Altered states of consciousness and emotional «qualia» in epilepsy [Alterazioni della coscienza e «qualia» emozionali in epilessia]

The last decade saw a renaissance of studies on consciousness, witnessed by the growing number of scientific publications on this topic. Our understanding of the nature and neurobiological bases of consciousness - otherwise stated «soul» - is still at the very beginning, partly because of its intrinsic elusiveness. The concept of consciousness is central in epileptology, despite the methodological difficulties concerning its application to the multifaceted phenomenology of seizures. The authors propose a simple bidimensional model for the description of seizure-induced alterations of the states of consciousness, which entails a quantitative and a qualitative feature, namely the level and the contents of consciousness. The neurophysiological correlates of ictal loss and impairment of consciousness are reviewed. Special attention is paid to the subjective experiential states or emotional «qualia» associated with temporal lobe epilepsy. This strategy provides useful insights in ictal phenomenology as perceived from the first-person perspective of the patient experiencing peculiarly altered states of consciousness. Epilepsy is confirmed to represent a privileged window over basic neurobiological mechanisms of consciousness.