Read the following text and get ready to discuss it

Lesson 3 Brain research techniques

1. Study the following words:

Ablation [Wb ' leiGn] – ампутация, удаление

stimulation [@stimjL ' leiGn]– стимуляция

recording [ri ' kC:diE]– запись (сигналов)

chemicals [ ' kemiklz] – химические препараты

cortex [ ' kC:teks] – кора головного мозга

thalamus – таламус

2. Read the following word combinations and remember them:

markedly different – заметно отличающийся

computer axial tomography – компьютерная томография

positron tomography – позитронная томография

stages of sleep – стадии сна

3. Write the three forms of the following regular verbs and divide them into three groups according to the pronunciation of the ending -ed:

Study, group, use, obtain, try, function, involve, remove, map, determine, record, place, observe, produce, relate.

4. Write the derivatives to the following words:

To alter, to research, to remove, to observe, to activate

5. Make sure that you know all the words in the box. Then read their definitions and match the words with the definitions:

Cortex, alteration, experiment, function, activity, method, behaviour,

• Outer layer of grey matter of the brain;
• Way of behaving, good or bad manners, treatment shown towards others;
• Special activity or purpose of a person or a thing;
• Way of doing something, system, order;
• Test or trial carried out carefully in order to study what happens and gain new knowledge;
• Being active or lively;
• Act of changing;

6. Give the Russian equivalents of the following words and word combinations. Use your dictionary if necessary:

basic methods, brain researchers, to function dynamically, experimental technique, to activate electrically, visual functions, auditory functions, ablation, stimulation, recording, alternative method, stimulation through the implantation, selectively, to map out, motor functions, brain activity, remaining parts, a small tube, an alteration, specific portions of the brain.

The brain is studied primarily through three basic methods: ablation, stimulation, and recording. All three methods are used in conjunction with one another by brain researchers in order to obtain a picture of how various systems in the brain function dynamically in the mediation of specific behaviours.

Ablation is an experimental technique used only for animals. It involves selectively removing portions of the brain and trying to determine what the sum total of remaining parts can or cannot do. In this way, for example, it is possible to map out regions of the cortex responsible for auditory or visual functions or to determine which portions of the thalamus are involved in sensory or motor functions.

The stimulation technique involves placing small electrodes in specific portions of the brain and electrically activating them to observe the effect on some behaviour or performed tasks. An alternative method of stimulation is through the implantation of small tubes that can carry chemicals to specific regions of the brain. As in the case of ablation, stimulation produces an alteration in the normal functioning of the brain.

A third method, recording, is passive and produces the least change in ongoing cerebral activity. Recording involves placing recording electrodes in specific brain structures and observing the electrical activity of these regions as a function of different activities. It has been found, for example, that the electrical activity of the brain is markedly different during the various stages of sleep and certain aspects of learning and that it is related to intentional state.

Recent techniques for recording brain activity include computer axial tomography (CAT) and positron tomography (PET). These, coupled with EEC, are beginning to allow scientists to study the brain as it functions in normal activities.

Notes:

* EEG (electroencephalography) is a non-invasive method of brain imaging which records the electrical activity of the brain whilst a person is seated in a chair, wearing a cap containing electrodes which pick up electrical activity through the scalp.

*CAT (computer axial tomography) –is the process of using digital processing to generate a three-dimensional image of the internals of an object from a series of two-dimensional x-ray axial images. The individual x-ray axial slice images are taken using an x-ray tube that rotates around the object taking many scans as the object is gradually passed through the gantry. The multiple scans from each 360 degree sweep are then processed to produce a single cross-section. The word "tomography" is derived from the Greek tomos (slice) and graphia (describing).

*(PET) Positron emission tomography is a nuclear medicine medical imaging technique which produces a three-dimensional image or map of functional processes in the body. The system detects pairs of gamma rays emitted indirectly by a positron-emitting radioisotope, which is introduced into the body on a metabolically active molecule. Images of metabolic activity in space are then reconstructed by computer analysis, often in modern scanners aided by results from a CT X-ray scan performed on the patient at the same time, in the same machine.

8. Answer the following questions:

1. What are the three basic methods of brain studies?
2. What experimental technique is used only for animals?
3. Why ablation is used only for animals?
4. What research technique involves placing small electrodes in specific portions of the brain?
5. What is the alternative method of stimulation?
6. What research method is passive?
7. What is observed by recording?
8. What do recent techniques for brain recording include?
9. What do these techniques allow to the scientists?

9. Say whether the following statements are false or true:

1. Ablation, stimulation, and recording are the three basic methods of the brain study.

2. Ablation is the less dangerous experimental technique.

3. Ablation involves selectively removing portions of the brain.

4. The stimulationtechnique is a passive one.

5. The stimulationtechnique produces an alteration in the normal functioning of the brain.

6. An alternative method of stimulation is through the implantation of small tubes.

7. Recording means observing the electrical activity of specific regions of the brain.

8. Recording produces the least change in ongoing cerebral activity.

10. Finish the following statements according to the text:

1. The brain is studied primarily through three basic methods…
2. Ablationis an experimental technique …
3. With the help of ablation it is possible …
4. The stimulationtechnique involves …
5. An alternative method of stimulation is …
6. Like ablation stimulation produces an alteration …
7. Recording involves …
8. Recording is a passive technique, and it produces…
9. Recent techniques for recording brain activity include…

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