An Introduction to Cognitive Psychology

Processes and Disorders

David Groome

• Publisher: Routledge
• Year: 2021
• ISBN:
  9781351020848
• Edition: 4
• Topic: Psychology
• Subtopic: History & Theory in Psychology
• Index: Psychology

An Introduction to Cognitive Psychology: Processes and Disorders provides a comprehensive, yet accessible, overview of the field for undergraduate students. The fourth edition has been thoroughly revised throughout to provide a comprehensive introduction to the core topics of cognition, including memory, perception, thinking, and language. Uniquely, alongside coverage of normal cognitive function, the book also includes chapters on clinical disorders such as agnosia, amnesia, and aphasia, providing a more balanced insight into the nature of cognition and its related disorders.

Key features:

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• Completely revised and updated throughout to provide a comprehensive overview of current thinking in the field

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• Accessibly written by experienced textbook authors and academic experts, including Michael Eysenck and Sophie Scott

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• A new chapter on Problem Solving, written by Fernand Gobet, a leading authority in the field

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• Greater coverage of neuropsychological disorders, with additional coverage of brain imaging research

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• Features a wealth of real-world examples throughout to bring research to life

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• Specially designed textbook features, chapter summaries, further reading, and a glossary of key terms

An Introduction to Cognitive Psychology will appeal to all students on an undergraduate psychology degree course, as well as to those studying in related clinical professions.

chapter 1

Introduction to cognitive psychology

David Groome

DOI: 10.4324/9781351020862-1

Contents

1.1 Cognitive processes

1.2 Experimental cognitive psychology

1.3 Computer models of information processing

1.4 Cognitive neuroscience and neuropsychology

1.5 Automatic processing

1.6 Minds, brains, and computers

Summary

Further reading

1.1 Cognitive processes

A definition of cognitive psychology

Cognitive psychology has been defined as the psychology of mental processes, or more specifically the way in which the brain processes information. Cognition includes the way we take in information from the outside world, how we make sense of that information, and what use we make of it. Cognition thus involves various different kinds of information processing, which occur at different stages.

Cognitive psychology The study of the way in which the brain processes information. It includes the mental processes involved in perception, learning and memory storage, thinking, and language.

Stages of cognitive processing

The main stages of cognitive processing are shown in Figure 1.1, arranged in the sequential order in which they would typically be applied to a new piece of incoming sensory input.

Figure 1.1
The main stages of cognitive processing.

Information taken in by the sense organs goes through an initial stage of perception, which involves an analysis of its content. Even at this early stage of processing the brain is already extracting meaning from the input, in an effort to make sense of the information it contains. The process of perception will often lead to the making of some kind of record of the input received, and this involves learning and memory storage. Once a memory has been created for some item of information, it can be stored for later use to assist the individual in some other setting or task. This will normally require the retrieval of the information. Retrieval is sometimes carried out for its own sake, merely to access some information stored in the past. On the other hand, we sometimes retrieve information to help us to perform further mental activities such as thinking. Thought processes often make use of memory retrieval, for example when we use previous experience to help us deal with some new problem or situation. However, thinking usually involves more than just the retrieval of old memories, as we often need to rearrange and manipulate stored information to make it fit in with a new problem or task.

The cognitive processes shown in Figure 1.1 are, in reality, a good deal more complex and interactive than this simple diagram implies. The diagram suggests that the various stages of cognitive processing are clearly distinct from one another, each one in its own box. This is a drastic oversimplification, and it would be more accurate to show the different stages as merging and overlapping with one another. For example, there is no exact point at which perception ceases and memory storage begins, because the process of perception in itself actually creates the memory trace, so in a sense these processes are continuous. In fact all of the stages of cognition shown in the diagram overlap and interact with one another, but a diagram showing all of these complex interactions would be far too confusing, and in any case, a lot of the interactions would be speculative. Figure 1.1 should therefore be regarded as a greatly simplified representation of the general sequential order of the cognitive processes which typically occur, but it would be more realistic to think of cognition as a continuous flow of information from the input stage through to the output stage, undergoing different forms of processing along the way.

Approaches to the study of cognition

There have been four main approaches to the study of cognitive psychology (see Figure 1.2).

Figure 1.2
The four main approaches to studying cognitive psychology.

In the first place there is the approach known as experimental cognitive psychology, which involves carrying out scientific experiments on human participants to investigate the ways in which they perceive, learn, remember, or think. A second approach to cognitive psychology is the use of computer modelling of cognitive processes. Typically this approach involves the simulation of certain aspects of human cognitive function by writing computer programs, in order to test out the feasibility of a possible mechanism of brain function. The third approach is known as cognitive neuropsychology, which involves the study of individuals who have suffered some form of brain injury. We can discover a great deal about the working of the normal brain by studying the types of cognitive impairment which result from lesions (i.e. damage) in certain regions of the brain. Brain damage can impair information processing by disrupting one or more stages of cognition, or in some cases by breaking the links between different stages. The fourth approach to cognition is known as cognitive neuroscience, and this involves the use of techniques such as brain imaging (i.e. brain scans) to investigate the neural activities that underlie cognitive processing. The two most widely used brain-imaging techniques are PET scans (positron emission tomography) and MRI scans (magnetic resonance imaging). PET scans involve the detection of positrons emitted by radioactive chemicals injected into the bloodstream, whereas MRI scans detect responses to a powerful magnetic field. Both techniques can provide accurate images of brain structures, but MRI is better at detecting changes over a period of time, as for example in measuring the brain’s response to a stimulus of some kind.

Experimental cognitive psychology The scientific testing of psychological processes in human and animal subjects.

Computer modelling The simulation of human cognitive processes by computer. Often used as a method of testing the feasibility of an information-processing mechanism.

Cognitive neuropsychology The study of the brain activities underlying cognitive processes, often by investigating cognitive impairment in brain-damaged patients.

Lesion Tissue damage, which in the brain is usually caused by a stroke, a tumour, an infection, a direct injury, or a progressive disease such as Alzheimer’s dementia.

Cognitive neuroscience The investigation of human cognition by relating it to brain structure and function, normally obtained from brain-imaging techniques.

Figure 1.3
An MRI scanner.

Source: Science Photo Library

These four approaches to cognition have all proved to be valuable, especially when it has been possible to combine different approaches to the same cognitive process. The rest of this chapter deals with these approaches to cognitive psychology, starting with experimental cognitive psychology (Section 1.2), then computer modelling (Section 1.3), and finally cognitive neuroscience and neuropsychology (Section 1.4). Subsequent chapters of the book will continue to apply the same four basic approaches in a more detailed study of each of the main areas of cognition.

1.2 Experimental cognitive psychology

The first cognitive psychologists

The scientific study of psychology began towards the end of the nineteenth century. Wilhelm Wundt set up the first psychology laboratory at Leipzig in 1879, where he carried out research on perception, including some of the earliest studies of visual illusions. In 1885, Hermann Ebbinghaus published the first experimental research on memory, and many subsequent researchers were to adopt his methods over the years that followed. Perhaps the most lasting work of this early period was a remarkable book written by William James in 1890 entitled Principles of Psychology. In that book James proposed a number of theories of cognition, which are still broadly accepted today, including (to give just one example) a theory distinguishing between short-term and long-term memory.

Figure 1.4
William James.

Source: Science Photo Library

The rise and fall of behaviourism

Cognitive psychology made slow progress in the early years due to the growing influence of behaviourism, an approach which constrained psychologists to the investigation of externally observable behaviour. The behaviourist position was clearly stated by Watson (1913), who maintained that psychologists should consider only events that were observable, such as the stimulus presented and any consequent behavioural response to that stimulus. Watson argued that psychologists should not concern themselves with inner mental processes (such as conscious experience and thought) which could not be directly observed. The behaviourists were essentially trying to establish psychology as a true science, using the same approach as other sciences such as physics or chemistry. This was a worthy aim, but like many worthy aims it was taken too far. The refusal to consider inner mental processes had the effect of restricting experimental psychology to the recording of externally observable behaviour, which was often a rather trivial result of complex mental processes. Indeed, some behaviourists were so keen to eliminate inner mental processes from their studies that they preferred to work on rats rather than on human participants.

Behaviourism An approach to psychology which constrains psychologists to the investigation of externally observable behaviour, and rejects any consideration of inner mental processes.

Figure 1.5
A rat learning to run through a maze.

Source: Shutterstock.

A human being brings a whole lifetime of personal experience to the laboratory, which cannot be fully observed or controlled by the experimenter. A rat presents rather fewer of these unknown and uncontrolled variables. A notable example of the behaviourist approach is the classic work carried out on learning by B.F. Skinner (1938), who trained rats to press a lever in order to obtain a food pellet as a reward (or ‘reinforcement’). The work of Ski...