I. Freewrite
Take out a sheet of paper and write down what you already know about the brain. Make a list of the parts, if you know them, and describe what you know about how the brain functions.
II. Pre-Reading
Carefully read the following pages taken directly from chapter 3 of your text. This is a skeletal version of the chapter. ( It includes the introduction, title, subtitles, boldfaced words/phrases, visual aids, first sentence of each paragraph, summary). These are the parts of a chapter that provide us with the main ideas.
III. After the Pre-Reading
Answer as many of the Review Questions on pp. 87-88 (from the text book) as you can.
IV. Review the Vocabulary
Dominance — Either the right or left hemisphere is dominant in each individual; hence one of them is preferred and controls the majority of actions performed.
Cerebral cortex — The unit that covers the lower brain and controls mental processes such as thought.
Lower brain — Basic "animal" units common to animals and humans that regulate basic functions such as breathing
Thalamus — The portion of the lower brain that functions primarily as a central relay station for incoming and outgoing messages from the body to the brain and the brain to the body.
Cerebellum — The portion of the lower brain that coordinates and organizes bodily movements for balance and accuracy.
Hypothalamus — The portion of the lower brain that regulates basic needs (hunger, thirst) and emotions such as pleasure, fear, rage, and sexuality.
Reticular activating system/ reticular formation/RAS — The alertness control center of the brain that regulates the activity level of the body.
V. List the Facts under Main Headings
Hemispheres and Handedness
1. Ten percent of the population is left-handed.
2. Left-handedness does not seem to be inherited – at least not in the same sense as something like eye color, which follows a clear family pattern.
3. The genetic instructions that make the brain have got to be complex beyond imagination.
4. The intelligence of right-versus left-handed people is about the same; that is, there seems to be about the same number of bright average, and dull people in both groups.
5. Before going on, though, we should mention the myth that if a left –hander is forced by the parent to use the right hand in childhood, this may cause insanity. That’s not true.
Tasks of the Hemispheres
1. Scientists have wondered for hundreds of years about why the brain has two halves.
2. We have already mentioned that nerve fibers hold the two hemispheres together in a unit called the corpus callosum.
3. In the first experiment, using a woman with a split brain, her right hemisphere was shown a photo of a nude woman (the left hemisphere "saw" nothing).
4. It seems that the left hemisphere (for right-handers and most left-handers) handles verbal or speech material.
5. Before leaving this topic, we want to make a final comment.
The Cerebral Cortex and the Lower Brain
1. While we haven’t formally said so, all the parts discussed so far (hemispheres, lobes, frontal association area, and so forth) are part of the cerebral cortex.
2. No matter how fantastic it is, though, the cortex will not keep the body running. For that, we need a "lower" brain.
3. The Thalamus The term thalamus comes from the Greek word for "couch."
4. The Cerebellum The cerebellum looks like a ball of yarn a little larger than a golf ball, and it hooks onto the base of the brain below the visual or occipital lobe.
5. The Hypothalamus The hypothalamus (hypo means "below") sits below the thalamus.
6. The Reticular Activating System The reticular activating system, also called reticular formation, RAS for short, sits right at the base of the brain inside the spinal cord.
7. The RAS regulates how alert or how sleepy we are.
Summary
1. The upper outer covering of the brain is the cerbral cortex. The cerebral cortex is divided into two halves called hemispheres. The halves are connected through the corpus callosum. The left half controls the right side of the body and vice versa.
2. The cortex is divided into sections or lobes. The frontal lobe contains the motor strip, which controls movement, and the frontal association area, which integrates the environment and carries on complex analyses. The sensory strip, which controls sensation, is in the parietal lobe. Hearing and speech are functions of the temporal lobe. The occipital lobe organizes visual information.
3. The lower brain controls basic bodily activity. The thalamus is the relay station to and from the cortex and the lower brain. The cerebellum guides coordination and balance. The hypothalamus is part of a system controlling rage, pleasure, hunger, thirst, and sexual desire. The reticular activating system keeps us alert or puts us to sleep.
4. Parts of the brain are connected to one another through neurons. The neurons have electricity running from the dendrite through the cell to the axon and out to the synapse. The brain is also connected to the body through neurons. Communication through the synapses is actually handled by neurotransmitters, chemicals that regulate different systems such as muscle movement or the recognition of pain.
5. The endocrine system uses hormones to provide a longer lasting method of chemical communication than the neurons can provide. The pituitary is the master gland that guides growth, but it also signals the thyroid for metabolism, the adrenal glands for emergencies, and the gonads for sexual activity.
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