more to the tune than can be found by an analysis into simple auditory sensations. The tune is in the perceived relationships between the notes, their patterning. Meanwhile, in the USA, William James opposed introspectionism with his ‘functionalist psychology’. 

Sounding remarkably like an exponent of what is now called evolutionary psychology, James stated that, ‘Our various ways of feeling and thinking have grown to be what they are because of their utility in shaping our reactions to the outer world’. These functions of the mind were, in James’s view, the proper subject matter for psychology. Perceiving and thinking, grief and religious experience, as psychological functions, were themselves to be the focus of interest, rather than the evanescent contents of consciousness on which the introspectionists had fixated. However, James’s ideas were soon to be largely swept aside by another and more powerful current in US thought, which was behaviourism.

 BEHAVIOURISM:

The founders of behaviourism were driven by various motives, not all shared in common. Watson, the principal standard-bearer for the new kind of psychology, was especially keen to move psychological research out of the laboratory and into ‘the real world’. He was less interested in fine distinctions of conscious experience than in how people act in everyday life, and in how they can be influenced. He wanted to see psychological knowledge applied to education, clinical problems and advertising, and he initiated work in all these areas. 

Not all behaviourists were as zealous as Watson when it came to applying psychology, but one belief they did have in common was that psychology should be scientific and objective; and by this they meant that its subject matter should be publicly observable. Consciousness is (at best) only privately observable; it is not publicly observable. What is publicly observable is behaviour and stimuli. So psychologists such as Thorndike, Watson and, later, Skinner, Eysenck and others argued that psychology should be scientific in its approach, and should seek to explain behaviour through reference only to stimuli. The emphasis on public observation wasintended to place psychology on an objective footing, akin to the natural sciences like physics and chemistry, and it reflected a wider philosophical consensus as to the proper nature of scientific enquiry.

 SCIENCE AND THE UNOBSERVABLE:

 In all human efforts to comprehend the world there is a tension between, on the one hand, observable events and, on the other hand, the often encountered need when explaining them to postulate unobservable theoretical entities and forces, whether gods or atoms. This  tension is central to science. A key idea in the development of science has been that knowledge should be empirical, based on experience not on received wisdom or purely rational calculation. 

Observation is one of the touchstones of science, but scientific theories also refer to unobservables. The explanation that physics offers for an apple falling to Earth invokes the notion of a gravitational force, something that is not directly observable. Similarly, in explaining why a compass needle points to magnetic north, physicists talk of magnetic fields, and lines of magnetic force. But these thingstoo are unobservable. If you have ever placed iron filings near a magnet, you will see that they will move to orient themselves along the lines of the magnetic field.

 But,strictly, we don’t observe the magnetic field, nor the lines of magnetic force, but rather their influence upon the iron filings. All naturalsciences employ unobservable, theoretical constructsthat are invoked in order to explain observations. For example, chemistry appeals to notions such as the energy levels of electrons in order to explain why compounds react. These levels are unobservable too, of course. So, the fact that a discipline is committed to explaining observed behaviour by reference to hypothesized, unobservable constructs does not in itself render the discipline unscientific. 

But to find scientific acceptance, unobservable constructs have to be seen to do useful theoretical work. When Newton proposed the notion of a gravitational force, certain critics immediately accused him of introducing a mystical notion into ‘the new science’. Newton’s ideas gained acceptance only because they met other scientific criteria – such as elegance,simplicity and rigour – and because the concept of gravitation, despite its somewhat mysterious nature, had a wide range of application. Gravitation explained not just the fall of objects to the ground but also the rhythm of the tides and the movements of the planets. It could also be precisely formulated mathematically as an inverse square law: the attraction between any two bodies varies as the square of the distance between them. In other words, the willingness of the scientific community to countenance a hypothetical unobservable depends on how useful it is judged to be on a range of criteria. Science has had to live with the necessity for unobservables. 

But acceptance through necessity is not liking, and science always receives a boost when a technical breakthrough for the first time brings a previously unobserved entity into the realm of observation. For example, Mendel postulated ‘units of heredity’ on the basis of his plant-breeding observations, but these ideas were felt to be on a firmer footing once new technology made it possible to see chromosomes and genes. 

Thus,scientists are forced somewhat grudgingly to accept the need for postulating unobservables. And because science – like all human institutions – is subject to swings of fashion, the willingness to countenance unobservable theoretical entities fluctuates over time. For reasons which we are unable to describe here, but which were rooted in the growing crisis of classical physics that would culminate in the birth of quantum theory and relativity theory, the late nineteenth and early twentieth century was a period during which scientists were particularly intolerant of unobservables. The importance of observation became enshrined in the assumption known as operationism. This is the idea that theoretical concepts are only meaningful to the extent that they can be exhaustively analysed in terms of thingsthat can be observed.

Back to behaviourism :

The bias against unobservables affected all the traditional sciences and also the newer, aspirant scientific disciplines such as physiology and psychology. The introspectionists, with their ‘observations’ of consciousness, had responded to it, but the intellectual climate seems to have been especially suited to propagating an emphasis on what could be publicly observed. With the decline of introspectionism, behaviourism was taken up enthusiastically, first in the USA and then more widely. While behaviourists could, perhaps, concede the existence of consciousness while arguing that it was not appropriate for scientific study, at least some of them felt that operationism committed them to the stronger claim that talk of consciousness was not even meaningful. Of course, behaviourism has never been a single view, and since the time of Watson and Thorndike behaviourists of various hue have modified their positions.

 Skinner, for example, conceded that internal mental events, including conscious experiences, might exist (indeed they were construed as forms of covert behaviour). But despite this rejection of operationism, even Skinner still thought that talk of internal events should be avoided within a scientific psychology. You might think that avoiding talk of internal events might make it impossible to explain many, or even most, psychological phenomena. However, behaviourists were concerned to show how even complex phenomena might be understood in terms of principles of learning, with behaviour seen as made up of learned responses to particular stimuli. 

One view of language production, for example, was that the utterance of a word could be seen as a learned response. The utterance of a whole sentence could be seen as involving a chain of stimulus–response pairs, in which each response (the utterance of a word) also serves as the stimulus that leads to the production of the next response (the next word). Despite the possibility of giving behaviourist explanations of complex activities such as the utterance of a sentence, behaviourists tended not to offer accounts of what we now refer to as higher mental processes – processes such as producing and understanding language, planning, problem solving, remembering, paying attention, consciousness and so on. As the years passed, however, some psychologists came to see this as a major failing.

 THE RETURN OF THE COGNITIVE:

In 1948, at a meeting known as the Hixon symposium, Karl Lashley gave a talk entitled ‘The problem of serial order in behaviour’ (Lashley, 1951). In this, he gave prominence to the problems posed for behaviourist accounts by complex actions in which behaviour segments are somehow linked together in a sequence, and where two segments depend upon one another, even though they may be separated by many intervening segments. Language, as you might have guessed, provides a prime example.

 In fact, the last sentence illustrates the point nicely: when I came to write the word ‘provides’ in the previous sentence I chose to end it with the letter ‘s’. I did so, of course, because this verb has to agree grammatically with the singular noun ‘language’, the subject of the sentence. In my actual sentence, these two words were separated by a clause, and so my action at the time of writing the word ‘provides’ depended upon a much earlier behaviour segment – my writing of the word ‘language’. Lashley argued that since the production of some words in a sequence could be shown to depend upon words produced much earlier, the simple view that each word is the stimulus that produces the subsequent word as a response could not properly explain language production.

 He also argued that many behaviour sequences are executed simply too rapidly for feedback from one segment to serve asthe trigger for the next. He cited examples such as the speed with which pianists and typists sometimes move their fingers, or with which tennis players adjust their whole posture in response to an incoming fast service. Lashley’s alternative to the chaining of behaviour segments was to suppose that complex sequences are planned and organized in advance of being initiated. 

 Lashley’s view that behaviourism could not properly explain how people produce (or comprehend) language was later reinforced by a review of Skinner’s book Verbal Behavior (1957) by the linguist Noam Chomsky (1959). Chomsky argued, contra behaviourism, that language could not be thought of as a set of learned responsesto a set ofstimulus events. His argument had a number of different aspects. 

For example, he argued that children seem to acquire their first language too effortlessly – if you have tried to learn a second language you can perhaps testify to the difference between learning a first and learning a second language. While the latter seems to require intensive and effortful study, the former is something that pretty much everyone does without the need for formal schooling. He also argued that if the behaviourists were right, then exposing children to impoverished or ungrammatical language should hinder their learning of the correct stimulus– response relationships. 

Yet studies show that much of the speech to which young children are exposed is indeed ungrammatical and otherwise impoverished, and this in no way preventsthem from learning the grammar of their native tongue. Similarly, he argued that general intelligence ought to influence the learning of stimulus– response relationships. Again, however, intelligence does not seem to influence whether or not children learn the underlying grammatical rules of their language. 

Chomsky presented many other arguments to the same effect, and though many of these have been thought to be contentious, his position was extremely influential in setting up an alternative, cognitive conception of language. Most significantly, Chomsky proposed that language is rule-based and that, far from children learning language by learning how to respond to particular stimuli, their acquisition of language involves acquiring its rule-base. On this view, my being able to write grammatical sentences involves deploying my (generally implicit, or unconscious) knowledge of the rules of language.

 In referring to such implicit knowledge, Chomsky proposed that an understanding of how people produce, comprehend or acquire language will necessarily involve reference to something that cannot be directly observed – their knowledge of the underlying rules, or organization, of the language. Although this emphasis on the role of planning, organization and rules in the generation of behaviour was to be hugely influential from the 1950s onwards, these ideas were certainly not new to psychology. 

As mentioned previously, the gestalt psychologists had drawn attention earlier in the century to the importance of patterning, or organization, for perception, and the same point was also made in relation to action. Someone who haslearned to sing or hum a tune can very probably manage to whistle it thereafter. Yet singing, humming and whistling call for very different sequences of muscle movements. This indicates that learning a tune must involve learning a set of abstract relationships between notes which can be instantiated as any of a variety of muscular productions.

 A similar idea, that what is learned must often be more abstract than straightforward stimulus–response connections, was also expressed by the school of ‘cognitive behaviourists’ associated with Tolman (1932). Rats that had learned, for example, repeatedly to turn left in a maze to find food were shown to swim left when the maze was flooded. Since the muscle movements of running and swimming are completely different from one another, the rats must clearly have learned something more abstract than a particular chain of muscular responses. 

Even before the writings of the gestalt psychologists or the work of Tolman, psychologists studying the acquisition of skills had realized the importance of planning and organization for the production of skilled behaviour, such as in morse telegraphy or typing (Bryan and Harter, 1899). At the time of the Hixon symposium, therefore, there were already existing traditions within psychology upon which the renewed interest in the planning and structure of behaviour could draw. 

And, of course, the intellectual climate of the mid twentieth century was changing rapidly in many other ways too. New technologies were influencing the ability of scientists to conceptualize the workings of complex systems. One of the most crucial issues related to the type of causal explanation that is appropriate to explain the behaviour ofsuch a system. 

Purposive, or teleological, explanations had been taboo in Western science since the time of thinkers such as Galileo and Newton. Where, for example, an ancient Greek philosopher might have said that a stone falls to earth ‘in order to’ reach its natural resting place at the centre of the earth (which was also the centre of the Greek universe), Newton said that the stone falls because it is acted upon by the force of gravity. 

The strategy of explaining phenomena in terms of causes that precede and ‘push’ their effects, rather than in terms of goals, or final states, towards which events are ‘pulled’, had proved highly successful in the physicalsciences. The move from goal-directed, purposive explanations to mechanical cause-effect explanations was usually considered to be a move from prescientific, animistic thinking to proper scientific thinking. 

Behaviourism was, and still is, an attempt to bring psychology into step with this way of analysing phenomena. A strict emphasis on an organism’s history of conditioning allows an explanation of behaviour in terms of prior causes rather than of future goals. However, the development of progressively more complex artificial devices started to call into question the universal applicability of explanations in terms only of prior causes. It became increasingly clear that, while the functioning of the mechanical parts of any such system can be explained in cause-effect terms, such explanations will never capture the function (or purpose) of the whole system. Central to the new kind of apparently purposive machines (known as servomechanisms) was a reliance on feedback loops. 

Feedback is information about the match or mismatch between a desired goal-state and an existing state of affairs. The classic example is the domestic central heating system, in which the thermostat setting selected by the householder is the goal-state and the temperature measured by an air thermometer is the existing state. The two are compared mechanically. If the existing temperature is less than the desired temperature, this negative feedback is transmitted to the boiler controls causing the boiler to be switched on. The boiler continues to fire until information has been fed back to the boiler controls that the discrepancy between the actual and desired temperatures has been eliminated. The system as a whole exhibits a simple but dynamic behaviour, with the boiler turning on and off in a manner that maintains room temperature at or about the desired level. Importantly, the function of maintaining a steady temperature cannot be localized to any one component of the heating system, such as the thermostat, the thermometer, the boiler or its controls, but is a property of the system – as a whole. 

Far more complicated servomechanisms with more complex feedback controls were also being developed. Anti-aircraft gunnery may not seem very pertinent to an understanding of animal and human behaviour, but it was partly as a result of working on gunnery problems in the Second World War that the mathematician Norbert Weiner developed the notion of ‘cybernetics’, the science ofself-governing, or goal-directed, systems. Accurate anti-aircraft gunnery requires that a projectile is fired, and timed to explode, not at the present location of the target aircraft but at its future location. 

This means not only predicting the future position of the plane but also rotating the gun so it faces in the appropriate direction and with the correct elevation. Clearly, humans successfully extrapolate flight paths and aim at future positions when, for example, shooting game birds. However, for planes flying at ever greater heights and speeds, calculation of the necessary trajectory of the projectile exceeds human capabilities and must be computed automatically. Moreover, using motors to move a gun weighing many tons is a very different matter from moving a shotgun, or indeed a bow and arrow, held in your arms.

 Although we are mostly unconscious of it, normal bodily movement is based upon continuous muscle, tendon and visual feedback about how the movement is proceeding. Unless similar feedback is designed into the gun control system, the swinging anti-aircraft gun may easily undershoot or overshoot the intended position, particularly as, depending on the air temperature, the grease packed round the mechanism will be more or less ‘stiff’.

 Apply too little power and the gun will undershoot the intended position, a second push will be required and the gun will ‘stutter’ towards its position. Apply too much force and the gun will overshoot, and will have to be pulled back, in what can turn into a series of increasingly wild oscillations.

 Engineers discovered that the smoothest performance was achieved by using feedback loops to dynamically control the turning force applied to the gun. Weiner, and other cyberneticists such as Ashby, recognized the importance of feedback and self-correction in the functioning of these new and complex technological devices, and they also saw analogies with complex natural systems. Weiner drew parallels between the effects of certain neurological conditions and damage to the feedback control of behaviour. For example, the tremors observed in Parkinsonian patients were likened to the oscillations of an anti-aircraft gun when its movement is insufficiently ‘damped’ by feedback control. An important intellectual leap for cognitive psychology came with the realization that just the same kind of analysis can be applied at any level of behavioural control. In other words, it is not just automatic homeostatic functions or unconsciously executed movements that can be analysed in terms of feedback loops but any function/behaviour from the wholly non-conscious to the fully conscious and intended. Miller et al. (1960) developed the notion of feedback control into the hypothesis that behaviour (of animals, humans or machines) can be analysed into what they called TOTE units. TOTE stands for Test-Operate-Test-Exit. A test is a comparison between a current state and a goal-state. If a discrepancy is registered, some relevant operation intended to reduce the discrepancy will be performed (e.g. switch on the boiler). A second test, or comparison, is then conducted. If a discrepancy remains, the operation can be repeated, followed by another test. If the discrepancy has been eliminated, the system exits the TOTE unit. Miller et al. conceived of the TOTE unit as an advance on the conditioned reflex notion of Pavlov and the conditioned response notion of Watson and Skinner, both of which can be conceptualized as TOTEs. 

The aim wasto develop a unit of analysis of behaviour that could apply to everything from a dog’s conditioned salivatory response to deliberate, planned action. The TOTE provides a basic pattern in which plans are cast; the test phase specifies what knowledge is necessary for a comparison to be made, and the operation phase specifies what the organism does about the outcome of the comparison. Although this scheme makes it possible to talk about purposive behaviour, and about unobservable goals and comparison operations, there is continuity from behaviourism. Cognitive psychology generally attempts to retain the scientific rigour of behaviourism while at the same time escaping from the behaviouristic restrictions in relation to unobservables. 

An important property of TOTEs is that they can be nested within hierarchies. The operation segment of any TOTE can itself be composed of one or more TOTE units. For example, the TOTE for starting the car might be nested within the operation of a larger TOTE for driving to the shops, which might itself be nested within a still larger unit having the goal of buying a present. This nesting of feedback loop units provides a way to conceptualize how behaviour can be complexly structured. In this scheme, moment-to-moment control of behaviour passes in sequence between a series of TOTE goal-states, with the TOTE units themselves nested in hierarchies. 

Miller et al. explicitly likened this ‘flow of control’ of behaviour to the way in which control in a computer program switches in orderly fashion from command line to command line as the execution of any particular subroutine is completed. (Note: what ‘flows’ around a TOTE can be energy, information or, at the highest level of conceptual abstraction, control.)