Pathologies of awareness: Bridging the gap between theory and practice
This special issue of Neuropsychological Rehabilitation provides an opportunity to characterise some of the key clinical issues concerned with assessing and managing pathologies of subjective or conscious awareness. By conscious awareness, we mean the cognitive processes that provide for our phenomenological experience (reported subjective states) and behavioural responses (objectively perceived actions). In considering subjective awareness, there has been an understandable tendency in the past to focus on clinical disorders given the epistemological and conceptual difficulties of researching and defining the construct of awareness in a “normal” context.
However, we believe it is important to emphasize that normal informational processing and psychosocial systems are the relevant domains over which any perceived clinical disorder of awareness must be meaningfully understood. Elucidating the cognitive processes underlying awareness, and their corresponding phenomenological experiences, provides the necessary theoretical platform to inform assessments and justify interventions aimed at compensating for, and/or reducing the functional consequences of, impaired awareness. This special issue represents an attempt to bring together previously disparate research findings and conceptual issues from relevant fields within medicine and the psychological sciences and, in so doing, provide for a more coherent, comprehensive account which clinicians and theoreticians can use to better understand the apparently obvious but unwieldy construct of awareness.
First, we consider conceptual issues. Contributors to this section critically review the key conceptual frameworks that have been proposed to explain the underlying neuropsychological and psychological processes mediating conscious awareness, and consider the implications for rehabilitation. Papers in this section highlight shortcomings in previous accounts, and allow practising clinicians to identify, compare and contrast current accounts in terms of their underlying assumptions, operational measures and clinical diagnostic potential. Adam Zeman opens this section with a wide-ranging analysis of what we mean by “conscious” and “awareness”. He considers the meanings of these terms in the context of a range of contrasts that highlight both the scientific complexity of the issues and the importance of the cultural and social framework within which these constructs are grounded. Awareness, therefore, needs to be approached on a number of levels, all of which may contribute to a comprehensive explanatory account. Peter Halligan continues this theme with a discussion of the nature of consciousness and awareness. He considers some fundamental questions about the nature of conscious experience. Much of our conscious experience arises as a late-stage product following considerable pre-conscious processing, and in clinical cases, it is often the dissociation between explicit accounts on the one hand and behaviour on the other hand that is the most clinically relevant and theoretically striking. Tony Ro and Bob Rafal draw on perspectives from cognitive neuroscience, taking as their starting point the puzzling phenomenon of blindsight, where visual information is processed without apparent conscious awareness. Detailed exploration of the neural processes underlying blindsight suggests possible parallels with the processes available for recovery of visual function, and offers possible directions for developing rehabilitation strategies. Laura Bach and Tony David discuss the relevance of neuropsychological and neuroanatomical models for understanding impairments of social self-awareness following brain injury. They argue that existing cognition-based models do not provide adequate explanations and propose a role for psychological constructs such as “theory of mind”. The ecological and phenomenological relevance of cognition-based accounts needs to be further supplemented and contextualised by an appropriate psychosocial framework that considers not just impairments but also relevant issues arising at the personal level, such as volitional choice, phenomenological experience and sociocultural influence. Finally in this section Tamara Ownsworth, Linda Clare, and Robin Morris draw a distinction between focal types of awareness deficit that relate directly to underlying neuropathology and the broader awareness deficits sometimes seen following brain injury or in the early stages of Alzheimer's disease. They argue in the latter case for an integration of cognitive neuropsychological and biopsychosocial explanatory models, emphasising the need to take account of psychological processes and social influences alongside the impact of specific neuropsychological impairments.
In the second section, we consider some of the measures used to assess, and clinical management strategies used in response to, impaired awareness. Not unlike other neurospsychological conditions, many of the symptoms attributed to deficits of conscious awareness are defined ostensibly by the tasks used to reveal them rather than by any fundamental understanding of their nature. Papers in this section, however, aim to demonstrate the extent to which it has been possible operationally to measure components or general features of the construct as delineated either by cognitive theory or more commonly from phenomena seen in clinical practice, and following such assessment, to provide effective rehabilitation interventions. A comparison of the existing approaches to assessment, together with a review of their strengths and limitations, is provided by Ivana Marková and German Berrios. The literature describes a range of approaches for assessing awareness, and these can vary on a number of dimensions. Most importantly, they are based on differing definitions of awareness and are addressed to different objects of awareness, and hence not surprisingly elicit different awareness phenomena. Consequently, there are problems with making comparisons between the results obtained from different measures. This may help to explain some of the contradictory and variable findings reported in awareness studies. Rehabilitation strategies clearly need to be developed specifically for particular impairments of awareness. Finally, Jenny Fleming and Tamara Ownsworth review current treatment-based approaches that have attempted, albeit often on the basis of a very limited theoretical framework, to modify the functional effects of disorders of awareness. The most appropriate intervention for a given individual understandably depends on the nature of, and interactions between, factors contributing to that individual's awareness deficits, whether primarily neurological, psychological or socio-environmental. Key elements of interventions directed at each of these three levels are outlined. Intervention for awareness deficits are not without important ethical implications, and increasing awareness per se is not always considered the primary goal of therapy. Instead, treatment directed at awareness deficits is usually conducted in the context of interventions aimed at improving other aspects of cognitive functioning. Since increased awareness might result in increased distress, it is vital that interventions aim to produce functional gains that contribute to enhancing the person's quality of life.
In focusing on disorders of conscious awareness as a crucial and over-riding factor when planning specialised rehabilitation, the modest aims of this special issue are to provide a representative snapshot of the current theoretical pitfalls, variety of measures and potential interventions available for clinical practice.