. Design for a brain. Brain -- Physiology; Central nervous system -- Mathematical models; Neurophysiology. PARAMETERS 6/4 300- 200 state and change of field, can hardly be over-estimated. In order to make the distinction clear I will give some examples. In a working clock, the single variable defined by the reading of the minute-hand on the face is absolute as a one-variable system ; for after some observations of its behaviour, we can predict the line of behaviour which will follow any given state. If now the regulator (the parameter) is moved to a new position, so that the clock runs at a di
. Design for a brain. Brain -- Physiology; Central nervous system -- Mathematical models; Neurophysiology. PARAMETERS 6/4 300- 200 state and change of field, can hardly be over-estimated. In order to make the distinction clear I will give some examples. In a working clock, the single variable defined by the reading of the minute-hand on the face is absolute as a one-variable system ; for after some observations of its behaviour, we can predict the line of behaviour which will follow any given state. If now the regulator (the parameter) is moved to a new position, so that the clock runs at a different rate, and the system is re-examined, it will be found to be still absolute but to have a different field. If a healthy person drinks 100 g. of glucose dissolved in water, the amount of glucose in his blood usually rises and falls as A in Figure 6/4/1. The single variable c blood-glucose ' is not absolute, for a given state ( 120 ml.) does not define the subsequent behaviour, for the blood- glucose may rise or fall. By adding a second vari- able, however, such as ' rate of change of blood-glucose ', which may be positive or negative, we obtain a two- variable system which is sufficiently absolute for illustration. The field of this two-variable system will resemble that of A in Figure 6/4/2. But if the subject is diabetic, the curve of the blood-glucose, even if it starts at the same initial value, rises much higher, as B in Figure 6/4/1. When the field of this behaviour is drawn (B, Fig. 6/4/2), it is seen to be not the same as that of the normal subject. The change of value of the parameter 4 degree of diabetes present' has thus changed the field. Girden and Culler developed a conditioned reflex in a dog which was under the influence of curare (a paralysing drug). When later the animal was not under its influence, the conditioned reflex could not be elicited. But when the dog was again put under its influence, the conditioned reflex returned. We need not en
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Keywords: ., bookcentury1900, bookpublishernewyorkwiley, booksubjectneurophys
