Many review papers have been devoted to surveys on the investigations dealing with the motor control of the central nervous system, which is one of the most fundamental processes of nervous activity. However, they are foccussed mainly on the neural mechanisms of local circuitries relating to these motor controls. Little attention has been paid on the mechanisms of pattern formation of the movement.
In this review, an attempt is made to disclose some features of the neural mechanisms underlying the pattern formation of movements. In the first section, some aspects of the neural control mechanisms of electric organs of electric fish are described. In the second and third sections, wave-form movements and locomotive movements are discussed. Finally, some problems of the control role of the cerebellum are dealt with under two headings : cerebellum and spatial pattern formation; and the cerebellum and the temporal pattern formation.

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Many papers have been devoted to discussions of the mechanism of conditioned reflex, which is the most fundamental process in animal learning and pattern recognition. Their discussions are mainly focussed on the mechanism of discriminating different patterns. Thus their models are poor in generalization which is the most essential feature of conditioned reflex and animal learning. Besides, learning process of these models is quite different from that of conditioned reflex as was reported by Pavlov.
In this paper the author presents a model of conditioned reflex which is capable of simulating the following essential features of conditioned reflex : derivation of conditioned response by reinforcement, extinction of the formerly established reflex, delayed reaction, external inhibition and disinhibition, generalization and differentiation, etc.
The model is composed of four types of neurons, two excitatory (S & R) and two inhibitory (T & V). Input and output of these cells are non-negative continuous quantity. Each cell has threshold and gives output proportional to suprathreshold input.
Conditioned stimuli are sent to sensory cell S and unconditioned stimuli are sent to response cell R. Output of cells S is sent to cell R and forward inhibitory cell T, which may inhibit cell R. Output of cell R may evoke certain response of uncoditioned reflex, in the meantime inhibiting cells S and T via backward inhibitory cell V.
In this model, as was experimentally proven by Pavlov, extinction of a conditioned reflex is not due to decay of once established connections but to development of new connections which are to overcome the effect of the former ones. Inhibitory cell T works for development of delayed reaction and extinction, while backward inhibitory cell V works for external inhibition of conditioned reflex and disinhibition.
The learning of the model is done by changing the weights of connections of neurons. Mathematical reinforcement rule is formulated from physiological reinforcement conditioning. Some examples are given to show the learning process of the model.

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In order to clarify the neural extracting mechanism of movement information which is transmitted by the movement fibres in the crayfish optic tract, the time-dependent process of the movement fibre responses was investigated by means of spatially stationary flickering light of various temporal patterns.
The following results were obtained.
1. The movement fibre does not respond at all to regular flickering light (inter-flash interval : 100-250 ms). This type of non-responsiveness should be termed as “habituation”. It is indicated from the experimental evidences that during habituation, a periodic activity synchronizing with the flickering light is constructed in neural network at the level of the optic ganglia and this periodic activity possesses some kind of “memory” of inter-flash interval and light value of flash.
2. When the regular flickering light is turned off, transient response, e.g., “dishabituation” appears. The timing of dishabituation measured from the final flash-on has a linear relation to inter-flash interval of the flickering light.
3. The irregularity of test flash given after regular flickering light elicits the response. In this case, the response time is determined by the result of comparison with the parameters of the preceding regular flickering light and those of the subsequent test flash. In this comparing function, each inter-flash interval is checked up and relative light value of each preceding flash is compared with one of the subsequent flashes.
4. As described above, the minimum peripheral requirement for movement perception does not involve the spatial transfer of the form dx/dt, where x is the angular distance of the ommatidium perceiving the movement, but the irregularity appeared newly in the spatio-temporal pattern of the background.

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