12. A method of user verification employing a processor operating to perform actions in response to executing computer program instructions, comprising: receiving an access request; generating, by a nontransitory computer readable medium having stored thereon instructions for generating, one or more video-based automated tests that are based on at least two properties of human vision comprising at least persistence of vision and simultaneous contrast wherein simultaneous contrast comprises enhancement or diminishment, relative to normal, of perception, cognition and related performance as a result of immediately previous or simultaneous exposure to a stimulus of lesser or greater value in the same dimension wherein generating the one or more video-based automated tests further comprises generating a video of a target image comprising text data of one or more of randomly selected letters or meaningful words, segmenting the target image into a grid of segments wherein each segment is of a predetermined size, generating a set of colors for inclusion into the target image in the video, and splitting the grid of segments across a plurality of framesets such that occurrence rates of the positive data comprising the target image or the text data and negative data including the whitespace data is the same; issuing the one or more tests; receiving a response to the one or more tests from the access requestors; and verifying that the access request originated from a human user based at least on the response.
12. A method of user verification employing a processor operating to perform actions in response to executing computer program instructions, comprising: receiving an access request; generating, by a nontransitory computer readable medium having stored thereon instructions for generating, one or more video-based automated tests that are based on at least two properties of human vision comprising at least persistence of vision and simultaneous contrast wherein simultaneous contrast comprises enhancement or diminishment, relative to normal, of perception, cognition and related performance as a result of immediately previous or simultaneous exposure to a stimulus of lesser or greater value in the same dimension wherein generating the one or more video-based automated tests further comprises generating a video of a target image comprising text data of one or more of randomly selected letters or meaningful words, segmenting the target image into a grid of segments wherein each segment is of a predetermined size, generating a set of colors for inclusion into the target image in the video, and splitting the grid of segments across a plurality of framesets such that occurrence rates of the positive data comprising the target image or the text data and negative data including the whitespace data is the same; issuing the one or more tests; receiving a response to the one or more tests from the access requestors; and verifying that the access request originated from a human user based at least on the response. 14. The method of claim 12 , wherein generating a set of colors comprises generating a set of three or more colors that exploits simultaneous contrast characteristic of human vision.