Definition of opacity for English Language Learners. : 1  the quality of a material that does not allow light to pass through it : the quality of being opaque. : 2  the quality of being difficult to understand or explain.
Research has shown that this is not true, and that brain cells can and do regenerate, especially in the areas related to learning, decision-making, visual recognition, and the way people perceive objects in space.weet. For a long time, scientists thought that it was impossible for brain cells to regenerate because they assumed that any new cells would disrupt the order of the brain.
For almost a century, scientists have believed that primate brains do not regenerate or add new neurons after maturity. It was a fundamental tenet of neuroscience that the brain could not repair itself or grow new cells.he cerebral cortex is responsible for higher level decision making and learning. The researchers found the formation of new nerve cells, a process called neurogenesis, in three areas of the cerebral cortex: 1  Prefrontal region which controls decision making.