There are 49 ways of making adjacent changes to a 50 letter string (50-bp read).

These workers presented letter strings to the left or right visual field for different durations.

Instead, they are simply given the task to memorize the letter strings for a memory.

Sayre states that in most cases, there are less than four resulting alternative letter strings, and usually one.

Only letter strings which appeared in this dictionary were considered to be correct.

While this system may produce more than one letter string as a result, this did not happen often.

This allowed illegal letter strings to be ruled out at an early stage.

Instead, participants develop their own rules based on small sections of each letter string.

Presentation of each letter string is brief, generally less than 100 ms, and central on the screen.

It is likely that many of these letter strings will not form English words.