Kapleau recounts how he was hooked up to a biofeedback machine that cost $200 (approximately $600 in 2014 dollars). He easily exceeded the parameter for relaxation. He gave his opinion of it: "You can achieve relaxation, and far more, with zazen--without spending two hundred dollars for a mechanical toy. Toys are for children not for adults!"
When asked his opinion of the claim that brainwave feedback could achieve results in far less time than traditional meditation, he exclaimed: "You must be kidding! Even if one is able while "plugged in" to ease into a relaxed state, this hardly brings deeper calm or inner peace of mind; it does not answer fundamental questions of existence; it does not transform one's life in any real way, all of which Zen awakening does" (p. 39). His last dismissive comment on the subject: "One who regularly plugs into a machine to relax loses the ability to act out of his own deepest resources and instead of being master of the machine becomes its slave. This is not Zen. Zen develops freedom, not neurotic dependence" (p. 40).
Kapleau sounds rather cranky, but he raises some interesting issues that may be relevant at this time when a new generation of meditation devices and apps is emerging. At the time that he wrote, the aim of the use of then available technology was primarily relaxation through enhanced alpha wave production. More ambitious agendas are likely to be pursued in present and future time with greater sophistication in targeting brainwaves at specific sites. But does the essence of his critique still stand? Can technology provide a shortcut on the path of awakening. Is the quantification available with these technologies a diversion from simply meditating? Will reliance on these technologies create an unhealthy dependency? If there is a valid role for these technologies, is there a tipping point beyond which they become a hindrance rather than an aid?