What is the Nature of Consciousness?
Definition of Consciousness
Consciousness is defined differently among psychologists. No particular definition of consciousness stands out or is widely accepted in the field of Psychology. However, for the purpose of briefly introducing and explaining a complex phenomenon like consciousness, here is Santrock's simple and easy-to-understand definition of consciousness: Consciousness is the awareness of external events, internal sensations, the self, and thoughts about experiences. Consequently, the different states of consciousness, as discussed below, correspond to differing qualities of awareness and information-processing.
Historical Development of the Study of Consciousness
The study of consciousness began in the 19th century from the ideas of Sigmund Freud and William James. Sigmund Freud, in his psychoanalytic theory, likens the mind to an iceberg, where a significant portion of the ice is hidden from consciousness. On the other hand, William James describes the mind as freely and continuously flowing, referring to it as the stream of consciousness. Although the conflict between these two fundamental theories on consciousness should have sparked controversies and debates similar to the early scientific approaches to psychology, interest in consciousness was shunned away in the 20th century when behaviorism dominated the scene of psychological research. It was only in the 21st century when psychologists developed renewed interest on the subject of consciousness, particularly subconsciousness. Today, large bodies of research have been made detailing the complex nature of consciousness.
States of Consciousness
As mentioned above, the different states of consciousness correspond to differing qualities of awareness and information-processing.
The conscious state is a state of awareness where the mind knows exactly what it is thinking of. Thinking in the conscious state is serial, that is, following a sequence, and is therefore slower, but more productive, compared to the other states of consciousness. The conscious state operates under high- and low-level of awareness. High-level of awareness in the conscious state involves controlled processing, where attention is most alert and selective, allowing us to focus. Low-level of awareness in the conscious state, on the other hand, involves automatic and semi-automatic processing, occurring simultaneously, thus dividing attention, as when you talk while eating, or when you daydream while listening to class instructions.
The subconscious state is a state of awareness involving parallel processing and binding, which are much faster than controlled, automatic and semi-automatic processing. Parallel processing and binding in the subconscious state are not conscious, producing sensations and perceptions as outputs, as when we see something but don't know how and why we see it. Often, we drop to a subconscious state when we are asleep, as when we are aware of external stimuli only to some degree. In an experiment by Ogilvie & Wilkinson (1998), participants are instructed to push hand-held buttons in response to hearing faint tones while asleep. Surprisingly, majority of the participants did the task well. In another experiment, Stickgold (2001) observed the brain activity of sleeping participants in response to different kinds of stimuli. He found that tones stimulate brain activity in the auditory processing regions of the brain, and that the participants' names stimulate the language areas of the brain, the amygdala and the prefrontal cortex. We can also function in a subconscious state when we are awake. This is often observed in people with neurological problems, particularly those with brain damages affecting the processes of sensations and perceptions. Milner and Goodale (1995) found that people with damaged visual cortex, but with fully-functioning sense of sight, are not aware, or conscious, of the physical dimensions of objects in their visual field, but are surprisingly able to precisely adjust their hands when instructed to reach for them. This means that visual sensory information somewhat reached the brain in a state where the mind is not conscious of it. A lot of far-reaching ideas are said to have emerged during a subconscious state, when the conscious mind is relaxed and unfocused. 20th century American engineer and inventor Frank Offner, who developed controls that made jet planes possible, and who invented the electrocardiogram (ECG) and electroencephalogram (EEG), said that most of his ideas spontaneously arise during the middle of the night. His doctoral dissertation on nerve excitation formula was even formulated while he was taking a shower. Renowned chemist August Kekule was also known to have developed the idea behind the benzene ring (1865) while he was asleep, when he dreamt of a snake that went in circles and bit his own tail. According to creativity expert Mihaly Csikszentmihalyi (1995), these spontaneous thoughts come from incubated ideas that make strong connections during a subconscious state, and suddenly pop out to consciousness.
The unconscious state is a state of awareness filled with unacceptable wishes, feelings and thoughts. They fail to get admitted into consciousness due to threats of anxiety of negative emotions. The idea of the unconscious mind was developed by Sigmund Freud (1917). Although controversial, the idea of an unconscious mind is important for recognizing the complexity of consciousness.
Lastly, the altered state of consciousness is a state of awareness achieved under the influence of special secondary stimuli or situations, such as drugs, trauma, fatigue, self-deprivation, and possibly, hypnosis, as observed among Zen monks and fasting Muslims.
Neuroscience and Consciousness
Behavioral neuroscientists found that there is no specific brain location for consciousness; rather, that consciousness involves connections of different processing systems in the brain, as shown with Stickgold's (2001) brain activation experiment (previously discussed in the section of subconscious state). By tracking neural pathways involved in differing states of consciousness, behavioral neuroscientists found that controlled processing is specifically tied in the cerebral cortex, particularly the frontal lobe and the association areas of the brain. They also found that neural pathways for sensation and perception, emotions and memory correspond to the different states and levels of consciousness.