Consciousness – A Mystery in Neuroscience
A very long time ago, Aristotle thought that the mind is closely related to the heart but we now know that he was wrong. Actually, the mind is related to certain aspects of the behaviour of the brain. Today in neurobiology, the most puzzling attribute of the mind is consciousness or awareness. William James, who is regarded as the father of American psychology, said a century ago, “Consciousness is not a thing but a process”.
Max Velmans and Susan Schneider wrote in The Blackwell Companion to Consciousness: “Anything that we are aware of at a given moment forms part of our consciousness, making conscious experience at once the most familiar and most mysterious aspect of our lives.” The word consciousness, has different interpretations at different levels. For example, in medicine, consciousness can be studied by observing the responses of a patient to various stimuli. The various responsive states can range from full alertness to delirium, loss of understanding of meaningful words to loss of movement and so on.
In philosophy, consciousness is another name of awareness. Awareness refers to the quality of an individual possessing thoughts, feelings and perceptions. The above mentioned definitions of consciousness are ill defined because there is still a lot of research being done in order to understand this phenomenon. That’s why experimental research on consciousness presents specific difficulties. In this article, I will try to describe here the phenomenon of consciousness and visual awareness with the help of simple experiments that have been done on humans and are still being done.
This is a famous painting named Reproduction Prohibited (1937), by René Magritte. This painting is basically used to study visual awareness in humans which is obviously part of consciousness. We know that the person above is seeing himself in the mirror so our brains are supposed to see the front side of the person. We know this is true because we would be very startled if a mirror revealed both the front and back as exactly alike.
Now coming to ambiguous images. Ambiguous images are optical illusion images which exploit graphical similarities and other properties of visual system interpretation between two or more distinct image forms. Optical illusion or visual illusion is a phenomenon in which the information gathered by the eye is processed in the brain to give a perception which does not tally with the physical measurement of the source of stimulus.
For example, look above at the picture of duck-rabbit illusion. Is it both duck and rabbit? At first glance, it may appear that this a picture of duck looking towards the left but if you look a little closer, you’ll also notice that it is also a picture of rabbit looking towards the right. The beak of the duck and ears of the rabbit are represented by the same part of the image.
Now, the last experiment to test the visual awareness includes the image depicting illusory contour.
This is an image of Kanizsa triangle, which is named after the psychologist Gaetano Kanizsa. The image comprises black circles with wedges facing the center point and three black angles on a white background. But some of you can also see a white triangle on top of three black disks and an outline triangle. The white triangle appears brighter than the white background and shows a contour even in regions where there is no luminance change in the image.
According to Francis Crick and Christof Koch, the best approach to the problem of explaining consciousness is to concentrate on finding the various processes in the brain which are responsible for consciousness. By locating the neurons in the specific areas of the brain, we can get full accounting of the manner in which subjective experience arises from these cerebral processes.
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