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.

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.

Auditory Reaction Times for Functional and Nonfunctional Hearing Loss

1977 ◽  
Vol 20 (1) ◽  
pp. 177-191 ◽  
Author(s):  
Thomas J. Wood ◽  
Edward L. Goshorn ◽  
Robert W. Peters
Keyword(s):  
Hearing Loss ◽  
Reaction Time ◽  
Reaction Times ◽  
Decision Processes ◽  
Sensation Level ◽  
Response Data ◽  
Level Data ◽  
Auditory Reaction Time ◽  
Standard Deviations ◽  
Probability Of Response

Differences in decision processes as measured by auditory reaction times of simulated or actual functional hearing-loss subjects and nonfunctional subjects were investigated. Sensation level data are presented that reflect marked differences between such individuals with regard to probability of response, and means and standard deviations of auditory reaction times. Means and standard deviations of auditory reaction times for nonfunctional subjects are greatly reduced when compared with results obtained by simulated or actual functional subjects. Probability of response data was less effective in differentiating functional from nonfunctional subjects. Individuals who were trained to simulate hearing loss responded in a manner similar to functional patients. The results of this study suggest that auditory reaction time measures can be employed to determine the existence or nonexistence of functional hearing loss with considerable accuracy.

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.

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.

Evidence of hearing loss in an Atlantic bottlenose dolphin (Tursiops truncatus)

1997 ◽  
Vol 102 (5) ◽  
pp. 3101-3101 ◽  
Author(s):  
Randall L. Brill ◽  
Patrick W. B. Moore ◽  
Lois A. Dankiewicz ◽  
Darlene R. Ketten
Keyword(s):  
Hearing Loss ◽  
Bottlenose Dolphin ◽  
Tursiops Truncatus ◽  
Atlantic Bottlenose Dolphin

From Simple to Complex or Vice Versa: Sequence Effects on the Detection of Embedded Figures

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 247-247
Author(s):  
I Ludwig
Keyword(s):  
Reaction Time ◽  
Error Rate ◽  
Reaction Times ◽  
Random Order ◽  
Error Rates ◽  
Presentation Order ◽  
The Other ◽  
Embedded Figures ◽  
Sequence Effects ◽  
Mean Reaction Time

In a series of studies concerning part - whole perception we have investigated effects of perceptual learning, and of systematically varied presentation orders on the detection of embedded figures. In the present study the effects of increasing and decreasing complexity orders on detection performance are reported. Stimuli were 170 pairs of whole and part figures. Half of them were positive items, ie the searched part was contained in the (simultaneously presented) whole. The other half were negative items, ie the searched part was not contained in the whole. The difficulty of all figure pairs was determined from earlier data. On the basis of these difficulty parameters three presentation orders were created: (1) increasing difficulty (from simple to complex), (2) decreasing difficulty (from complex to simple), and (3) randomised order. Sixty subjects performed each of these tasks in three sessions separated by one week. Effects of practice and samples were balanced by permutating the order of the three tasks. The reaction times and error rates for all presentations were registered. The results showed marked differences between the three tasks: The lowest mean reaction time was obtained in the presentation order with increasing difficulty. Error rate, on the other hand, was lowest in the decreasing-difficulty presentation order. For the random-order presentation error rate and reaction time was in between the other orders. Furthermore, differences in benefit from practice were observed between the three orders of difficulty. Results are discussed with respect to the question of how efficient search strategies may be learned and whether one can learn to bend the rules of Gestalt organisation if required.

Response to Simulated Traffic Signals Using Light-Emitting Diode and Incandescent Sources

2000 ◽  
Vol 1724 (1) ◽  
pp. 39-46 ◽  
Author(s):  
John D. Bullough ◽  
Peter R. Boyce ◽  
Andrew Bierman ◽  
Kathryn M. Conway ◽  
Kun Huang ◽  
...  
Keyword(s):  
Reaction Time ◽  
Light Emitting Diode ◽  
Reaction Times ◽  
Reaction Time Data ◽  
Traffic Signals ◽  
Time Data ◽  
Light Emitting ◽  
Color Identification ◽  
Mean Reaction Time

Simulated light-emitting diode (LED) traffic signals of different luminances were evaluated relative to incandescent signals of the same nominal color and at the luminances required by the specifications of the Institute of Transportation Engineers. Measurements were made of the reaction times to onset and the number of missed signals for red, yellow, and green incandescent and LED signals. Measurements also were made of subjects’ ability to correctly identify signal colors and of their subjective brightness and conspicuity ratings. All measurements were made under simulated daytime conditions. There were no significant differences in mean reaction time, percentage of missed signals, color identification, or subjective brightness and conspicuity ratings between simulated incandescent and LED signals of the same nominal color and luminance. Higher luminances were needed for the yellow and green signal colors to ensure that they produced the same reaction time, the same percentage of missed signals, and the same rated brightness and conspicuity as a red signal at a given luminance. Equations fitted to the reaction time data, the missed signals data, and the brightness and conspicuity ratings for the LED signals can be used to make quantitative predictions of the consequences of proposed changes in signal luminance for reaction time, brightness, and conspicuity.

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 Exploring changes in processing speed and intraindividual variability in youth following sports-related concussion

2019 ◽  
Vol 3 ◽  
pp. 205970021983958 ◽  
Author(s):  
Stephanie L Green ◽  
Michelle L Keightley ◽  
Nancy J Lobaugh ◽  
Deirdre R Dawson ◽  
Alex Mihailidis
Keyword(s):  
Working Memory ◽  
Reaction Time ◽  
Processing Speed ◽  
Coefficient Of Variation ◽  
Response Times ◽  
Reaction Times ◽  
Sports Participation ◽  
Intraindividual Variability ◽  
Return To Sports ◽  
Mean Reaction Time

Background Concussion represents a growing concern in sports participation for adults and youth alike. Studies exploring the neurocognitive sequelae of concussion, such as speed of processing typically compare mean reaction time scores to a control group. Intraindividual variability measures the consistency of reaction times between trials and has been previously explored in adults post-concussion. Some adult studies show increased variability following injury. Developmentally youth show higher intraindividual variability than adults, which may put them at higher risk of increased intraindividual variability change post-concussion. Exploring intraindividual variability may provide additional insight into fluctuating performance reported following injury. Despite preliminary findings of slowed reaction time in youth, a pre-/post-concussion comparison of intraindividual variability of reaction time has not been explored. Objective To describe and compare pre- and post-concussion measures of processing speed and intraindividual variability in youth. Methods A pre-/post-concussion design was used to compare mean reaction time and the coefficient of variation before and after sports-related concussion in 18 youth athletes aged 10–14 years using verbal and nonverbal working memory tasks. Pre-/post-concussion reaction time and coefficient of variation were compared using t-tests. Results The coefficient of variation for nonverbal working memory was significantly higher following concussion, but no changes in average reaction time were found. Conclusions Preliminary findings suggest that average response times are unchanged following concussion, but the fluctuation across response times is more variable during a nonverbal working memory task in youth. Increased variability in speed of reaction times could have implications for safe return to sports and reduced academic performance.

Reaction Time of the Fingers with Responses Measured on a Typewriter Keyboard

1978 ◽  
Vol 47 (3) ◽  
pp. 863-867 ◽  
Author(s):  
V. Hayes ◽  
Gerald Halpin
Keyword(s):  
Reaction Time ◽  
Repeated Measures ◽  
Rank Order ◽  
Reaction Times ◽  
Left Hand ◽  
Repeated Measures Analysis ◽  
The Mean ◽  
The Right ◽  
Mechanical Timer ◽  
Mean Reaction Time

Reaction times on each of the eight fingers were obtained for 24 skilled typists using an electric typewriter and a mechanical timer. Repeated-measures analysis of variance indicated significant differences among the mean reaction times of the eight fingers. Scheffé's multiple-comparison procedure indicated that the mean reaction time of each finger differed from that of every other finger and that the mean reaction time of the fingers on the left hand was significantly slower than the mean reaction time of fingers on the right hand. The average inter-class correlation coefficient among the fingers was .92 which indicated rank-order of reaction times to be similar across fingers.

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