Reflex Quotes (9 quotes)
If we denote excitation as an end-effect by the sign plus (+), and inhibition as end-effect by the sign minus (–), such a reflex as the scratch-reflex can be termed a reflex of double-sign, for it develops excitatory end-effect and then inhibitory end-effect even during the duration of the exciting stimulus.
It is distinctly proved, by this series of observations, that the reflex function exists in the medulla independently of the brain; in the medulla oblongata independently of the medulla spinalis; and in the spinal marrow of the anterior extremities, of the posterior extremities, and of the tail, independently of that of each other of these parts, respectively. There is still a more interesting and satisfactory mode of performing the experiment: it is to divide the spinal marrow between the nerves of the superior and inferior extremities. We have then two modes of animal life : the first being the assemblage of the voluntary and respiratory powers with those of the reflex function and irritability; the second, the two latter powers only: the first are those which obtain in the perfect animal, the second those which animate the foetus. The phenomena are precisely what might have been anticipated. If the spinal marrow be now destroyed, the irritability alone remains,—all the other phenomena having ceased.
Plants are extraordinary. For instance ... if you pinch a leaf of a plant you set off electrical impulse. You can't touch a plant without setting off an electrical impulse ... There is no question that plants have all kinds of sensitivities. They do a lot of responding to an environment. They can do almost anything you can think of.
Reflexes and instincts are not pretty. It is their decoration that initiates art.
The development of mathematics is largely a natural, not a purely logical one: mathematicians are continually answering questions suggested by astronomers or physicists; many essential mathematical theories are but the reflex outgrowth from physical puzzles.
The Law of Inhibition. The strength of a reflex may be decreased through presentation of a second stimulus which has no other relation to the effector involved.
The nervous system is the most complex and delicate instrument on our planet, by means of which relations, connections are established between the numerous parts of the organism, as well as between the organism, as a highly complex system, and the innumerable, external influences. If the closing and opening of electric current is now regarded as an ordinary technical device, why should there be any objection to the idea that the same principle acts in this wonderful instrument? On this basis the constant connection between the external agent and the response of the organism, which it evokes, can be rightly called an unconditioned reflex, and the temporary connection—a conditioned reflex.
The true-spinal system consists of a series of nerves passing principally from the cutaneous surface, and the surface of the mucous membranes, to the spinal marrow; and of another series of nerves passing from the spinal marrow to a series of muscles, destined to be moved simultaneously. The former, thence designated the incident nerves; the latter, reflex nerves: the spinal marrow is their common centre.
With the nervous system intact the reactions of the various parts of that system, the 'simple reflexes', are ever combined into great unitary harmonies, actions which in their sequence one upon another constitute in their continuity what may be termed the 'behaviour'.