Brain Damage & Behavior

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Localized Brain DamageRemember Phineas Gage? In

the 1800s, a rod was shot through his head.

The doctor was amazed that he survived the

accident. While talking to the doctor, part of his

brain fell out.

When he recovered, people said Phineas didn’t act like himself anymore. His behavior

and personality had changed.

Localized Brain Damage

Phineas is an early case study for localized brain damage: damage that affects only a certain area of the brain.

Localized damage is commonly associated with an injury in which the head strikes or is struck by an object.

The opposite of localized brain damage is diffuse brain damage: damage that covers a widespread area in the brain (this is slightly less common). Diffuse brain damage is usually due to the damaging or death of brain tissue.

Localized Brain DamageDamage to the frontal lobe:

Generally, damage to the frontal lobes causes loss of the ability to solve problems and to plan and initiate actions, such as answering a complex question. The frontal lobe also helps govern personality,

impulsivity, and our ability to tell good from bad. If damaged, a person may find he cannot control his anger or aggression. He may also make inappropriate comments to friends or strangers not realizing they are

inappropriate.

When did he become so rude

and socially inappropriate?

Localized Brain DamageDamage to the middle back part of the left frontal lobe (Broca’s area) causes people to have difficulty expressing themselves in words. They comprehend what people are saying and think clearly, but cannot make

comprehensible speech leave their mouths.

Localized Brain DamageDamage to the parietal lobe:

Affected people have difficulty identifying a sensation's location (where pain is coming

from) and type (if they are feeling something hot or cold). People may have difficulty

recognizing objects by touch. If the middle part is damaged, people can’t tell right from left and have problems with calculations and

writing. They may have problems sensing where parts of their body are. If the right parietal lobe is damaged, people may be

unable to do simple tasks, such as combing their hair or dressing. They have trouble

understanding space, and as a result may get lost in their own neighborhood.

Localized Brain DamageDamage to the temporal lobe:

Part of the left temporal lobe controls language comprehension. If that part is damaged, memory for

words can be drastically impaired. If certain areas of the right temporal

lobe are damaged, memory for sounds and music may be impaired. As a result, people may have trouble singing. Sometimes damage can cause

personality changes such as humorlessness, extreme religiosity,

and obsessiveness. Those affected may not be able to control

their feelings or to think clearly. HUMORLESS

Localized Brain DamageWernicke's area is located where the

temporal lobe and frontal lobe meet. Like Broca’s area, it is involved in speech

production. If someone has damage in this area, they comprehend what people are saying and think clearly, but they speak in gibberish, usually not knowing that they

are producing incorrect words.

Video 1: Broca’s Aphasia

Video 2: Wernicke's Aphasia

Localized Brain DamageDamage to the occipital lobe:

The occipital lobe contains the main center for processing visual information. If the

occipital lobe on both sides of the brain is damaged, people cannot see, even though the eyes themselves are functioning normally. If

the front part is damaged, people have difficulty recognizing familiar objects and faces

and accurately interpreting what they see.

http://www.merckmanuals.com

StrokeA stroke is the loss of brain function due to a lack of blood-supply to the brain. It can be caused by clotted (blocked) blood vessels, internal bleeding in the brain,

or other complications that arise as side-effects of certain diseases. After a stroke, the affected area of the brain

cannot function normally.

1 in 6 people worldwide will have a stroke in their lifetime

TumorTumors in the brain can put pressure on certain areas,

causing brain damage similar to the kinds that results from a traumatic brain injury. Language and communication, emotion

and personality, learning and memory, attention and concentration, and intellectual abilities can all be affected in

negative ways. A tumor is an abnormal tissue growth.