Single Touch Research Articles

触運動的図形の再生と描画過程

The present paper was to analyze experimentally how the immediate reproduction of tactually perceived geometrical figures was influenced by some factors of touching such as (i) the movement of the hand, (ii) the starting point of touching, and (iii) the extent in tactual surface and others, and to examine what S's drawing process in reproducing the figures were, in order to find out the conditions necessary for the tactile apprehension of figures.In Exp. I, the two conditions of touching were set; (a) the condition of active touch in which S with closed eyes was asked to feel actively, moving his forefinger once along the contour of the figures, and (b) the condition of passive touch in which S was asked to hold constantly the finger on the same position and to feel once, passively, the contour of the figures which were moved by E. The four starting points of touching were set in each stimulus figure (Fig. 1). After touching a figure S was asked to reproduce it with open eyes. The results were: (1) The apprehension of figures in Active touch was better than in Passive touch (Table 2 and Fig. 2). (2) Point a was the most favorable starting point of touching in the scalene square. In the square and the lozenge, the starting points and the conditions of touching were interacting, and the favorable points for apprehension varied with the variation of stimulus figures (Table 1 and Fig. 2). All these favourable points, however, coincided with the starting points or the terminal points of open eyed drawing of the same figure (Table 6). Thus they were relevant to the drawing processes of figures in some respects. (3) In both Active and Passive touch, most of the S's reproduced the figures in uninterrupted lines, repeating the same course as in the touching condition (“continuous reproduction”). On the other hand, “dividing construction” which one employed ordinarily with open eyes in drawing the figures, scarecely appeared (Table 4).In Exp. II a four segment (Table 7) and in Exp. II b eight patterns (Table 8) were used as stimulus figures. Besides the conditions of Active and Passive touch, the two conditions as to the direction of touching were set in each figure (Table 7 and 8). The results in Exp. II a were: (1) Only the perception of the orientation of the segments in Active touch was better than that in Passive touch (Table 7). (2) For the vertical and horizontal segments in the active condition, the directions of touching which were favorable for perceiving tend to correspond to those of drawing of the lines (Fig. 4). In Exp. II b, on the other hand, it was observed that (3) the perception of the angles contained by two segments, that of the orientation of each segment, and that of the equivalence between a vertical segment and a horizontal one were all better under the active touch condition than were under the passive touch condition (Table 8 and 9), (4) In Active touch of the stimulus patterns consisting of a horizontal segment and a vertical one, the touching in the direction opposite to that of the drawing was more favorable for the correct perception than the touching in the same direction as that of drawing, in contrast with Exp. II a (Table 8). (5) In Exp. II a and II b most of Ss employed the “continuous reproduction”.In Exp. III Ss were allowed to feel a figure freely to their satisfaction, with one finger, one hand or both hands, respectively. The results were: (1) As the condition of touching shifted from “single touching” (Exp. I) to “free touching” with one finger (Exp. III), the perception of a figure gradually improved (Fig. 6). (2) The increase of tactual surface, however, did not necessary result in the improvement of the perception of a figure (Fig. 5). (3) “Dividing construction” remarkably increased in every condition of Exp. III (Table 13). (4) It was suggested that if

The discharge in single touch receptors elicited by defined mechanical stimuli.

AbstractTo understand how a touch stimulus is coded in nerve impulses it is fundamental to know the significance of its wave form. This has been studied in the toad by means of a special technique for stimulation of individual touch receptors in situ with simultaneous recording of the skin displacement. Stimuli of various gradients, amplitudes and durations were applied to the skin surface over the receptor, and the impulse discharge in the afferent fibre was recorded from thin filaments of the dorsal root.The threshold amplitude was remarkably independent of the stimulus gradient. When the latter was increased gradually from the minimum effective value (critical slope) and upwards, the threshold fell sharply at first but then remained at the same level (Fig. 3 and 4).Prolongation of a threshold stimulus by adding a plateau phase to the initial moving phase did not result in a repetition of the response and did not make it possible to reduce the amplitude (Fig. 1). The repetitive response usually obtained on suprathreshold stimulation was either limited to the moving phase or had the highest impulse frequency during this phase (Fig. 2).Since the strongest excitation occurred during the moving phase of the stimuli, it was concluded that the deformation is the adequate stimulus. The deformed state is normally followed by no response at all or, in some receptors, by a rapidly adapting discharge.

Behaviors of cervical muscles in labyrinthine and skin-pressure reflexes.

Electromyographic observations were made in rabbits on the following muscles: M. trapezius pars cervicalis as a superficial muscle and M. rect. cap. dors. maj. et min., long. atl. and rect. cap. vent, as deep muscles.Pressure applied to the root of earlobe facilitated muscle tone of rect. cap. dors. maj. et min. and inhibited the other muscles in ipselateral side. Reversed effect was observed with the same stimulus in contralateral side. Under this condition touch of the skin caused a transient burst in such a manner that the head returned to the level.There was a continuous train of impulses in deep muscles, the discharge of right dorsal muscles was facilitated in tilting to the right or linear acceleration to the left. Opposed effect was observed in the left side. In the ventral muscles effects are in opposite sense. These effects were summed algebraically with those of pressure.In horizontal rotation, rapid and slow phase of head nystagmus were seen in electromyographic records. The effect of pressure was summed algebraically in slow phase, modifying the rapid phase reciprocally. In bilateral pressure stimuli, rapid phase was not observed. Rhythmical discharge was sometimes caused by a single touch applied during the rotation.These results were discussed in relation to tonic and kinetic activity of central nervous system.

感應理論の研究 (第四報告)

Problem: Although we know very little about the physiology of cortica activity, it may be assumed with high degree of probability that the excitatory process initiated in a definite point of the cortex by stimulation of the receptor apparatus irradiates into the surrounding region, deminishing in intensity as the distance increases from the original excitatory focus. One of the best evidences to support this hypothesis was presented by the suggestive research of Bernstein. It was pointed out by him that in the case of cutaneous perception there is a spread of ex citation by stimulation with a single point; thus, two stimulus points close together give rise to an impression of a single touch. I think we may say that all psychologists can hardly doubt the validity of this theory in its general implication. My own treatment of the subject in this paper follows a line which is similar in some respects to that of Bernstein's theory. However, the similarity is dictated not by adherence to the truth of his explanation itself but rather by a common basis of thought in brain physiology. In short, it is one of the ultimate objects of my investigation to infer the cortical interaction in response to visual stimulation by using the amount of the illusion as an index of irradiation.Experiments: In the preceding papers the writer has reported a series of experiments on the illusion of contrast and confluence and on the illusion of filled space. In the present paper the preceding analysis will be extended to cover other new illusion figures which are assumed to play an important part in our investigation.Now, the limiting case of the illusion of filled space may be reached by gradually altering the length of the interpolated inner line of the ordinary illusion diagram (Fig. 1. A, A, A.). The outside distances of the diagram A, A, A, although actually equal, appear to be of unequal length, owing to the different infiuences of the interpolated inner stimuli. Using these diagrams, an attempt was made to obtain quantitative data on the effect of the inner longer line upon the outer picture.We shall begin with an experiment in which the space interval between the outer two lines was varied, the size of the inner line being kept constant (Fig. 1. C, C, C). The general course of the change of the illusion is shown in Fig. 2. The ordinate indicates the amount of the illusion, the abscissa the outer distance. From the curve we see quite clearly that the space tends to be underestimated (contrast) when the outer lines are closely adjacent to the inner one. This facts seems to show that the amount of the illusion depends on the strength of the interpolated stimulus. If strong, it has a contrast effect (underestimation), if weak, an assimilative one (overestimation).Fig. 1.Fig. 2.There is another experiment that seems to support the present result. In the above experiment a measurment was made with the diagram in which the distance between the outer lines was variable, while the size of the inner line Was kept constant. In the following experiment I have sought, on the contrary, to determine a relation between the size of the inner line and the amount of the illusion, the size of the outer picture being kept constant (Fig. 1. A, A, A). The experimental result is shown in Fig. 3. It follows from the curve that the amount of the illusion varies quite regularly with the change in the length of the inner line. The overestimation (assimilation) decreases with the increase in size of the inner line, and the illusion is reversed when the inner line is sufficiently long; so that there is a critical point (an indifferent point) between the two, where no effect results.

Pulsation in Animals 1

JELLY-FISHES have been the subjects of frequent J experimentation-?we need only refer to the admirable researches of Romanes?and Mr. Alfred G. Mayer, director of the Department of Marine Biology of the Carnegie Institution of Washington, has been able to draw some new and exceedingly interesting general conclusions from a study of their pulsations. When the marginal sense-organs of the jelly-fish Cassiopea are cut off, the disc is paralysed and does not pulsate in sea-water. If a ring-like cut, or a series of concentric broken-ring-like cuts, be made through the muscular tissue of the subumbrella, the mutilated disc (without marginal sense-organs) responds to a momentary stimulus, e.g. a mechanical or electrical shock, or a single touch with a crystal of potassium sulphate, and suddenly springs into unusually rapid rhythmical pulsation. This is regular and sustained like clockwork, and continues indefinitely in normal sea-water without further external stimulation. The waves of pulsation all arise from the stimulated point, and the labyrinth of sub-umbrellar tissue around this centre must form a closed circuit—the stimulus being transmitted by the diffuse nervous or epithelial elements of the subumbrella. Any cut that breaks the circuit stops the waves of pulsation, and continuous movement cannot again be started. When each wave in a complete circuit returns to the centre it is reinforced and again sent out through the circuit. The centre once established remains a fixed point, while the disc continues to pulsate. The pulsation is fully twice as rapid as that of a normal Medusa, its rate varying with the length of the circuit, and it is self-sustaining (i.e. sustained by internal stimuli) once it be started by an external momentary stimulus.