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Biological Bases of Behaviors

Unit 2 Biopsychology Psychology 40S

C. McMurray

Source: David Myers Worth Publishers

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History of Mind

In 1800, Franz Gall suggested that bumps

of the skull represented mental abilities. His theory,

though incorrect, nevertheless proposed that

different mental abilities were

modular.

Phrenology

Bettm

an/ Corbis

Phineas Gage• In 1848, Phineas Gage, a

railroad worker was packing gunpower into a rock with a tamping iron. A spark ignited the gunpowder, shooting the rod up through his left cheek and out the top of his skull, leaving his frontal lobes massively damaged. To everyone’s amazement, Gage was immediately able to sit up and speak. Although his mental abilities and memories were intact, his personality was not. The soft spoken Gage was now irritable, profane and dishonest. Gage was no longer Gage.

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"You have brains in your head.You have feet in your shoes.

You can steer yourselfAny direction you choose.”

Watch video:

Human brain built for survival

http://videos.howstuffworks.com/discovery/6835-human-body-built-for-survival-video.htm

The Brain

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Older Brain Structures

The Brainstem is the oldest part of the brain, beginning where the spinal cord swells and enters the skull. It is responsible for automatic survival

functions.

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Brain Stem

The medulla is the base of the brainstem that

controls heartbeat and breathing.

The pons above the medulla are responsible

for sleep.

Reticular Formation is a nerve network in the

brainstem that plays an important role in

controlling arousal.

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Brain Stem

The Thalamus is the brain’s sensory

switchboard, located on top of the

brainstem. It directs messages to the

sensory areas in the cortex and transmits

replies to the cerebellum and

medulla.

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The “little brain” (cerebellum)

attached to the rear of the brainstem. It

helps coordinate voluntary

movements and balance.

Cerebellum

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The Limbic System is a doughnut-shaped system of neural structures at the

border of the brainstem and

cerebrum, associated with emotions such as fear, aggression and

drives for food and sex. It includes the hippocampus,

amygdala, pituitary gland and

hypothalamus.

The Limbic System

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Amygdala

The Amygdala consists of two almond-shaped

neural clusters linked to the emotions of fear and

anger.

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Hypothalamus

The Hypothalamus lies below (hypo) the thalamus. It directs several maintenance activities like eating,

drinking, body temperature, and

control of emotions. It helps govern the

endocrine system via the pituitary gland.

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The Cerebral CortexThe intricate fabric of interconnected neural cells

that covers the cerebral hemispheres. It is the body’s ultimate control and information processing

center.

brain map

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Structure of the Cortex

Each brain hemisphere is

divided into four lobes that are separated by

prominent fissures. These lobes are the

frontal lobe (forehead), parietal

lobe (top to rear head), occipital lobe

(back head) and temporal lobe (side

of head).

Brain Lobes

• The Frontal Lobes are involved in speaking and muscle movements and in making plans and judgments.

• The Parietal Lobes receive sensory input for touch and body position.

• The Occipital Lobes receive visual information from the opposite visual field.

• The Temporal Lobes receive auditory information primarily from the opposite ear.

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Functions of the Cortex

The Motor Cortex is the area at the rear of the frontal lobes that control voluntary

movements. The Sensory Cortex (parietal lobe) receives information from skin

surface and sense organs.

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The brain is sculpted by our genes but also by our experiences.

Plasticity refers to the brain’s ability to modify itself after some type of injury or

illness.

rubber hand illusionWatch the brain that changes itself

Ellen Degeneres rubber hand episode

The Brain’s Plasticity

The Split Brain Experiments

• In the 1960s, there was no other cure for people who suffered from a special kind of epilepsy than by cutting off the connection, corpus callosum, between the two hemispheres. This made it possible for the patients to live a normal life after the operation, and it was only when carrying out these experiments one could notice their somewhat "odd behavior.“

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Left HemisphereLanguageMathLogic

Right HemisphereSpatial abilitiesFace recognitionVisual imageryMusic