Modified PowerPoint from: Aneeq Ahmad -- Henderson State University.

Worth Publishers © 2007

●Can you…

●Describe the nervous system and its subdivisions

and functions:

○central and peripheral nervous systems;

○major brain regions, lobes, and cortical areas;

○brain lateralization and hemispheric specialization.

○We will do this today by discussing the lobes in notes

and applying the lobes to our brain mobiles

Accounts for about 80% of brain’s total mass and

does most of the sophisticated information

processing in the brain

Each brain hemisphere is divided into four lobes,

almost identical in each hemisphere, separated by

prominent fissures.

They are:

●frontal lobes (forehead)

●parietal lobes (top to rear head)

●occipital lobes (back head)

●temporal lobes (side of head)

The frontal lobe controls functions like:

●judgment

●planning

●producing speech sounds

●emotions (controlling them)

●personality

●temperament

●movement (motor cortex)

○Works w/the motor cortex to make precise

movements

In 1848 Gage was a respected, polite railroad foreman who

was working to clear a path on the rails.

As Gage was filling a hole with dynamite, it exploded sending

a rod (3 ft. long) into Gage’s head (entering beneath his left

eye and exiting through the top of his skull)

He survived the accident -- no speech or motor difficulties

and his memory was intact

BUT… his personality was greatly changed – he became

difficult to be around, short-tempered & often said

inappropriate things

○frontal lobed damaged…this prevented the censoring of

thoughts and ideas.

PHINEAS GAGE

PHINEAS GAGE

Homunculus ??

Largely responsible for the voluntary movement of the

parts of the body

(located in the back of the frontal lobe)

●if a part of the motor cortex

was electrically stimulated, it

would cause that body part to

move

●movements that are precise or

delicate are controlled by

considerably larger portions of the

motor cortex

Motor Homonculus

The parietal lobes control functions like:

●body position

●spatial reasoning like

○touch

○pressure

○temperature

○pain

●somatosensory cortex

Largely responsible for perceiving touch and

pressure on parts of the body

(located in the front of parietal lobe)

●if a part of the sensory cortex

was electrically stimulated, it

would cause the person to “feel”

pressure on that part of the body

●the more sensitive the area, the

greater area of sensory cortex

dedicated to it Sensory Homonculus

The temporal lobes control functions like:

●hearing (primary auditory cortex)

●storing long term memories

●speech and language

understanding

The occipital lobes control functions like:

●all aspects of vision(primary visual cortex)

●each piece of visual cortex

corresponds to a particular

place on the retina…receiving

only information from that

place…the pieces are later

put together to form the whole

Uncommitted (to sensory or motor functioning) areas of

the cortex that are involved in higher mental functioning

– these areas integrate, interpret & act on information

from the sensory/motor areas

Broca’s Area: in left frontal lobe

that directs muscle movements

involved in speech

Wernicke’s Area: in left temporal

lobe that is involved in language

comprehension and expression

●Write down the part of the brain each situation

is talking about…

○Low brain chemicals and an

underdevelopment in this area cause a person

to be a hermit who can’t play the social game.

They just seem odd to other people.

○Imprints on the inside of skulls belonging to the

supposed human ancestor Homo habilis

indicate that it was probably during this stage

of evolution that speech evolved. It’s found on

the left hemisphere of the brain, in the front

○A football player hits the back of his helmet on

the ground and experiences blurred vision.

Frontal

Lobe

Broca’s

Area

Occipital

Lobe

The two hemispheres are roughly mirror images

of one another…

The hemispheres communicate via

the corpus callosum…

●whatever occurs on one side

is communicated with the

other in a criss-cross

fashion (right hemi controls

left side of body & vise versa)

Females have thicker corpus callosums which

means…faster processing

Brain is sculpted by our genes but also by our

experiences…in other words, the more it is used,

the more connections are made!

If you don’t use it, you lose it!!

Plasticity refers to the brain’s ability to modify itself

after some type of injury or illness.

A procedure in which the two hemispheres of the brain

are isolated by cutting the connecting fibers (mainly those

of the corpus callosum).

Usually only performed in cases of severe epilepsy!

Corpus

Callosum

Martin M.

Rother

Courtesy of Terence Williams, University of

With the corpus callosum severed, objects

presented in the right visual field can be named.

Objects in the left visual field cannot. WHY???

Let’s see how your two hemispheres work

together…try drawing two shapes with both of you

hands simultaneously.

BB

C

Left hand… Right hand…

Why was that so difficult, even with an intact

brain????

https://www.youtube.com/watch?v=wfYbgdo8e-8

What you Need to Prove you Know

● What the split-brain patient is able to do when information

goes to each of the hemispheres

○ What can they do?

○ What can’t they do?