Indicia-reading systems that interface with a user's nervous system include a device with electrodes capable of detecting electromagnetic signals produced in the brain or skeletal muscles of a user. The systems also include a computer with a processor and memory. The computer is configured to monitor the electromagnetic signals that are detected by the electrodes. The computer is also configured to perform operations in response to certain monitored electromagnetic signals. The computer may be an indicia-reading device configured to acquire indicia information in response to certain detected electromagnetic signals. The computer may also be a vehicle-mounted computer configured to sound an alarm in response to certain detected electromagnetic signals.