scholarly journals Human manual control precision depends on vestibular sensory precision and gravitational magnitude

2018 ◽  
Vol 120 (6) ◽  
pp. 3187-3197 ◽  
Author(s):  
Marissa J. Rosenberg ◽  
Raquel C. Galvan-Garza ◽  
Torin K. Clark ◽  
David P. Sherwood ◽  
Laurence R. Young ◽  
...  

Precise motion control is critical to human survival on Earth and in space. Motion sensation is inherently imprecise, and the functional implications of this imprecision are not well understood. We studied a “vestibular” manual control task in which subjects attempted to keep themselves upright with a rotational hand controller (i.e., joystick) to null out pseudorandom, roll-tilt motion disturbances of their chair in the dark. Our first objective was to study the relationship between intersubject differences in manual control performance and sensory precision, determined by measuring vestibular perceptual thresholds. Our second objective was to examine the influence of altered gravity on manual control performance. Subjects performed the manual control task while supine during short-radius centrifugation, with roll tilts occurring relative to centripetal accelerations of 0.5, 1.0, and 1.33 GC (1 GC = 9.81 m/s2). Roll-tilt vestibular precision was quantified with roll-tilt vestibular direction-recognition perceptual thresholds, the minimum movement that one can reliably distinguish as leftward vs. rightward. A significant intersubject correlation was found between manual control performance (defined as the standard deviation of chair tilt) and thresholds, consistent with sensory imprecision negatively affecting functional precision. Furthermore, compared with 1.0 GC manual control was more precise in 1.33 GC (−18.3%, P = 0.005) and less precise in 0.5 GC (+39.6%, P < 0.001). The decrement in manual control performance observed in 0.5 GC and in subjects with high thresholds suggests potential risk factors for piloting and locomotion, both on Earth and during human exploration missions to the moon (0.16 G) and Mars (0.38 G). NEW & NOTEWORTHY The functional implications of imprecise motion sensation are not well understood. We found a significant correlation between subjects’ vestibular perceptual thresholds and performance in a manual control task (using a joystick to keep their chair upright), consistent with sensory imprecision negatively affecting functional precision. Furthermore, using an altered-gravity centrifuge configuration, we found that manual control precision was improved in “hypergravity” and degraded in “hypogravity.” These results have potential relevance for postural control, aviation, and spaceflight.

1986 ◽  
Vol 30 (7) ◽  
pp. 684-688 ◽  
Author(s):  
K. B. Bennett ◽  
D. D. Woods ◽  
E. M. Roth ◽  
P. H. Haley

The operators of nuclear power plants are asked to perform a task that has proven to be particularly difficult: manual control of feedwater during startup. We have initiated a research and development program to address human factors issues related to this task. An analysis of cognitive aspects of the feedwater control task was used to develop a generic part-task simulator. New displays to enhance manual control performance (including a predictor display) were developed with the simulator. The test capability provided by the simulator allowed precise measurement of performance differences associated with these displays in a mixed-fidelity laboratory experiment. The results suggest that the displays reduced the complexity of the task and resulted in improved operator performance.


2011 ◽  
Author(s):  
Yukio Horiguchi ◽  
Keisuke Yasuda ◽  
Hiroaki Nakanishi ◽  
Tetsuo Sawaragi
Keyword(s):  

2021 ◽  
Author(s):  
Xia Yin ◽  
Tianyi Zhao ◽  
Jie Yi

Abstract The water channeling and excess water production led to the decreasing formation energy in the oilfield. Therefore, the combined flooding with dispersed particle gel (DPG) and surfactant was conducted for conformance control and enhanced oil recovery in a high temperature (100-110°C) high salinity (&gt;2.1×105mg/L) channel reservoir of block X in Tahe oilfield. This paper reports the experimental results and pilot test for the combined flooding in a well group of Block X. In the experiment part, the interfacial tension, emulsifying capacity of the surfactant and the particle size during aging of DPG were measured, then, the conformance control and enhanced oil recovery performance of the combined flooding was evaluated by core flooding experiment. In the pilot test, the geological backgrounds and developing history of the block was introduced. Then, an integrated study of EOR and conformance control performance in the block X are analyzed by real-time monitoring and performance after treatment. In addition, the well selection criteria and flooding optimization were clarified. In this combined flooding, DPG is applied as in-depth conformance control agent to increase the sweep efficiency, and surfactant solution slug following is used for improve the displacement efficiency. The long term stability of DPG for 15 days ensures the efficiency of in-depth conformance control and its size can increase from its original 0.543μm to 35.5μm after aging for 7 days in the 2.17×105mg/L reservoir water and at 110°C. In the optimization, it is found that 0.35% NAC-1+ 0.25% NAC-2 surfactant solution with interfacial tension 3.2×10-2mN/m can form a relatively stable emulsion easily with the dehydrated crude oil. In the double core flooding, the conformance control performance is confirmed by the diversion of fluid after combined flooding and EOR increases by 21.3%. After exploitation of Block X for 14 years, the fast decreasing formation energy due to lack of large bottom water and water fingering resulted in a decreasing production rate and increasing watercut. After combined flooding in Y well group with 1 injector and 3 producers, the average dynamic liquid level, daily production, and tracing agent breakthrough time increased, while the watercut and infectivity index decreased. The distribution rate of injected fluid and real-time monitoring also assured the conformance control performance. The oil production of this well group was increased by over 3000 tons. Upon this throughout study of combined flooding from experiment to case study, adjusting the heterogeneity by DPG combined with increasing displacement efficiency of surfactant enhanced the oil recovery synergistically in this high salinity high temperature reservoir. The criteria for the selection and performance of combined flooding also provides practical experiences and principles for combined flooding.


2021 ◽  
pp. 1-14
Author(s):  
Khoi D. Vo ◽  
Audrey Siqi-Liu ◽  
Alondra Chaire ◽  
Sophia Li ◽  
Elise Demeter ◽  
...  

Abstract Attention and working memory (WM) have classically been considered as two separate cognitive functions, but more recent theories have conceptualized them as operating on shared representations and being distinguished primarily by whether attention is directed internally (WM) or externally (attention, traditionally defined). Supporting this idea, a recent behavioral study documented a “WM Stroop effect,” showing that maintaining a color word in WM impacts perceptual color-naming performance to the same degree as presenting the color word externally in the classic Stroop task. Here, we employed ERPs to examine the neural processes underlying this WM Stroop task compared to those in the classic Stroop and in a WM-control task. Based on the assumption that holding a color word in WM would (pre-)activate the same color representation as by externally presenting that color word, we hypothesized that the neural cascade of conflict–control processes would occur more rapidly in the WM Stroop than in the classic Stroop task. Our behavioral results replicated equivalent interference behavioral effects for the WM and classic Stroop tasks. Importantly, however, the ERP signatures of conflict detection and resolution displayed substantially shorter latencies in the WM Stroop task. Moreover, delay-period conflict in the WM Stroop task, but not in the WM control task, impacted the ERP and performance measures for the WM probe stimuli. Together, these findings provide new insights into how the brain processes conflict between internal representations and external stimuli, and they support the view of shared representations between internally held WM content and attentional processing of external stimuli.


2019 ◽  
Vol 49 (2) ◽  
pp. 113-125 ◽  
Author(s):  
Sarah Barendswaard ◽  
Daan Marinus Pool ◽  
Marinus M. Van Paassen ◽  
Max Mulder

1992 ◽  
Vol 114 (4) ◽  
pp. 563-570 ◽  
Author(s):  
W. S. Newman

Theoretical performance limits of controlled systems which interact with dynamic environments are analyzed from consideration of simple, single-axis mass-spring-damper systems. A measure of interaction control performance is defined which is independent of environment dynamics. It is shown that unmodelled dynamics between actuators and sensors places severe constraints on interaction control performance. An ultimate performance limit to guaranteed-stable interaction control is derived. A general algorithm is proposed for the design of guaranteed-stable interaction controllers which applies to arbitrary linear, time-invariant systems, and which approaches the optimal admittance while providing good disturbance rejection. The approach is illustrated in simulations.


Author(s):  
Y. Horiguchi ◽  
K. Yasuda ◽  
H. Nakanishi ◽  
T. Sawaragi
Keyword(s):  

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