ABSTRACT
Between the 1960s and the 1980s there has been an increase in the Journal of Motor Behavior (JMB) of neuromuscular theories of control, of continuous records showing amplitude or force over time, and of electromyograms (EMGs). Investigations of the advance programming of complex movements have also increased. There has been a decrease in paced manual tracking, in movements along a fixed path, and in studies of proprioception. Investigations of transfer or interference, of motor learning, and of muscular fatigue have also decreased. Some investigators still appear to be unaware of the contraction bias or regression effect.
Subject(s)
Illusions , Optical Illusions , Adult , Aged , Female , Humans , Male , Middle Aged , Reading , Space PerceptionSubject(s)
Color Perception , Darkness , Female , Judgment , Male , Physical Stimulation , PsychophysicsSubject(s)
Loudness Perception , Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Pitch Perception , Psychoacoustics , Set, PsychologyABSTRACT
This article illustrates the biases that can occur in making quantitative judgements. The mechanisms that produce the biases are described. Ways are suggested to avoid some of the biase, but it is not possible to avoid them all.
ABSTRACT
An acclaimed important discovery was made in the early 1950s that noise degrades the performance of certain manual tasks directly, by a mechanism other than the masking of sounds. It now appears that this is not so. The unravelling of the mystery is described, together with some of the repercussions and implications.
Subject(s)
Equipment and Supplies , Noise/adverse effects , Science/history , Task Performance and Analysis , Arousal , Cues , History, 20th Century , Humans , Perceptual Masking , PsychologySubject(s)
Loudness Perception , Adult , Female , Humans , Judgment , Middle Aged , Models, PsychologicalSubject(s)
Stress, Physiological/complications , Stress, Physiological/psychology , Transfer, Psychology , Attention/physiology , Hot Temperature/adverse effects , Humans , Male , Motor Skills/physiology , Noise/adverse effects , Reaction Time , Research Design , Scopolamine/adverse effects , Sleep DeprivationSubject(s)
Sensation , Auditory Perception , Humans , Judgment , Sensory Thresholds , Touch , Visual PerceptionABSTRACT
The human body resonates at a vertical frequency of 5 Hz. Yet in vigilance tasks when motivation is low, performance improves reliably with vertical vibration at 5 Hz. This is because the vertical vibration of the shoulders at 5 Hz can be reduced by tensing the trunk muscles. The increased muscle tension helps to maintain alertness. The alerting mechanism is not mentioned in the international standard for human exposure to vibration. Drivers who travel long distances on deserted motorways at night with modern well-sprung car bodies and seats are deprived of the alerting mechanisms. They would be well advised to use some other form of stimulation to help them to stay alert.
Subject(s)
Efficiency , Physical Exertion , Physicians , Sleep Deprivation , Adult , Female , Humans , Male , Time FactorsABSTRACT
Altogether 168 men searched briefly for colored sloping lines embedded in a background of random color. Using a separate-groups experimental design, search for six kinds of target was found to be less effective after practice than search for a single kind of target. Reducing the number of colors of targets from three to one was considerably more beneficial than reducing the number of main directions of slope from two to one. Reducing the number of kinds of target without reducing the number of relevant stimulus values was also found to improve the effectiveness of search, but search was even more effective when the number of relevant stimulus colors was reduced. The results can be predicted from the total number of selection operations required. However, a more precise fit needs to reflect the considerably greater difficulty of searching for a number of directions of slope. When targets were poorly camouflaged, search was equally effective whether there were four colors or only a single color of target to search for.
Subject(s)
Color Perception , Discrimination, Psychological , Adolescent , Adult , Form Perception , Humans , Information Theory , Male , Orientation , Perceptual Masking , Time FactorsABSTRACT
Noise masks sounds, that is, it prevents people from being able to hear what they want to listen to. Noise arouses people and may make them feel annoyed. At night noise may arouse them from sleep, or keep them awake. Intermittent noise is distracting. It has been claimed that continuous broadband noise of 100 dB has a detrimental effect upon work which is distinct from the effects of noise in masking sound. Evidence is presented which indicates that the claim is not correct, and should never have been made.
ABSTRACT
An ergonomic colour code for sizes should use colours the way people think they should be used for sizes. The results of a simple investigation suggest that red should represent the largest size, and probably white the smallest size. The intermediate sizes could be represented by colours arranged in rainbow order.
