Research Methods --- Charting the Brain's Inner Realms

Question 1

Computed tomography (CT)

Answer 1

A radiographic technique for quickly producing detailed, three-dimensional images of the brain or other soft tissues. An X-ray beam is passed through the tissue from many different locations, and the different patterns of radiation absorption are analyzed and synthesized by a computer. Because a CT scan produces many slice-by-slice pictures of the head, chest, or abdomen, it is possible to locate abnormalities, such as lesions or tumors, without exploratory surgery.

Question 2

Magnetic resonance imaging (MRI)

Answer 2

A noninvasive diagnostic technique that uses the responses of hydrogen in tissue molecules to strong magnetic impulses to form a three-dimensional picture of body organs and tissues.

Question 3

Localization of function

Answer 3

The concept that specific parts of the cerebral cortex are relatively specialized for particular types of cognitive and behavioral processes. Also called cortical localization.

Question 4

Clinical case study

Answer 4

A detailed investigation of a single person, especially one suffering from some injury or disease.

Question 5

Neurological soft signs

Answer 5

Subtle behavioral signs of brain dysfunction, including clumsiness, an awkward gait, poor hand-eye coordination, and other perceptual and motor problems.

Question 6

Electrical stimulation of the brain (ESB)

Answer 6

electrical stimulation of the brain (ESB)

Question 7

Electrode

Answer 7

An instrument with a positive-pole cathode and a negative-pole anode used to stimulate biological tissues electrically or record electrical activity in these tissues.

Question 8

Ablation

Answer 8

The removal or destruction of part of a biological tissue or structure by a surgical procedure (e.g., mechanical or laser excision) or a toxic substance (e.g., chondroitinase), usually for treatment or to study its function.

Question 9

Deep lesioning

Answer 9

Removal of tissue within the brain by use of an electrode.

Question 10

Microelectrode technique

Answer 10

Intracellular microelectrodes with tips less than 1 lm in diameter are able to stimulate and record activity within a single neuron.

Question 11

What kind of information do CT and MRI provide?

Answer 11

They are used to visualize the internal structures of the body.

Question 12

Electroencephalograph (EEG)

Answer 12

A method of studying brain waves using an instrument (electroencephalograph) that amplifies and records the electrical activity of the brain through electrodes placed at various points on the scalp.

Question 13

Positron emission tomography (PET)

Answer 13

An imaging technique that results in a computer-generated image of brain activity, based on glucose consumption in the brain.

Question 14

Are more active brains better?

Answer 14

Using PET scans, psychologist Richard Haier and his colleagues first found that the brains of people who perform well on a difficult reasoning test consume less energy than those of poor performers. Haier believes this shows that intelligence is related to brain efficiency: Less efficient brains work harder and still accomplish less

Question 15

Functional magnetic resonance imaging (fMRI; functional MRI)

Answer 15

A form of magnetic resonance imaging used to localize areas of cognitive activation, based on the correlation between brain activity and blood property changes linked to local changes in blood flow to the brain. During periods of cognitive activation, blood flow is always increased to a greater extent than oxygen extraction. In consequence, the proportion of oxygenated hemoglobin in the red blood cells transiently increases in an active region, leading to a local increase in the signal detected by fMRI.

Question 16

Confabulation

Answer 16

The falsification of memory in which gaps in recall are filled by fabrications that the individual accepts as fact. It is not typically considered to be a conscious attempt to deceive others. Confabulation occurs most frequently in korsakoff’s syndrome and to a lesser extent in other conditions associated with neurologically based amnesia (e.g., Alzheimer’s disease). In forensic contexts, eyewitnesses may resort to confabulation if they feel pressured to recall more information than they can remember.