: Edward Bradford Titchener
: A Beginner's Psychology Psychology: What it Is and What it Does?
: Cheapest Books
: 9786052259696
: 1
: CHF 2.30
:
: Angewandte Psychologie
: English
: 254
: kein Kopierschutz
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: ePUB

I is an acknowledged fact that we perceive errors in the work of others more readily than in our own. 
-Leonardo da Vinci 
 
In this Beginner's Psychology I have tried to write, as nearly as might be, the kind of book that I should have found useful when I was beginning my own study of psychology. That was nearly thirty years ago; and I read Bain, and the Mills, and Spencer, and Rabier, and as much of Wundt as a struggling acquaintance with German would allow. Curiously enough, it was a paragraph in James Mill, most unpsychological of psychologists, that set me on the introspective track,-though many years had to pass before I properly understood what had put him off it.  
 
A book like this would have saved me a great deal of labour and vexation of spirit. Nowadays, of course, there are many introductions to psychology, and the beginner has a whole library of text-books to choose from. Still, they are of varying merit; and, what is perhaps more important, their temperamental appeal is diverse. 
I do not find it easy to relate this new book to the older Primer,-which will not be further revised. There is change all through; every paragraph has been rewritten.  
 
The greatest change is, however, a shift of attitude; I now lay less stress than I did upon knowledge and more upon point of view. The beginner in any science is oppressed and sometimes disheartened by the amount he has to learn; so many men have written, and so many are writing; the books say such different things, and the magazine articles are so upsetting!

CHAPTER II:Sensation


Now that these points have been determined, let us proceed to a general discussion of the whole subject of Sensation.—Aristotle

§ 9.Sensations from the Skin.—The skin is part of our organic birthright. One of the great differences between the living and the not-living lies in the possession of a skin; stone and iron weather and rust, but even the naked amœba has its ectosarc, and flowers of tan their plasmoderm. The skin is also the oldest of the sense-organs, and the mother of all the rest; how old, we dare hardly guess; but we know that the chemical elements which make up living tissue took form early in the history of our planet, earlier than the heavy metals. So it is natural to begin our survey of sensations by questioning the skin.

The skin is a shifty witness; and to get positive answers, we must literally cross-examine it; we must go over its surface point by point and line by line, with all sorts of mechanical and thermal and electrical and chemical stimuli. The outcome is a little surprising; we find onlyfour sensations, pressure, cold, warmth and pain. The organs of these sensations are dotted in a sort of irregular mosaic all over the skin, and the intervening spaces are insensitive. The organs of pressure, distributed over about 95% of the bodily surface, are nerve-skeins twined about the roots of the hairs; on the hairless areas of the body, we find the nerve-skein by itself. The organ of pain is probably a little brush-like bunch of nerve-fibrils just below the epidermis. The organs of warmth and cold are certainly distinct; the sensations are not degrees of one sensation, as the thermometer might lead us to suppose; but the precise nature of their nerve-endings has not yet been made out.

You may easily find pressure spots by fastening a short horsehair with sealing-wax at right angles to the end of a match, and applying the horsehair point to the back of the hand above a hair-bulb, that is, just to windward of the issuing hair; dot the horsehair about, here and there, till the sensation flashes up. You may find cold spots by passing the blunt point of a lead pencil slowly across the closed eyelid. Warm spots are more difficult to demonstrate. For pain, take the shaft of a pin loosely between finger and thumb of the right hand, and bring the point down sharply on the back of the left hand; you get two sensations; the first is a pressure, the second—which pricks or stings—is a pain.

As a rule, these organs are not stimulated separately but in groups. Itch, for instance, is due to the light stimulation of a field of pain-endings, and superficial tickle to that of a field of pressure-organs. The experience ofheat, curiously enough, is a blend of warmth and cold; there are no heat spots. It may be observed in this way: if you apply a surface of increasing warmth to a region of the skin which has both cold and warm spots, you feel for some time only the warmth; but when the stimulus has reached a certain temperature, the cold spots, suddenly and paradoxically, flash out their sensations of cold; and the blend of warmth and of paradoxical cold is felt as heat. Cement a smooth copper coin to a handle, and apply it at gradually increasing temperature to the middle of the forehead just under the hair; you will presently find the heat. Or if you cannot do that, note the shiver of cold when you next step into an overhot bath.

When we compare these results with the show that the skin makes as a sense-organ in everyday life, we can hardly help bringing against it the charge of dishonesty. The pressure spots give us tickle, contact or light pressure, and pressure proper; the pain spots, itch, prick or sting, and pain proper. The cold spots give cold and cool, the warm spots lukewarm and warm; cold and warm spots