The Quest for Covert Consciousness Bringing Neuroethics to the Bedside

Plato, in his Allegory of the Cave, contemplates a group of people who have lived their entire lives facing a wall of a cave and whose impressions of the world are constrained to perceptual experiences of shadows cast on the wall by entities that are never directly observed. Since time immemorial, conscious states of others have been like Platonic shadows, inferred only imperfectly and indirectly through close observation of behaviors. Although for centuries philosophers and neuroscientists have sought to bring us closer to understanding consciousness, an influx of neurotechnologies now enables clinicians and researchers to potentially improve detection of consciousness and prediction of its recovery.(1) Innovations in neuroimaging and electrophysiologic techniques now may permit detection of states of consciousness not readily discernible by bedside examination, known as covert consciousness or cognitive motor dissociation.(2) The discovery of covert consciousness raises distinctive issues surrounding both the diagnosis and prognosis of persons with disorders of consciousness (DoC), highlighting the need for caution during the acute phase of neuroprognostication and exposing gaps in knowledge about the epidemiology and phenomenology of covert consciousness. These innovations represent a possible step forward from philosophical and scientific traditions that relied on behavioral observations to detect consciousness. In turn, these breakthroughs prompt reconsideration of standard approaches to the evaluation of persons with DoC and necessitate appraisal of how clinicians should communicate results of novel techniques with indeterminate meanings to surrogates. Proactive integration of neuroethical insights in clarifying responsible ends to which these technologies should be directed is essential for addressing these timely challenges. This article proposes an ethical framework to help the clinical and research community consider how to use these emerging neurotechnologies responsibly, calls for careful consideration of the consequences of searching for covert consciousness in practice, and highlights critical avenues for further study of how the finding of covert consciousness might help predict goal-concordant functional recovery.