The article "Covert Cortical Processing: A Diagnosis in Search of a Definition" by Michael J. Young, Matteo Feccchio, Yelena G. Bodien, and Brian L. Edlow explores the emerging field of covert cortical processing (CCP) in patients with disorders of consciousness (DoC). Historically, clinical evaluation of unresponsive patients following brain injury relied on behavioral assessments to detect signs of consciousness and track recovery. However, advances in neuroimaging and electrophysiologic techniques have enabled clinicians to identify residual brain functions in the absence of overt behavioral signs. These techniques, including functional MRI (fMRI), electroencephalography (EEG), transcranial magnetic stimulation-EEG (TMS-EEG), and positron emission tomography (PET), have expanded the ability to sub-stratify behaviorally unresponsive patients by querying and classifying covert brain activity. The article highlights the distinction between covert consciousness, which has received extensive attention, and CCP, which is less understood. CCP is defined as an emerging state of consciousness marked by intact association cortex responses to environmental stimuli in the absence of behavioral evidence of stimulus processing. This state is not monotonic but encompasses a spectrum of possible association cortex responses from rudimentary to complex and to a range of stimuli. The authors emphasize the need for clinicians, philosophers, and researchers to inform and sensitize diagnostic criteria and disorders of consciousness nosology to these emerging conditions. They also stress the importance of democratizing access to resources necessary for clinical identification of CCP, which is an emerging clinical and ethical imperative. The article reviews historical milestones in the field, including early studies on brain activity and consciousness, and discusses the development of techniques such as fMRI, EEG, and PET. It highlights the challenges in interpreting the diagnosis of MCS (minimally conscious state) and the need for more nuanced nomenclature. The authors also explore the use of passive and active paradigms in neuroimaging and electrophysiologic studies to improve the diagnosis and prognosis of consciousness in patients with chronic brain injuries. Finally, the article discusses the perturbational complexity index (PCI) as a promising measure of brain complexity that may provide further granularity in understanding CCP. The authors suggest that PCI could be a superior test for patients with sensory or motor impairments, as it bypasses these limitations and causally probes thalamocortical network connectivity implicated in human consciousness. In conclusion, the article provides a critical evaluation of the current state of CCP and its diagnostic implications, emphasizing the need for further research and ethical considerations in this evolving field.The article "Covert Cortical Processing: A Diagnosis in Search of a Definition" by Michael J. Young, Matteo Feccchio, Yelena G. Bodien, and Brian L. Edlow explores the emerging field of covert cortical processing (CCP) in patients with disorders of consciousness (DoC). Historically, clinical evaluation of unresponsive patients following brain injury relied on behavioral assessments to detect signs of consciousness and track recovery. However, advances in neuroimaging and electrophysiologic techniques have enabled clinicians to identify residual brain functions in the absence of overt behavioral signs. These techniques, including functional MRI (fMRI), electroencephalography (EEG), transcranial magnetic stimulation-EEG (TMS-EEG), and positron emission tomography (PET), have expanded the ability to sub-stratify behaviorally unresponsive patients by querying and classifying covert brain activity. The article highlights the distinction between covert consciousness, which has received extensive attention, and CCP, which is less understood. CCP is defined as an emerging state of consciousness marked by intact association cortex responses to environmental stimuli in the absence of behavioral evidence of stimulus processing. This state is not monotonic but encompasses a spectrum of possible association cortex responses from rudimentary to complex and to a range of stimuli. The authors emphasize the need for clinicians, philosophers, and researchers to inform and sensitize diagnostic criteria and disorders of consciousness nosology to these emerging conditions. They also stress the importance of democratizing access to resources necessary for clinical identification of CCP, which is an emerging clinical and ethical imperative. The article reviews historical milestones in the field, including early studies on brain activity and consciousness, and discusses the development of techniques such as fMRI, EEG, and PET. It highlights the challenges in interpreting the diagnosis of MCS (minimally conscious state) and the need for more nuanced nomenclature. The authors also explore the use of passive and active paradigms in neuroimaging and electrophysiologic studies to improve the diagnosis and prognosis of consciousness in patients with chronic brain injuries. Finally, the article discusses the perturbational complexity index (PCI) as a promising measure of brain complexity that may provide further granularity in understanding CCP. The authors suggest that PCI could be a superior test for patients with sensory or motor impairments, as it bypasses these limitations and causally probes thalamocortical network connectivity implicated in human consciousness. In conclusion, the article provides a critical evaluation of the current state of CCP and its diagnostic implications, emphasizing the need for further research and ethical considerations in this evolving field.