As I understand it, in Shibata & c.'s experiment subjects learned 'X' not by seeing 'X' or being told about 'X' but instead by generating the brain activation pattern of a person who knows 'X' and who learned 'X' in the customary way.
To generate the brain activation pattern of a person who knows 'X', subjects reacted to 'neurofeedback': a green circle indicating how close the subject's activation pattern was to the pattern produced by people who know 'X.' Subjects were able to change their brain firing by changing the green circle, and once their brains were firing the way brains fire when brains know 'X,' the subjects knew 'X,' too.
Without ever having seen or been told about 'X.'
For the record, I have experienced neurofeedback myself, and I can tell you that it works. Back in college, as the T.A. for a Learning and Memory course, I was once hooked up to electrodes and directed to produce alpha waves with my eyes open instead of closed (which is when we normally produce alpha waves). I was the demonstration project.
Obviously I had no idea how to produce an alpha wave on purpose, but after just a few minutes of neural feedback in the form of a tone that sounded every time my brain randomly produced an alpha wave, I was able to produce alpha waves intentionally.
I was able to turn the tone on and keep it on.
(Producing alpha waves with my eyes open, by the way, was not a particularly pleasant sensation. Producing alpha waves with my eyes closed was relaxing; producing alpha waves with my eyes open made me feel sleepy and semi-blind. Very strange.)
Ever since that day I've wondered why biofeedback, which is what it was called back then, never took off.
Articles & excerpts:
With an online-feedback method that uses decoded functional magnetic resonance imaging (fMRI) signals, we induced activity patterns only in early visual cortex corresponding to an orientation without stimulus presentation or participants’ awareness of what was to be learned.Related:
[W]e developed a functional magnetic resonance imaging (fMRI) onlinefeedback method, by which activation patterns corresponding to the pattern evoked by the presentation of a real and specific target orientation stimulus were repeatedly induced without the participants’ knowledge of what is being learned and without external stimulus presentation [see supporting online materials (SOM) and methods]. The mere induction of the activation patterns resulted in significant behavioral performance improvement on the target stimulus orientation, but not on other orientations.
Although previous fMRI online feedback training is a promising technique for influencing human behaviors (10–13), as in lesion or TMS studies, it could at best reveal influences of the entire extent of an area/region on learning/memory, which is a certain limitation for neuroscientific research (20). In contrast, the present decoded fMRI neurofeedback method induces highly selective activity patterns within a brain region, thus allowing the investigator to influence specific functions. It can “incept” a person to acquire new learning, skills, or memory, or possibly to restore skills or knowledge that has been damaged through accident, disease, or aging, without a person’s awareness of what is learned or memorized.
Perceptual Learning Incepted by Decoded fMRI Neurofeedback Without Stimulus Presentation by Kazuhisa Shibata,* Takeo Watanabe,*† Yuka Sasaki,‡ Mitsuo Kawato
In this study, we have shown that it is possible to directly condition neural activity using reward feedback derived from fMRI. Subjects were able to discriminate between two cues and respond to each by activating the appropriate region of their left sensorimotor cortex, while suppressing activity in a second region.
Direct Instrumental Conditioning of Neural Activity Using Functional Magnetic Resonance Imaging-Derived Reward Feedback
Signe Bray,1 Shinsuke Shimojo,1,2 and John P. O’Doherty1,3