Conscious and unconscious states after brain damage

During resting conditions spontaneous experience is ongoing, dynamic, and rich in mental content taking the form of mental states. Mental states are transient cognitive or emotional occurrences that are described in terms of particular content (what the state is ‘about’) and the relation we bear to this content (e.g. imagining, remembering, fearing). Ongoing experience can also show moments of mind blanking during which there is a failure to report the content of thoughts, often accompanied by a post-hoc realization that our mind “went away”. Here, I will discuss the possibility of a contentless mind and will delineate the brain physiology which underlies contentless phenomenology. This work essentially proposes that non-reportable mental events can happen during wakefulness, and challenges the view of the mind as a constant thought-oriented operator.

Starting from the clinical mandate, I investigate how consciousness can be inferred in non-communicating individuals due to pathological (brain-injury) or pharmacological reasons (anesthesia). The use of neuro-technologies and computational analyses have aided this endeavor significantly. By means of functional MRI, I will show how systems-level intrinsic functional connectivity combined with machine learning has proved an effective way to determine biomarkers which can separate single patients in different classes. This work has contributed to the understanding of rare clinical cases, such as patients with disorders of consciousness and hemispherotomies, has facilitated the resolution of medico-ethical debates, and paved the way towards an approach to the human mind which embraces both brain and peripheral body functions.