Effect of mean reaction time on saccadic responses to two-step stimuli with horizontal and vertical components

1975 ◽  
Vol 15 (8-9) ◽  
pp. 1021-1025 ◽  
Author(s):  
S.G. Lisberger ◽  
A.F. Fuchs ◽  
W.M. King ◽  
L.C. Evinger
Keyword(s):  
Reaction Time ◽  
Saccadic Responses ◽  
Mean Reaction Time

scholarly journals Effect of shift work on fatigue and sleep in neonatal registrars

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245428
Author(s):  
Ajay P. Anvekar ◽  
Elizabeth A. Nathan ◽  
Dorota A. Doherty ◽  
Sanjay K. Patole
Keyword(s):  
Reaction Time ◽  
Vigilance Task ◽  
Sleep Diary ◽  
Secondary Outcome ◽  
Subjective Sleepiness ◽  
Working Day ◽  
Psychomotor Vigilance ◽  
Night Shifts ◽  
Mean Reaction Time

Objective We aimed to study fatigue and sleep in registrars working 12-hour rotating shifts in our tertiary neonatal intensive unit. Methods and participants This study involved neonatal registrar’s working day (08:00–21:00) and night (20:30–08:30) shifts. Participants maintained a sleep diary, answered a self-reported sleepiness questionnaire assessing subjective sleepiness, and performed a 10-minute psychomotor vigilance task (PVT) at the start and end of each shift. Primary outcomes: (1) Fatigue at the (i) “start vs end” of day and night shifts, (ii) end of the “day vs night” shifts, and (iii) end of “first vs last shift” in block of day and night shifts. (2) Duration and quality of sleep before the “day vs night” shifts. Mean reaction time (RTM), relative coefficient of variation (RTCV), and lapses (reaction time > 500ms) were used as measures of fatigue on PVT. Secondary outcome: Subjective sleepiness (self-reported sleepiness questionnaire) at the ‘start vs end” of day and night shifts. Results Fifteen registrars completed the study. Acuity was comparable for all shifts. (1) Psychomotor responses were impaired at the end vs start of day shifts [RTM (p = 0.014), lapses (p = 0.001)], end vs start of night shifts [RTM (p = 0.007), RTCV (p = 0.003), lapses (p<0.001)] and end of night vs day shifts [RTM (p = 0.007), RTCV (p = 0.046), lapses (p = 0.001)]. Only lapses were significantly increased at the end of the last (p = 0.013) vs first shift (p = 0.009) in a block of day and night shifts. (2) Duration of sleep before the night (p = 0.019) and consecutive night shifts was decreased significantly (p = 0.034). Subjective sleepiness worsened after day (p = 0.014) and night shifts (p<0.001). Conclusion Fatigue worsened after the 12-hour day and night shifts with a greater change after night shifts. Lapses increased after block of day and night shifts. Sleep was decreased before night shifts. Our findings need to be confirmed in larger studies.

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.

Intermittent Hypoxic Exposure Improves Mean Reaction Time (MRT) Upon Rapid Ascent to High Altitude

2008 ◽  
Vol 40 (Supplement) ◽  
pp. S171
Author(s):  
Julie Barnes ◽  
Reina Chamberlain ◽  
Trevor Stanley ◽  
Tiffanie Tsui ◽  
Ashley Artese ◽  
...  
Keyword(s):  
Reaction Time ◽  
High Altitude ◽  
Hypoxic Exposure ◽  
Rapid Ascent ◽  
Mean Reaction Time

Emphasizing Nonword Decisions in Word-Decision Performance

2008 ◽  
Vol 103 (1) ◽  
pp. 97-101
Author(s):  
C. Darren Piercey
Keyword(s):  
Reaction Time ◽  
Lexical Decision ◽  
Reaction Times ◽  
Instruction Condition ◽  
Decision Performance ◽  
The Difference ◽  
Speed And Accuracy ◽  
Mean Reaction Time

A robust finding in the lexical decision literature is that decisions to words are made more quickly and accurately than decisions to nonwords. When instructions are presented to participants prior to an experiment, an emphasis is usually placed on identifying words. This study assessed whether instructing participants to emphasize nonword decisions would affect the performance of the speed and accuracy of identification. A total of 98 individuals took part, 49 in a Word Instruction condition and 49 in a Nonword Instruction condition. Analysis indicated changes in emphasis on words versus nonwords decreased the difference in mean reaction time between word and nonword decisions. An interesting finding is that the manipulation of instructions affected reaction times to words but not to nonwords. The analysis of accuracy yielded no significant comparisons. Further research is required to assess the importance of the finding that the manipulation of instructions affects only word decisions.

Startle Reflex Habituation in Children with Cerebral Palsy

1979 ◽  
Vol 48 (3_suppl) ◽  
pp. 1135-1139 ◽  
Author(s):  
Joel Goldberg ◽  
David E. Anderson ◽  
Stephen Wilder
Keyword(s):  
Cerebral Palsy ◽  
Reaction Time ◽  
Auditory Stimulus ◽  
Visual Stimulus ◽  
Stimulus Presentation ◽  
Startle Reflex ◽  
Startle Stimulus ◽  
Normal Children ◽  
Children With Cerebral Palsy ◽  
Mean Reaction Time

Two groups of children (9 with cerebral palsy and 10 normals, matched for sex and age) participated in a study of the startle reflex. Each child was instructed to press a button as soon as possible after the onset of a visual stimulus on a box on the table at which they were seated. During some of the trials, a sudden and intense auditory stimulus (85 dB) was presented concomitantly with the onset of the visual stimulus, and effects on reaction time recorded. Mean reaction time of normal children was significantly faster than that of the group with cerebral palsy. The magnitude of disruption associated with the first startle stimulus presentation was significantly greater for cerebral palsied children. The course between groups of habituation to the startle stimuli was not significantly different. Data support the hypothesis that startle reflexes of children with cerebral palsy are more marked than are those of normal children.

Performance of Retardates on the Stroop Color-Word Test

1976 ◽  
Vol 43 (3_suppl) ◽  
pp. 1259-1262 ◽  
Author(s):  
John E. Bassett ◽  
George C. Schellman
Keyword(s):  
Reaction Time ◽  
Interference Effect ◽  
Color Word ◽  
Incongruent Condition ◽  
Stimulus Size ◽  
Normal Populations ◽  
Incongruent Color ◽  
Stroop Color Word Test ◽  
The Difference ◽  
Mean Reaction Time

Institutionalized retardates were examined on a special format of a task requiring them to name the colors of 36 color patches and to name the color of the ink in which 36 incongruent color words were printed on separate cards. Mean reaction time for the incongruent condition was significantly longer than that for the color patches and the difference was independent of fatigue and stimulus size. The color-word interference effect previously reported with normal populations when given the Stroop test was demonstrated for this retarded sample using a special format.

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 Decreased ability to acquire food of a captive deaf dolphin (Tursiops truncatus): Slower reaction times and lower success rates

SURG Journal ◽  
2011 ◽  
Vol 4 (2) ◽  
pp. 63-70
Author(s):  
Katherine A. Wright
Keyword(s):  
Hearing Loss ◽  
Reaction Time ◽  
Success Rate ◽  
Tursiops Truncatus ◽  
Reaction Times ◽  
Anthropogenic Noise ◽  
Success Rates ◽  
Noise Levels ◽  
Atlantic Bottlenose Dolphin ◽  
Mean Reaction Time

Oceanic anthropogenic noise, such as naval sonar, can cause temporary hearing loss in cetaceans, but it is not known to what extent hearing loss affects cetacean behaviours such as feeding. This study used a captive deaf Atlantic bottlenose dolphin (Tursiops truncatus) to test the hypothesis that hearing loss would decrease a dolphin’s ability to acquire food by preventing echolocation (using echoes to locate fish). Reaction time (time to acquire dropped fish) and success rate (percentage of successfully acquired fish) were measured for the deaf dolphin and for two dolphins with no known hearing disabilities at Dolphins Plus in Florida in May 2009. The deaf dolphin had a significantly slower mean reaction time and a significantly lower mean success rate than those of the two other dolphins. A hydrophone suggested that the deaf dolphin could not echolocate, and thus relied mainly on vision. The results illustrate that hearing loss can negatively affect a dolphin’s ability to acquire food. Therefore, sources and effects of dolphin hearing loss require further investigation in order to provide targets for anthropogenic noise levels.

Sign in / Sign up

Export Citation Format

Share Document