Sensory experience

“ What is required will be found if we turn our attention from the sensory qualities of the imagery to the more fundamental qualities upon which its efficacy in modifying the rest of the experience depends. It has been urged above that images which are different in their sensory qualities may have the same effects. ”

“ In the first place, we may put down as an absolute requisite such an environment of sensory stimuli as will tempt every sense to be awake and at its best, that we may be led into a large acquaintance with the objects of our material environment. No one's stock of sensory images is greater than the sum total of his sensory experiences. No one ever has images of sights, or sounds, or tastes, or smells which he has never experienced.
Likewise, he must have had the fullest and freest possible liberty in motor activities. ”

“ When our sense organs are stimulated, the stimulus is conveyed by means of sensory nerves to the brain and there gives rise to sensation, the sense organs are sensitive to various kinds of stimuli, the stimulus to the eyes gives the sensation of sight, to the ears the sensation of sound and so on. ”

“ Thus, when a sensation of light instead of giving rise to a subsequent idea gives rise to a sensation of sound, for instance, we have the phenomenon of secondary sensation. Here the secondary sensations stand out free and distinct, but they are really always present in our ordinary perceptive experiences as bound up secondary sensory elements, as secondary sensations grouped round primary sensations. ”

“ Many sensations we know nothing about; when we become aware of our sensations it is because communications are sent by nerve fibres, acting as telegraph wires, from the sensorium to the thinking brain, and this happens when we give our attention to any one of the multitudinous messages carried by the sensory nerves. ”

“ For this reason, I think, we must suppose that certain sense-stimuli and combinations of stimuli not only produce in the sensory areas of the brain the appropriate sensations, but that their effects are prolonged, overflowing into the motor channels and there causing a total reaction of the organism, the conscious aspect of which is a vague feeling. The organic resonance is too slight and diffuse to produce a true emotion ”

“ A Sensation is an impression made by some external object on the Senses; the motion thus excited is propagated along the appropriate nerve, until it reaches the Sensory in the Brain, and it is there and there only, felt or perceived. ”

“ So far as these experiments go there appear to be at least four sensory factors of importance in the formation of a simple labyrinth habit: the chemical sense, touch, vision and the muscle sense. That the chemical sense and touch are valuable guiding senses is evident from even superficial observation, and of the importance of vision and the muscle sense we are certain from the experimental evidence at hand. ”

“ Sensations of touch and sight have in a pre-eminent degree a certain peculiar continuity which differentiations of extensity entail, and which we shall have presently to consider further under the title of local signs. The various sensations classed together as organic, hunger, thirst, physical pain, &c., are left to the physiologist to describe.
Our motor presentations contrast with the sensory by their want of striking qualitative differences. They are divided Movements. ”

“ Moreover, because these mental and bodily activities, being our own, can be rehearsed in what we call our memory without the repetition of the sensory stimulations which originally started them, and even in the presence of different ones.
In terms of mental science, colour and sound, like temperature, texture, taste and smell, are sensations; while shape is, in the most complete sense, a perception. This distinction between sensation and perception is a technicality of psychology ”

“ It will be seen that a synaesthesia—which may involve taste, smell, and other senses besides hearing and sight—causes an impression of one sensory order to be automatically and involuntarily linked on to an impression of another totally different order. ”

“ For a sound stimulus awakens not only a sensory process in the ear, the correlative of which is a sensation, but also incipient motor reactions, which, if carried out, would be an emotion, but which, being too slight and diffuse, produce only what we call a mood. Every sensation has a meaning for the organism in an environment where it has constantly to be on its guard for danger or assistance; every sensation is therefore connected with the mechanism of reaction, with its attendant emotions. ”

“ We found that when a sense organ is stimulated by its appropriate type of stimulus, this stimulation travels through the sensory nerves and sets up an excitation in the brain. This excitation in the brain gives us sensation. We see if the eye is stimulated. ”

“ In this new section we by no means cut loose from what is sensory in a subjective sense, for of course we become conscious of our own movements only through the sensory paths of sight and what is collectively called touch, chiefly sensations of contact, and tendon and joint sensations. ”

“ The sensorium, or central ganglion, receives impressions from the external world representing, in a way, various phases of reality. The brain has no source of knowledge other than sensation. All human knowledge comes through human experience. ”

“ As long as the visual stimulus operates as a stimulus on its own account, there is no apprehension, no noting, of color or light at all. To much the greater portion of sensory stimuli we react in precisely this wholly non-cognitive way. ”

“ The idea or image bears the same relation to the sensation as a photograph bears to the original, or rather as a symbol to the thing it represents. Ideas, images, representations substitute, represent sensations, but they are not sensations. A sensory process is fundamentally different. A sensation is not an intense idea, nor is an idea a weak sensation. Ideas differ far more qualitatively from sensations than visual sensations, for instance, differ from olfactory sensations. ”

“ I will begin with an example drawn from the borderland between the psychological and the physiological, one dealing with the sensory concomitants of nervous process in a case of experimental interference with the integrity of the nervous system. ”

“ The several works which these nerves do are called the senses. By means of these sensory nerves we receive impressions from the external world, sensations of heat, cold, roughness, good and bad odors, taste, sound, and the color and form of things. Thus impressions of the external world are made upon the brain, and it is these impressions that stimulate the brain to action. The brain worked on by them, through ways that we know not of, governs the muscles, sends commands by the motor nerves, and rules the body as a conscious, intelligent will. ”

“ The hardness, the smoothness, the bodily resistance are perceived by the visual sense and are visual, but as such they, of course, differ from the sensations experienced by their appropriate sense organs, as when for instance the same sensations are given by touch or by muscular and kinesthetic sensations. Those muscular and tacto-motor sensations appearing as visual are not memory-images, but they are actual sensations, they are secondary sensations; they are secondary sensory elements which give the fullness of content to the percept, having visual sensory elements as its nucleus. ”

“ It may be also of practical money value to the printer to know such facts, and to always be conscious of a fact more likely to be of practical use, namely, that the sensation of color is produced upon our sensory nerves in a manner closely analogous to that which produces the sensation of harmony: by ether waves set in motion in a different way. These sensory nerves are the most57 easily entered avenues to our pleasurable sensations; far more delicate and responsive than the different brain organs to the more obvious consciousnesses, as personal regard and literary appreciation, etc. ”

“ The brain is the great central station of the sensory nerves, the latter having countless sending stations in all parts of the body, the "wires" terminating in the skin. When these nervous terminal stations are irritated or excited, they send to the brain messages calling for attention. This is true not only of the nerves of touch or feeling, but also of those concerned with the respective senses of sight, smell, taste, and hearing. In fact, the best authorities hold that all the five senses are but an evolution of the primary sense of touch or feeling. ”

“ Numerous other examples of a similar character might be related to illustrate the fact that the brain is a reservoir of sensory impressions, some of which, at the moment of their original incidence, have aroused the mind to a greater or less degree of conscious attention, and have then all lapsed into a latent or potential condition. ”

“ For illustration, it is perfectly evident that we can not understand what is taking place in an organ for receiving sensory impressions without first understanding its mechanism and the nature of the connections between it and the central part of the nervous system. ”

“ How is consciousness of these sensations brought about? No doubt, in a manner similar to that of the mediation of such sensations as odors and tones: through the stimulation of sensory neurons and the propagation of nervous processes toward the motor points of the body. The place of stimulation must be somewhere in our organs of nutrition, and thus these organs must be regarded also as a kind of sense organ. That the sensory function can be attributed to an organ in addition to another function has been proved by the example of the skin, muscles, and joints. ”

“ There is a greater distinction between the two than between Sensation, the reaction of a sensory organ, and Perception, the216 combined result of sensory and cerebral reactions; or than that between Contractility, the property of the muscles, and Flying, the function of a particular group of muscles. It is not possible to have Consciousness without Sensibility; but perfectly possible to have Sensations without Consciousness. ”

“ The secondary sensory elements are not images, nor ideas, nor representations, different terms employed for the same state by various writers, the secondary elements of the percept are essentially sensations. Now sensations are qualitatively different from images, ideas or representations. The image of a light does not shine, the idea of a voice does not sound, and the representation of a perfume does not smell. A sensation, or presentation as it is sometimes termed, differs from an image or representation qualitatively, fundamentally. ”

“ If a man could possess in the highest degree and in combination all of the possible extremes of sensory appreciativeness seen in disease, in hysteria, and in the hypnotic state, we should have a being of extraordinary capacities for observation. ”

“ The second finds that whatever stimulus is applied to a sensory nerve, the nerve always reacts with the same sort of sensation, and conversely, that if the same stimulus affects different nerves, the sensations will belong to different senses. The psychologist, lastly, finds that all the data of sense are instinctively and invariably referred to external existences, and never to the observer's internal condition. ”

“ 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. ”

“ 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. ”

“ The seat of sensation is after all the brain. Originally we experience sensation through some excitation of the end organs of sense, the ear, the nerves of [13] touch, the retina; but these sensations become associated with verbal images in the mind, and finally the excitation of the verbal images results also in the revival of the original sensation. There is perhaps no one of us who has not seen wholly imaginary moving shadows or flashing lights in the dark. ”

“ The whole forms an interlacing feltwork formed of watery nerve cells and processes, and not only receives sensory stimuli and transmits them as motor impulses, but is more or less permanently modified by each sensory thrill which enters it, memorising each, more or less, for longer or shorter time according to its character or intensity. ”

“ But all the evidence that we possess goes to show that the sensory centres, stimulated by what we will assume to be the taste of the morsel, are different from those which are affected by sight, and the movements concerned in pecking. So that the consciousness which is effective in guiding future action is an accompaniment of the stimulation of centres that are different from those concerned in the behaviour over which guidance is exercised. ”

“ If we inspect the percept more closely, we find that there is some important difference in the character of the various constituent sensory elements. The central elements forming the nucleus of the percept are given directly by the sense-organ stimulated by its appropriate sensory stimuli, while the subordinate sensory elements are given indirectly,―they cannot be traced to appropriate sensory stimuli exciting those particular sense-organs on the activity of which those subordinate elements depend for their manifestation. ”