Neuropsychology

From Theory to Practice

David Andrewes

• Publisher: Psychology Press
• Year: 2015
• ISBN:
  9781317313205
• Edition: 2
• Topic: Psychology
• Subtopic: History & Theory in Psychology
• Index: Psychology

The second edition of this comprehensive textbook for students of Neuropsychology gives a thorough overview of the complex relationship between brain and behaviour. With an excellent blend of clinical, experimental and theoretical coverage, it draws on the latest research findings from neuroscience, cognitive neuroscience, neurochemistry, clinical neuropsychology and neuropsychology to provide students with new insights in this fast moving field.

The book is organised around the main neuropsychological disorders in the areas of perception, executive dysfunction, attention, memory, cerebral asymmetry, language, emotion and consciousness. There is a clear emphasis on bridging the gap between theory and practice with links throughout to clinical issues of both assessment and rehabilitation to build a clear understanding of the application of the theoretical issues. The final section in each chapter illustrates the importance of a more systematic approach to intervention, which takes into account theoretical views of recovery from brain damage.

New to this edition:

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• A new chapter format that includes a "basic topic" section, which contains up-to-date essential knowledge of the topic and a "further topics" section for a more advanced treatment of the area.

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• A new section on neuroscientific approaches to rehabilitation in each chapter to make links between scientific knowledge and clinical treatment.

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• A brand new chapter on consciousness

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• A new full colour layout with increased pedagogical features, including key terms, section summaries, 'study questions' and improved presentation of figures and brain diagrams

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• A companion website including related weblinks, guidance on answering the 'study questions', and flashcards.

This book will be invaluable for undergraduate students in Neuropsychology and students who wish to take the subject further to the various clinical fields.

An Introduction to Neuropsychology

Contents

1.1A General Introduction

1.1.1What is Neuropsychology?

1.1.2An Introduction to this Chapter

1.1.3How Neuropsychology is Related to Other Disciplines and Research Methods

1.2Brain Evolution and Interspecies Comparisons

1.2.1The Evolution of Cerebral Structure

1.2.2What is it about Our Brain that Helps Us to Adapt?

1.2.3Summary of Brain Evolution and Interspecies Comparisons

1.3Essential Elements of Brain Structure and the Vascular System

1.3.1Grey Matter and White Matter and Cytoarchitecture

1.3.2The Cerebrovascular System

1.3.3Summary of the Essential Elements of Brain Structure and the Vascular System

1.4A Historical Introduction to Theoretical Perspectives

1.4.1Introduction

1.4.2Early Historical Perspectives within Neuropsychology

1.4.3Alexander Luria and the Functional Systems Model

1.4.4The Thinking Brain

1.5A Guide to this Book

1.1A General Introduction

1.1.1What is Neuropsychology?

Whether you are a student or a lecturer in neuropsychology, the study of the relationship between brain and behaviour always surprises. In this book there are descriptions of patients who fail to attend to one side of space, some who are blind and yet still believe they can see, some who do not know the meaning of objects around them, others who have completely lost their ability to learn new information, and still others who even believe that their own family are imposters. All these disorders, and many more, make neuropsychology a fascinating and exciting area of study. The question that neuropsychologists ask is: ‘What is it about this patient’s brain damage that makes them behave in the way they do?’

The study of neuropsychology is the study of how the brain functions to produce the behaviours and thought processes that we take so much for granted. Neuropsychology is the study of how the brain operates to produce the higher mental functions that broadly come under the headings of cognition (mental processes), emotion and movement. The models used by neuropsychologists may be in terms of broad concepts that prompt pioneering research or they may be more specific in terms of describing interactions between brain areas within networks. At yet another level, neuropsychological research may be in terms of the roles of different neurotransmitters, being the different types of electrochemical messages that pass between the basic unit of the brain, the neuron or neurone.

The neuron or neurone. The brain is estimated to be made up of 86 billion neurons, including glial cells with a multitude of interconnections between them (Azevedo et al., 2009). It is the electrochemical activity between neurons that allows processing within the brain. The neuron is made from a dark cell body (grey matter) and a white stalk or axon (white matter) that allows projection to other neurons, some of which are in other brain areas (see Figure 1.7).

Most of the chapters of this book are divided into two sections, a first section that endeavours to describe a basic understanding and a further topics section that describes emerging areas and a more speculative approach according to recent findings. At the end of each chapter there is a section on the scientific approach to rehabilitation. This last section is not designed to be comprehensive coverage of rehabilitation techniques but is a means of showing how a good understanding of neuropsychology may help the development of neuropsychological rehabilitation.

Over the years the author has noted apprehension among some students when they are faced with the many unfamiliar neuroanatomical terms that describe parts of the brain. This task is not nearly so challenging when brain structures are described alongside their function. Therefore, while it is assumed that the reader will have access to an additional neuroanatomical text, the uninitiated reader should not be alarmed at the large number of neuroanatomical terms described in this first chapter, since all these terms and descriptions are repeated throughout the book many times. It is expected that the student will learn much of their working neuroanatomy as this book progresses through the various chapters, in a gradual, and hopefully meaningful, process.

1.1.2An Introduction to this Chapter

This first chapter is designed to orient the newcomer to neuropsychology. First, there is a brief section on how neuropsychologists are described as a profession and broadly how research is carried out in the science.

In order to ease the reader into a grasp of basic concepts, this chapter combines an introduction to important brain structures with some reference to their evolutionary significance. Many of the patients studied in neuropsychology have some form of damage to the arterial flow of the brain, therefore there is also a discussion of the main arteries of the brain using the clinical disorder of stroke as a basic exercise. This is continued within Appendix 1.

In the second half of this chapter there is a brief description of the history of neuropsychology. Here there is an accent, not so much on what past researchers have done but rather on their various viewpoints on how brain organisation should be conceived. There is a description ranging from researchers who first introduced the scientific study of neuropsychology to more recent influences. In the final part of this chapter, an initial model of brain function is proposed with two concepts: top-down versus bottom-up processing, and controlled versus passive processing.

1.1.3How Neuropsychology is Related to Other Disciplines and Research Methods

The knowledge base of neuropsychology is also dependent on other allied scientific endeavours, including the study of cognitive psychology and other areas that may be loosely described as neurobiological. This includes neuroscience, neuroanatomy, neuropharmacology and neurophysiology. In this book each chapter describes a disorder of a psychological function (e.g. memory disorders). This approach is largely focused on the interests of clinical and research neuropsychologists (or clinical psychologists who wish to specialise in neuropsychology). Clinical neuropsychologists assess persons through clinical testing in order to describe the psychological impairment and strengths in association with the patient’s brain damage. They will also help other clinicians in the process of diagnosis. Clinical neuropsychologists will aim to describe the patient’s strengths and weaknesses in order to give advice concerning the patient’s management and rehabilitation. Their occupational goal is not so much describing where the brain damage is located, since this can usually be done better with neuroimaging techniques or brain scans. However, in order to report a patient’s ability through assessment, it is necessary to have a knowledge of how brain damage may influence the patient’s functioning in their everyday life. Part of this knowledge will include an understanding of the contribution of brain areas and networks towards their behaviour, cognition and emotional functioning. Research or experimental neuropsychologists assess brain-impaired patients and also persons without brain impairment in order to model and further understand how the brain functions. There are a variety of techniques that might be used by a research or experimental neuropsychologist and these are described through this text (see Appendix 2). Other disciplines have their own specialties. There are Neuropsychiatrists and Behavioural Neurologists, but there are also a variety of professions that work with brain-damaged patients such as Occupational Therapists, Speech Pathologists, Physiotherapists and Rehabilitation Medical Practitioners. These are professions that also have an interest in neuropsychology from their own professional viewpoint.

This book, and the study of neuropsychology generally, has been based on a wide variety of research approaches. Neuropsychiatry is focused on understanding the neuropsychology of mental illness, e.g. schizophrenia, depression; Behavioural Neurology is focused on understanding the behaviour of neurological disorders, and both of these areas have been influenced by the practitioners’ approaches and interests. Cognitive Neuropsychology provides an approach which is more focused on single cases, with the belief that individual differences are so great that it is preferable to model the process of function, e.g. how we process language, rather than describe the function of neural areas. Neuroscience could be seen as the opposite approach, in which the stress is on isolating neural components and testing their function. Neuroscience traditionally has been, and still is, associated with non-human research. While at one time there was a general approach in neuroscience of researching brain function from lower cellular to higher mental function using species such as the mouse, the rat and the macaque monkey, the term has now broadened to cover certain types of research with humans, such as Affective Neuroscience and Cognitive Neuroscience. The last two approaches use the word ‘neuroscience’ because of their attachment to using technical approaches to research. Affective Neuroscience studies emotions in the laboratory using heart rate monitors and other psychophysiological measures, while Cognitive Neuroscience is focused on neuroimaging and other approaches using humans as subjects. Cognitive Neuroscience has made huge contributions to neuropsychological understanding in the last 10 years and is devoted to a number of research approaches; the most dominant of these is the use of neuroimaging, in which scans of the brain are taken at the same time that the participant is carrying out a task (methods are described in Appendix 2). This basic assessment has now been added to by a variety of techniques that are able to map the pathways between brain areas. The basic unit of the brain is the neuron, which has a cell at one end (brain cell) and a stalk or axon that allows it to communicate with other brain cells (see Figure 1.7). A collection of brain cells is referred to as grey matter, while the connecting axon is covered in a fatty white insulating material and so the connections between brain areas are referred to as white matter. New techniques are able to map white matter and are used in conjunction with other techniques that are able to measure brain activity. In this way we now can realise the way brain areas interact to form networks. In this way networks or hubs may be identified that contribute to a particular function, e.g. reading. There are other branches of neuropsychology and neuroscience which have developed in more recent years, such as Social Neuroscience, which studies more general influences on the relationship between brain and social behaviour: for example, the way genetics may effect social behaviour through brain changes during development, or how the practices of therapy may cause measurable changes in the brain (see Nature Neuroscience (2012) 15(5) for some examples).

Lesion is the term broadly used to describe any type of brain damage other than the progressive brain atrophy associated with the dementias.

For many years the only form of human neuropsychological research consisted of comparing groups of patients or individuals with a lesion in a particular location with those without or with a differently located lesion. Differences in performance of the groups led to some inference as to function of the brain area. For example, if one group had lesions in brain area B and they failed on a memory test when compared to a control group, then it would be inferred that area B contributed to memory in some way. While this approach remains an important one, there is a disadvantage in using humans in lesion studies because the natural lesions, such as those following stroke and traumatic brain injury (head injury), are often diffuse and therefore difficult to localise to a functionally discrete area. Also, such approaches provided little understanding of how brain areas interact in a networked dynamic way to produce function. For this reason some studies use patients following brain surgery for their more discrete lesions; however, the nature of the surgery still depends on the disease process, which usually fails to lesion the exact site of theoretical interest. Therefore, it is easy to see the attraction of using non-human animals as models in research despite the problems of generalisation to the human brain.

Because of the difficulties with lesion research there was some excitement when functional neuroimaging was first introduced (Functional Magnetic Resonance Imaging, fMRI) because it offered a non-invasive method of research that showed some promise of localising function. Typically, in these studies the person would be given a task while in the brain scanner. This would show what parts of the brain appeared to be active as they completed certain aspects of the task (see Appendix 2 for a detailed discussion). Nevertheless, thes...