EEG data from mental concentration task

This experiment has 20 subjects. Subjects asked to mentally concentrate on 

a target (see published article for more information) for periods of about 

15 seconds.

There are 4 verbal instructions given to subject by an automated computer

program connected to a speakerphone:

- The instruction is to wait until the experiment starts

- The instruction is to relax

- The instruction is to get ready as the trial is about to start

- The instruction is to mentally concentrate on the target

All the experiment is performed eye's closed. Relax periods last for about

9 seconds, are then followed by a period of 6 seconds where the participants

is asked to "get ready" for the trial, followed by a period of 15 seconds of

concentration. This sequence is repeated 20 times for each participant.