It wasn't exactly spontaneous activation in the sense that people often expect. I still did not know all the information consciously, I was just able to get the answers for the tests, whether the questions were multiple choice, short answer or essay.
NLP training certainly played a big roll in activating in that it taught me to communicate with my unconscious and in doing so gave me verification that it was not only possible but that it was easy to do. The techniques where this ability came from were the Six Step Reframe, Integration Technique (variation of the Visual Squash,) and arm levitation as used in hypnosis. Though the yes/no signal in the Six Step Reframe can be in any modality I chose kinesthetic and without being taught had ideomotor movements for the signal. From there is was just a simple step from having a finger for "yes" and another for "no" to having one for each answer on a multiple choice test. For the other types of question relaxing and asking my unconscious for the answer worked well. Of course doing a short hypnosis session to get rid of any stress and program my mind to do well on the test also had an effect. For that part entering the Accelerated Learning State or using the Silva Method would also work. Interesting things are possible with the Silva Method and it is too bad I dismissed it back then since it wasn't NLP (yeah, I know that was stupid.) It would have been interesting to use in school. All these techniques will work even if you read and study normally.
If I did not know how to Photoread I would still have been able to use all those skills when taking tests, however, I would have had to read everything normally and it would have taken much longer. Had I actually used every step in the process it would probably have worked better but I wanted to Photoread the book and automatically know everything in it without doing the super reading and rapid reading steps.
In short, I don't think NLP is neccessary to learn Photoreading but if you have skills in NLP, hypnosis, or the Silva Method you will have a big advantage in using your unconscious mind.
