Furthermore, there are additional features of the content of consciousness across the context of our brain ( Figure 1). Important Component of Consciousness: WakefulnessĪccording to the latest neurosurgical research there are two key features of consciousness: (1) the state of consciousness (i.e., wakefulness) and (2) the content of consciousness (i.e., awareness) ( Zeman, 2006 Bayne et al., 2016 Fazekas and Overgaard, 2016). Questions that should be asked include: where is the material basis of consciousness? The physical basis of consciousness is the most important internal factor of consciousness.

Others believe that consciousness is created in areas of the hindbrain, including the occipital/parietal and central posterior regions of the brain ( Koch et al., 2016 Seth, 2018). For example, some researchers believe that consciousness is aroused in the frontal region of the brain, including the prefrontal and central anterior cortex. However, in recent times, many different opinions have been proposed. The reticular neurons, and especially the neurons of the ascending reticular activation system, play a vital role in maintaining behavioral arousal and consciousness ( Jones, 2003 Englo et al., 2017). In the past, the traditional viewpoint was that consciousness required the proper functioning of midline brain structures and that the content of an experience was supported by the activity of neurons in specific areas of the cerebral cortex ( Jang and Lee, 2015). Neuroscientists have conducted extensive research on consciousness for many years. This review presents the latest progress in consciousness research and proposes our assumptions with regard to the network of consciousness. In addition, research efforts that help elucidate the concept of consciousness have important scientific and clinical significance. Additionally, an accurate assessment of the level of consciousness may strengthen our awareness of this concept and provide new ideas for patients undergoing clinical treatment of consciousness disorders. However, to establish a greater understanding of the concept of consciousness, more detailed, intrinsic neurobiological research is needed. Currently, consciousness research is an intensely focused area of neuroscience. The definition of consciousness remains a difficult issue that requires urgent understanding and resolution.

2Center for Neuroscience Research, Loma Linda University School of Medicine, Loma Linda, CA, United States.

1Department of Neurosurgery, Huashan Hospital, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Collaborative Innovation Center for Brain Science, Shanghai Medical College, Fudan University, Shanghai, China.

Tong Zhao 1†, Yiqian Zhu 1†, Hailiang Tang 1†, Rong Xie 1†, Jianhong Zhu 1* and John H.

50 States of Consciousness by DJ Jones