Global Visual Persistence Survey
Warning - this visual persistence test uses flickering images. Please exercise judgment and caution if you know you are disturbed by flickering images.

   

IMAGE DISPLAY and GAP DURATION

Click on these radio buttons to control the speed of the displays

20 ms 40 ms 80 ms 120 ms 160 ms 200 ms 240 ms 280 ms 320 ms 380 ms

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Some people find different colour combinations easier to see.
If you find any of these colour combinations particularly good or bad,
click the buttons beneath the display to show us which ones are good or bad.

 
Instructions
 
 

The object of this exercise is to find out how much the speed of human word and number perception varies, and how that affects reading comfort and choice of career. Specifically -

how long does the image of a number or a word have to be displayed, in order for you to see it clearly,

and how much time gap do you need between images for you to see them clearly?

I am conducting this on-line survey to collect global data about the relationship between Visual Persistence (VP) speed (see below) and reading ability.

The research questions are;

What is the distribution of VP speeds in the human population?

Is VP speed correlated with reading ability/difficulty, first written language or age?

Is VP speed correlated with choice of work / profession?

Is VP speed effected by colour contrasts?

Visual Persistence is a feature of our perceptual system. Visual images (letters of the alphabet for example), persists in our visual system for around 40 - 300 milliseconds after the stimulus is removed from view. Some people have a fast image decay time and others hold images for longer. When we are presented with a rapid sequence of images (such as when reading or tracking movement) a backlog of persisting images can build up, resulting in multiple images persisting simultaneously. The brain reacts by paying more attention to some of the conflicting images and ignoring or delaying the perception of others.

This phenomenon (one image being prioritized over another) is often called 'masking' in the literature and may result in a range of perceptual distortions and deletions - letters appearing to move about or change position, reversals, parts of words or letters missing, etc. We (gts-training.co.uk) have found that all our 'dyslexic' students have a VP speed near the longer end of this natural range, (and read relatively slowly) and that all our teaching staff have VP speeds near the shorter end of the range, and can read very fast. This raises the question of whether people's choice of occupation may be effected by their visual persistence.

If you can spare a few minutes to take part in this anonymous survey - this is what we would like you to do.

Click either of the 'START. . . ' buttons at the top of the page. This starts the display of a sequence of numbers or words. You can control the speed of the displays by clicking on the radio buttons above the display - these control the time delays in milliseconds (ms). You can stop the display at any time with the 'Stop Displays' button. You can then restart either display.

Please find the fastest speed at which you can VERY comfortably see ALL the numbers or words clearly. When you have found your fastest comfortable speed, stop the display, and move on to the anonymous survey form below. The current speed setting at the time you submit the survey form will be added anonymously to the research database.

The displays use a range of different foreground and background colours. Please click the appropriate button if any of these colour combinations are particularly good or bad for your visual system.

 

 
 

When you have found your preferred speeds - please answer a few questions below, and press the submit button, which will record the answers on our database anonymously.

Please describe your- reading speed

Please describe your - reading comprehension - when you are reading on your own in perfect circumstances

Please describe your - reading comprehension when reading aloud to other people

Is your reading ability reduced by any of the following?

Most disturbing
Second most disturbing
Third most disturbing

What is your...

Education Level?
Age in Years?
First Written Language?

Study subject / Occupation / Profession?

If you would like to be sent the results of this survey please enter your e-mail address (OPTIONAL)