QUIZ FRIDAY (10/14): 104-111: Phineas Gage, Prefrontal Cortex, Brain Lobes, and Aphasias

Phineas Gage

In 1848, railroad worker Gage had a railroad spike shoot through his skull and take out part of his frontal lobe (specifically the prefrontal cortex).

He had trouble holding a job afterwards and his friends said that "Gage was no longer Gage." He had lost his social inhibitions, he was vulgar, rude, impatient, and inconsiderate.

His lost part of his prefrontal cortex, where decisions and planning for the future take place

Prefrontal Cortex

The "Central Executive" in charge of "executive functions"- self control, maintaining emotional control (regulates emotion from the amygdala), planning, decision making, problem solving, judgement - these things make up your personality

The anterior (front) part of the frontal lobe

Cerebral Cortex

The top, wrinkled surface of the brain

A thin (1-mm) layer of densely packed neurons

This top layer is divided into four lobes

This layer covers the rest of the brain, including most of the structures we have described

Lobes of the Cerebral Cortex

Lobe areas of the cerebral cortex: frontal, parietal, temporal, occipital

Know this brain map

Accidents

Early psychologists studied accidents as a way to investigate brain function

Accidents resulting in injuries to specific brain areas (such as the Phineas Gage case study) helped psychologists get an idea about the function of each part of the brain

Autopsies after death also provide important brain research information

Frontal Lobes

Located at the top front part of the brain behind the eyes

The anterior (front) part of THIS is called the prefrontal cortex (PFC)

Parietal Lobes

Helps with you knowing where things are and where you are: Integrates sensory info, spatial awareness, and navigation of the space around you

ALSO: Contains the sensory cortex (also known as the somatosensory cortex)

Damage to it could cause hemineglect (visual neglect)

Located on the outside layer of the cerebral cortex

Occipital Lobes

Located at the very back of our brain on the cerebral cortex, farthest from our eyes. One of the major functions of this lobe is to interpret messages from our eyes in our visual cortex.

Impulses from the right half of each retina are processed in the visual cortex in the right lobe. Impulses from the left part of each retina are sent to the visual cortex in our left lobe.

Broca's Aphasia (nonfluent aphasia)

Damage to THIS area in the left hemisphere will cause the affected person to be unable to speak fluently and to speak haltingly

Non-fluent aphasia

When describing the story about her stroke, Sarah Scott could only say "Stroke.... English class .... Book..." It looked like she didn't know the answer, but in reality she really couldn't match the answer with words.

Association Area

Any area of the cerebral cortex that is not associated with receiving sensory information or controlling muscle movements

Motor Cortex

The vertical strip at the back of the frontal lobe on the cerebral cortex

This part of the cerebral cortex sends signals to our muscles, controlling our voluntary movements

Visual Cortex

Impulses from the retinas in our eyes are sent here to be interpreted.

Part of the occipital lobe on the cerebral cortex

Temporal Lobes

Process sound sensed by the ears on the cerebral cortex

Sound waves are processed by the ears, turned into neural impulses and interpreted in the auditory cortices.

Broca's Area

This area helps us speak FLUENTLY and coordinate the muscle movements for speech, so damage to this area (aphasia) would cause someone to lose language fluency

Language is in the left hemisphere

Area is located in the frontal lobe

Wernicke's Area

THIS area is in the temporal lobe and is involved in the ability to UNDERSTAND the meaning of sensory information

If this was damaged (aphasia) the person would speak in a "word salad" - lots of words but you couldn't understand what they were saying

Language is in the left hemisphere

This is located in the temporal lobe

Auditory Cortex

In the temporal lobes on the cerebral cortex

This cortex is not lateralized like the visual cortices are. Sound received by the left ear is processed in the cortex in both hemispheres.

Wernicke's Aphasia (fluent aphasia)

condition resulting from damage to THIS area in the left hemisphere, will cause the affected person to be unable to understand or produce meaningful language

When asked what are you doing today, the elderly stroke victim said "we stayed with the water over here at the moment and talked with the people of them over there, they're diving for them at the moment with they'll savor the moment they'll have water very soon" (word salad)