To finish up our discussion of Premotor Cortex, let's go back to a discussion of where
in the brain premotor cortex is located. One of the minigames planned for Escaping Titan is conceptually similar to the old "Operation" home electronic game that humorously mimics a surgical procedure (often gone terribly wrong!) in which players identify and "surgically remove" body parts. While Escaping Titan will not exactly require deft manipulation of the "funny bone" or "water on the knee" it will be important to have a general knowledge of the anatomical locations of the various brain regions involved in "hacks" or specific applications of Synapse Stimulant Implants.
To start with, I'm going to include what I consider to be a very poor diagram of the Premotor Cortex:
Why do I consider this a bad image? Well, for starters, McGraw Hill should be ashamed of themselves. The premotor area is huge and takes in most of the prefrontal cortex. The prefrontal area is about one-third what it should be. The visual cortex is shrunken, the lobes are not marked, and hardly any functions are noted for the temporal lobe.
The following figure used in last month's blog is much better:
Premotor cortex lies just in front of the primary motor cortex, and is about the same width as the motor area. Most of the area tagged as premotor in the first diagram is really prefrontal association area, and while it may be partially involved in motor planning, it is mostly involved in integration of information used to make decisions that will eventually be used to plan movement – but are at several steps removed from the movement itself.
Some important landmarks are the Frontal Eye Fields
involved in visual searching (about where the line from the text "Premotor cortex" intersects the light blue shading. Just "south" or down from that point is the area that controls hand-eye coordination. This is conveniently located adjacent to the hand region of Motor Cortex and Frontal Eye Fields. Opposite the face/mouth/tongue motor areas at the lowermost extent of Motor Cortex is Broca's Area
responsible for spoken language. In fact, the entire area of the Sylvian Fissure
along the margins of the Frontal, Parietal and Temporal lobes (see below) is involved in language – from Wernicke's area (which should be a little higher in the image below) which processes hearing and reading language – to Broca's area which processes heard and read language into speech.
I like this diagram of the lobes of the brain for another reason – while it identifies the major lobes of the brain, it also distinguishes the primary input-output region for the body: Somatosensory Cortex
for input and Motor Cortex
for output. It's worth noting that the Central Sulcus
, the line dividing Somatosensory and Motor cortex is really a dividing line for input and output in the brain as a whole – the structures behind (right) the Central Sulcus are involved in information input (hearing, touch, vision, smell, taste) while structures in front (left) of the Central Sulcus are involved in physical output (speech, movement, decisions and expressions of emotion, reason, personality).
This finishes our section on Premotor Cortex. Next month we'll move on to Hypothalamus and discuss normal functions as well as the in-game settings for Healing SSIs.
Keep using (and protecting) your brain, it's the only one you've got!