PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 1266736

Work scheduling under normal and prolonged-vibration environments.

T M Khalil·M M Ayoub
View original source ↗Export metadata ↓

Abstract

This paper summarizes the research conducted to study human performance and recovery under prolonged, whole-body, vertical vibration. The results showed that performance under vibratory environment is inferior to that under normal environment. Interaction between work-rest schedules and the vibratory environment was detected. Parameters affecting selection of optimum work-rest schedules are discussed.

Explore related subjects

AttentionHumansReaction TimeRestTask Performance and AnalysisVibrationWorkJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

T M Khalil, M M Ayoub. 1976. Work scheduling under normal and prolonged-vibration environments.. https://doi.org/10.1080/0002889768507440

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed1992

Heightened motor activity level in male offspring of substance abusing fathers.

Heightened activity level has been implicated in the liability for substance abuse, but no prior research has directly examined motor activity in a sample of prepubertal boys at high-risk for substance abuse. The magnitude of behavioral activity of 10-12 year-old sons of substance abusing fathers (SA +) (n = 42) and controls (SA -) (n = 60) was assessed using a microprocessor-based activity monitor during tasks that demanded significant concentration, effort, and constraint on motor activity, and when no such demands were present. Psychiatric status, measures of temperament traits, and measures of internalizing and externalizing behaviors were also obtained on the boys. Although the groups did not differ during the lower demand task, SA + boys showed significantly greater motor activity than SA - boys during the tasks that required concerted effort, attention, and behavioral suppression. Multiple regression analysis indicated that under the low-demand condition, the presence of an anxiety disorder in the boy was the only significant predictor of activity level. However, under the conditions that demanded effort, concerted attention and behavioral suppression, SA + group membership, and having low rhythmicity (as a temperament trait) predicted heightened activity. Statistically controlling for rhythmicity, the SA + boys were estimated to have about 24% higher activity than control boys. The results suggest that heightened motor activity may be associated with susceptibility to substance abuse.

Attention↗
PubMed1992

Attention-based motion perception.

Two "attentive" tracking tasks reveal the existence of an attention-based motion process. In the first task, oppositely rotating luminance and color gratings were superimposed. Because of masking from the color grating, the bars of the luminance grating were not visible; nevertheless, their motion was visible and it determined the perceived direction of the stimulus rotation. On the other hand, the bars of the color grating were visible but they could only be seen to move (in the opposite direction to the overall stimulus rotation) when they were tracked with attention. In a second task, the perceived velocity of a color grating, typically slow at equiluminance, speeded up when individual bars were attentively tracked. These findings demonstrate two independent motion processes: one that is "low-level" or automatic in that it signals motion even in the absence of attention to the stimulus, and one that is mediated by attention to visible features and provides accurate velocity judgments independently of the features being tracked.

Attention↗
PubMed1992

Attentional asymmetry in schizophrenia: controlled and automatic processes.

Two versions of Posner's covert orienting task were administered to 14 drug-free schizophrenic patients and 12 normal controls. In the schizophrenic subjects, automatic orienting to exogenous cues in the right visual field was impaired. However, this lateralizing general deficit was not present when the schizophrenics were able to direct attention effortfully in the second version of the task using endogenous cues. These findings support the hypothesis that there is a deficit in left hemispheric mechanisms mediating visual spatial attention in schizophrenia. However, when schizophrenics are given the opportunity to use an attentional strategy they are able to partially overcome this lateralized processing deficit.

Attention↗