Stimulus (psychology)

“ When the outer stimulus comes and those tracts vibrate with the sensation A, they discharge as directly into the paths which lead to B as when there is no outer stimulus and they only vibrate with the idea a. ”

“ When a stimulus promptly arouses a reaction, and that ends the matter, we speak of reflex action--provided, of course, the connection between stimulus and response is native. But when a stimulus sets up a tendency to a reaction that cannot be immediately executed, or towards an end-result which cannot immediately be reached, and when the tendency so aroused persists for a time in activity, and gives rise to preparatory reactions, then we speak of instinct. ”

“ Taking an initial stimulus with its concomitant sensory effect as the starting point we add by degrees small unperceived stimuli until a point is reached when a barely perceptible change of the external stimulation is effected in consciousness. ”

“ One can express this state of things otherwise by saying that the whole of the stimulus does not seem to be effective in giving us the perception of 'more,' and the simplest interpretation of such a state of things would be physical. The loss of effect would take place in the nervous system. If our feelings resulted from a condition of the nerve-molecules which it grew ever more difficult for the stimulus to increase, our feelings would naturally grow at a slower rate than the stimulus itself. ”

“ It is merely a matter of the stimulus and the response becoming connected in that way as the result of experience. Our meaning is that an act can be touched off or prompted by any stimulus. Our nervous organization makes this possible. The particular stimulus that calls forth a particular response depends upon how we have been trained, how we have learned. In most cases our acts are coupled up with the ideas of the acts. ”

“ For every stimulus which produces in consciousness a definite content of sensation is also a definite degree of disturbance, and therefore makes a call upon the forces of the nerves; and the sum of these little changes, which in their character as disturbances are not so diverse as the contents of consciousness they give rise to, produce the general feeling which, added to the inability to distinguish, deludes us into the belief in an actual absence of diversity in our sensations. ”

“ Sensation is the first response aroused by a stimulus, or at least the first response that is conscious. Perception is a second response, following the sensation, and being properly a direct response to the sensation, and only an indirect response to the physical stimulus. The chain of events is: stimulus, response of the sense organ and sensory nerve, first cortical response which is sensation, second cortical response which is perception. ”

“ To call a sensation a form of reaction means, then, that the sensation is not something done to the person, nor passively received by him from outside, but something that he himself does when aroused to this particular form of activity. What comes from outside and is received by the individual is the stimulus, and the sensation is what he does in response to the stimulus. It represents the discharge of internal stored energy in a direction determined by his own inner mechanism. ”

“ To call all mental processes reactions means that it is always in order to ask for the stimulus. Typically, the stimulus is an external force or motion, such as light or sound, striking on a sense organ. There are also the internal stimuli, consisting of changes occurring within the body and acting on the sensory nerves that are distributed to the muscles, bones, lungs, stomach and most of the organs. The sensations of muscular strain and fatigue, and of hunger and thirst, are aroused by internal stimuli, and many reflexes are aroused in the same way. ”

“ But other factors in reality are present; for we find the reaction-time more prolonged by the concomitant stimulation when the stimulus is weak than when it is strong I made experiments in which the principal impression, or signal for reaction, was a bell-stroke whose strength could be graduated by a spring against the hammer with a movable counterpoise. ”

“ Even though it may teach us in a general way that with the strength of the outward physical stimulus the strength of the concomitant sensation waxes or wanes, still it leaves us without the slightest knowledge of whether the sensation varies in exactly the same proportion as the stimulus itself, or at a slower or a more rapid rate. In a word, we know by our natural sensibility nothing of the law that connects the sensation and its outward cause together. ”

“ All stimuli whose first nerve-vibrations have not yet ceased seem to be conditions of our getting this feeling of the specious present. They give rise to objects which appear to the mind as events just past. [572]
When we have been exposed to an unusual stimulus for many minutes or hours, a nervous process is set up which results in the haunting of consciousness by the impression for a long time afterwards. The tactile and muscular feelings of a day of skating or riding, after long disuse of the exercise, will come back to us all through the night. ”

“ A sensation or image then may be followed by any series of images without the intermediacy of external excitations and peripheral physiological processes. A sensation, however, cannot be followed by a series of sensations without the intermediacy of external stimulations. A sensation can only be initiated by its own appropriate stimulus and by its own specialized peripheral physiological processes. ”

“ The simplest relation would obviously be that the sensation should increase in identically the same ratio as the stimulus, thus that if a stimulus of strength one occasioned a sensation one, a stimulus of two should occasion sensation two, stimulus three, sensation three, etc. ”

“ In such cases, the organic state, once set up in response to a certain stimulus, persists after the reaction to that stimulus is finished and predisposes the individual to make the same sort of reaction to other stimuli. ”

“ Sense perception, then, is a response of areas adjacent to the sensory areas, and this response is aroused by nerve currents coming along "association fibers" from the sensory areas which are first aroused from the sense organs.
The whole chain of events, from the time the stimulus reaches the sense organ to the time the fact is perceived, occupies only a fifth or even a tenth of a second in simple cases, and the interval between the beginning of the sensation to the beginning of the perception is not over a twentieth when the fact is easily perceived. ”

“ The degree of concentration of the attention has much to do with determining the reaction-time. Anything which baffles or distracts us beforehand, or startles us in the signal, makes the time proportionally long.
The Summation of Stimuli.—Throughout the nerve-centres it is a law that a stimulus which would be inadequate by itself to excite a nerve-centre to effective discharge may, by acting with one or more other stimuli (equally ineffectual by themselves alone) bring the discharge about.{129} The natural way to consider this is as a summation of tensions which at last overcome a resistance. ”

“ HOW SENSATIONS, PERCEPTIONS AND THOUGHTS MAY BE CONSIDERED AS FORMS OF INNER RESPONSE, AND HOW THESE HIGHER REACTIONS ARE RELATED IN THE NERVOUS SYSTEM TO THE SIMPLER RESPONSES OF THE REFLEX LEVEL.
Having defined a reaction as an act of the individual aroused by a stimulus, there is no reason why we should not include a great variety of mental processes under the general head of reactions. Any mental process is an activity of the organism, and it is aroused by some stimulus, external or internal ”

“ Whereas a stimulus pushes him from behind, a goal beckons to him from ahead. This element of action directed towards some end is absent from the simple response to a stimulus.
In short, we have to find room in our stimulus-response psychology for action persistently steered in a certain direction by some cause acting from within the individual. We must find room for internal states that last for a time and direct action. In addition, we sometimes, though not always, need to find room for conscious foreknowledge of the goal towards which the action is directed. ”

“ The mental set is itself a response to a stimulus. It is an inner response thrown into activity by some stimulus, such as the stimulus of being asked to give the opposites of a series of words that are presently to be shown or spoken. This inner response of getting ready for the task can be introspectively observed by a person who is new to this type of test. It may take the form of mentally running over examples of opposites--or whatever kind of responses are to be called for--or it may take the form of calling up some image or diagram or gesture that symbolizes the task. ”

“ We can quickest reach a result with our observations if we start with an arbitrary strength of stimulus, notice what sensation it gives us, and then see how much we can increase the stimulus without making the sensation seem to change. If we carry out such observations with stimuli of varying absolute amounts, we shall be forced to choose in an equally varying way the amounts of addition to the stimulus which are capable of giving us a just barely perceptible feeling of more. A light, to be just perceptible in the twilight need not be near as bright as the starlight ”

“ The response in imagination we have already defined, in a general way, as mental manipulation, and the end-result as the placing of facts into new combinations or relationships. The stimulus consists of the facts, either perceived at the moment or recalled from past perception, that are now freshly related or combined. The more precise question regarding the stimulus is, then, as to what sort of facts make us respond in an inventive or imaginative way ”

“ A stimulus is pleasant, then, because the nerve currents started by it find smooth going through the brain centers, and another stimulus is unpleasant because it finds the going poor.
While this theory looks good in some ways, and fits some cases very well--as the great unpleasantness of blocked reaction, where you cannot make up your mind what to do--there are two big objections to it. The first objection is found in the facts of practice. Practising any reaction makes it more and more smooth-running and free from inner obstruction, and should therefore make it more and more pleasant ”

“ Grasping for your hat when you feel the wind taking it from your head is an example. These acquired reactions never reach the extreme speed of the quickest reflexes, but at best may have about the speed of the simple reaction. Though often useful enough, they are not so fundamentally necessary as the reflexes. The reflex connection of stimulus and response is something essential, native, closely knit, and always ready for action. ”

“ These rare cases are especially found among very intelligent For the stimulus words corresponding to the numbers see the formulary on the first and second pages of Lecture I. and educated chronic patients who after many years of practice have learned to control their outward behavior and therefore outwardly display very little if anything of their neuroses. On superficial observation they can be taken as normal, yet in some places they show disturbances which betray the repressed complex. ”

“ The more times it passes the same way, the greater is the probability that at any given time the stimulus will take the accustomed route and bring about the usual response. At first any sort of action is possible. A nerve stimulus can take any one of the many routes to the different muscles. By chance or by conscious direction, the stimulus takes a certain path, and by repetition we fix and make permanent this particular route. This constitutes a nerve tendency or habit. ”

“ The mind can know nothing except as the stimulus is transmitted by sense-channels over the nerves of sense, and received by a conscious brain. A baby born without sight, hearing, taste, smell, or touch would remain a mere bit of clay. ”

“ The error of those who refer pain solely to intensity of stimulation is in considering objective conditions only; they forget the part played by the sentient subjects. Pains which depend on the quality of the stimulus are especially of subjective origin, because the degree of excitability in the patient’s nervous elements is the essential ruling factor. ”

“ A nerve tendency is simply the likelihood that a stimulus will take a certain course rather than any other. This likelihood is brought about by getting the stimulus to take the desired route through the nervous system to a group of muscles and to continue following this route. ”

“ This same truth is still more clearly brought out in the fact that, if we take a certain stimulus as a unit, giving rise to a definite sensation, then as we progressively ascend and add more and more units of the same stimulus, the intensity of stimulation is far from rising proportionately. If we take, for instance, the weight of an ounce as our unit of stimulation, then the successive moments of unit stimulations, that is, of ounces, will not give rise to as distinct and similar sensations as the initial sensation. ”

“ The subconscious sensations experienced are transmitted as abstract ideas to the focus of consciousness.
Often instead of the particular idea being transmitted, only the general aspect of it reaches the focus. Thus the patient is not able to guess the particular nature of the stimulus, but he may give the character of the unfelt stimuli. This reveals the reverse movement from the subconscious to the conscious. ”