PSYB65 Lecture 2
• Oldest parts of brains are in the back, deal with most primitive aspects and
functions, as we evolved we built on these functions and took on more
important function and specialized functions. The front of the brain is the
most advanced, the emotional area of the brain, feels anger and hatred and
• Anatomic representation of the brain, the globes and divide them into lobes.
Cover what they are, what they do, how they are organized.
• The cortex of the brain of rats are very smooth, contrasted to human brains
where they grow large and squish into one another. Folds into itself.
• Sulci are the valleys, indentations to tell us where we are in the brain, where
one thing ends and one thing begins.
• Gyrus (gyri) are the mountains. If the sulcus is very deep and prominent, it is
called a fissure. Deep.
• Human brains have two hemispheres, most of them are symmetrical.
• The brain is divided by the longitudinal fissure, seperate the left and right
brain. Connected at the bottom by the fiber pathways.
• Sensory information comes into the brain, and motor information going out
from the brain.
• Everything is crossed, left hand side of your universe, goes to your right
brain. Right hand side of your universe, goes to your left brain.
• Left brain controls right hand, right brain controls left hand etc.
• Corpus callosum, connects the two sides of the brain, the two hemispheres.
Connects the right to the left. The two portions speak to one another.
• The central fissure/sulcuss. Prominent groove that separates two brain areas.
Sulculs in the central brain.
• Sylvian fissure: large fissure on the side.
• The cortex is divided into major core sections. Divided into lobes. Four of
them on each side
○ Frontal lobe: begins at the very anterior portion of your brain, the very
front of your brain, continues backward to the central sulcus. Deals
with motor functions, output part of the brain. Motor movement, gets
things moving. Involves planning of movement too, since as humans
we have much more complicated processes. Plans your whole life,
what to do to get there. When you have frontal lobe damage, you lose
the awareness of what to do and how to get there. What’s appropriate
for you to go where you want to go.
Inhibition of inappropriate behaviour
Precentral gyrus: this is the primary strip, where the main strip of movement is
done. Everything else is associational. All information goes out from associational to
primary strip. Associational are the consults. Primary motor strip has the homunculus. The little man in the brain (body then hands and feet). The sensory
cortex also has one They are in front of one another, so they are not side by side.
The motor strip homunculus controls the movement and use of these limbs, while
the sensory cortex is the perception. Motor cortex does not have a humuculous area
for the genitals, cannot really move them. While the sensory cortex humuculous
does have perception for the genitals, and thus an area. Humuculous adhere to the
cross hemisphere notion where right side brain damage indicates a problem with
left side of body and vice versa. Brodman’s area 4 and 6.
Central sulcuss seperates the frontal lobe and parietal lobes.
post central gyrus.
○ Parietal lobe: starts at the central sulcus, and moves backward since
the primary ends at the central sulcus. Responsible for sensations from
the body. Somatosensory input. Everything under than the special
senses of the eyes or ears. Moving your toes goes into the parietal
cortex. Sensation of feeling is from stimulation of those neurons from
there. The primary strip is in the postcentral gyrus. Little mountain
after the central fissure. It starts at the postcentral gyrus and the
primary sensory strip is also there. Brodmans for association 1,2 and 3.
Primary sensory stirp also has the humunculous
• The humunculous is the little man, areas of sensory information with regards
to your whole body. Starts off with the feet, toes and hands. Lips areo n the
• What body portion is af