Assistive technologies = for persons suffering from some kind of disability?
The problem is that it is really specific to the need of the user. A person with an important visual deficiency requires another intervention than a person with a motor disability or one with dyslexia. Hey, why mention dyslexia in relation to assistive technologies. Some studies suggest that some color contrasts that appear very weird to others help dyslexics to better focus on the reading material.
I have some general resources on accessibility in education, but this is more about making sure that the resources you produce are available to a large range of pupils than assistive technologies.
A starting point may be, the wikipedia entry on assistive technology and the various links at the bottom of that page.
If you really are after serious research papers, use citeseer. Here run a google search that is webdomain specific, assistive site:citeseer.ist.psu.edu. The interest of citeseer is that (1) papers are free and (2) they list all the articles that have some level of similarity with the current paper. You can then rapidly identify all papers in the area that interest you (with the inconvenient that if you don't have a specific area, you can spend days exploring all papers). Check that out with this example paper on POMDP Models for Assistive Technology (2005).
Still another option, citeUlike. They appear to have a tag listing all content having to do with assistive related content.
A great site to find info and research on AT would be MATN Online This is the Maryland Assistive Technology Network, which is out of Johns Hopkins University's Center for Technology in Education. This covers the basics, offers indepth information on AT Consideration, and has a section that summarizes current research in AT. Another great resource is www.closingthegap.com
Assistive Technology is defined as " any devices or services that are necessary for a child to benefit from special education or related services or to enable the child to be educated in the least restrictive environment." (34 C.F.R. §300.308). While these often include specialized devices, it can also include many technologies that would be available in any education setting. The important thing is that Assistive Technology included on a students IEP (Individual Education Plan) is a legally mandate device or strategy, that is considered necessary in order to make progress on goals and objectives, and may also be needed for instruction and testing. An IEP team MUST consider Assitive Technology for any student with an IEP. For ideas, strategies, and solid research on how to front load any classroom with technologies that support all students, including those with special needs, take a look at www.cast.org