Classic Cases in Neuropsychology

Chris Code, Yves Joanette, André Roch Lecours, Claus-W Wallesch, Chris Code, Yves Joanette, André Roch Lecours, Claus-W Wallesch

• Editorial: Psychology Press
• Año: 2004
• ISBN:
  9781135472443
• Edición: 1
• Categoría: Psicologia
• Categoría: Storia e teoria della psicologia

The importance of detailed examination and theoretical interpretation of the single case has been increasingly recognized in neuropsychology. This book brings together in one volume discussion of the classic cases which have shaped the way we think about the relationships between brain, behaviour and cognition. The single cases covered may be ancient or modern, famous or less well-known. But the book is comprehensive in its coverage of contemporary neuropsychological issues. Represented are classic cases in language, memory, perception, attention and praxis. Some of the cases included are rare, or have acted as catalysts to the development of theory. Some have remained the definitive case; many were the first of their type to be described and gave rise to the development of new syndrome entities. Some are still controversial. In some instances, the cases resulted in major paradigm shifts. Some, while still highly influential, were misinterpreted. But most of them were read only by a few in their original form. Each chapter highlights the relevance of the case for the development of neuropsychology, describes the particular features of the case that are interesting and discusses the theoretical implications.

1
Classic Cases: Ancient and Modern Milestones in the Development of Neuropsychological Science

Chris Code
Brain Damage and Communication Research, School of Communication Disorders, University of Sydney, Australia.

Developments in neuropsychology owe much to the discovery and careful examination of sometimes rare and remarkable individuals. From Broca’s first and most famous case Leborgne and the frontal lobe case Phineas Gage, through the commissurotomy, lobectomy, and hemispherectomy cases, right up to the highly influential deep dyslexia cases of contemporary times, the single case—especially the extraordinary case—has provided new directions and improved our understanding of the way mental life is represented in the brain. In some instances, the interpretation of the case has proved nothing less than revolutionary.

Both the older and the more modern classic cases represent milestones in neuropsychology’s journey. We owe most of what we know about the brain’s control of cognition and behaviour to the damaged brains of a range of often unusual people. Many of these cases have become celebrated and have consequently been established in the annals of neuropsychological history. The patterns of specificity of impairment in these human beings has guided neuropsychology’s central quest, comprehension of the nature of the relationship between brain structure and brain function. Consequently, what is often the most significant contribution of a single case might be the way particular functions may be seen to dissociate or fractionate following brain damage with findings informing theory on the organisation of mental processing. For several of the cases in this book, dissociation of function following brain damage has been the focus of interest.

The significant role of the single case in neuropsychology no doubt owes much to the fact that the origins of neuropsychology lie in neurology and the founding fathers of the field were medical men; the single case has always played a significant role in the development of medicine. While the case study has been important in neuropsychology from its earliest beginnings, there was a period between the wars and on into the 1960s when the relevance of the case was forgotten as workers attempted to take the field forwards through group research. During this period we saw the development of theories of brain and behaviour based on psychometric models derived from group studies. However, coupled with developments in technology and theory, the single case study has returned and has in recent years once more taken centre stage.

Case studies in neuropsychology vary quite widely. Shallice (1979) observed that the case study can last for just a few clinical sessions or several years (see, for instance, Parkin’s Chapter 23 on the bilateral temporal lobectomy H.M. and the continuing studies of that individual’s amnesia). Shallice has suggested that, however long the study lasts, it will usually go through four distinct stages. Firstly, the patient will be selected for study because their pattern of deficits and retained abilities are of potential and special interest. Secondly, the patient is, or at least should be, fully assessed using psychometrically controlled tests and the results should allow the patient to be assigned to a provisional syndrome category. Many of the older case reports, while often rich in qualitative information, lacked adequate quantitative specification. The third stage entails detailed quantitative study of the specific deficits that are of particular interest. For novel syndromes, like some of the cases described in this book, this may simply involve describing the history of the syndrome. For other cases assessment would focus on the specific processing domains that are impaired. More complexly, testing might aim to uncover how impaired mechanisms operate. Theories and methodology from cognitive, experimental, or physiological psychology will probably need to be involved during the more complex stages. Results of testing may demonstrate that the original provisional diagnosis was not appropriate and the study will be abandoned. Finally, Shallice suggests, the results need to be statistically analysed. Of course, Shallice’s criteria refer mainly to contemporary case study research and were often not considered in many of the earlier classic case studies.

But, even for contemporary study, not everyone agrees with the detail of Shallice’s agenda for single case research, particularly in his insistence that quantitative measures be used and that for contemporary study “the psychometric tests performed in clinical assessment are essential baseline tests for any competently conducted case study” (p. 187, 1979), or his suggestion that “the concept of a ‘syndrome’ is essential to the usefulness of the case study” (p. 189, 1979). Alternative views within cognitive neuropsychology on the value of the syndrome approach (Caramazza, 1984; Ellis, 1987; Schwartz, 1984) and psychometric testing (Byng, Kay, Edmundson, & Scott, 1990) have been expressed with many feeling that the syndrome approach to research has outlived its usefulness. However, syndromes have intuitive appeal, and even in cognitive neuropsychology there are strong arguments for the retention of the syndrome approach (Coltheart, 1987; Shallice, 1979). This book is not so much concerned with issues of design of single case studies; discussion on issues of statistical analysis and single case research design can be found in Caramazza (1984), Miller (1993), Shallice (1979), and Willmes (1990).

This notwithstanding, within all branches of neuropsychology, case studies have been centrally influential in theoretical development. Indeed, for neuropsychology it is almost possible to pinpoint certain major changes in direction or conception with the discovery, description and interpretation of an important individual case. This is true of the classic Leborgne of Broca (Chapter 7 by Ryalls and Lecours), the description of whom is generally considered to have proclaimed the very beginnings of modern neuropsychology and the birth of dominance theory. Right up to contemporary times Leborgne’s preserved brain is still capable of generating discussion of theoretical importance (Lecours, Nespoulous, & Pioger, 1987). Although Broca’s case represents the, as it were, “authorised” beginnings of neuropsychology, Broca, like many great scientific originals, owed much to those who had gone before, such as Gall and Bouillaud. As De Renzi points out in Chapter 10, “it is a feature of the history of science that for every discovery attributed to an author a forerunner will sooner or later be found”. Some famous cases, like Phineas Gage (Macmillan in Chapter 18), have been over interpreted. The neuropsychologically useful information we have on Gage has not curbed the extent to which he has been cited as a basis for research and development.

Another case which had a significant impact and continues to inform development is H.M. (Chapter 23 by Parkin), who heralded new ideas on the role of the temporal lobes in memory. Other classic cases from the rich past of neuropsychology include Wernicke’s case of pure agraphia (Chapter 2 by De Bleser), Charcot’s case of impaired imagery (Chapter 3 by Young and van de Wal), Bodamer’s first cases of prosopagnosia (Chapter 6 by Ellis), Poppelreuter’s case of neglect (Chapter 7 by Humphreys, Riddoch, and Wallesch), Liepmann’s original cases of apraxia (Chapter 9 by Gonzalez Rothi and Heilman), Lewandowsky’s case of object-colour agnosia (Chapter 11 by Davidoff) and Monrad-Krohn’s first case of foreign-accent syndrome (Chapter 12 by Moen). Paterson and Zangwill’s case of unilateral neglect (Chapter 13 by Mattingley) while not the first represents, as Mattingley puts it, “a paradigm shift towards objectivity, both in the approach to assessment of patients with unilateral neglect, and in the interpretation of their preserved and impaired capacities.” In Chapter 10, De Renzi brings together classic cases described by Badal, Balint, and Holmes with attentional and oculomotor disorders to delineate a new entity, Balint-Holmes Syndrome.

But while the classic historical case is a well-known phenomenon, no less important are the modern classics. Cases like G.R., who is the first deep dyslexic in the contemporary literature described by Marshall and Newcombe (1966) (discussed in Chapter 14 by Barry), Warrington and Shallice’s (1984) category-specific aphasic case J.B.R. (discussed in Chapter 16 by Semenza and Bisiacchi) and W.L.P. (Schwartz, Marin, & Saffran, 1979), a case which shows that the dissolution of language in dementia can be subject to individual variability and modular deficits can be revealed (discussed in Chapter 15 by Funnell). It is with these contemporary classic cases that the most influential development in recent years began, the advent of cognitive neuropsychology.

A number of cases discussed in this book are concerned with that central quest for much neuropsychology, understanding the nature of the representation of function in structure. The commissurotomy studies of the early 1960s conducted on the Bogen-Vogel series of cases began to have major consequences for how we viewed the lateralisation of language, relationships between the hemispheres, and the very integrity of consciousness (Bogen & Vogel, 1962; Gazzaniga, 1988; Gazzaniga, Bogen, & Sperry, 1962). Chapter 21 by Sauerwein and Lassonde discusses some of the earliest “split-brain” cases investigated by Akelaitis in the 1940s. A small range of cases which have caused us to think again about the left hemisphere’s dominating role in the control of behaviour, especially language, are those individuals who have had a left hemisphere surgically removed. The left hemispherectomy cases E.C. and N.F. (discussed by Code in Chapter 22) provide us with insights into the role of the right hemisphere in speech production. Schweiger (in Chapter 19) re-examines Bramwell’s celebrated crossed aphasia case. He points out that what Bramwell described as crossed aphasia—aphasia in a left-handed adult with left hemisphere damage—is different to what we call crossed aphasia today; that is, aphasia in a right-handed adult with right hemisphere damage. This fact is usually not acknowledged or appreciated in contemporary work on crossed aphasia. Parkin in Chapter 23 outlines the extraordinary and continuing story of H.M., the most celebrated of all amnesic patients, whose impairments in memory resulted from bilateral surgical removal of the temporal lobes. As Parkin’s chapter shows, H.M. continues to represent a benchmark for research in amnesia. Gail D. (discussed by Bradshaw in Chapter 24) is one of the deaf aphasic signers studied in recent years at the Salk Institute. This case in particular illustrates that the development of an auditory-sequential language system is not necessary for hemispheric specialisation for language to develop. This unique case appears to show that the left hemisphere may not have an innate predisposition for the core components of language, which is independent of modality.

While the influence of some cases is widely appreciated, many, like those originally described in languages other than English, are recent discoveries for many English readers. The case of Johann Voit (discussed in Chapter 5 by Bartels and Wallesch) is an intensively studied case in the German literature, but relatively little is known of him in English. Likewise, the early psychosurgery cases of Burckhardt (discussed in Chapter 20 by Whitaker, Stemmer, and Joanette) and the possible first case of primary progressive aphasia described in French by Sérieux (Chapter 4 by Ceccaldi, Soubrouillard, Poncet, and Lecours) have received little attention in the past. Similarly, the case of “mind-blindness” described in German by Wilbrand (Chapter 8 by Solms, Kaplan-Solms, and Brown) is little known in English and earlier translations have caused misapprehensions to arise concerning the disorder.

The re-emergency of the single case suggests that in some sense neuropsychology was reinvented about 15 years ago by a group of workers, many of whom were new to neuropsychology. Cognitive psychology and psycholinguistics began at the same time to inform and be informed by neuropsychology. A mutually beneficial relationship was cultivated as cognitive neuropsychology developed. With cognitive neuropsychology a new era of single case research began. An important development in cognitive neuropsychology, and one which has encouraged the re-emergence of the single case to the centre stage, has been a re-examination of the earlier cases within a cognitive neuropsychological theoretical framework. Cognitive neuropsychology figures very widely in this book and a number of contributors discuss cases in terms of their place in contemporary theory. For this reason we will spend a little time below outlining the main features of the theory.

Cognitive neuropsychology brought together the information-processing metaphor, the notion of a mind organised in modules and, significantly, the rediscovery of the view that progress in the scientific investigation of the nature of cognition could be achieved best by careful investigation of individuals with brain damage through a process of hypothesis testing using tests controlled for a range of manipulable variables. Cognitive neuropsychology embraced the traditional single case approach and brought it back in from the cold. A common central view for many workers in the field is that a theory-driven approach to the investigation of individual patients is preferable to attempts to compare heterogenous groups of patients categorised according to classical syndrome models.

The notion of a modular organisation for cognition is a form of faculty psychology going back to Gall’s phrenology (Chomsky, 1980; Fodor, 1983). Essential features of modularity which have their origins with Gall are the view that there exist independent, autonomous, domain-specific, and innately specified cognitive subsystems. The neural networks engaged in one faculty, say language, are formally disparate to those networks engaged in other cognitive faculties, such as perception or memory. The psychological processes involved in the encoding and decoding of speech, for instance, are unconscious processes which are unique to language. Cognitive neuropsychology has seen a return of what Head (1926) referred to disparagingly as “the diagram makers” in the form of information processing. The information processing metaphor lies at the centre of the cognitive neuropsychology model. This framework allows for a characterisation of how cognitive representations are related one to another within modules. A central contention of cognitive neuropsychology “is that behavioral observations of brain-damaged subjects can stand on their own in the development of a meaningful cognitive science” (Caramazza, 1992, p. 85). The agenda for cognitive neuropsychology is to determine the nature of the cognitive architecture by testing out these models on brain-damaged people for whom cognitive processes may have fractionated and dissociated in various patterns. Through detailed case studies of brain-damaged individuals the components and subcomponents of cognition can be mapped in terms of the information processing framework made up of units and input-output routes between units. Analysis of performance entails examining the stages and routes involved in such functions as reading single words aloud, recognising objects, or repeating words. Much of the research concentrates on characterising a deficit or constellation of deficits in terms of failure in access to a module or combination of modules and impairment to a module or modules. Within cognitive neuropsychological studies in language impairment, there is current controversy over the extent to which semantic information is categorised within the semantic system in separate subordinate categories (e.g. fruit or vegetables). If there is a modular organisation to language in the brain then we would expect to observe patients with deficits which affect very specific components and subcomponents of the language s...