Can we define consciousness? How can a small collection of neurones in the human brain appreciate everything from their own minute size to the vast scale of the universe?
Google will tell you that consciousness is ‘being aware and responsive to one’s surroundings’. However, a single definition of consciousness has not been agreed. Another description is that is it the linking of information in the brain, allowing complex thoughts.
Some people argue that because we are conscious ourselves, it is not possible for our brains to have an understanding of consciousness. I find this logic difficult to believe, since we have so far been capable of understanding research into the functioning of the human brain and nervous system.
There are several theories of consciousness but dualism and physicalism are the two main contradictory ideas:
-Dualism is the theory that living organisms contain a non-physical element creating consciousness, such as a soul, making them different from inanimate objects. Panpsychism is a related belief, which states that all matter has some psychological properties.
-Physicalism is the theory that consciousness is simply created by a physical arrangement of atoms.
From studies of the brain itself, it is believed that only some areas are capable of consciousness. For example, the cerebellum is not conscious because it simply passes information on to other areas of the brain.
Robert Ornstein’s book, ‘The Evolution of Consciousness’, explains how the unconscious brain receives sensory information and decides whether or not it should become conscious. A conscious decision takes at least half a second to make, and therefore we are not conscious of many of our actions. This mechanism has led to some alarming experimental results, showing that people begin to perform actions before they have consciously made the decision to do so. This may lead people to believe that we have no free will, and can not control our actions.
How did we become conscious? Well, form a biological perspective, it must be possible for consciousness to have evolved. The Evolution of Consciousness explains that the mind evolved to provide a ‘rough-and-ready perception of reality’. If this is the case, then I find it difficult to see what advantage we are given by the ability to play musical instruments and read Shakespeare etc.
‘The Selfish Gene’ suggests that consciousness evolved as a result of ‘memory, decision making and imagination’ presenting an evolutionary advantage. Robert Trivers also explains how reciprocally altruistic behaviour, which benefits another organism whilst appearing detrimental to the organism itself, can actually increase evolutionary success. If this resulted in friendship, empathy, gratitude, etc. being an advantage, then I imagine that consciousness could evolve, improving these abilities. Therefore, although simply perceiving the world may have been the initial advantage of consciousness, many other uses may have later developed. However, how the processes creating consciousness came into being is entirely unknown.
Patients with damage to one side of their visual cortex lose their vision on one side, however, experiments have shown that they are still able to point to an object in the area that they can not see. This is known as blind sight, and occurs because the patient is actually receiving visual information from this side, but is not conscious of it. These results led VS Ramachandran to ask the question ‘Why can’t the rest of the brain do without consciousness?’ in his 2003 Reith Lecture. He believes that by studying the processes which require consciousness, and those that don’t and identifying the differences could help us to better understand consciousness.
Can we Measure Consciousness?
By monitoring brain activity using EEG, it is possible to identify the loss of consciousness in patients undergoing general anaesthetic. Through this technique, the reduction in high-frequency brain waves, and increase in low-frequency and alpha frequency waves can be observed as consciousness is lost.
In order to create an index of consciousness, Adenauer Casali, Marcello Massimini, and Giulio Tononi combined EEG recordings with transcranial magnetic stimulation (TMS) in order to measure the connectivity between neurones. Using this technique they were able to predict whether their patient was conscious, as high levels of connectivity indicate consciousness. These recordings of brain activity also support the Physicalism theory.
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