STUDIES ON INTERCEPTION OF VISUAL INFORMATION DURING THE TARGET AIMING TASK

Abstract

Some behavioral characters in the event of interception of the visual information during the visual-motor aiming task was studied. Subjects were 9 healthy adults. Target aiming task was assigned as task exerting the visual-motor system. The task was performed by using an apparatus for measuring the aiming performance by a telescope. The visual information was intercepted by covering the telescope. After the target aiming task was made for 60 seconds under the condition with the visual information (former period), the task with interception of the visual information was kept for 30 seconds. Successively, for 60 seconds, the task with the visual information was done (later period). The total duration of measurement was 150 seconds. 10 measurements were made for each subject. Two postures of the subjects were taken during the measurement; the posture with the elbow free and the one with the elbow rested upon the desk (E-posture). The measured scales were as follows; Lshowed the averaged error level and D/L showed the relative reliability of the aiming task, D being the deviation from the average, the duration of aiming maintained with the interception of the visual information and the time required for the reversion to the former task-level at the re-insertion of visual information. The task level for assessing those periods was drawn at the former L puls D or 2D. The results were as follows: 1) L in the former period was larger than L in the later period (significant at 6% level). But D/L did not show significant changes. 2) The duration of aiming maintained with interception of the visual information was 3.8 sec at [L+D] level and 4.9 sec at [L+2D] level. 3) The time required for the reversion to the former task level at the re-insertion of visual information was 4.4 sec at [L+2D] level and 5.4 sec at [L+D] level. 4) Correlation coefficients between each of the measured scales were culculated, and 3 factors were extracted by means of factor analysis. 5) In the occasion when the aiming level just befor the interception of visual information was higher than L, the duration of maintained aiming after the interception of visual information was longer than that at the opposite occasions. And, in the occasion when the direction of feedback control was approaching to the target, the same results were observed. 6) With E-posture, L in the former period became similar to the level in the later period, and the difference of L between both of the periods was not observed. The duration required for the recovery of aiming after the interception of visual information became longer. In view of these experimental results, it is concluded that the visual information system and the deep sensory information sysytem may also participate in the target aiming performance.