Cerebral Cortex

• A region of grey matter that forms the outer rim of the cerebrum
• Consists of lots of folds, called gyri
• Longitudinal fissure separates the cerebrum into right and left halves called cerebral hemispheres
• Each cerebral hemisphere is split into four lobes named after the bones that cover them, so frontal, parietal, temporal and occipital lobes
• Within each cerebral cortex are sensory, motor and association areas.

Sensory areas:

Primary somatosensory area – Located directly posterior to the central sulcus in each parietal lobe. Receives nerve impulses for touch, pressure, vibration, itch, tickle, temperature, pain and proprioception

Primary visual area – Located on the posterior tip of the occipital lobe. Receives visual information and is involved in visual perception

Primary auditory area – Located in the superior part of the temporal lobe. Involved in auditory perception

Primary gustatory area – Located in the parietal cortex. Receives impulses for taste and is involved in taste discrimination

Primary olfactory area – Located on the medial aspect of the temporal lobe. Receives impulses for smell and is involved in olfactory perception

Motor areas:

Primary motor area – Located directly in front of the central sulcus (in the precentral gyrus) in each frontal lobe. Controls voluntary contractions of specific muscles or groups of muscles (internally generated movements)

Broca’s speech area - Located in the frontal lobe only in the LEFT cerebral hemisphere. Involved in the articulation of speech eg the coordinated contractions of your speech and breathing muscles in order to allow you to speak. A stroke in this area will result in a person still having clear thoughts but unable to form words (non-fluent aphasia)

Association areas:

Somatosensory association area - Parietal lobe.

Allows you to determine the exact size and shape of an object by feeling it, determine where one body part is in relation to another, storage of memories of past somatic sensation, enabling you to recognize objects simply by touching them

Visual association area - Occipital lobe

Relates present and past visual experiences so that you can recognise what you see

Wernicke’s area - Broad region in only the LEFT temporal and parietal lobes

Allows you to interpret the meaning of speech by recognising spoken words

Stroke in this area means people can still speak but cannot arrange words in a coherent fashion (fluent aphasia)

Prefrontal cortex - Anterior portion of the frontal lobe

Personality, intellect, complex learning abilities, recall of information, initiative, judgement, foresight, reasoning, conscience, intuition, mood, planning for the future and development of abstract ideas.

Premotor areas - Immediately in front of the primary motor area

Deals with learned motor activities of a complex, sequential nature.

Generates nerve impulses that cause specific groups of muscles in contract in a specific sequence.