Proposal: The spine tingler


What if the scary book you were reading could really shock you?

This piece of biofeedback-based experimental book art detects the rising fear or excitement in a reader and then amplifies it, by causing tingling in the hands through to mild electric shocks. This effect is created by a wrap-around book cover that can sense the physiological changes that occur when a person sustains fear or other arousal, and then responds by injecting a small electric current through the book jacket and into the hands. Alternatively, for safety, the book could contain a vibration motor that buzzes when activated.

The science

In essence, the book jacket acts as a lie detector. (Lie detectors don’t detect lies, but they do effectively measure increased activity of the sympathetic nervous system—the fight or flight response.) When you read something that excites you, your sympathetic nervous system ramps up leading to the galvanic skin response, in which the electrical resistance of the skin changes. The response kicks in with fear, anger, being startled, or sexual feelings.

When the device measures the increase, it switched mode to send an electrical current/vibration proportional to the level of sympathetic nervous system response through the book cover. It starts out feeling as a very slight tingling, increasing to enough of a shock/vibration that most people would naturally recoil from it, probably dropping the book.

How it works

The first stage of the Spine Tingler algorithm is to detect the galvanic skin response. This could be achieved by using a cloth cover with embedded conductive thread. [More advanced concept: Use of a home-made combination resistive and capacitive touch panel. It consists of one sheet of conductive polymer and two sheets of striated conductive polymer—conducting plastic—separated by a very thin sheet of non-conductive plastic. (The capacitive touch panel is similar in principle to the iPhone touch screen but not quite the same.)]

The first few minutes of holding the book are used for calibrating the resistance, which depends on the person and changes on time scales of hours or days. Just hope the literary shocks don’t come during calibration in the first few pages or the proper effects won’t be felt!

Once calibrated, the galvanic skin response is measured in detail, looking for small but consistent changes in resistance. The level of GSR is determined based on the resistance measured through the conductive thread. A heuristic algorithm will be required to detect the difference between changing the position of hands holding the book and actual changes in the GSR.

With the measurement of GSR made, the book can respond by either injecting a small current into the hands or, more likely, activating a vibration motor in the spine.

View Working notes on Hackpad.