Reproduction of rapid precision movements


The method of reproducing and repeat ing f rom memory a movement with one or more of i ts pa rame te r s having a r igidly assigned value, i .e . , a skilled prec is ion movement developed under exteroceptive (usually v i sua l )cont ro l , is widely used in the study of the organizat ion of skilled movements . Such a method enables the prec is ion and s tabi l i ty of the propr iocept ive-effector engrams of the movement to be de termined, and in the presence of v isual control of movements reproduced f rom memory-v i sua l engrams of the movement i tself or of i ts pattern. In other words, it demons t ra tes the cha rac te r of memor iz ing of the skil led movement . On the assumption that these engrams are largely uti l ized in a react ion ca r r i ed out under exteroceptive control , the reproduct ion method can provide mate r i a l for postulat ing the re la t ive role of two factors in an in vest igated ski lh f i r s t , cor rec t ions introduced in the course of a movement , and second, the e lements of the movement which were planned beforehand-i .e . , to some extent it can enable the s t ruc ture of the skill to be defined. In previous invest igat ions on reproduct ion of movement , the precis ion of memor iz ing of one par t icu lar pa rame te r was usual ly investigated, or a general verbal descr ipt ion of the change in the react ion was given during i ts reproduct ion f rom memory. The object of the presen t invest igat ion is to a s se s s quanti tat ively the reproduct ion of a se r i e s of pa ramete r s charac te r iz ing a movement in order to study the pat tern of memor iz ing the react ion as a whole. The skilled movement studied consis ted of following or t racking with the hand a spot of light moving with a high, constant velocity. The movement was studied in two se r ies , distingxlished by the absence (the first) or the presence (the second) of v isual control of the movement by the subject. The invest igat ion showed (5) that, despite the movement of the target at constant velocity, in both s e r i e s the velocity curve of most of the movements was unimodal with a gradual r i se and fM1, the m a x i m u m occur r ing roughly in the middle of the movement . The presence of marked deviations f rom the posit ion and velocity of the ta rge t did not give r i se to abrupt changes in the velocity of individual cor rec t ing mic romovements . The picture descr ibed is very r emin i scen t of the ba l l i s t ic type of movement of a l imb to a prese t distance. However, i n t h i s c a s e the e lec t romyogram (EMG) of the agonist was recorded throughout the movement , often in conjunction with activity of the antagonist . The general cha rac te r of the movement remained unchanged with t ra in ing, but in the f i r s t se r i es the r eac t ion t ime fell s teadily and the durat ion of the movement inc reased f rom one exper iment to another. This was caused en t i re ly by an increase in the duration of the f i r s t period of the movement (from the beginning unti l the moment of a t ta ining maximal velocity), whereas the durat ion of the second period (from the moment of maximal velocity unti l the end of the movement) osci l la ted about a cer ta in constant value. This fact shows that the descr ibed movement is not monoli thic, and that there are re la t ively independent mechan i sms of regulat ion of the different port ions of the movements . Investigation of the organizat ion of the movement showed that the durat ion of i ts f i r s t period is inverse ly proport ional , and the maximal velocity direct ly proport ional , to the reac t ion t ime. An inverse re la t ionship was also discovered between the dura t ions of the f i r s t and second periods of the react ion, although this was less marked than the re la t ionship between the f i r s t period and the react ion t ime. These re la t ionships between the values of the individual p a r a m e t e r s of movements appearing in the f i r s t

DOI: 10.1007/BF01124652

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@article{Zalkind2005ReproductionOR, title={Reproduction of rapid precision movements}, author={M. S. Zalkind}, journal={Neuroscience Translations}, year={2005}, volume={1}, pages={101-108} }