Timing and Torque Involvement in the Organisation of a Rapid Forearm Flexion

1983 ◽  
Vol 35 (2) ◽  
pp. 323-331 ◽  
Author(s):  
D. M. Baba ◽  
R. G. Marteniuk
Keyword(s):  
Movement Time ◽  
Reaction Times ◽  
Motor Reaction ◽  
Movement Execution ◽  
Total Moment ◽  
Central Processing ◽  
Fast Movement ◽  
Time Required ◽  
Timing Requirement ◽  
Central Processing Time

The study was designed to determine whether the magnitude of force and the timing of force are response parameters involved in the organisation of a rapid forearm flexion to a target. The magnitude of torque and the timing of torque were manipulated independently through manipulations of the total moment of inertia and movement time, and the effect of these manipulations on premotor and motor reaction times was observed. Planned comparison analyses revealed that premotor and motor reaction times increased when a movement, which required the same magnitude of torque as in a fast movement, was performed slower. However, premotor and motor reaction times were not affected when movements were performed at the same speed, but differed with respect to the magnitude of torque required. These results indicate that a different timing requirement in the forthcoming movement is associated with a corresponding change in the amount of central processing time required. Therefore, the timing of torque appears to be a parameter of the movement that is organised in advance of movement execution. However, a change in the specification for the magnitude of torque does not affect the amount of time needed to organise the movement.

scholarly journals Risk Analysis of Road Tunnels: A Computational Fluid Dynamic Model for Assessing the Effects of Natural Ventilation

2020 ◽  
Vol 11 (1) ◽  
pp. 32
Author(s):  
Ciro Caliendo ◽  
Gianluca Genovese ◽  
Isidoro Russo
Keyword(s):  
Natural Ventilation ◽  
Fluid Dynamic ◽  
Movement Time ◽  
Radiant Heat ◽  
Heat Fluxes ◽  
Maximum Heat ◽  
Road Tunnels ◽  
Maximum Heat Release ◽  
Computational Fluid Dynamics Cfd ◽  
Time Required

We have developed an appropriate Computational Fluid Dynamics (CFD) model for assessing the exposure to risk of tunnel users during their evacuation process in the event of fire. The effects on escaping users, which can be caused by fire from different types of vehicles located in various longitudinal positions within a one-way tunnel with natural ventilation only and length less than 1 km are shown. Simulated fires, in terms of maximum Heat Release Rate (HRR) are: 8, 30, 50, and 100 MW for two cars, a bus, and two types of Heavy Goods Vehicles (HGVs), respectively. With reference to environmental conditions (i.e., temperatures, radiant heat fluxes, visibility distances, and CO and CO2 concentrations) along the evacuation path, the results prove that these are always within the limits acceptable for user safety. The exposure to toxic gases and heat also confirms that the tunnel users can safely evacuate. The evacuation time was found to be higher when fire was related to the bus, which is due to a major pre-movement time required for leaving the vehicle. The findings show that mechanical ventilation is not necessary in the case of the tunnel investigated. It is to be emphasized that our modeling might represent a reference in investigating the effects of natural ventilation in tunnels.

scholarly journals A Behavioral and Electrophysiological Investigation of Effects of Visual Congruence on Olfactory Sensitivity During Habituation to Prolonged Odors

2020 ◽  
Vol 45 (9) ◽  
pp. 845-854
Author(s):  
Nicholas Fallon ◽  
Timo Giesbrecht ◽  
Anna Thomas ◽  
Andrej Stancak
Keyword(s):  
Cognitive Processing ◽  
Visual Cues ◽  
Reaction Times ◽  
Event Related Potential ◽  
Detection Sensitivity ◽  
Moderate Intensity ◽  
Odor Perception ◽  
Potential Analysis ◽  
Odor Detection ◽  
Central Processing

Abstract Congruent visual cues augment sensitivity to brief olfactory presentations and habituation of odor perception is modulated by central-cognitive processing including context. However, it is not known whether habituation to odors could interact with cross-modal congruent stimuli. The present research investigated the effect of visual congruence on odor detection sensitivity during continuous odor exposures. We utilized a multimethod approach, including subjective behavioral responses and reaction times (RTs; study 1) and electroencephalography (EEG, study 2). Study 1: 25 participants received 2-min presentations of moderate-intensity floral odor delivered via olfactometer with congruent (flower) and incongruent (object) image presentations. Participants indicated odor perception after each image. Detection sensitivity and RTs were analyzed in epochs covering the period of habituation. Study 2: 25 new participants underwent EEG recordings during 145-s blocks of odor presentations with congruent or incongruent images. Participants passively observed images and intermittently rated the perceived intensity of odor. Event-related potential analysis was utilized to evaluate brain processing related to odor–visual pairs across the period of habituation. Odor detection sensitivity and RTs were improved by congruent visual cues. Results highlighted a diminishing influence of visual congruence on odor detection sensitivity as habituation occurred. Event-related potential analysis revealed an effect of congruency on electrophysiological processing in the N400 component. This was only evident in early periods of odor exposure when perception was strong. For the first time, this demonstrates the modulation of central processing of odor–visual pairs by habituation. Frontal negativity (N400) responses encode the aspects of cross-modal congruence for odor–vision cross-modal tasks.

Fluidized bed heat treatment of aluminum cast components

2004 ◽  
Vol 120 ◽  
pp. 555-562
Author(s):  
D. Apelian ◽  
S. K. Chaudhury
Keyword(s):  
Heat Treatment ◽  
Fluidized Bed ◽  
Processing Time ◽  
Reaction Times ◽  
Experimental Results ◽  
Fluidized Bed Reactors ◽  
The Past ◽  
Conventional Furnace ◽  
Time Required ◽  
Solutionizing Time

Heat Treatment and post casting treatments of cast components has always been an important step in the control of microstructure, and resultant properties. In the past, the solutionizing, quenching and ageing process steps may have “required” in total over 20 hours of processing time. With the advent of fluidized bed reactors (FB), processing time has been dramatically reduced. For example, instead of 8-10 hours solutionizing time in a conventional furnace, the time required in FB is less than an hour. Experiments with Al-Si-Mg alloy, (both modified with Sr, and unmodified) were performed, having different diffusion distances (different DAS), and for different reaction times and temperatures. Both the model and the experimental results are presented and discussed.

scholarly journals Action Boundary Proximity Effects on Perceptual-Motor Judgments

2019 ◽  
Vol 90 (12) ◽  
pp. 1000-1008
Author(s):  
Caleb D. Johnson ◽  
Alice D. LaGoy ◽  
Gert-Jan Pepping ◽  
Shawn R. Eagle ◽  
Anne Z. Beethe ◽  
...  
Keyword(s):  
Intraclass Correlation ◽  
Reaction Times ◽  
Correlation Coefficients ◽  
Proximity Effects ◽  
Testing Time ◽  
Good Reliability ◽  
Intraclass Correlation Coefficients ◽  
Coefficients Of Variation ◽  
Time Required ◽  
Action Coupling

INTRODUCTION: Designed as a more ecological measure of reaction times, the Perception-Action Coupling Task (PACT) has shown good reliability and within-subject stability. However, a lengthy testing period was required. Perceptual-motor judgments are known to be affected by proximity of the stimulus to the action boundary. The current study sought to determine the effects of action boundary proximity on PACT performance, and whether redundant levels of stimuli, eliciting similar responses, can be eliminated to shorten the PACT.METHODS: There were 9 men and 7 women who completed 4 testing sessions, consisting of 3 familiarization cycles and 6 testing cycles of the PACT. For the PACT, subjects made judgments on whether a series of balls presented on a tablet afford “posting” (can fit) through a series of apertures. There were 8 ratios of ball to aperture size (B-AR) presented, ranging from 0.2 to 1.8, with each ratio appearing 12 times (12 trials) per cycle. Reaction times and judgment accuracy were calculated, and averaged across all B-ARs. Ratios and individual trials within each B-AR were systematically eliminated. Variables were re-averaged, and intraclass correlation coefficients (ICC) and coefficients of variation (CVTE) were calculated in an iterative manner.RESULTS: With elimination of the 0.2 and 1.8 B-ARs, the PACT showed good reliability (ICC = 0.81–0.99) and consistent within-subject stability (CVTE = 2.2–14.7%). Reliability (ICC = 0.81–0.97) and stability (CVTE = 2.6–15.6%) were unaffected with elimination of up to 8 trials from each B-AR.DISCUSSION: The shortened PACT resulted in an almost 50% reduction in total familiarization/testing time required, significantly increasing usability.Johnson CD, LaGoy AD, Pepping G-J, Eagle SR, Beethe AZ, Bower JL, Alfano CA, Simpson RJ, Connaboy C. Action boundary proximity effects on perceptual-motor judgments. Aerosp Med Hum Perform. 2019; 90(12):1000–1008.

A New Apparatus for measuring Sensori-motor Reaction Times.

1923 ◽  
Vol 16 (Electro_Ther) ◽  
pp. 63-70
Author(s):  
M. D. Hart ◽  
W. Whately Smith
Keyword(s):  
Reaction Times ◽  
Motor Reaction ◽  
New Apparatus

A Theoretical and Experimental Examination of Auditory-Visual Interaction

1969 ◽  
Vol 29 (1) ◽  
pp. 23-33 ◽  
Author(s):  
Kenneth Gaarder
Keyword(s):  
Sensory Processing ◽  
Visual Information ◽  
Reaction Times ◽  
Time Sharing ◽  
Central Processing ◽  
Systems Model ◽  
Concurrent Processing ◽  
Complex Interactions ◽  
General Systems ◽  
Sense Modalities

The general systems model of central sensory processing used in this study is based on the assumption that central processing is discontinuous and raises this question: Is concurrent processing of different sense modalities serial, parallel, or independent? Since an eye-jump indicates input of visual information, if the auditory system is stimulated by clicks with fixed delays after eye-jumps, intermodality relationships are tested. Reaction times and evoked responses show complex interactions which are interpreted to suggest serial processing analogous to time sharing computers.

A Study of Human Pointing Features on Touch-Screens -Age Effect, Difference by Gender, and Difference in Direction-

2007 ◽  
Vol 19 (6) ◽  
pp. 715-723 ◽  
Author(s):  
Masanobu Komazaki ◽  
◽  
Masanori Idesawa
Keyword(s):  
User Interfaces ◽  
Dynamic Properties ◽  
Movement Time ◽  
Touch Screen ◽  
Practice Effect ◽  
Touch Screens ◽  
And Gender ◽  
Set Up ◽  
Time Required ◽  
Interface Devices

We set up guidelines for designing graphic user interfaces (GUI), e.g., software-keyboards, for touch screens easier to used than conventional input (or interface) devices for IT systems such as keyboards and mice. We studied aging and gender differences in the dynamic properties of user pointing on a touch screen. We obtained the following results: (1) Standard Fitts’law did not hold very well when subjects repeated pointing using one finger between two targets close together on the touch screen. Movement-Time (MT) -the time required for pointing- increased linearly with the index of difficulty (ID) - the ratio of distance between targets (D) to target size (S). (2) Neither α -the ratio of the increase of MT to ID- nor β -MT when ID is 0- differed significantly between men and women. (3) α took almost the same value in older, middle-aged, and younger subjects, whereas β differed significantly between these groups. β increased linearly with age. (4) α and β did not differ significantly between left-right and depth in pointing. (5) The practice effect reduced the dispersion of α and β.

Fractionated Reaction Times and Movement Times of Down Syndrome and Other Adults with Mental Retardation

1991 ◽  
Vol 8 (3) ◽  
pp. 221-233 ◽  
Author(s):  
Walter E. Davis ◽  
William A. Sparrow ◽  
Terry Ward
Keyword(s):  
Down Syndrome ◽  
Mental Retardation ◽  
Reaction Time ◽  
Time Delay ◽  
Movement Time ◽  
Reaction Times ◽  
Elbow Extension ◽  
Total Reaction ◽  
Time Motor ◽  
Total Reaction Time

A fractionation technique was employed to determine the locus of reaction time delay in Down syndrome (DS) and other adult subjects with mental retardation (MH). Twenty-three subjects (8 nondisabled, 8 MH, and 7 DS) responded to a light, sound, and combination light/sound signal. Dependent measures of premotor time, motor time, total reaction time, and movement time were obtained during a 20° elbow extension movement and were analyzed separately. As expected, both MH and DS subjects were slower and more variable in their responses than the subjects without disabilities. In turn, DS subjects were significantly slower but not more variable than the MH subjects. There were no significant differences between the DS and MH subjects on movement times. Evidence for both a specific (premotor) and a generalized (both premotor and motor) locus of delay was found. Some difference in signal effect was also found for the DS subjects.

Sign in / Sign up

Export Citation Format

Share Document