Neuromarketing is a relatively new field of marketing that studies consumers' sensorimotor, cognitive, and affective response to marketing stimuli.
Researchers use technologies such as functional magnetic resonance imaging (fMRI) to measure changes in activity in parts of the brain, electroencephalography (EEG) to measure activity in specific regional spectra of the brain response, and/or sensors to measure changes in one's physiological state (heart rate, respiratory rate, galvanic skin response) to learn why consumers make the decisions they do, and what part of the brain is telling them to do it.
Companies such as Google, CBS, and Frito-Lay amongst others have used neuromarketing research services to measure consumer thoughts on their advertisements or products.
Russell's recommended reading list in this area can be found at the Theme Zoom Bookstore. The current position Russell takes on Neuromarketing is that the market is getting more and more "self aware" about the manipulative tactics used by marketers who attempt to alter behaviors and responses in ways that feel invasive. Social media (especially private and personal "friend" networks) has created a safe environment for people to retreat to a "safer" environment where any attempt at direct marketing is violently opposed by the social network of friends.UPDATED: Facebook has been monitized much more since the original writing of this post, but the ads are targetted to causes and latent semantic indexing is used to target profile interests.
An understanding of online Social Media and online social behavior is coined Neurosocial behavior, but this is really just a fancy name for social psychology.
To see Russell's recommended reading list for Social Media and Neurosocial studies, visit the Neurosocial Media Section of the Theme Zoom Bookstore.
Also you may wish to listen to the Podcast by Sue Bell and Russell Wright about How Social Media Could Be Bad for Your Business.