The Study of Anosognosia is a remarkably comprehensive text that reviews the state of the art theoretical and clinical accounts of anosognosia and related syndromes. The book consists of 22 chapters written by such prominent authors as Kenneth Heilman, Sergio Starkstein, Alfred Kaszniak, and Daniel Tranel, to name a few, as well as several contributions from George Prigatano, the Editor. The chapters are organized into eight parts that span the historical perspectives on anosognosia; models of anosognosia for motor, language, and visual impairments; the relationship among anosognosia, hysteria, and cognitive and affective dysfunction; anosognosia in various clinical populations; and advances in the study of anosognosia including neuroimaging, behavioral assessments, and clinical interventions.
To fully appreciate this book, the reader is encouraged to read the preface, which provides important context for what this book aims to accomplish. In particular, as the preface explains, this tome is principally a collection of chapters prepared by researchers and clinicians with interest in anosognosia who attended the 2008 anosognosia conference sponsored by the Barrow Neurological Institute in Phoenix, Arizona. As such, the book does not follow the typical schema of edited texts. In other words, the book does not lead the reader in a linear fashion from one topic to the next, nor is it organized hierarchically, from broader, overarching topics to more discrete areas of interest. Rather, each chapter stands on its own, providing historical, contextual, and theoretical background that reflects the personal perspectives or preferences of the respective authors. Consequently, some redundancies exist: Many contributors provide some historical overview, or, in the very least, acknowledge Babinski's work from the early 20th century. Many offer definitions of anosognosia, or provide a brief overview of the most prominent theoretical models of anosognosia that consider insight, self-awareness, or sense of agency. Most speak to the issue of hemispheric asymmetry in anosognosia and the importance of the right frontal lobe and the right insular cortex for self-awareness. In other words, it is obvious that the contributors were given free rein to include whatever they deemed important or appropriate to present their particular perspective.
Given this approach, the book may be slightly frustrating to a reader who expects to find a ready reference or a detailed and focused literature review of a discrete topic. However, if the reader abandons this expectation and instead approaches this book as a collection of scientific essays, the frustration is bound to melt away, and the reader is likely to find delight in discovering each author's unique point of view.
Specific Overview
Part I, Historical Overview and Introduction, consists of one chapter that reviews the history of anosognosia from the first accounts by von Monakow and Babinski to the theoretical and clinical accounts of the 21st century. The chapter ends, quite appropriately, with a list of questions about the construct of anosognosia that remain to be answered, providing a framework for the readers as they make their way through the remainder of the text.
Part II, Anosognosia of Motor and Language Impairments, consists of six chapters that together explore the theoretical and neuroanatomic underpinnings of anosognosia (in particular anosognosia for motor impairment), as well as various clinical ramifications. Different theoretical perspectives, relying to varying degree on lesion, electrophysiologic, neuroimaging, and cognitive methods, offer explanations for the bizarre phenomenology of anosognosia. Disturbances in motor control and intention to move, sense of agency and body ownership, and subjective awareness represent some of the key constructs that are examined. Although there is some considerable overlap in the literature reviewed in these chapters, this in the end serves the reader well by communicating the true state of the art in anosognosia research.
Part II also includes a chapter on anosognosia for language impairment, and this chapter, while interesting, feels a bit at odds with the first four chapters in this section, and might fit better in a section on “other” anosognosias, together with Anton syndrome that has a section of its own later in the book. Lastly, Part II concludes with a chapter on assessment of anosognosia, which provides excellent guidance for both clinicians and researchers. Again, however, this otherwise excellent chapter feels slightly misplaced here, perhaps fitting thematically better with later chapters on assessment and technology.
If there was any doubt about the unifying theme of Part II, Part III, Anosognosia Observed in Various Neurologic Disorders, delivers in a straightforward fashion exactly what the section title promises. This part consists of six chapters that examine in turn Huntington's disease, Parkinson's disease, Alzheimer's disease (two chapters), traumatic brain injury, and schizophrenia. These chapters are excellent and leave the reader wishing more disorders were included, such as chapters on frontotemporal-lobar degeneration, multiple sclerosis, and epilepsy.
Part IV, Anosognosia and Specific Cognitive and Affective Disturbances, consists of three chapters that examine deficits in self-awareness and insight regarding one's own personality, feelings, interpersonal behavior, and processing of errors in one's own performance. While Chapters 14 and 16 specifically tackle these topics from the standpoint of deficits associated with neurodegenerative disorders and traumatic brain injury, respectively, Chapter 15 examines individual differences (along a continuum that spans normal, neuropsychiatric, and neurologic populations) in discrete cognitive processes, such as vigilant attention and awareness.
Part V, Anosognosia and Hysteria, includes one chapter that reviews theoretical and empirical literature on conversion disorder. Although the first two-thirds of this chapter focus virtually exclusively on anosognosia, the last third provides a comprehensive review of the relatively small body of research on hysteria. In the end, this chapter offers a neuroanatomic model of awareness that integrates in an elegant fashion an array of disorders from anosognosia to kinesthetic illusions to hysteria, providing a viable framework for hypothesis-driven research and practice.
Together, Parts IV and V investigate topics that are rarely considered in neuropsychological conceptualizations of anosognosia, and provide a nice theoretical extension of the construct at hand. By bridging emotional and cognitive processes and considering individual differences outside of neurologic disorders, these two sections are aligned with the ever-increasing interest in cognition as an important contributor to personality and psychopathology.
Part VI, Measurement Issues and Technology, has two chapters that cover functional neuroimaging and behavioral measures of anosognosia. Although the title of Part VI gives the impression that this section of the book will review the current methodology in the study of anosognosia, in reality, much of the first chapter focuses on a review of the results of select studies that examined substrates for self-awareness using functional imaging. Although this review of the literature is interesting and nicely integrated, it is only the last third of the chapter that reviews methodological considerations, and as such leaves the reader wishing for more. In contrast, the second chapter in Part VI provides a thorough overview of assessment instruments for anosognosia and related phenomena, and can serve as an excellent guide for researchers and clinicians alike.
Part VII, Anosognosia and Visual Loss, consists of one chapter that covers clinical, theoretical, and empirical accounts of Anton's syndrome, and proposes a taxonomy of syndromes characterized by unawareness of blindness or other visual disturbances. As is alluded to in the chapter, such taxonomy can greatly improve study design and can move our limited understanding of this syndrome forward.
Lastly, Part VIII, Advances in the Study of Anosognosia, consists of two chapters that together review the most recent empirical findings, methodologies, theories, and approaches to clinical management and rehabilitation. These two chapters provide an excellent integration of the topics found throughout the book and, in an effortless fashion, bring together science and clinical practice.
In conclusion, The Study of Anosognosia is a remarkably comprehensive text. Taken together, the chapters in this book cover most any aspect of anosognosia one could imagine, as they bridge cognition, emotions, and personality, and effortlessly integrate theory and practice. Each chapter truly stands on its own, as most chapters touch upon certain key topics, such as the history of anosognosia, the neuroanatomic underpinning, the principal models of anosognosia, and clinical implications. The downside, if it could be called that, is that there is some redundancy in the information provided in each chapter and that the thematic organization of the eight parts is not always immediately obvious. The upside is that this book gives each author an independent voice and avoids imposing a structure that could lead to biased or incomplete accounts. Once the reader “gets” what the book aims to accomplish, perusing each chapter becomes a delightful journey that is bound to leave the reader enriched and intrigued about anosognosia and beyond.