Recoding DNA is pretty much impossible. The exact same DNA is inherent in every cell in your body. There is no way to "recode" or change the DNA sequence in all cells in your body.
Occasionally DNA does change, but it happens randomly in a cell or small group of cells and is due to a variety of events including exposure to toxic chemicals, too much sunlight (or UV rays), and some viruses.
Changing the DNA code in a cell is usually not regarded as something positive. Many, many cancers are caused by a very small change (or mutation) in just a very very small part of a piece of DNA in just one cell. The cell begins to grow and divide out of control and produces a tumor.
There are several scientific and medical machines that can read the electromagnetic waves that your brain produces. The most common of these is the EEG. The famous and "text-book" examples of EEG use are to examine the differences between different phases of sleep such as REM. Each phase of sleep produces a unique wave pattern that is similar between most people.
An MRI is very different from an EEG. And MRI uses radio frequencies and a very strong magnetic field to determine the different chemical structures that make up the matter in your brain. Based on this, sophisticated computer software is able to reassemble this data into a 3D picture of your brain.
"I'm going to end up in a rubber room calling myself the Mesiah of Cheese." -The Great Ashby
"never eat tatertots again. enjoy long, but overwhelmingly assy, cheese-free life."-Dan