No. It's a myth. Psychologist and neuroscientist Barry L. Beyerstein puts the (gray) matter to rest at Scientific American.com:
"With the aid of instruments such as EEGs, magnetoencephalographs, PET scanners and functional MRI machines, researchers have succeeded in localizing a vast number of psychological functions to specific centers and systems in the brain. With nonhuman animals, and occasionally with human patients undergoing neurological treatment, recording probes can even be inserted into the brain itself. Despite this detailed reconnaissance, no quiet areas awaiting new assignments have emerged."
