The study of consciousness remains a mystery to contemporary science. However, it is increasingly becoming a key factor in the recovery of patients who have suffered an acquired brain injury. Many therapeutic processes of neuropsychological rehabilitation fail because they cannot count on the patient’s collaboration, as he or she does not adhere to the prescribed guidelines, refuses to undergo group rehabilitation sessions or does not show up for scheduled consultations. This is not due to a lack of will or understanding, but is part of a neuropsychological disturbance that causes the patient not to perceive his deficit and to act as if everything is fine.

What is consciousness?

Consciousness is an extremely complex construct. If today we do not have a univocal definition of this mental function, it is probably because of its extraordinary ubiquity in the brain and its multifaceted nature. The British philosopher John Locke (1632-1704) defined consciousness as the “perception of what is going on in one’s own mind“. More modern definitions hold that consciousness is characterized as “a private, personal, subjective and qualitative state of mind that integrates in a unitary, coherent and continuous way multiple personal experiences (qualia)”.

Differences between conscious and consciousness

To be conscious would be the same as being awake and alert, receptive to the stimuli of the environment, so that consciousness from this point of view would be what one has when awake and what one loses when deeply asleep or under anesthesia. Consciousness, on the other hand, would refer more to the capacity of the human being to know its own thoughts and to understand objectively the world and oneself, while maintaining a sense of subjectivity.

These properties of consciousness would have an identifiable neuroanatomical basis in the brain, although knowledge about its neuronal localization is still frankly uncertain. To be conscious we need activation and alertness, basic functions that would depend on structures in the brainstem, the ascending reticular activating system (A.R.A.A.) and fronto-parietal noradrenergic circuits, lateralized to the right hemisphere when we speak specifically of arousal. The ability to focus attention on a specific perception would depend on posterior parietal areas and some thalamic nuclei such as the pulvinar. The generation of conscious experiences has been related to reverberant cortico-thalamic circuits, consistently in bands of neuronal discharges synchronized at 40 hertz. Finally, self-consciousness, i.e., the substrate of reflection on self, identity and theory of mind, would be located in the prefrontal cortex.

Therefore, as we see, consciousness is not a unitary construct. Moreover, as already distinguished in philosophy, there are different types of consciousness with different neuroanatomical bases, which contribute to generate the conscious and self-conscious experiences we have in our daily lives.

Lack of awareness of deficits: anosognosia

One of the things that most surprises the novice neuropsychologist is the lack of awareness of deficits in patients with acquired brain injury. Patients with Wernicke’s aphasia who believe they speak coherently and are understood, patients with hemineglect who bump into doors or do not eat the food that is on the contralateral side of the plate, patients with severe problems of emotional self-regulation and insight after frontal damage who deny any kind of problem, are common cases in neuropsychology consultations. All of them constitute a challenge for the clinician both in the assessment and in the treatment plan.

What is anosognosia?

The term anosognosia was first introduced by the French neurologist Charles Babinski in 1914 when he reported a case of hemiplegia in which the patient was unaware of his deficit. Subsequently, the term ‘anosognosia’ has become popular and widespread to refer, in general, to the absence of awareness of deficits, whether physical, cognitive, emotional, interpersonal, or personality.

Anosognosia or lack of awareness of deficits is a disorder frequently observed in patients who have suffered brain damage, whether traumatic, stroke, neoplastic or infectious. Its prevalence, according to various studies, is between 33% and 52%. In addition, nearly half of them still present this alteration one year after suffering acquired brain damage. Its presence constitutes a poor prognostic factor, since it usually translates into lack of motivation, low adherence to treatment, poor participation in programmed activities and mismatches between the patient’s expectations of his or her own capacity and reality.

Therapeutic approach to the lack of awareness of deficits in acquired brain injury

When planning an intervention program in neuropsychology, it is recommended to follow a series of principles that will help us to design the best possible intervention adapted to the specific needs of our patient. To do so, we must start from theoretical reference models that allow us to interpret the results obtained in the tests, adopt an interdisciplinary and multiple perspective and focus rehabilitation more on the disability than on the deficits. This usually implies making an exhaustive analysis of the functional consequences that the acquired brain injury has had on the patient’s life and trying to achieve the greatest possible social and occupational adaptation.

The lack of awareness of the deficits can produce a marked interference in the daily life of people suffering from a neuropsychological disorder. It can also hinder adherence to rehabilitation sessions. Therefore, the therapeutic approach to the lack of awareness of deficits in the context of acquired brain injury, if present, becomes the first therapeutic target that the neuropsychologist must take into account in treatment planning.

Most of the intervention programs developed to improve awareness of deficits have common objectives focused on increasing the patient’s knowledge of the injury, working on the acceptance of his or her limitations and reducing the mismatch between his or her expectations of functioning and actual performance. In addition, establishing a good therapeutic alliance is fundamental in this process, especially if by increasing awareness of deficits the patient begins to show depressive symptoms, anxiety or even denial.

Intervention strategies for the rehabilitation of awareness of deficits in acquired brain injury

In a recent systematic review, Villalobos and coworkers (2020) outline the most commonly employed intervention strategies in the rehabilitation of awareness of deficits in acquired brain injury: psychoeducation, feedback, confrontation, behavioral therapy, and psychotherapy.

Psychoeducation

Psychoeducation provides information adapted to the patient’s capacity to understand the nature of his or her disorder, the associated deficits and the functional repercussions it produces, with the aim of increasing his or her knowledge of the problem.

Feedback

The purpose of feedback is to inform the patient about his performance on a particular task. This will allow him to know if he is reaching the target or, how far he is from it in order to adjust his performance or look for appropriate strategies to achieve it.

Confrontation

Confrontation is used to measure the mismatch between the patient’s expectations and his actual performance on a task. For this purpose, structured tasks are designed to allow self-monitoring and self-evaluation, always based on the patient’s current capabilities at that moment. The patient must make a forecast of his or her performance on the task before performing it, and then analyze and compare it with the result obtained. Experiential rehearsal usually has a great impact on the patients’ knowledge of their new reality. Therefore, it is necessary to proceed with caution and carefully evaluate the pros and cons of this type of intervention, as well as to choose the most appropriate moment within the rehabilitation process of acquired brain injury.

Behavioral therapy

Precisely, when we suspect that confrontation may produce anxiety or be psychologically harmful to the patient, it is advisable to begin with training in compensatory strategies as well as working on the acquisition of procedural habits that allow the patient to gain functionality.

Psychotherapy

Psychotherapy can be useful in different phases of recovery from acquired brain injury, especially when it incorporates lack of awareness of deficits. In the scientific community, controversy surrounds the etiology of anosognosia, which could have a neurological origin, but also a psychological one, through mechanisms of denial. In any case, psychotherapy can be useful both to help the patient to manage the emotional disturbances that this type of disorder entails, as well as to reestablish a new meaning in his or her life, and to outline new goals, adjusted to his or her new reality.

Conclusions on awareness of deficits as a key factor in recovery from acquired brain injury

The therapeutic approach to the lack of awareness of deficits is arousing growing interest among researchers and neuropsychologists alike. As we have seen, rehabilitating cognitive, emotional or behavioral impairment after acquired brain injury can be much more difficult if the patient is unaware of his or her deficit. Numerous investigations have highlighted the predictive capacity of the lack of awareness of deficits for the reintegration of patients affected by acquired brain injury. In fact, the lower the deficit awareness, the worse the reintegration.

For this reason, it is increasingly necessary to develop new theoretical models, measurement instruments and rehabilitation programs that allow us to continue advancing in order to offer patients the best therapeutic tools adapted to their disorder. It is clear that, in some way, we already work on these aspects with patients, but this must be done in a more systematic and structured way. Only in this way will we be able to improve our knowledge of the processes of consciousness monitoring and contribute to the development of evidence-based neuropsychology.

References on acquired brain injury and awareness deficits

Adolphs, R. (2015). The unsolved problems of neuroscience. Trends in Cognitive Science, 19(4) 173-75.

Aznar-Casanova, J.A. (2017). La consciencia: la interfaz polinómica de la subjetividad [Consciousness: the polynomial interface of subjectivity]. Madrid: Pirámide.

Locke, J. (1690/1980). Ensayo sobre el entendimiento humano [Essay on human understanding]. Editora Nacional, Madrid.

Flashman, L. A. & McAllister, T.W. (2002). Lack of awareness and its imact in traumatic brain injury. Neurorehabilitation, 17(4), 185-96.

Graziano, M. (2015). Consciousness and the social brain. New York: Oxford University Press.

González, B., Paúl, N., Blázquez, J. L. & Ríos, M. (2006). Factores relacionados con la falta de consciencia de los déficits en el daño cerebral [Factors related to lack of awareness of deficits in brain damage]. Acción Psicológica, 4(3), 87-99.

Muñoz-Céspedes, J.M. & Tirapu-Ustárroz, J. (2001). Rehabilitación neuropsicológica [Neuropsychological rehabilitation]. Madrid: Síntesis

Robertson, K. & Schmitter-Edgecombe, M. (2015). Self-awareness and traumatic brain injury outcome, Brain Injury, 29:7-8, 848-858, DOI: 10.3109/02699052.2015.1005135.

Tirapu-Ustárroz, J. (2008). ¿Para qué sirve el cerebro? [What is the brain for?] Bilbao: Desclée de Brouwer.

Villalobos, D., Bilbao, A., López-Muñoz, F. & Pacios, J. (2020). Conciencia de déficit como proceso clave en la rehabilitación de pacientes con daño cerebral adquirido: revisión sistemática. [Deficit awareness as a key process in the rehabilitation of patients with acquired brain injury: systematic review] Revista de Neurología, 70(1), 1-11.