Reappraisal of four different approaches for finding the mean reaction time in the multi-trap variant of the Adam–Delbrück problem

2004 ◽  
Vol 120 (19) ◽  
pp. 9390-9393 ◽  
Author(s):  
Jorge Martins ◽  
Eurico Melo ◽  
K. Razi Naqvi
Keyword(s):  
Reaction Time ◽  
The Mean ◽  
Mean Reaction Time

Reaction Time and Time Course of Neuronal Responses in MT and MST at Different Stimulus Contrasts

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 157-157 ◽  
Author(s):  
A Thiele ◽  
K-P Hoffmann
Keyword(s):  
Reaction Time ◽  
Single Cell ◽  
Single Cells ◽  
Direction Selectivity ◽  
Contrast Level ◽  
Population Activity ◽  
Temporal Area ◽  
Population Mean ◽  
The Mean ◽  
Mean Reaction Time

Direction-selective neurons from the middle temporal area (MT) and the middle superior temporal area (MST) were recorded while a monkey performed a direction discrimination task. Stimuli consisted of evenly spaced bars moving in one of the four cardinal directions. Monkey's reaction time, single-cell latency, and direction selectivity were calculated when stimuli of 53%, 24%, and 4% contrast were presented, and the monkey indicated a correct decision. Mean reaction time was 359±77 ms at 53% contrast, 391±107 ms at 24% contrast, and 582±374 ms at 4% contrast. Most neurons exhibiting direction selective responses at 53% contrast was also active at 24% contrast (MT, 99%; MST, 88%). The number of neurons still exhibiting stimulus-related activity at 4% contrast dramatically decreased (MT to 28%; MST to 41%). Shortest latencies were found at high contrast level (53% contrast; MT, 29 ms; population mean, 76±40 ms; MST, 35 ms; population mean, 77±27 ms). Single cell and population latency increased at lower contrast (4% contrast: MT minimum, 86 ms; population mean, 180±76 ms; MST minimum, 97 ms; population mean, 205±56 ms). This indicates that the mean increase in latency at the single-cell level only partially reflects the increase in reaction time (mean reaction time increased by 223 ms, while mean single-cell latency increased by ∼100 ms in MT and MST). We therefore calculated the normalised population response at different contrast levels. The maximal population activity was always found at the highest contrast level and this was set to 1. In MT it took 75 – 80 ms from stimulus onset until half maximal activity (0.5) was reached at 53% contrast. To reach 0.5 took 85 – 90 ms at 24% contrast and 205 – 210 ms at 4% contrast. For MST the respective values were 85 ms (53% contrast), 90 ms (24% contrast) and 255 ms (4%) contrast. Thus the time to reach half the maximal population activity much better reflects the reaction time than the mean of the latencies calculated from single cells.

Effect of Visual Complexity in Identification of Tachistoscopic Images

1994 ◽  
Vol 78 (3) ◽  
pp. 971-978 ◽  
Author(s):  
Robert Geheb ◽  
Keith E. Whitfield ◽  
Linda Brannon
Keyword(s):  
Reaction Time ◽  
Left Hemisphere ◽  
Right Hemisphere ◽  
Visual Complexity ◽  
Reaction Times ◽  
Right Cerebral Hemisphere ◽  
The Mean ◽  
The Times ◽  
The Right ◽  
Mean Reaction Time

The present study of gender differences in hemispheric processing involved identification of tachistoscopically presented images of varying complexity. A computerized tachistoscopic program was administered to 24 men and 34 women. Time to identify contour and detailed pictures presented to the left or right cerebral hemisphere was recorded. Mean reaction time for contour pictures was significantly faster than for detailed pictures, and mean reaction time to the right hemisphere was significantly faster than that to the left hemisphere. The mean reaction time for men to identify pictures exposed to the left hemisphere was significantly slower than that for exposure to the right hemisphere for women. The mean reaction time for both men and women to identify contour pictures exposed to the right hemisphere was significantly faster than the mean time to identify detailed pictures presented to the left hemisphere. The interaction of gender, hemisphere, and complexity was also significant in that mean reaction times for men to identify detailed pictures presented to the left hemisphere were slower than the times for women to identify contour pictures presented to the right hemisphere. The results are discussed in relation to theories about hemispheres, gender, and differences in picture features.

scholarly journals Oral Associative Reactions of Russians and Germans to Names of Mental States: Comparative and Quantitative Analysis

2020 ◽  
Vol 2020 (3) ◽  
pp. 46-57
Author(s):  
Ekaterina M. Alekseeva
Keyword(s):  
Quantitative Analysis ◽  
Reaction Time ◽  
Mental States ◽  
Cross Cultural ◽  
Experimental Procedure ◽  
Cross Cultural Study ◽  
Quantitative Content ◽  
The Mean ◽  
Speech Response ◽  
Mean Reaction Time

The article describes a cross-cultural study of associative oral representation of mental states. 32 Russian and 33German students – 53 female and 12 male aged from 20 up to 24 years participated in the research. The experimental procedure was developed on the basis of the DMDX program allowed to measure the time of speech response to the shown stimuli – names of 25 mental states. In the conditions of time deficiency probands had to call free and estimated associations (adjectives). The mean reaction time was calculated, quantitative content of associative fields was analyzed. In the Russian group associations (both free and estimated in the form of an adjective) to names of mental states were more quickly named. The average time of free oral associative reaction in the Russian group was 2114.6 ms, in the German - 2163.6 ms. The estimated associative response proved slower than the free associative response in both groups: the average time of the estimated oral associative reaction in the Russian group was 2246.9 ms, in the German – 2384.6 ms. During the experiment more evaluation associations in the form of adjectives were named than free ones. The vast majority of free associations to names of mental states were nouns. Most of the associations to names of mental states are unique.

scholarly journals Universal kinetics of imperfect reactions in confinement

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Thomas Guérin ◽  
Maxim Dolgushev ◽  
Olivier Bénichou ◽  
Raphaël Voituriez
Keyword(s):  
Reaction Time ◽  
Transport Process ◽  
Reaction Times ◽  
Complex Environments ◽  
Analytical Treatment ◽  
Volume Limit ◽  
Normal Diffusion ◽  
The Mean ◽  
Kinetics Of ◽  
Mean Reaction Time

AbstractChemical reactions generically require that particles come into contact. In practice, reaction is often imperfect and can necessitate multiple random encounters between reactants. In confined geometries, despite notable recent advances, there is to date no general analytical treatment of such imperfect transport-limited reaction kinetics. Here, we determine the kinetics of imperfect reactions in confining domains for any diffusive or anomalously diffusive Markovian transport process, and for different models of imperfect reactivity. We show that the full distribution of reaction times is obtained in the large confining volume limit from the knowledge of the mean reaction time only, which we determine explicitly. This distribution for imperfect reactions is found to be identical to that of perfect reactions upon an appropriate rescaling of parameters, which highlights the robustness of our results. Strikingly, this holds true even in the regime of low reactivity where the mean reaction time is independent of the transport process, and can lead to large fluctuations of the reaction time - even in simple reaction schemes. We illustrate our results for normal diffusion in domains of generic shape, and for anomalous diffusion in complex environments, where our predictions are confirmed by numerical simulations.

Investigations on the Emergence of Larvae from the Cysts of the Potato-root Eel worm, Heterodera rostochiensis.

1951 ◽  
Vol 25 (1-2) ◽  
pp. 49-56 ◽  
Author(s):  
D. W. Fenwick
Keyword(s):  
Standard Deviation ◽  
Reaction Time ◽  
Potato Root ◽  
Maximum Information ◽  
Larval Emergence ◽  
Heterodera Rostochiensis ◽  
The Mean ◽  
Mean Reaction Time

Immersion of cysts of Heterodera rostochiensis in potato-root diffusate results in larval emergence which may occupy up to two or three months. In a previous paper (Fenwick, 1950), the author dealt with the form of the hatching curve, and showed that any given curve was controlled by three parameters; the number of larvae finally emerging, the mean reaction time of the hatchable larvae and the standard deviation of that mean reaction time expressed in log-time units. Since it was also shown that each of these parameters was subject to considerable variation, it is obvious that maximum information and accuracy can only be obtained by continuing a hatching test until all larval emergence has ceased and plotting cumulative hatches at selected intervals of tune against log-time; in this way detailed information may be obtained regarding the parameters of the hatching curve.

The effect of frequent ejaculation in the ram on some semen characteristics

1964 ◽  
Vol 15 (6) ◽  
pp. 950 ◽  
Author(s):  
S Salamon
Keyword(s):  
Reaction Time ◽  
Citric Acid ◽  
High Volume ◽  
Volume Density ◽  
Multiple Factor Analysis ◽  
Citric Acid Concentration ◽  
The Mean ◽  
High Concentrations ◽  
Mean Reaction Time ◽  
Multiple Factor

(1) Series of 13 ejaculates per day for 10 successive days were collected from each of five Merino rams. Every third ejaculate was examined for volume, density, and fructose and citric acid concentrations — 250 samples in all. (2) The mean fructose and citric acid concentrations were 596 and 91 mg% respectively. While the mean fructose concentrations differed significantly (P < 0.001) during the successive 10 days of collection, the citric acid concentrations did not. Both seminal constituents declined with ejaculates within days (P < 0.01 ; P< 0.001). There were significant declines in mean volume and density and an increase in mean reaction time with successive days and with collections within days (P < 0.001). Rams differed significantly in all characteristics examined (P < 0.001). (3) Multiple factor analysis revealed that three factors were mainly responsible for variances in the characteristics studied during the 10 days and within days of collection. The variances in characteristics contributed to by sequence of ejaculates in individual rams over the 10 days were: 68–96% for volume, 90–100% for density, 28–98% for reaction time, and practically nil for fructose and citric acid concentrations. There were marked ram differences in contribution of the sequence of ejaculates to the within-day variance in volume (0–90%), density (0–98%), citric acid concentration (0–98%, and reaction time (0–97%). The ejaculates collected had practically no contribution to the within-day variance in fructose concentration. (4) The rams with relatively low sexual response (long mean reaction time) tended to ejaculate semen of relatively high volume and with high concentrations of fructose and citric acid.

Evidence for Psychological Refractory Effect in Motor Inhibition for a Dual-Response Go/No-Go Task

1997 ◽  
Vol 85 (2) ◽  
pp. 563-568
Author(s):  
Miya Muroi ◽  
Eiichi Naito ◽  
Michikazu Matsumura
Keyword(s):  
Reaction Time ◽  
Human Subjects ◽  
Reaction Times ◽  
Motor Programming ◽  
Motor Inhibition ◽  
Motor Execution ◽  
Dual Response ◽  
Discrete Responses ◽  
The Mean ◽  
Mean Reaction Time

Human subjects exhibit difficulty in initiating two independent, discrete responses in close succession, a difficulty known as the ‘psychological refractory effect.’ It is not yet known whether motor-inhibition processes are under the influence of this effect, as are motor-execution processes. This study examined the temporal changes of subjects' reaction times, interpreted in terms of motor programming for inhibition, in a dual-response Go/No-Go task that required two independent responses in close succession Light subjects performed the task with both a shorter (400 msec.) and a longer interstunulus interval (800 msec). The mean reaction time for the second stimulus (RT2) in the Go response of the 400-msec. condition was significantly longer than that of the 800-msec. condition. For committed error responses during the No-Go trials, the mean RT2 in the 400-msec. condition was longer than that in the 800-msec. condition. The total number of these errors in the 400-msec. condition was significantly greater than that in the 800-msec. condition. These results suggested that both the motor-execution processes and motor-inhibition processes were influenced by the psychological refractory effect.

scholarly journals Evaluation of analgesic and anti-inflammatory properties of the Allium cepa extract in rats

2021 ◽  
Vol 10 (7) ◽  
pp. 789
Author(s):  
Purna Prasad Meegada ◽  
Rama Mohan Pathapati ◽  
Sriharsha Rayam ◽  
Raveendra Kumar Nallabothula
Keyword(s):  
Reaction Time ◽  
Allium Cepa ◽  
Tail Flick ◽  
High Dose ◽  
Paw Edema ◽  
Hot Plate ◽  
Plate Method ◽  
The Mean ◽  
Anti Inflammatory ◽  
Mean Reaction Time

Background: The onion plant (Allium cepa) is the most widely cultivated species of the genus Allium. It has antibiotic, antidiabetic, antihypercholesterolemic, antioxidant, hemostatic, antimutagenic effects. The current study is aimed to evaluate analgesic and anti-inflammatory properties of Allium cepa extracts in rat models.Methods: In this study analgesic activity in rats is tested by Eddy’s hot plate method, tail flick method. In Eddy’s hot plate method rats are individually placed on the heated plate of the analgesic meter maintained at 550C and mean reaction time was calculated at regular time intervals. In tail flick method the tail withdrawal from the heat (flicking response) is taken as the end point. Anti-inflammatory property is studied by carrageenan induced paw edema model, in which the paw volume is measured with a plethysmograph.Results: In Eddy’s hot plate method the mean reaction time increased significantly (p<0.05) with high dose of Allium cepa at 1 hour and 2 hours when compared to control. In tail flick method the mean reaction time is increased significantly (p<0.05) with high dose of Allium cepa at 1 hour and 1.5 hour when compared to control. In carrageenan induced paw edema method Allium cepa exhibited anti-inflammatory activity by significant (p<0.05) suppression of paw edema when compare to control at 1 hour after carrageenan injection to rat paw.Conclusions: Allium cepa has significant analgesic and anti-inflammatory activity in hot plate, tail flick and carrageenan induced paw edema model.

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