The Cerebrum: Lobes and Functional Areas

Key points

• • The cerebrum has two hemispheres, each divided by grooves into four lobes: frontal, parietal, temporal and occipital.
• • The central sulcus separates the frontal from the parietal lobe; the primary motor area lies just in front of it and the primary sensory area just behind it.
• • The body is mapped upside down along these strips (the homunculus), with the leg near the midline at the top and the face low down at the side.
• • The primary visual area is in the occipital lobe and the primary hearing area is in the temporal lobe.
• • In most people language sits in the left hemisphere: classically, Broca area in the frontal lobe helps produce speech and Wernicke area in the posterior temporal region helps understand it, though language depends on a wider network.
• • Damage to Broca area gives halting speech with preserved understanding, while damage to Wernicke area gives fluent but meaningless speech with poor understanding.