Ch 5 The Research of Methods of Biopsychology

Question 1

Magnetic resonance imaging (MRI)

Answer 1

A structural brain imaging procedure in which high-resolution images are constructed from the measurement of waves that hydrogen atoms emit when they are activated by radio-frequency waves in a magnetic field.
-provide high spatial resolution Ability of a recording technique to detect differences in spatial location (e.g., to pinpoint a location in the brain).

Question 2

Contrast x-ray techniques

Answer 2

• X-ray techniques involve the injection into one compartment of the body a substance that absorbs x-rays either less than or more than the surrounding tissue. The injected substance then heightens the contrast between the compartment and the surrounding tissue during x-ray photography.
• one kind is cerebral angiography, uses the infusion of a radio-opaque dye into a cerebral artery to visualize the cerebral circulatory system during x-ray photography

Question 3

Optogenetics

Answer 3

• Opsins are light-sensitive ion channels that are found in the cell membranes of certain bacteria and algae. When opsins are illuminated with light, they open and allow ions to enter the cell. Depending on the particular opsin, light can either hyperpolarize or depolarize the cell membrane they are embedded in.
• A method that uses genetic engineering techniques to insert the opsin gene, or variants of the opsin gene, into particular types of neurons. By inserting an opsin gene into a particular type of neuron, a researcher can use light to hyperpolarize or depolarize those neurons.

Question 4

Lordosis quotient

Answer 4

The proportion of mounts that elicit lordosis.

Question 5

Electroencephalography (EEG)

Answer 5

• electroencephalogram (EEG) is a measure of the gross electrical activity of the brain. It is recorded through large electrodes by a device called an electroencephalograph (EEG machine), and the technique is called electroencephalography.
  -scalp EEG signal reflects the sum of electrical events throughout the head. These events include action potentials and postsynaptic potentials as well as electrical signals from the skin, muscles, blood, and eyes.
• EEG waveforms are associated with particular states of consciousness or particular types of cerebral pathology (e.g., epilepsy).
  -For example, alpha waves are regular, 8- to 12-per-second, high-amplitude waves that are associated with relaxed wakefulness.
• EEG signals decrease in amplitude as they spread from their source, a comparison of signals recorded from various sites on the scalp can sometimes indicate the origin of particular waves.
  -P300 wave The positive EEG wave that usually occurs about 300 milliseconds after a momentary stimulus that has meaning for the subject
  -Far-field potentials EEG signals recorded in the attenuated form at the scalp because they originate far away—for example, in the brain stem
  -Event-related potentials (ERPs) The EEG waves that regularly accompany certain psychological events.
  -One commonly studied type of event-related potential is the sensory evoked potential—the change in the cortical EEG signal elicited by the momentary presentation of a sensory stimulus.
  Signal averaging - A method of increasing the signal-to-noise ratio by reducing background noise.

Question 6

Cognitive neuroscience

Answer 6

A division of biopsychology that focuses on the use of functional brain imaging to study the neural mechanisms of human cognition.

Question 7

Token test

Answer 7

A preliminary test for language-related deficits that involves following verbal instructions to touch or move tokens of different shapes, sizes, and colors.

Question 8

Pavlovian conditioning paradigm

Answer 8

the experimenter pairs an initially neutral stimulus called a conditional stimulus (e.g., a tone or a light) with an unconditional stimulus (e.g., meat powder)—a stimulus that elicits an unconditional (reflexive) response (e.g., salivation). As a result of these pairings, the conditional stimulus eventually acquires the capacity, when administered alone, to elicit a conditional response (e.g., salivation)—a response that is often, but not always, similar to the unconditional response.

Question 9

Transcranial magnetic stimulation (TMS)

Answer 9

A technique that can be used to stimulate (“turn on”) or turn off an area of the cortex by creating a magnetic field under a coil positioned next to the skull.

Question 10

Operant conditioning paradigm

Answer 10

the rate at which a particular voluntary response (such as a lever press) is emitted is increased by reinforcement or decreased by punishment. One widely used operant conditioning paradigm in biopsychology is the self-stimulation paradigm. In the self-stimulation paradigm, animals press a lever to deliver electrical stimulation to particular sites in their own brains; those structures in the brain that support self-stimulation have often been called pleasure centers.

Question 11

Radial arm maze

Answer 11

A maze in which several arms radiate out from a central starting chamber commonly used to study spatial learning in rats.
At the end of each arm is a food cup, which may or may not is baited, depending on the purpose of the experiment.
- the foraging rat must learn and retain a complex pattern of spatially coded details. It must not only learn where morsels of food are likely to be found but must also remember which of these sites it has recently stripped of their booty so as not to revisit them too soon.

Question 12

Sodium amytal test

Answer 12

A test involving the anesthetization of first one cerebral hemisphere and then the other to determine which hemisphere plays the dominant role in language.
-involves injecting the anesthetic sodium amytal into either the left or right carotid artery in the neck. This temporarily anesthetizes the ipsilateral (same-side) hemisphere while leaving the contralateral (opposite-side) hemisphere largely unaffected. Several tests of language function are quickly administered while the ipsilateral hemisphere is anesthetized. Later, the process is repeated for the other side of the brain. When the injection is on the side dominant for language, the patient is completely mute for about 2 minutes. When the injection is on the nondominant side, there are only a few minor speech problems. Because the sodium amytal test is invasive, it can be administered only for medical reasons

Question 13

Functional MRI (fMRI)

Answer 13

• produces images representing the increase in oxygen flow in the blood to active areas of the brain.
• Functional MRI is possible because of two attributes of oxygenated blood. First, active areas of the brain take up more oxygenated blood than they need for their energy requirements, and thus oxygenated blood accumulates in active areas of the brain. Second, oxygenated blood has magnetic properties that influence the radio-frequency waves emitted by hydrogen atoms in an MRI.
• signal recorded by fMRI is called the BOLD signal (the blood-oxygen-level-dependent signal).
• fMRI technology has a poor temporal resolution, that is, it is poor at specifying the timing of neural events = Ability of a recording technique to detect differences in time (i.e., to pinpoint when an event occurred).

Question 14

dichotic listening test

Answer 14

A test of language lateralization in which two different sequences of three spoken digits are presented simultaneously, one to each ear, and the subject is asked to report all of the digits heard

Question 15

Plethysmography

Answer 15

refers to the various techniques for measuring changes in the volume of blood in a particular part of the body (plethysmos means “an enlargement”)

Question 16

Conditioned taste aversion

Answer 16

An avoidance response that develops to the taste of food whose consumption has been followed by illness.

Question 17

Default mode network

Answer 17

default mode - brain activity when humans sit quietly and let their minds wander—this level of activity has been termed the brain’s
Default mode network - Brain structures typically active in the default mode and less active during cognitive or behavioral tasks are collectively

Question 18

electrocardiogram (ECG or EKG)

Answer 18

• an electrical signal associated with each heartbeat can be recorded through electrodes placed on the chest. The recording is called an electrocardiogram
• The normal resting blood pressure for an adult is about 130/70 mm Hg. A chronic blood pressure of more than 140/90 mm Hg is viewed as a serious health hazard and is called hypertension (high blood pressure/chronic), measured with a sphygmomanometer—a crude device composed of a hollow cuff, a rubber bulb for inflating it, and a pressure gauge for measuring the pressure in the cuff (sphygmos means “pulse”).

Question 19

Plethysmography

Answer 19

refers to the various techniques for measuring changes in the volume of blood in a particular part of the body (plethysmos means “an enlargement”)

• One method of measuring these changes is to record the volume of the target tissue by wrapping a strain gauge around
• Another plethysmographic method is to shine a light through the tissue under investigation and to measure the amount of light absorbed by it. The more blood there is in a structure, the more light it will absorb.

Question 20

Repetition priming tests

Answer 20

Tests of implicit memory; in one example, a list of words is presented, then fragments of the original words are presented and the subject is asked to complete them.

Question 21

Digit span

Answer 21

The longest sequence of random digits that can be repeated correctly 50 percent of the time—most people have a digit span of 7.

Question 22

Electrooculography

Answer 22

A technique for recording eye movements through electrodes placed around the eye.
-is based on the fact that a steady potential difference exists between the front (positive) and back (negative) of the eyeball. Because of this steady potential, when the eye moves, a change in the electrical potential between electrodes placed around the eye can be recorded. It is usual to record EOG activity between two electrodes placed on each side of the eye to measure its horizontal movements and between two electrodes placed above and below the eye to measure its vertical movements

Question 23

Aspiration

Answer 23

A lesion technique in which tissue is drawn off by suction through the fine tip of a glass pipette.

Question 24

Constituent cognitive processes

Answer 24

Simple cognitive processes that combine to produce complex cognitive processes.

Question 25

Skin conductance response (SCR) & skin conductance level (SCL)

Answer 25

• Emotional thoughts and experiences are associated with increases in the ability of the skin to conduct electricity
• The SCL is a measure of the background level of skin conductance that is associated with a particular situation, whereas the SCR is a measure of the transient changes in skin conductance that are associated with discrete experiences
• there is considerable evidence implicating the sweat glands. Although the main function of sweat glands is to cool the body, these glands tend to become active in emotional situations, causing the release of sweat that in turn increases the electrical conductivity of the skin.

Question 26

Elevated plus-maze

Answer 26

An apparatus for recording defensiveness or anxiety in rats by assessing their tendency to avoid the two open arms of a plus sign–shaped maze mounted some distance above the floor.

Question 27

Species-common behaviors

Answer 27

Behaviors that are displayed in the same manner by virtually all like members of a species.

Question 28

Paired-image subtraction technique

Answer 28

The use of PET or fMRI to locate constituent cognitive processes in the brain by producing an image of the difference in brain activity associated with two cognitive tasks that differ in terms of a single constituent cognitive process.

Question 29

Computed tomography (CT)

Answer 29

is a computer-assisted x-ray procedure that can be used to visualize the brain and other internal structures of the living body. During cerebral computed tomography, the neurological patient lies with his or her head positioned in the center of a large cylinder, On one side of the cylinder is an x-ray tube that projects an x-ray beam through the head to an x-ray detector mounted on the other side. The x-ray tube and detector automatically rotate around the head of the patient at one level of the brain, taking many individual x-ray photographs as they rotate. The meager information in each x-ray photograph is combined by a computer to generate a CT scan of one horizontal section of the brain. Then the x-ray tube and detector are moved along the axis of the patient’s body to another level of the brain, and the process is repeated.

Question 30

Positron emission tomography (PET)

Answer 30

was the first brain-imaging technique to provide images of brain activity (functional brain images) rather than images of brain structure (structural brain images).

• In one common version of PET, radioactive fluorodeoxyglucose (FDG) is injected into the patient’s carotid artery (an artery of the neck that feeds the ipsilateral cerebral hemisphere). Because of its similarity to glucose, the primary metabolic fuel of the brain, fluorodeoxyglucose is rapidly taken up by active (energy-consuming) cells. However, unlike glucose, fluorodeoxyglucose cannot be metabolized; it therefore accumulates in active neurons—or in associated astrocytes—until it is gradually broken down
• PET scan is an image of the levels of radioactivity (indicated by color coding) in various parts of one horizontal level of the brain.
• PET technology is its use in identifying the distribution in the brain of molecules of interest (e.g., particular neurotransmitters, receptors, or transporters) This is readily accomplished by injecting volunteers with radioactively labelled ligands (ions or molecules that bind to other molecules under investigation)

Question 31

Gene knockout techniques

Answer 31

Procedures for creating organisms that lack a particular gene.

Question 32

Gene replacement techniques

Answer 32

• a gene is replaced with one that is identical except for the addition of a few bases that can act as a switch, turning the gene off or on in response to particular chemicals
• Pathological genes from human cells can be inserted in other animals such as mice—mice that contain the genetic material of another species are called transgenic mice
• transgenic mice by inserting a defective human gene that had been found to be associated with schizophrenia
• The transgenic mice displayed a variety of cerebral abnormalities (e.g., reduced cerebral cortex and enlarged ventricles) and atypical behaviors reminiscent of human schizophrenia.

Question 33

Cerebral dialysis

Answer 33

A method for recording changes in brain chemistry in behaving animals in which a fine tube with a short semipermeable section is implanted in the brain and extracellular neurochemicals are continuously drawn off for analysis.

Question 34

Cannula

Answer 34

A fine, hollow tube that is implanted in the body for the purpose of introducing or extracting substances.

Question 35

Mean difference image

Answer 35

In the context of functional neuroimaging, the average of the difference images (obtained via paired-image subtraction) obtained from multiple participants.

Question 36

2-deoxyglucose (2-DG) technique

Answer 36

• entails placing an animal that has been injected with radioactive 2-DG in a test situation in which it engages in an activity of interest. Because 2-DG is similar in structure to glucose—the brain’s main source of energy—neurons active during the test absorb it at a high rate but do not metabolize it. Then the subject is killed, and its brain is removed and sliced. The slices are then subjected to autoradiography:
• Autoradiography ( technique of photographically) they are coated with a photographic emulsion, stored in the dark for a few days, and then developed much like film. Areas of the brain that absorbed high levels of radioactive 2-DG during the test appear as black spots on the slides. The density of the spots in various regions of the brain can then be color-coded

Question 37

Intromission

Answer 37

Insertion of the penis into the vagina.

Question 38

Green fluorescent protein (GFP) & Brainbow

Answer 38

-is a protein that exhibits bright green fluorescence when exposed to blue light.
- general strategy is to activate the GFP gene in only the particular cells under investigation so that they can be readily visualized. This can be accomplished in two ways: by inserting the GFP gene in only the target cells or by introducing the GFP gene in all cells of the subject but expressing the gene in only the target cells.
- making minor alterations to the GFP gene resulted in the synthesis of proteins that fluoresced in different colors
Brainbow - A technique that uses multiple fluorescent proteins to label neurons with any one of many different colours. Such labelling permits a researcher to trace neural axons to their destinations through the cellular morass.

Question 39

Electromyography

Answer 39

A procedure for measuring muscle tension.

Question 40

Behavioural paradigm

Answer 40

A single set of procedures developed for the investigation of a particular behavioral phenomenon.

Question 41

Magnetoencephalography (MEG)

Answer 41

A technique for measuring changes in magnetic fields on the surface of the scalp that are produced by changes in underlying patterns of neural activity.

Question 42

Reversible lesions

Answer 42

Methods for temporarily eliminating the activity in a particular area of the brain while tests are being conducted.
-can be produced by cooling the target structure or by injecting an anesthetic (e.g., lidocaine) into it.

Question 43

Colony-intruder paradigm

Answer 43

A paradigm for the study of aggressive and defensive behaviours in male rats; a small male intruder rat is placed in an established colony in order to study the aggressive responses of the colony’s alpha male and the defensive responses of the intruder.

Question 44

Conditioned defensive burying

Answer 44

rats receive a single aversive stimulus (e.g., a shock, air blast, or noxious odor) from an object mounted on the wall of the chamber just above the floor, which is littered with bedding material. After a single trial, almost every rat learns that the test object is a threat and responds by flinging bedding material at the test object with its head and forepaws
- Antianxiety drugs reduce the amount of conditioned defensive burying, and thus the paradigm is used to study the neurochemistry of anxiety

Question 45

open-field test

Answer 45

the subject is placed in a large, barren chamber, and its activity is recorded
- common in the open-field test to count the number of boluses (pieces of excrement) that were dropped by an animal during the test. Low activity scores and high bolus counts are frequently used as indicators of fearfulness. Fearful rats are also highly thigmotaxic; that is, they rarely venture away from the walls of the test chamber and rarely engage in such activities as rearing and grooming. Rats are often fearful when they are first placed in a strange open field, but this fearfulness usually declines with repeated exposure to the same open field.

Question 46

Morris water maze

Answer 46

The rats are placed in a circular, featureless pool of cool milky water in which they must swim until they discover the escape platform—which is invisible just beneath the surface of the water. The rats are allowed to rest on the platform before being returned to the water for another trial. Despite the fact that the starting point is varied from trial to trial, the rats learn after only a few trials to swim directly to the platform, presumably by using spatial cues from the room as a reference. The Morris water maze is useful for assessing the navigational skills of brain-lesioned or drugged animals

Question 47

Stereotaxic surgery (stereotaxic atlas & Stereotaxic instrument)

Answer 47

• surgery is the means by which experimental devices are precisely positioned in the depths of the brain. Two things are required in stereotaxic surgery: an atlas to provide directions to the target site and an instrument for getting there
• stereotaxic atlas is used to locate brain structures, the brain has 3 dimensions, the brain is represented in a stereotaxic atlas by a series of individual maps, one per page, each representing the structure of a single, two-dimensional frontal brain slice. In stereotaxic atlases, all distances are given in millimeters from a designated reference point. In some rat atlases, the reference point is bregma—the point on the top of the skull where two of the major sutures (seams in the skull) intersect.
• stereotaxic instrument has two parts: a head holder, which firmly holds each subject’s brain in the prescribed position and orientation; and an electrode holder, which holds the device to be inserted.

Question 48

Wisconsin Card Sorting Test

Answer 48

A neuropsychological test that evaluates a patient’s ability to remember that previously learned rules of behavior are no longer effective and to learn to respond to new rules.

Question 49

In situ hybridization

Answer 49

A technique for locating particular proteins in the brain; molecules that bind to the mRNA that directs the synthesis of the target protein are synthesized and labeled, and brain slices are exposed to them.

Question 50

Immunocytochemistry

Answer 50

is a procedure for locating particular neuroproteins in the brain by labeling their antibodies with a dye or radioactive element and then exposing slices of brain tissue to the labeled antibodies. Regions of dye or radioactivity accumulation in the brain slices mark the locations of the target neuroprotein.

• immunocytochemistry can be used to locate neurotransmitters by binding to their enzymes.
• This is done by exposing brain slices to labeled antibodies that bind to enzymes located in only those neurons that contain the neurotransmitter of interest

Question 51

Diffusion tensor imaging

Answer 51

A magnetic resonance imaging (MRI) technique that is used for identifying major tracts.

Question 52

Transcranial magnetic stimulation (TMS)

Answer 52

is a technique that can be used to turn off an area of human cortex by creating a magnetic field under a coil positioned next to the skull. The magnetic stimulation temporarily turns off part of the brain while the effects of the disruption on cognition and behavior are assessed. TMS can also be used to “turn on” an area of cortex

Question 53

Transcranial direct current stimulation (tDCS)

Answer 53

is a technique that can be used to stimulate (“turn on”) an area of the cortex by applying an electrical current through two electrodes placed directly on the scalp. The electrical stimulation temporarily increases activity in part of the brain while the effects of the stimulation on cognition and behavior are assessed