Applied Psychology for Nurses | Page 5

animal life, or to that of the newborn babe when he first opens his eyes to life.
Consciousness, then, in its elements, is the simplest mental reaction to what the senses bring.
How shall we determine when consciousness exists? What are its tests?
The response of the mind to stimuli, made evident by the body's reaction, gives the proof of consciousness in man or lower animal.
But what do we mean by a stimulus?
Light stimulates me to close my eyes when first entering its glare from a dark room, or to open them when it plays upon my eyelids as I sleep and the morning sun reaches me. It is a stimulus from without.
The fear-thought, which makes my body tremble, my pupils grow wide, and whitens my cheeks, is a stimulus from within.
An unexpected shot in the woods near-by, which changes the whole trend of my thinking and startles me into investigating its cause, is a stimulus from without causing a change within.
A stimulus, then, is anything within or without the body that arouses awareness; and this is usually evidenced by some physical change, however slight--perhaps only by dilated pupils or an expression of relief. When we see the reaction of the body to the stimulus we know there is consciousness. On the other hand, we cannot say that consciousness is always absent when the usual response does not occur; for there may be injury to organs accounting for the lack of visible reaction, while the mind itself may respond. But with due care, in even such cases, some external symptoms of response can usually be found if consciousness exists.
We have already realized how complex, intricate, and changing is fully developed consciousness.
THE UNCONSCIOUS
But the mind of man knows two distinct conditions of activity--the conscious and the unconscious. Mind is not always wide awake. We recognize what we call the conscious mind as the ruling force in our lives. But how many things I do without conscious attention; how often I find myself deep in an unexplainable mood; how the fragrance of a flower will sometimes turn the tide of a day for me and make me square my shoulders and go at my task with renewed vigor; or a casual glimpse of a face in the street turn my attention away from my errand and settle my mind into a brown study. Usually I am alert enough to control these errant reactions, but I am keenly aware of their demands upon my mind, and frequently it is only with conscious effort that I am kept upon my way unswerved by them, though not unmoved.
When we realize that nothing that has ever happened in our experience is forgotten; that nothing once in consciousness altogether drops out, but is stored away waiting to be used some day--waiting for a voice from the conscious world to recall it from oblivion--then we grasp the fact that the quality of present thought or reaction is largely determined by the sum of all past thinking and acting. Just as my body is the result of the heritage of many ancestors plus the food I give it and the use to which I subject it, so my mind's capacity is determined by my inheritance plus the mental food I give it, plus everything to which I have subjected it since the day I was born. For it forgets absolutely nothing.
"That is not true," you say, "for I have tried desperately to remember certain incidents, certain lessons learned--and they are gone. Moreover, I cannot remember what happened back there in my babyhood."
Ah, but you are mistaken, my friend. For you react to your task today differently because of the thing which you learned and have "forgotten." Your mind works differently because of what you disregarded then. "You" have forgotten it, but your brain-cells, your nerve-cells have not; and you are not quite the same person you would be without that forgotten experience, or that pressing stimulus, which you never consciously recognized, but allowed your subconsciousness to accept. Some night you have a strange, incomprehensible dream. You cannot find its source, but it is merely the re-enacting of some past sensation or experience of your own, fantastically arrayed. Some day you stop short in your hurried walk with a feeling of compulsion which you cannot resist. You know no reason for it, but some association with this particular spot, or some vague resemblance, haunts you. You cannot "place" it. One day you hit the tennis-ball at a little different angle than you planned because a queer thought came unbidden and directed your attention aside. Again, under terrific stress, with sick body and aching nerves, you go on and do your stint almost mechanically. You do not know where the strength or the skill is derived. But your unconscious or subconscious--as you will--has asserted