<p>This depends on intensity but it is shorter at most intensities than your screen could possibly present a stimulus.  Don't worry about it or cite references.  It would be like citing a reference for why you don't need to worry about quantum effects when testing the best kind of screwdriver.</p>

CC BY-SA 3.0
2013-01-25T23:41:32.847Z
2013-01-25T23:41:32.847Z
John
<p>In psychophysics, this is known as an <a href="http://en.wikipedia.org/wiki/Absolute_threshold">absolute threshold</a>. The absolute threshold will depend on a variety of factors such as brightness, size, etc.</p>

<p>It is also important to keep in mind that the time needed to <em>detect</em> a stimulus may be too short to cause some desired effect on the participant (e.g. a manipulation). For example, the time needed to detect a stimulus is necessarily shorter than the time needed to identify a stimulus. Though research on <a href="http://en.wikipedia.org/wiki/Subliminal_messaging">subliminal stimuli</a> suggests stimuli can sometimes be presented <em>below</em> threshold and still achieve some manipulation. However, some of this research is controversial.</p>

<p>Often, researchers will choose a range of display times specifically in order to unravel the time course of some cognitive process. For instance, when displaying a cluster of dots, how long is needed in order to <a href="http://en.wikipedia.org/wiki/Subitize">subitize</a> them?</p>

<p>There is insufficient information in your question to give you an exact number, but I suggest looking at similar studies and see what sort of display times they use.</p>

CC BY-SA 3.0
2013-01-26T02:21:48.793Z
2013-01-26T02:21:48.793Z
Jeff
<p>My experiment involves presenting simple visual stimuli briefly on screen (200 ms to 1000 ms). The stimuli would be simple enough (e.g. a circle and a line) but I want to use a range of durations to test out some hypotheses. I would like to know if there's a minimal time for human eyes to perceive simple visual stimuli, so I could say "the durations I've chosen for my experiment are safely above the minimal value suggested by 'so and so' in the psychophysics experiment.   </p>

<p>I am sure many factors would have an impact on such a value, such as the participant's condition and how far the target is (in my case it's the distance between someone, sitting at their desk, and the computer screen), etc., but perhaps there are data and rules already established? If anyone knows of applicable guidelines or literature, I would really appreciate it. </p>

<p>(I've tried searching under "tachistoscopic presentation minimum time" but haven't discovered anything useful yet. Any other search term combo would also be helpful.)</p>

CC BY-SA 3.0
2013-01-26T18:55:38.417Z
You do not need to cite something to justify the chosen presentation times, instead just look at your data. If your participants responded to almost all stimuli with the shortest presentation times, you obviously did choose a time above the minimum detection time. If your participants did not respond to a large amount of those stimuli, your presentation time was too short. That's it and no citation could change this...
H.Muster
CC BY-SA 3.0
2013-07-08T22:58:29.920Z
A technical aspect that might be relevant to take into consideration here is the monitor's refresh rate, especially concerning [V-sync](http://en.wikipedia.org/wiki/Refresh_rate), such that you do not introduce measuring errors
awdz9nld
<perception><experimental-psychology><vision><psychophysics>
Minimum duration for presenting a visual stimulus on screen
Wynn
# Minimum duration for presenting a visual stimulus on screen

(Asked by: username_0 on 2013-01-25)

My experiment involves presenting simple visual stimuli briefly on screen (200 ms to 1000 ms). The stimuli would be simple enough (e.g. a circle and a line) but I want to use a range of durations to test out some hypotheses. I would like to know if there's a minimal time for human eyes to perceive simple visual stimuli, so I could say "the durations I've chosen for my experiment are safely above the minimal value suggested by 'so and so' in the psychophysics experiment.

I am sure many factors would have an impact on such a value, such as the participant's condition and how far the target is (in my case it's the distance between someone, sitting at their desk, and the computer screen), etc., but perhaps there are data and rules already established? If anyone knows of applicable guidelines or literature, I would really appreciate it.

(I've tried searching under "tachistoscopic presentation minimum time" but haven't discovered anything useful yet. Any other search term combo would also be helpful.)

**Tags:** perception, experimental-psychology, vision, psychophysics

> **Comments:**
> **username_1**: You do not need to cite something to justify the chosen presentation times, instead just look at your data. If your participants responded to almost all stimuli with the shortest presentation times, you obviously did choose a time above the minimum detection time. If your participants did not respond to a large amount of those stimuli, your presentation time was too short. That's it and no citation could change this...  
> **username_2**: A technical aspect that might be relevant to take into consideration here is the monitor's refresh rate, especially concerning [V-sync](http://en.wikipedia.org/wiki/Refresh_rate), such that you do not introduce measuring errors  

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## 2 answers

### Answer by username_4 on 2013-01-26. Score: 5 | Accepted answer

In psychophysics, this is known as an [absolute threshold](http://en.wikipedia.org/wiki/Absolute_threshold). The absolute threshold will depend on a variety of factors such as brightness, size, etc.

It is also important to keep in mind that the time needed to *detect* a stimulus may be too short to cause some desired effect on the participant (e.g. a manipulation). For example, the time needed to detect a stimulus is necessarily shorter than the time needed to identify a stimulus. Though research on [subliminal stimuli](http://en.wikipedia.org/wiki/Subliminal_messaging) suggests stimuli can sometimes be presented *below* threshold and still achieve some manipulation. However, some of this research is controversial.

Often, researchers will choose a range of display times specifically in order to unravel the time course of some cognitive process. For instance, when displaying a cluster of dots, how long is needed in order to [subitize](http://en.wikipedia.org/wiki/Subitize) them?

There is insufficient information in your question to give you an exact number, but I suggest looking at similar studies and see what sort of display times they use.


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### Answer by username_3 on 2013-01-25. Score: 3

This depends on intensity but it is shorter at most intensities than your screen could possibly present a stimulus. Don't worry about it or cite references. It would be like citing a reference for why you don't need to worry about quantum effects when testing the best kind of screwdriver.


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