REGIONAL CEREBRAL BLOOD FLOW (RCBF RCBF): Regional cerebral blood flow monitoring may help boost the validity of the regional localization theory, in which specific parts of the brain control specific functions.. measure of the blood flow in a specific area of the brain, using positron emission tomography (PET scans) and/or single photon emission computed tomography.
If a dog goes on his back to you he is accepting you as his master. This is part of the answer but here's a little more in-depth version as reported by USA Today. In general, dogs lie on their back for three reasons.
A: Reading canine body language accurately can add tremendous value to a rehabilitation program. Spotting anxiety comes more easily. Owners are less likely to push a dog past what it can tolerate. However, contrary to popular belief, a wagging tail does not always mean a happy dog. It is just not possible to take one isolated behaviour and draw a conclusion. Extrapolating information in this fashion is similar to assuming that a spouse is lying because they looked away during a conversation.