The opportunities offered by embedding multimedia files have a number of foreseeable implications for publications that communicate medical data. From a scientific point of view, the greatest asset is presumably that the transparency of the presented data can be expected to increase, while the need for explanatory supplemental material will largely become obsolete. In recognising these opportunities, the Journal of Neuroscience has recently decided to ban supplemental material altogether [9]. Instead, authors are encouraged to 'publish articles with embedded movies or three-dimensional models, both online and in downloadable PDFs'. PDF files with embedded multimedia content are available as a single download and may be viewed online as well as offline at the reader's discretion. As stressed by the editor of the Journal of Neuroscience, this new policy 'eliminates the only essential role of supplemental material' and is meant to strengthen the desirable concept of an article as 'a complete, self-contained scientific report' [9].
We regard it also as important to point out that articles with embedded information are more likely to be written such that their multimedia content will be referred to as an integral part of the text (see, for example, [2–7]). Clearly, the implementation of such a reader-friendly approach to disseminating multimedia content will aid the transition from paper-based to pure electronic publishing. Having already stressed that publishers should adjust to publications with integrated multimedia content [10], we are confident that the acceptance of this novel format will be growing, as authors and publishing houses alike begin to realise its potential (see [5] for a number of examples). In our eyes, the universal acceptance of the PDF for the publication of scientific data guarantees a considerable life expectancy of this file format. We are confident that future software developments will take the existence of millions of PDF-based publications into account, providing future generations with the necessary backwards software compatibility.
Obviously, the form of communicating scientific results proposed by us is especially suited for electronic publishing, and in particular for those journals with an open access policy. In line with the entire philosophy behind the latter, all embedded multimedia content will become freely accessible over the web, resulting in the widespread dissemination of medical data such as those depicted here. In this scenario, limitations imposed by file size will no longer be an issue, since scientists can send each other a direct link to the article download site without the need to send individual papers by email.
The examples that we provide suggest that multiple medical disciplines will profit from the adoption of PDF-integrated 3D models or audiovisual content. However, a PDF-based scientific article must still be seen as a means to communicate scientific results in a reprocessed form, as opposed to the deposition of raw data in a database that permits a more comprehensive exploitation of this information, but requires also an advanced knowledge of computation or visualisation software tools [11].