UNIT II: THE HUMAN BRAIN

Goal Understand that different parts of the brain control different aspects of our behavior. Identify those major parts.

The Freshmen Brain

Inquiring minds wanted to know…

Franz Joseph Gall – 1st phrenologist Early 1800s…

The idea of “self” was in the brain and not in the soul or the heart. 1 st to suggest that different parts of the brain relate to specific functions “Gall” was not lost…

“The Curious Case of Phineas Gage” – Or – “Why you shouldn’t play with tamping rods” – Or – “How we came to love and understand the brain.” And now, a story:

Phineas Gage

While destroying a part of the brain may not kill you, it can affect you in a myriad of ways, not least of which your personality. – (hidden danger of concussions) Different areas of the brain really do affect different functions. What can we learn from Phineas?

If you watch reality TV it may seem like it, but no. -Sorry, “Lucy”, you wrong. You too, “Limitless”. Nearly every region of the brain lights up even during simple tasks like walking and talking. So, do we really only use 10% of our brain?

Evolutionary Psychologists: Our brain uses 20% of our body’s energy – No sense in throwing that much energy into something that is only minimally active. More evidence?

The proof is in your head! We can trace our ancestors through our brain structures. “Evolution is for Real!”

The following slides contain the “reptilian brain”, or the basic parts that function to keep any animal alive. Basically this is where the brain stops for most reptiles and lower intelligence creatures: The Reptilian Brain

Medulla At the top of the spinal cord controls vital reflexes, such as respiration, heart rate, and blood pressure.

Pons Helps coordinate movement Connects messages from spinal cord to brain Makes the chemicals involved in sleep

Midbrain The reward or pleasure center Stimulated by food, sex, money, music, attractive faces, and some drugs. Controls visual and auditory reflexes – like automatically turning your head towards a noise.

Cerebellum coordinates movement recognizes passage of time helps perform timed motor responses – like playing sports or games Also easily affected by alcohol, hence the term “tipsy”

Forebrain Most of this is made up of the “cerebrum”; largest part of the brain – has left and right hemisphere Each hemisphere controls many functions like: – learning, memory, speaking, emotions, thinking, planning, and feeling sensations.

The following slides contain lobes that distinguish more intelligent creatures from lesser animals. The following lobes are the outer most layer of cells of the brain, the part you see in TV and movie brain surgery. In humans, these areas are only 2-4mm thick! The Cerebral Cortex

Frontal Lobe Command center Performs voluntary movements, interprets and performs emotional behaviors, how to behave in social situations, your personality, making decisions, and planning. These are considered executive functions.

Parietal Lobe Processes sensory information from the body parts – including touching, locating positions of limbs, and feeling temperature and pain – also carries out cognitive functions like manipulating objects.

Occipital Lobe Processes visual information, including colors, perceiving and recognizing objects, animals, and people.

Temporal Lobe Involved in hearing, speaking coherently, understanding verbal and written material. (later we will discuss two very important speech disorders, Broca’s and Wernicke’s aphasia, which originates here)