The Double Step Analysis of Rapid Manual Aiming Movements

1988 ◽  
Vol 40 (2) ◽  
pp. 299-322 ◽  
Author(s):  
Nicholas C. Barrett ◽  
Denis J. Glencross
Keyword(s):  
Control System ◽  
Initial Response ◽  
Response Amplitude ◽  
Step Response ◽  
Oculomotor Control ◽  
Second Step ◽  
Double Step ◽  
Home Base ◽  
Transition Functions ◽  
Corrective Response

The present paper examines the control principles underlying rapid manual tracking responses to horizontal double-step stimuli. The paper reports an experiment concerned with responses made to step-stimuli presented in quick succession. The amplitude of the second-step was varied between the initial step-position and the home-base. Double-step response parameters were analysed as a function of the determinant time interval (D) between the second step and the onset of the initial response. The initial response amplitude was observed to vary as a function of D. Amplitude transition functions were constructed representing the transition of the initial response amplitude between the two step positions; their slopes, furthermore, depended on the amplitude of the second target step. No delays in the initial reaction time with the interstimulus interval were observed. Minor delays to the onset of a corrective response were observed. These delays were in part related to a movement time constraint that is independent of any limitations in central processing capacity. The present findings for the manual control system are compared to double-step tracking analyses of the oculomotor control system.

scholarly journals Flexible planning of corrective responses for double-step reduction in the number of potential targets

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ryoji Onagawa ◽  
Kazutoshi Kudo
Keyword(s):  
Control System ◽  
Weighted Average ◽  
Double Step ◽  
Average Behavior ◽  
Potential Target ◽  
Flexible Planning ◽  
Corrective Response

AbstractHumans are often required to plan/execute movements in the presence of multiple motor targets simultaneously. Under such situations, it is widely confirmed that humans frequently initiate movements towards the weighted average direction of distinct motor plans toward each potential target. However, in situations where the potential targets change in a step-by-step manner, the strategy to proceed towards the weighted average direction at each time could be sub-optimal in light of the costs of the corrective response. Herein, we tested the sensorimotor strategy followed during a step-by-step reduction of potential goals. To test the hypothesis, we compared the corrective responses when the number of targets went from three to two, and when the number of targets went from three to one at the same time. As the results, weak corrections were confirmed when the number of targets was reduced from three to two. Moreover, the corrective responses when the number of targets went from three to two was smaller than the average behavior estimated from the corrective responses when the number of targets went from three to one at the same time. This pattern of corrective responses reflects the suppression of unnecessary corrections that generate noise and cost to the control system. These results suggest that the corrective responses are flexibly modulated depending on the necessity, and cannot be explained by weighted average behavior.

scholarly journals Analysis of double-step response to an interplanetary shock in the dayside magnetosphere

2014 ◽  
Vol 32 (10) ◽  
pp. 1293-1302 ◽  
Author(s):  
K. Andréeová ◽  
L. Juusola ◽  
E. K. J. Kilpua ◽  
H. E. J. Koskinen
Keyword(s):  
Magnetic Field ◽  
Field Enhancement ◽  
Initial Response ◽  
Interplanetary Shock ◽  
Geostationary Orbit ◽  
Step Response ◽  
Double Step ◽  
Horizontal Magnetic Field ◽  
Magnetic Field Enhancement ◽  
Shock Impacts

Abstract. We present an analysis of double-step magnetic field enhancement caused by interplanetary (IP) shock impacts on the Earth's magnetosphere. The structures were observed by the GOES-8, 10, 11, and 12 spacecraft in the dayside geostationary orbit, particularly during northward interplanetary magnetic field (IMF) conditions. The double-step structures, similar to what is observed in the ground horizontal magnetic field (H) component at low and mid latitudes, were observed preferentially on the dayside. Structures observed around 12–15 magnetic local time (MLT) displayed the steepest initial enhancement step, followed by a magnetic field strength decrease before the second enhancement step. At other dayside MLTs of the geostationary orbit, the initial response was smoother, and no decrease was observed before the second step. We suggest that this MLT asymmetry in the decrease of the total magnetic field is caused by the pushing of the plasmaspheric ions over the geostationary orbit due to the magnetospheric compression.

scholarly journals Short-term saccadic adaptation in the macaque monkey: a binocular mechanism

2013 ◽  
Vol 109 (2) ◽  
pp. 518-545 ◽  
Author(s):  
K. P. Schultz ◽  
C. Busettini
Keyword(s):  
Saccadic Eye Movements ◽  
Initial Response ◽  
Macaque Monkey ◽  
Double Step ◽  
Adaptive Process ◽  
Adaptive Mechanisms ◽  
Second Shift ◽  
The Subject ◽  
The Brain ◽  
Saccadic Responses

Saccadic eye movements are rapid transfers of gaze between objects of interest. Their duration is too short for the visual system to be able to follow their progress in time. Adaptive mechanisms constantly recalibrate the saccadic responses by detecting how close the landings are to the selected targets. The double-step saccadic paradigm is a common method to simulate alterations in saccadic gain. While the subject is responding to a first target shift, a second shift is introduced in the middle of this movement, which masks it from visual detection. The error in landing introduced by the second shift is interpreted by the brain as an error in the programming of the initial response, with gradual gain changes aimed at compensating the apparent sensorimotor mismatch. A second shift applied dichoptically to only one eye introduces disconjugate landing errors between the two eyes. A monocular adaptive system would independently modify only the gain of the eye exposed to the second shift in order to reestablish binocular alignment. Our results support a binocular mechanism. A version-based saccadic adaptive process detects postsaccadic version errors and generates compensatory conjugate gain alterations. A vergence-based saccadic adaptive process detects postsaccadic disparity errors and generates corrective nonvisual disparity signals that are sent to the vergence system to regain binocularity. This results in striking dynamical similarities between visually driven combined saccade-vergence gaze transfers, where the disparity is given by the visual targets, and the double-step adaptive disconjugate responses, where an adaptive disparity signal is generated internally by the saccadic system.

Application of an Improved Internal Model Controller Based on the Particle Swarm Optimization in Network Control System

2013 ◽  
Vol 397-400 ◽  
pp. 1137-1144
Author(s):  
Wei Chen ◽  
Wen Bin Wang ◽  
Zhi Kai Zhao ◽  
Zhi Yuan Yan
Keyword(s):  
Particle Swarm Optimization ◽  
Control System ◽  
Internal Model ◽  
Particle Swarm ◽  
Internal Model Control ◽  
Network Control ◽  
Step Response ◽  
Network Control System ◽  
Swarm Optimization ◽  
Internal Model Controller

Internal Model Control (IMC) is widely used in Network Control System (NCS) with its strong robustness and simple parameter adjustment. But the accurate dynamic inversion of the IMC model is not easy to find out. To solve this problem, an improved Internal Model Controller is designed with a PID controller and feedback loop, then the Particle Swarm Optimization (PSO) is used to optimize all the parameters of the improved controller. At last, simulation results show that the improved Internal Model Controller can maintain the system stability and the performance of the step response is extremely great in terms of rapidity and anti-interference ability, compared with the classic internal model controller, which enables NCS to achieve a better control effect.

The Effect of Superseding Signals

1966 ◽  
Vol 18 (3) ◽  
pp. 236-249 ◽  
Author(s):  
Robert Gottsdanker
Keyword(s):  
Human Subjects ◽  
Initial Response ◽  
Tracking Task ◽  
Response Amplitude ◽  
Combined Effect ◽  
Detectable Effect ◽  
Adult Human ◽  
Almost All

Eight adult human subjects were given a step-tracking task in which an occasional second signal within 50, 70, 90, 120, or 240 millisec, called for curtailing or reversing the first command. It was found for inter-signal intervals through 120 millisec. that the shorter the interval the greater was the reduction in amplitude and duration of the majority of responses, with no delay in the effect of the second signal. Where a larger change of response was called for, reversal rather than curtailment, there was a greater effect. A second signal occurring at the 240 millisec. interval (in almost all cases after the start of the response), had no detectable effect. Since the over-all RT was about 180 millisec., it is evident that for at least the first two-thirds of the RT period the initial response is not typically impervious to the effect of a second signal. Contrary to the expectations of the uncommitted-period version of the hypothesis of substitutive grouping a reversing signal at the 50 millisec. interval did not yield many reversed responses. Moreover this view cannot accommodate the finding that for intervals through 120 millisec., relatively few distributions of response amplitude can be accounted for by the summation of instances of response to the first signal alone and to the second signal alone. It is concluded that for these intervals, there were generally either overlapping responses to the two signals or else unitary responses in which the two signals were grouped to produce a combined effect.

A neurological integrator for the oculomotor control system

1976 ◽  
Vol 30 (3-4) ◽  
pp. 341-352 ◽  
Author(s):  
B.Yeshwant Kamath ◽  
Edward L. Keller
Keyword(s):  
Control System ◽  
Oculomotor Control
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