Side by side
| Compared | Broca’s area | Wernicke’s area |
|---|---|---|
| Where it is | In the frontal lobe of the dominant hemisphere (usually the left): the pars opercularis and pars triangularis of the inferior frontal gyrus, just above the front of the lateral fissure (Brodmann areas 44 and 45). [1] | In the temporal lobe of the dominant hemisphere (usually the left): traditionally the back part of the superior temporal gyrus (Brodmann area 22), below the lateral fissure and behind the primary auditory cortex. Its exact borders are still debated. [2] |
| What it does | Linked to speech production; it also takes part in language comprehension and in processing grammar. [1] | Linked to understanding written and spoken language, as opposed to producing it. [2] |
| Connects with | Joined to Wernicke’s area by the arcuate fasciculus, a bundle of fibres arching round the back of the lateral fissure. [4][1] | Joined to Broca’s area by the arcuate fasciculus; it lies next to the primary auditory cortex in the same gyrus, which receives hearing signals relayed from the thalamus. [4][5] |
| Size measured from the model | Left inferior frontal gyrus (holds Broca’s area): 63 mm front to back, 60 mm top to bottom, 35 mm side to side [3] | Left superior temporal gyrus (holds Wernicke’s area): 106 mm front to back, 49 mm top to bottom, 43 mm side to side [3] |
Size is the box each part fits in on this one model (left inferior frontal gyrus (holds Broca’s area); left superior temporal gyrus (holds Wernicke’s area)), not its volume. Real brains vary. A part that comes as a left and a right copy is measured on its left copy; the right one mirrors it.
How far apart are they?
Measured from the model [3], from the left inferior frontal gyrus (holds Broca’s area) to the left superior temporal gyrus (holds Wernicke’s area):
- Centre to centre: 48 mm in a straight line.
- The centre of the left superior temporal gyrus (holds Wernicke’s area) is 43 mm further back, 19 mm lower and 8 mm further from the midline than the centre of the left inferior frontal gyrus (holds Broca’s area).
- Nearest points of the two shapes: under 1 mm apart.
A “centre” here is the average position of the points on the part’s 3D surface, so for a curved part such as a C shape it can sit outside the part itself. The nearest-points figure is measured between the corners of the simplified meshes, so a gap of 2 or 3 mm or less is within the model’s coarseness: read it as “touching or nearly so”.
How to tell them apart
- Each is named after the doctor who described it: Broca’s area after the French physician Pierre Paul Broca (1861), Wernicke’s area after the German neurologist Carl Wernicke (1874). [1][2]
- Frontal and above the lateral fissure is Broca’s; temporal and below it, further back, is Wernicke’s. On the 3D model, the orange gyrus runs along the lower lip of the fissure and the blue one sits above its front end. [6][1][2]
- “Broca’s area produces, Wernicke’s area understands” is the classic textbook model (the Wernicke–Geschwind model); later research found language spread over wider networks, with both areas taking part in more than one job. [7][1]