HERE’s a mind-bending idea: The US military is paying scientists to study ways to read people’s thoughts. The hope is that the research could someday lead to a gadget capable of translating the thoughts of soldiers who have suffered brain injuries on the battlefield. The research also raises concerns that such mind-reading technology could be used to interrogate the enemy. Armed with a $4 million grant from the Army, scientists are studying brain signals to try to decode what a person is thinking and to whom the person wants to direct the message. But scientists say it is still too early for the technology to be of practical use to the military.