A basic assumption underlying neuromarketing is that people are not conscious of their nonconscious thinking processes. So it is important for researchers who are poking around in those unrecognized sources of judgments and behavior to ensure the privacy and confidentiality of their research subjects. That is Job #1 for neuromarketing researchers.
A second ethical consideration that is especially relevant to neuromarketing is transparency of methods. When you are providing measures of responses that exist only in the mind, and in the nonconscious mind at that, you have a special obligation to provide independent evidence supporting the validity and reliability of those measures.
These issues, and several others, are taken up in a 2008 article by Murphy, Illes, and Reiner called "Neuroethics of Neuromarketing" (an online copy is available here). We wrote a blog post about this article (here) and used the article's ethical principles as a key element in our chapter on ethics in Neuromarketing for Dummies. Murphy et al. was an excellent start for a serious discussion of ethics and neuromarketing in five areas:
We believe this is a topic that can profitably be taken up by the new industry trade association, Neuromarketing Science and Business Association (NMSBA). They have produced a Code of Conduct that we discuss elsewhere in this section of our website.