University of Maryland


PEAT helps authors identify seizure-inducing content

July 6th, 2009

A new, and significantly improved, beta release of the Photosensitive Epilepsy Analysis Tool (PEAT) is available for download from the University of Wisconsin-Madison Trace Center. PEAT is a free, first-of-its-kind resource that developers can use to identify seizure risks in their web content or computer software.

The software was developed specifically for web and computer applications and can be used to evaluate content for conformance with requirements in Web Content Accessibility Guidelines (WCAG) 2.0, related to seizure prevention.

“As web content gets more dynamic and web pages begin to resemble television it is important that we not start inadvertently triggering seizures in people with photosensitive seizure disorders.” Said Gregg Vanderheiden, Director of the Trace Center and co-chair of the W3C Web Content Accessibility Guidelines working group. “This free tool can help prevent that.”

About one in four thousand people are diagnosed with photosensitive epilepsy and are subject to seizures triggered by certain types of flashing in web, computer or television content where large areas of the screen rapidly flash on and off repeatedly. The condition, known as photosensitive epilepsy, usually begins before the age of 20 years and is most common between the ages of seven and 19.

Hazardous, seizure-inducing content has been inadvertently broadcast on television in the past. For example, in 1997 a Pokémon episode broadcast in Japan showed a sequence of flickering images that sent almost 700 people, most of whom were children, to the hospital.

“As web content becomes more interactive and media-rich, it is increasingly important that content developers be aware of photosensitive seizure disorders and take steps to avoid causing seizures.” said Vanderheiden.

With this release, it is now possible to use PEAT’s built-in video capture capability to more easily analyze web content and software for seizure risk. Developers can now initiate a video capture of a Web browser or application window from within the PEAT software. If content requires clicking on a link or a series of links to invoke an animation or navigation through a series of pages, the program will record all actions in the window. When the capture process is completed, the video can be played back or analyzed. This release also includes a variety of performance improvements and new features including improved keyboard shortcuts, the ability to save analysis results in HTML and significantly expanded user documentation.

“To be sure – PEAT is a great tool already – it makes possible something that was not possible before,” said Peter Lakov, Windows Accessibility Program Manager at Microsoft. “I am certain that many companies out there will benefit by testing their UIs with it.”

The software is the result of a collaboration between the Trace Center, Cambridge Research Systems and Dr. Graham Harding, who is a leading expert in photosensitive seizure disorders. The first PEAT beta was released in April of 2006 and played an important role in the development of requirements in WCAG 2.0 related to seizure prevention.

Anyone interested in this free software is encouraged to download the latest version and give it a try.

Continuing support for Trace’s work in this area has been provided by the National Institute on Disability and Rehabilitation Research (NIDRR), U.S. Department of Education, under grants H133E980008, H133E030012, and H133E080022.

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