- Lack of access to high quality, peer-reviewed research - Unlike Open Source where one can simply download large and complex software (such as the Linux kernel) to examine in depth how it all works, or search large online repositories to discover discussions and explanations around key areas, scientific research papers typically have restricted access. You can find most papers online, but expect to pay upwards of $35-$50 USD per paper with only a brief paragraph-long abstract to help you determine if the information within is relevant or useful.
- The "easy" discoveries have already been made - EEG research specifically goes back to at least 1875, though many of the major discoveries still referenced today occurred in the 1960's and 1970's as the equipment got better and more sensitive. All of the classical realms of science have been around much longer of course.
- Lack of access to research-grade equipment - One way to push the boundaries of the known is with improved equipment which can take more accurate readings, thus providing information which may not have been previously explored. Again referring to EEG specifically, although various consumer-grade hardware has been released recently, the quantity and location of sensors does not match locations used by current research and the signal-to-noise ratios of the sensors themselves are quite low by comparison.
- Lack of access to large, unbiased test groups - If you lack the equipment to explore new depths, you might be able to explore new applications of known phenomena instead. However this requires access to statistically significant test groups, or in other words you can't simply do all of your experimenting on yourself or family and friends (and pets!). You need unbiased subjects and for all tests to be carried out in a carefully controlled environment if you want your results taken seriously. Which brings up the final point:
- Difficultly in presenting your results - If you don't have a PhD in your field of research, chances are you will have difficulty being taken seriously, especially if your work leapfrogs or even contradicts established work in the field. You will likely need to find another party with credentials who is willing to review your work and possibly attach their name to any publications which result. Setting the barrier to entry somewhat high does help to keep out the "kooks" after all.
All that said, don't be discouraged and best of luck with your chosen field of research. If you do decide to turn to EEG feel free to contact me directly for more information or perhaps even to collaborate.