Consciousness is defined as the nature of the brain portrayed through the states of awareness and arousal. As a concept, it is multifaceted and can only be explained through an understanding of the different aspects it entails. In this regard, the essay describes brain consciousness through the concepts of arousal and awareness. Arousal is taken to refer to the state of wakefulness. On the other hand, awareness describes the cognition of the surrounding. Laureys et al. (1133) distinguish the two concepts through the assertion that arousal defines the level of consciousness while awareness describes its content. As such, one can be awake yet not aware. Awareness is most commonly examined clinically through testing the motor responses of an individual (Laureys et al. 1133). This results in the classification of cases into five different states of consciousness.
The states of consciousness are the comatose state, vegetative state, minimally conscious state (MCS), locked-in syndrome (LIS), and the conscious state. Each of these states manifests itself through different symptoms, which are used for clinical classification. For instance, an individual in a coma is in a state of unarousable unresponsiveness (Laureys et al. 1134). Such individuals demonstrate a deficiency in their arousal systems and are also unaware of the environment and of themself. Those in the vegetative state (VS) are awake or arousable yet unresponsive to motor stimuli, indicating unawareness. The MCS state follows the vegetative state in that individuals in this state are awake, aware as indicated by emotional responses and pursuit of motion, yet unable to communicate their feelings and thoughts functionally. Those in the LIS state are the most pitiable since the individuals are aware yet remain both immobile and mute. The LIS state is described as horrifying since such patients look unconscious only due to severe paralysis and yet are aware of their environment and their surroundings. The VS, MCS, and LIS states are outcomes of the comatose state. The conscious state, on the other hand, is the state of ultimate wakefulness and awareness (Laureys et al. 1134–1136).
Laureys, Steven,Melanie Boly, Moonen George, and Maquet Philips. “Two Dimensions of Consciousness: Arousal and Awareness.”Encyclopedia of Neuroscience 2, 1133–1142.
“Exploring the Nature of Consciousness.”YouTube, uploaded by science and non duality, 9 April 2015,