brainlocation

For learning, not medical advice.

All parts of the brain › Compare two parts › Frontal lobe vs prefrontal cortex

Frontal lobe vs prefrontal cortex: where is each, and what is the difference?

The prefrontal cortex is not a separate part next to the frontal lobe but the front part of it: the frontal lobe is the whole front of each hemisphere, ahead of the central sulcus, and the prefrontal cortex covers its front, behind the forehead. The rest of the lobe, toward the central sulcus, holds the motor areas; the prefrontal cortex is the association cortex for planning, judgement and controlling behaviour (executive function). [1][2]

The 3D brain needs JavaScript. The legend and the table below still say where each part is.

Slice

The frontal lobe is lit in blue, the prefrontal cortex in orange. Drag to turn, pinch or scroll to zoom; tap a part on the brain or in the legend to name it on its own; .

The prefrontal cortex is part of the frontal lobe, so the two cannot be lit as separate parts: orange is the model’s prefrontal cortex (the superior, middle and inferior frontal gyri and the orbital gyri) and blue is the rest of the frontal lobe, which on this model is only the precentral gyrus. Together the two colours are the whole frontal lobe. The real border lies further forward than this model can draw: the premotor cortex and supplementary motor area, at the back of the superior and middle frontal gyri just in front of the precentral gyrus, belong to the frontal lobe but not to the prefrontal cortex, yet here they fall inside the orange set. [2][1][3]

Measured from the model: the centre of the left prefrontal cortex is 52 mm from the centre of the left rest of the frontal lobe (its precentral gyrus) in a straight line [4].

Side by side

Compared Frontal lobe Prefrontal cortex
Where it isThe front of each cerebral hemisphere, in front of the parietal lobe (behind the central sulcus) and above the temporal lobe (below the lateral fissure); the largest lobe of the human brain. [1]The front part of the frontal lobe, ahead of the premotor cortex and the primary motor cortex. By the commonest definition it spans Brodmann areas 8–14, 24, 25, 32 and 44–47. [2]
What it doesAs a whole: the primary motor cortex and premotor areas control voluntary movement, and the lobe also holds Broca’s area for speech production and the prefrontal cortex for attention, planning and working memory. [1]Executive function: planning complex behaviour, decision-making, holding goals in working memory and adjusting social behaviour. [2]
Connects withIts motor cortex sends the corticospinal tract to the spinal cord; the lobe also holds most of the dopamine-sensitive neurons of the cerebral cortex. [5][1]Heavily connected with the rest of the cortex and the brainstem; one classic definition of the prefrontal cortex is the area that receives projections from the mediodorsal nucleus of the thalamus. [2]
Size measured from the modelLeft rest of the frontal lobe (its precentral gyrus): 66 mm front to back, 66 mm top to bottom, 62 mm side to side [4]116 mm front to back, 97 mm top to bottom, 61 mm side to side [4]

Size is the box each part fits in on this one model (left rest of the frontal lobe (its precentral gyrus); left prefrontal cortex), 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 rest of the frontal lobe (its precentral gyrus) to the left prefrontal cortex:

  • Centre to centre: 52 mm in a straight line.
  • The centre of the left prefrontal cortex is 49 mm further forward, 16 mm lower and 8 mm closer to the midline than the centre of the left rest of the frontal lobe (its precentral gyrus).
  • 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

  • Ask “is it the whole front, or only its front part?”: every bit of the prefrontal cortex is frontal lobe, but the frontal lobe also includes the motor strip (precentral gyrus), the premotor cortex and the supplementary motor area, which are not prefrontal. [2][1][3]
  • Pre- in prefrontal means in front of: the name says it lies at the very front of the frontal lobe. [2]

Sources

  1. Wikipedia: Frontal lobe
  2. Wikipedia: Prefrontal cortex
  3. Wikipedia: Premotor cortex
  4. BodyParts3D 4.0 (3D model measured on this page), © DBCLS, CC BY-SA 2.1 Japan
  5. Wikipedia: Primary motor cortex

Facts describe anatomy and normal function only. The 3D model is the adult male BodyParts3D brain (credits and licence); real brains vary in size and shape, so its measurements describe one model, not anyone’s brain. Compare other pairs.