Center for Neurotechnology Studies Director Prof. James Giordano, PhD, says neurofeedback "brain games" can be lots of fun - but warns they're not for everybody. As Dr. Giordano points out, the market has seen an explosion of products that claim to harness the power of the brain for a variety of purposes. Neurofeedback uses sensors which, when placed in contact with the head, are able to pick up electrical output caused by brain activity. The signals may be input to a computer that translates them into a display, or - in games and toys - another device that uses them to power simple actions such as moving a ball. Dr. Giordano says neurofeedback is safe and valuable when used in a clinical setting. But when used as a toy, he says the potential for harm is not fully known. He warns the devices should not be used by people with psychological or emotional disorders or conditions, and may not be ideal for children, either. Click below to hear comments by Dr. Giordano on the "brain games" craze.