Limits...
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.


Related in: MedlinePlus

Stimuli and task. Stimuli were high-contrast bulls eyes presented to the left or right hemifield for a duration of 200 ms at randomized stimulus onset asynchronies (SOAs) that ranged from 1000 to 1800 ms in five 200 ms steps in Experiment 1, and from 1000 to 2000 ms in five 250 ms steps in Experiment 2. Stimuli could occur in the visual hemifield ipsilateral (shown) or contralateral to the responding hand. Subjects responded to all stimuli as rapidly as possible by depressing the mouse button with the index finger of their dominant hand (i.e., right-handed subjects depressed the left mouse button and left headed subjects depressed the right mouse button).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4374455&req=5

Figure 1: Stimuli and task. Stimuli were high-contrast bulls eyes presented to the left or right hemifield for a duration of 200 ms at randomized stimulus onset asynchronies (SOAs) that ranged from 1000 to 1800 ms in five 200 ms steps in Experiment 1, and from 1000 to 2000 ms in five 250 ms steps in Experiment 2. Stimuli could occur in the visual hemifield ipsilateral (shown) or contralateral to the responding hand. Subjects responded to all stimuli as rapidly as possible by depressing the mouse button with the index finger of their dominant hand (i.e., right-handed subjects depressed the left mouse button and left headed subjects depressed the right mouse button).

Mentions: As shown in Figure 1, subjects responded as rapidly as possible to stimuli presented to the left or right hemifield by depressing a response button with the index finger of their dominant hand. The task was designed to elicit SRTs with short latencies, and incorporated a number of design features to assure precise SRT measurement: (1) The response button was a computer gaming mouse designed for ultrafast responding with minimum force, displacement, and timing uncertainty; (2) Stimuli were large and of high luminance and contrast; (3) SRT windowing functions excluded response latencies less than 110 ms and greater than 1000 ms; (4) Twenty practice trials were given to each subject, and SRTs were gathered from 120 test trials; (5) Computer hardware and software delays were measured.


Factors influencing the latency of simple reaction time.

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

Stimuli and task. Stimuli were high-contrast bulls eyes presented to the left or right hemifield for a duration of 200 ms at randomized stimulus onset asynchronies (SOAs) that ranged from 1000 to 1800 ms in five 200 ms steps in Experiment 1, and from 1000 to 2000 ms in five 250 ms steps in Experiment 2. Stimuli could occur in the visual hemifield ipsilateral (shown) or contralateral to the responding hand. Subjects responded to all stimuli as rapidly as possible by depressing the mouse button with the index finger of their dominant hand (i.e., right-handed subjects depressed the left mouse button and left headed subjects depressed the right mouse button).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: Stimuli and task. Stimuli were high-contrast bulls eyes presented to the left or right hemifield for a duration of 200 ms at randomized stimulus onset asynchronies (SOAs) that ranged from 1000 to 1800 ms in five 200 ms steps in Experiment 1, and from 1000 to 2000 ms in five 250 ms steps in Experiment 2. Stimuli could occur in the visual hemifield ipsilateral (shown) or contralateral to the responding hand. Subjects responded to all stimuli as rapidly as possible by depressing the mouse button with the index finger of their dominant hand (i.e., right-handed subjects depressed the left mouse button and left headed subjects depressed the right mouse button).
Mentions: As shown in Figure 1, subjects responded as rapidly as possible to stimuli presented to the left or right hemifield by depressing a response button with the index finger of their dominant hand. The task was designed to elicit SRTs with short latencies, and incorporated a number of design features to assure precise SRT measurement: (1) The response button was a computer gaming mouse designed for ultrafast responding with minimum force, displacement, and timing uncertainty; (2) Stimuli were large and of high luminance and contrast; (3) SRT windowing functions excluded response latencies less than 110 ms and greater than 1000 ms; (4) Twenty practice trials were given to each subject, and SRTs were gathered from 120 test trials; (5) Computer hardware and software delays were measured.

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.


Related in: MedlinePlus