The cerebral cortex is the part of the brain that sets humans apart from and above all other animals. This sector is primarily responsible for interpreting information sent by the senses such as sight, sound, smell and touch as well as initiating voluntary directed action such as walking or talking. Although most mammals, even small animals such as rats, possess the important surface layer called the "new cortex" or neocortex, it is most highly developed in the human brain. Strikingly, the fundamental building structures of the neocortex such as neurons and supporting cells are the same throughout the animal kingdom. Both humans and rats have the same type of neurons, which are comprised of the same basic type of genetic constitution. The distinguishing characteristic between the brain of a human and any other animal is found in the surface area of the neocortex. Disproportionately large in humans compared to other animals, the neocortex appears to grant the privilege of higher mental abilities. These higher processes include such intellectual pursuits as planning, reasoning, and problem solving. Some scientists believe that the neocortex is linked to self-awareness and consciousness.