Side by side
| Compared | Frontal lobe | Temporal lobe |
|---|---|---|
| Where it is | The front of each hemisphere: in front of the central sulcus and above the lateral fissure; the largest of the four lobes. [1][5] | The lower side of each hemisphere, below the lateral fissure, behind the temple and above the ear; it rests in the middle cranial fossa of the skull. [2][6] |
| What it does | Its precentral gyrus is the primary motor cortex, which sends the commands for voluntary movement; Broca’s area (usually on the left) produces speech; the prefrontal cortex plans, decides and holds information in working memory. [1][7][8] | Its superior temporal gyrus holds the primary auditory cortex; Wernicke’s area (usually on the left) understands language; the fusiform gyrus recognises faces; the hippocampus inside it forms long-term memories. [2][9][10][11] |
| Connects with | The corticospinal tract runs from its motor cortex down to the spinal cord; the arcuate fasciculus links Broca’s area to Wernicke’s area in the temporal lobe. [12][13] | Sound arrives from the medial geniculate body of the thalamus; the uncinate fasciculus hooks from its front end round to the orbital surface of the frontal lobe. [14][15] |
| Size measured from the model | 130 mm front to back, 97 mm top to bottom, 63 mm side to side [4] | 114 mm front to back, 60 mm top to bottom, 61 mm side to side [4] |
Size is the box each part fits in on this one model (left frontal lobe; left temporal lobe), 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 [4], from the left frontal lobe to the left temporal lobe:
- Centre to centre: 58 mm in a straight line.
- The centre of the left temporal lobe is 35 mm further back, 44 mm lower and 17 mm further from the midline than the centre of the left frontal lobe.
- 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
- The lateral (Sylvian) fissure is the dividing line on the side of the brain: frontal lobe above its front part, temporal lobe below. Pull its lips apart and a fifth lobe, the insula, lies hidden in the depth. [3][16]
- Hearing sits in the temporal lobe, not the frontal lobe: the primary auditory cortex lies on the upper surface of the superior temporal gyrus, partly inside the lateral fissure. [9][17]