Monitor

From Orson Scott Card Wiki

The monitor is used by the International Fleet to screen children who might make good students at Battle School. Generally this monitor is left in for less than three years. The longer a monitor is used the more dangerous it is when removed.

The monitor is placed in the back of the neck, and supposedly screens nervous impulses in the spinal column, which can be studied to determine a person's true personality. The International Fleet used the monitors to watch promising children and decide whether they had the right traits for Battle School.

[edit] References

Ender's Game "Chapter 1: Third"