The neural correlates of consciousness (NCC) are the minimum neural mechanisms necessary for any specific conscious experience. Recent research suggests that these correlates are primarily located in a posterior cortical hot zone, including sensory areas, rather than in a fronto-parietal network involved in task monitoring and reporting. The review discusses candidate neurophysiological markers of consciousness, such as gamma activity and the P3b wave, which have not shown predictive power, and highlights more promising quantitative indices of consciousness. It also outlines the inherent limitations of empirical research programs in this area. Experiences are private, but we can infer consciousness through behavioral criteria, such as the ability to respond to commands. However, consciousness can be present even without reliable behavioral responses, as seen in minimally conscious patients. In experimental settings, the content of consciousness is typically evaluated through verbal reports or button-press responses. These reports can vary due to criterion shifts, and forced-choice procedures can determine whether a participant is objectively aware of a stimulus. The no-report paradigm involves trials with and without explicit reports, using indirect physiological measures to infer perception. This allows the NCC to be distinguished from events preceding or following conscious experience. The hot zone is a temporo-parieto-occipital region in the posterior cerebral cortex where the best current anatomical candidates for full and content-specific NCC are located. The content-specific NCC are neurons that support specific phenomenological distinctions, such as faces. The vegetative state is a disorder of consciousness where patients remain unresponsive but can open their eyes and maintain autonomic reflexes. The full NCC are the neural substrates supporting conscious experiences in general, regardless of specific content. Identifying the content-specific NCC involves comparing neural activity when a stimulus is perceived with when it is not, while keeping other factors constant. This has revealed that a broad fronto-parietal network is activated during visual-motor tasks contrasting perceived stimuli with invisible ones. However, it has become clear that some neural activity co-varying with perception reflects processes preceding or following the experience, such as selective attention and task planning. Recent experimental paradigms have been designed to address these issues, varying factors that modify consciousness thresholds to distinguish true NCC from prerequisite activity. No-report paradigms have identified a more restricted content-specific NCC, typically including posterior cortical areas but not the prefrontal cortex. Identifying the full NCC involves contrasting brain activity during conscious and diminished states. These studies often find that a fronto-parietal network is activated when conscious. However, major changes in brain physiology affect not only consciousness but also other functions like vigilance and attention. A within-state, no-task paradigm has been used to study spontaneous fluctuations of consciousness, revealing that the full NCC are localized to a temporo-parieto-occipital region associated with perceptual experiences and a frontal region associated with thought-like experiences. The role of subcortical structures in consciousness remains debated.The neural correlates of consciousness (NCC) are the minimum neural mechanisms necessary for any specific conscious experience. Recent research suggests that these correlates are primarily located in a posterior cortical hot zone, including sensory areas, rather than in a fronto-parietal network involved in task monitoring and reporting. The review discusses candidate neurophysiological markers of consciousness, such as gamma activity and the P3b wave, which have not shown predictive power, and highlights more promising quantitative indices of consciousness. It also outlines the inherent limitations of empirical research programs in this area. Experiences are private, but we can infer consciousness through behavioral criteria, such as the ability to respond to commands. However, consciousness can be present even without reliable behavioral responses, as seen in minimally conscious patients. In experimental settings, the content of consciousness is typically evaluated through verbal reports or button-press responses. These reports can vary due to criterion shifts, and forced-choice procedures can determine whether a participant is objectively aware of a stimulus. The no-report paradigm involves trials with and without explicit reports, using indirect physiological measures to infer perception. This allows the NCC to be distinguished from events preceding or following conscious experience. The hot zone is a temporo-parieto-occipital region in the posterior cerebral cortex where the best current anatomical candidates for full and content-specific NCC are located. The content-specific NCC are neurons that support specific phenomenological distinctions, such as faces. The vegetative state is a disorder of consciousness where patients remain unresponsive but can open their eyes and maintain autonomic reflexes. The full NCC are the neural substrates supporting conscious experiences in general, regardless of specific content. Identifying the content-specific NCC involves comparing neural activity when a stimulus is perceived with when it is not, while keeping other factors constant. This has revealed that a broad fronto-parietal network is activated during visual-motor tasks contrasting perceived stimuli with invisible ones. However, it has become clear that some neural activity co-varying with perception reflects processes preceding or following the experience, such as selective attention and task planning. Recent experimental paradigms have been designed to address these issues, varying factors that modify consciousness thresholds to distinguish true NCC from prerequisite activity. No-report paradigms have identified a more restricted content-specific NCC, typically including posterior cortical areas but not the prefrontal cortex. Identifying the full NCC involves contrasting brain activity during conscious and diminished states. These studies often find that a fronto-parietal network is activated when conscious. However, major changes in brain physiology affect not only consciousness but also other functions like vigilance and attention. A within-state, no-task paradigm has been used to study spontaneous fluctuations of consciousness, revealing that the full NCC are localized to a temporo-parieto-occipital region associated with perceptual experiences and a frontal region associated with thought-like experiences. The role of subcortical structures in consciousness remains debated.