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Factors influencing the latency of simple reaction time.

Woods DL, Wyma JM, Yund EW, Herron TJ, Reed B - Front Hum Neurosci (2015)

Bottom Line: Mean SRT latencies were short (231, 213 ms when corrected for hardware delays) and increased significantly with age (0.55 ms/year), but were unaffected by sex or education.SRT latencies increased with age while SDT latencies remained stable.Precise computer-based measurements of SRT latencies show that processing speed is as fast in contemporary populations as in the Victorian era, and that age-related increases in SRT latencies are due primarily to slowed motor output.

View Article: PubMed Central - PubMed

Affiliation: Human Cognitive Neurophysiology Laboratory, Veterans Affairs Northern California Health Care System, Martinez CA, USA ; The Department of Neurology, University of California Sacramento, Davis CA, USA ; Center for Neurosciences, University of California Davis, Davis CA, USA ; Center for Mind and Brain, University of California Davis, Davis CA, USA.

ABSTRACT
Simple reaction time (SRT), the minimal time needed to respond to a stimulus, is a basic measure of processing speed. SRTs were first measured by Francis Galton in the 19th century, who reported visual SRT latencies below 190 ms in young subjects. However, recent large-scale studies have reported substantially increased SRT latencies that differ markedly in different laboratories, in part due to timing delays introduced by the computer hardware and software used for SRT measurement. We developed a calibrated and temporally precise SRT test to analyze the factors that influence SRT latencies in a paradigm where visual stimuli were presented to the left or right hemifield at varying stimulus onset asynchronies (SOAs). Experiment 1 examined a community sample of 1469 subjects ranging in age from 18 to 65. Mean SRT latencies were short (231, 213 ms when corrected for hardware delays) and increased significantly with age (0.55 ms/year), but were unaffected by sex or education. As in previous studies, SRTs were prolonged at shorter SOAs and were slightly faster for stimuli presented in the visual field contralateral to the responding hand. Stimulus detection time (SDT) was estimated by subtracting movement initiation time, measured in a speeded finger tapping test, from SRTs. SDT latencies averaged 131 ms and were unaffected by age. Experiment 2 tested 189 subjects ranging in age from 18 to 82 years in a different laboratory using a larger range of SOAs. Both SRTs and SDTs were slightly prolonged (by 7 ms). SRT latencies increased with age while SDT latencies remained stable. Precise computer-based measurements of SRT latencies show that processing speed is as fast in contemporary populations as in the Victorian era, and that age-related increases in SRT latencies are due primarily to slowed motor output.

No MeSH data available.


Simple reaction times (SRTs) as a function of age. From subjects in Experiment 1 (blue diamonds) and Experiment 2 (open red squares). Eight subjects from Experiment 1 with mean SRTs above 350 ms are not shown. The linear trend line is from Experiment 1 data.
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Figure 2: Simple reaction times (SRTs) as a function of age. From subjects in Experiment 1 (blue diamonds) and Experiment 2 (open red squares). Eight subjects from Experiment 1 with mean SRTs above 350 ms are not shown. The linear trend line is from Experiment 1 data.

Mentions: Figure 2 shows Experiment 1 SRT latencies (blue diamonds) as a function of age, and Table 2 shows the different measures for each of the seven age groups and for the entire experiment. An ANOVA for repeated measures showed a significant effect of Age-Group on SRT [F(6,1462) = 15.52, p < 0.0002, ω2 = 0.06]. SRT latencies were shorter than those seen for the other studies in Table 1. SRT latencies increased from 217.8 ms (200 ms when latencies were corrected for hardware delays) in the youngest subject group, to 239.1 ms (222.3 ms, delay-corrected) in the oldest subject group. However, the effect size of age was relatively small: power analysis showed that a 99% probability of detecting a significant (p < 0.05) effect of age would require 458 subjects. Age-related slowing occurred throughout the age range, with significant (p < 0.05, uncorrected) pairwise differences seen between Group 1 (G1) and G3–G7, between G2 and G4–G7, between G3 and G5–G7, between G4 and G5–G7, and between G6 and G7.


Factors influencing the latency of simple reaction time.

Woods DL, Wyma JM, Yund EW, Herron TJ, Reed B - Front Hum Neurosci (2015)

Simple reaction times (SRTs) as a function of age. From subjects in Experiment 1 (blue diamonds) and Experiment 2 (open red squares). Eight subjects from Experiment 1 with mean SRTs above 350 ms are not shown. The linear trend line is from Experiment 1 data.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4374455&req=5

Figure 2: Simple reaction times (SRTs) as a function of age. From subjects in Experiment 1 (blue diamonds) and Experiment 2 (open red squares). Eight subjects from Experiment 1 with mean SRTs above 350 ms are not shown. The linear trend line is from Experiment 1 data.
Mentions: Figure 2 shows Experiment 1 SRT latencies (blue diamonds) as a function of age, and Table 2 shows the different measures for each of the seven age groups and for the entire experiment. An ANOVA for repeated measures showed a significant effect of Age-Group on SRT [F(6,1462) = 15.52, p < 0.0002, ω2 = 0.06]. SRT latencies were shorter than those seen for the other studies in Table 1. SRT latencies increased from 217.8 ms (200 ms when latencies were corrected for hardware delays) in the youngest subject group, to 239.1 ms (222.3 ms, delay-corrected) in the oldest subject group. However, the effect size of age was relatively small: power analysis showed that a 99% probability of detecting a significant (p < 0.05) effect of age would require 458 subjects. Age-related slowing occurred throughout the age range, with significant (p < 0.05, uncorrected) pairwise differences seen between Group 1 (G1) and G3–G7, between G2 and G4–G7, between G3 and G5–G7, between G4 and G5–G7, and between G6 and G7.

Bottom Line: Mean SRT latencies were short (231, 213 ms when corrected for hardware delays) and increased significantly with age (0.55 ms/year), but were unaffected by sex or education.SRT latencies increased with age while SDT latencies remained stable.Precise computer-based measurements of SRT latencies show that processing speed is as fast in contemporary populations as in the Victorian era, and that age-related increases in SRT latencies are due primarily to slowed motor output.

View Article: PubMed Central - PubMed

Affiliation: Human Cognitive Neurophysiology Laboratory, Veterans Affairs Northern California Health Care System, Martinez CA, USA ; The Department of Neurology, University of California Sacramento, Davis CA, USA ; Center for Neurosciences, University of California Davis, Davis CA, USA ; Center for Mind and Brain, University of California Davis, Davis CA, USA.

ABSTRACT
Simple reaction time (SRT), the minimal time needed to respond to a stimulus, is a basic measure of processing speed. SRTs were first measured by Francis Galton in the 19th century, who reported visual SRT latencies below 190 ms in young subjects. However, recent large-scale studies have reported substantially increased SRT latencies that differ markedly in different laboratories, in part due to timing delays introduced by the computer hardware and software used for SRT measurement. We developed a calibrated and temporally precise SRT test to analyze the factors that influence SRT latencies in a paradigm where visual stimuli were presented to the left or right hemifield at varying stimulus onset asynchronies (SOAs). Experiment 1 examined a community sample of 1469 subjects ranging in age from 18 to 65. Mean SRT latencies were short (231, 213 ms when corrected for hardware delays) and increased significantly with age (0.55 ms/year), but were unaffected by sex or education. As in previous studies, SRTs were prolonged at shorter SOAs and were slightly faster for stimuli presented in the visual field contralateral to the responding hand. Stimulus detection time (SDT) was estimated by subtracting movement initiation time, measured in a speeded finger tapping test, from SRTs. SDT latencies averaged 131 ms and were unaffected by age. Experiment 2 tested 189 subjects ranging in age from 18 to 82 years in a different laboratory using a larger range of SOAs. Both SRTs and SDTs were slightly prolonged (by 7 ms). SRT latencies increased with age while SDT latencies remained stable. Precise computer-based measurements of SRT latencies show that processing speed is as fast in contemporary populations as in the Victorian era, and that age-related increases in SRT latencies are due primarily to slowed motor output.

No MeSH data available.