LanguageLanguage• AphasiaAphasia is an is an impairment of languageimpairment of language, ,

usually caused by left hemisphere usually caused by left hemisphere damage either to damage either to Broca’s areaBroca’s area (impaired (impaired speaking) or to speaking) or to Wernicke’s areaWernicke’s area (impaired understanding).(impaired understanding).

Broca’s Area Broca’s Area Receives impulse from Receives impulse from

Wernicke’s Area and Wernicke’s Area and converts it into motor converts it into motor commands. commands.

Damage: disrupts Damage: disrupts speakingspeaking

Person Person can understand can understand languagelanguage

Words may not be properly Words may not be properly formed formed

Speech is slow and slurred.Speech is slow and slurred. Patients may get frustrated Patients may get frustrated

because because they know they know that that something is wrong.something is wrong.

Wernicke’s AreaWernicke’s Area The area in our brain that allows The area in our brain that allows

understandingunderstanding of spoken and written of spoken and written language. language.

It is the It is the part that enables a person part that enables a person to interpret languageto interpret language, so damage to , so damage to this part causes the person to become this part causes the person to become unaware of his own speech and the unaware of his own speech and the speech of others.speech of others.

Sometimes the person can speak Sometimes the person can speak clearly, but the words that are put clearly, but the words that are put together make no sense. This way of together make no sense. This way of speaking has been called speaking has been called "word salad" "word salad" because it appears that the words are because it appears that the words are all mixed up like the vegetables in a all mixed up like the vegetables in a salad.salad.

Might use complete nonsense words.Might use complete nonsense words. Often Often not aware not aware of their problem.of their problem.

Examples of Aphasia – Examples of Aphasia – Broca’s and Wernicke’s Broca’s and Wernicke’s

AreaArea Broca’s AreaBroca’s Area

http://www.youtube.com/watch?v=f2IiMEbMnPM

http://www.youtube.com/watch?v=1aplTvEQ6ew&feature=fvw

Wernicke’s AreaWernicke’s Area http://www.youtube.com/watch?http://www.youtube.com/watch?

v=dKTdMV6cOZw&feature=related v=dKTdMV6cOZw&feature=related http://www.youtube.com/watch?http://www.youtube.com/watch?

v=aVhYN7NTIKU&feature=related v=aVhYN7NTIKU&feature=related

The Cerebrum:The Cerebrum:_____ Hemispheres, _____ _____ Hemispheres, _____

LobesLobes Cerebral HemispheresCerebral Hemispheres – two specialized – two specialized

halves connected by the halves connected by the corpus corpus callosumcallosum. .

Left hemisphereLeft hemisphere – – verbal processingverbal processing: language, : language, speech, reading, writingspeech, reading, writing

Right hemisphereRight hemisphere – – nonverbal processingnonverbal processing: : spatial, musical, visual recognitionspatial, musical, visual recognition

The Corpus Callosum: The Corpus Callosum: communication between communication between

hemisphereshemispheres If you were to pull the two halves of the brain apart If you were to pull the two halves of the brain apart along the fissure, about midway down you would see a along the fissure, about midway down you would see a bundle of fibers called the bundle of fibers called the corpus callosumcorpus callosum. . This bundle of fibers is made up of several This bundle of fibers is made up of several millionmillion myelinated myelinated

axons and it is what allows each half of the brain _____________ axons and it is what allows each half of the brain _____________ with the other half.with the other half.

Split-BrainSplit-Brain

Doctors severed the corpus callosum Doctors severed the corpus callosum of patients with epileptic seizuresof patients with epileptic seizures Seizures all but eliminated Seizures all but eliminated Patients now have Patients now have split brainssplit brains How did this surgery impact their How did this surgery impact their

personality and intellect?personality and intellect? ..

It’s Opposite Day!It’s Opposite Day! Each hemisphere controls the Each hemisphere controls the oppositeopposite

side of the body. The left hemisphere side of the body. The left hemisphere controls movement and sensation on the controls movement and sensation on the right side of the body, and the right right side of the body, and the right hemisphere controls the left side of the hemisphere controls the left side of the body.body.

When it comes to our vision, this is a When it comes to our vision, this is a little different. Our eyeballs are little different. Our eyeballs are basically divided into two halves, one basically divided into two halves, one half from each eye sends information to half from each eye sends information to one half of our brain. one half of our brain.

Because the two halves of our brains Because the two halves of our brains communicate, we end up understanding communicate, we end up understanding the whole picture instantly.the whole picture instantly.

Split-BrainsSplit-Brains

Read on page 84 -85 – Examine Read on page 84 -85 – Examine DiagramsDiagrams

Right Brain/Left Brain: Right Brain/Left Brain: Visual InputVisual Input

Split Brain PatientsSplit Brain Patients

With the corpus callosum severed, objects (apple) With the corpus callosum severed, objects (apple) presented in the right visual field can be named. presented in the right visual field can be named.

Objects (pencil) in the left visual field cannot.Objects (pencil) in the left visual field cannot.

Divided ConsciousnessDivided Consciousness

Try This!Try This!

Try drawing one shape with your left hand Try drawing one shape with your left hand and one with your right hand, and one with your right hand,

simultaneously.simultaneously.BBC

Watch this man’s experiments in action! http://www.youtube.com/watch?v=ZMLzP1VCANo

Hemisphere Dominance Hemisphere Dominance and “Handedness”and “Handedness”

Hemisphere Dominance:Hemisphere Dominance: Many psychologists believe that a person can be “Right-Many psychologists believe that a person can be “Right-

brain dominant” or “left-brain dominant,” where that brain dominant” or “left-brain dominant,” where that side of their brain tends to influence them more than side of their brain tends to influence them more than the other the other

Take the dominance quiz to see your results.Take the dominance quiz to see your results.

““Handedness”Handedness” – – Lefties- The right hemisphere Lefties- The right hemisphere dominatesdominates, so odds are , so odds are

they will be better at and deal more with their right they will be better at and deal more with their right hemisphere. This increases the chances that they will do hemisphere. This increases the chances that they will do well in art, music, architecture, etc. well in art, music, architecture, etc.

Righties- The left hemisphere Righties- The left hemisphere dominatesdominates, so odds are , so odds are they will be better at and deal more with their left they will be better at and deal more with their left hemisphere. This increases the chances that they will do hemisphere. This increases the chances that they will do well in verbal activities, debate, logic, writing, etc. well in verbal activities, debate, logic, writing, etc.

There is no real evidence for “right-brain” or There is no real evidence for “right-brain” or “left-brain” people, or handedness for that “left-brain” people, or handedness for that matter…but it is still interesting to consider!matter…but it is still interesting to consider!

Figure 3.16 Structures and areas in the human brain

RecapRecap

For more information, see http://serendip.brynmawr.edu/bb/kinser/Structure1.html

Figure 3.19 The cerebral cortex in humans