The cerebral cortex is the cerebrum 's (brain) outer layer of neural tissue in humans and other mammals.It is divided into two cortices, along the sagittal plane: the left and right cerebral hemispheres divided by the medial longitudinal fissure.he cerebral cortex plays a key role in memory, attention, perception, awareness, thought, language, and consciousness. The human cerebral cortex is 2 to 4 millimetres (0.079 to 0.157 in) thick. In large mammals, the cerebral cortex is folded, giving a much greater surface area in the confined volume of the skull.