Impairments of manual tracking performance during spaceflight are associated with specific effects of microgravity on visuomotor transformations

Ergonomics ◽  
2003 ◽  
Vol 46 (9) ◽  
pp. 920-934 ◽  
Author(s):  
Herbert Heuer ◽  
Dietrich Manzey ◽  
Bernd Lorenz ◽  
Jörg Sangals
Author(s):  
Betty-Lynn Morrice ◽  
Werner J. Becker ◽  
J.A. Hoffer ◽  
Robert G. Lee

ABSTRACT:Manual tracking performance was studied in five patients with cerebellar incoordination due to unilateral cerebellar hemisphere lesions. The subjects were required to track a target on an oscilloscope screen by moving a cursor controlled by flexion-extension movements of the wrist. In comparison to normal subjects, the cerebellar patients, using their clinically affected arm, demonstrated irregular tracking patterns with inappropriate accelerations and decelerations, numerous high velocity peaks of movement, and an increased time lag between the cursor and the target.The addition of a viscous load provided by feeding back wrist velocity to a torque motor coupled to the apparatus resulted in significant improvement in tracking performance and suppression of the high velocity peaks. Increasing elastic stiffness by feeding back wrist position or inertial load by adding weights to the hand did not improve performance on this task. It is proposed that a hypotonic cerebellar limb behaves like an underdamped mechanical system. The addition of viscous loads helps restore more normal damping during voluntary movements of the arm.


2000 ◽  
Vol 32 (4) ◽  
pp. 361-378 ◽  
Author(s):  
Min-Ju Liao ◽  
Richard J. Jagacinski

Ergonomics ◽  
2000 ◽  
Vol 43 (5) ◽  
pp. 589-609 ◽  
Author(s):  
Dietrich Manzey ◽  
Bernd Lorenz ◽  
Herbert Heuer ◽  
Jorg Sangals

Author(s):  
Michael L. Hershberger

An experiment was conducted to investigate man's ability to perform image motion compensation tracking for earth reconnaissance from space. The study investigated: (1) two control system tracking modes—computer-aided tracking and manual tracking, (2) control dynamics—rate and acceleration, (3) controller gain—low, medium, and high, and (4) magnification—1 to 200 power. The two control modes were treated in separate studies based on large performance differences observed during pilot studies. A major objective of the study was to determine the type of control system and the amount of magnification necessary to meet a 0.05 mr/sec image motion compensation tracking performance criterion. The results of the investigation revealed that the manual tracking mode was unacceptable in terms of the system performance criterion; whereas, the computer aided tracking mode yielded performance which met the criterion at several combinations of experimental conditions. Magnification and controller gain levels were found to have highly significant effects on tracking performance. The results are discussed in terms of reconnaissance system design applications.


Author(s):  
Kaleb A. Lowe ◽  
Wolf Zinke ◽  
M. Anthony Phipps ◽  
Josh Cosman ◽  
Micala Maddox ◽  
...  

2016 ◽  
Vol 75 (3) ◽  
pp. 133-140
Author(s):  
Robert Busching ◽  
Johannes Lutz

Abstract. Legally irrelevant information like facial features is used to form judgments about rape cases. Using a reverse-correlation technique, it is possible to visualize criminal stereotypes and test whether these representations influence judgments. In the first step, images of the stereotypical faces of a rapist, a thief, and a lifesaver were generated. These images showed a clear distinction between the lifesaver and the two criminal representations, but the criminal representations were rather similar. In the next step, the images were presented together with rape scenarios, and participants (N = 153) indicated the defendant’s level of liability. Participants with high rape myth acceptance scores attributed a lower level of liability to a defendant who resembled a stereotypical lifesaver. However, no specific effects of the image of the stereotypical rapist compared to the stereotypical thief were found. We discuss the findings with respect to the influence of visual stereotypes on legal judgments and the nature of these mental representations.


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