But both Japanese and US investigators continue to examine and test the batteries to understand why they failed after they were integrated into the 787 electrical system and operated on commercial flights.
When researchers zero in on electrical activity in yet another area, they can tell which parts of commercial messages, if any, are encoded in the experimental subjects' long-term memories.
The Dreamliner is the first commercial aircraft to have extensive use of novel lithium-ion batteries, which can hold more electrical power in a smaller, lighter space.