Psych 3224 Chapter 3

Front 1

angiography

Back 1

Clinical imaging method used to evaluate the circulatory system in the brain and diagnose disruptions in circulation.Helps visualize blood distribution by highlighting major arteries and veins. Dye injected into vertebral or carotid artery, followed by X ray

Front 2

Cerebral vascular accidents (strokes)

Back 2

Occur when blood flow to the brain is suddenly disrupted

Front 3

Brain Lesions

Back 3

Result from tumours

Front 4

Tumor/ neoplasm

Back 4

Mass of tissue that grows abnormally and has no physiological function

Front 5

Traumatic Brain Injury (TBI, 2 types)

Back 5

closed/ open head injury

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Open Head Injury

Back 6

When an object penetrates the skull

Front 7

Closed Head Injury

Back 7

object does not penetrate/ shatter skull

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epilepsy

Back 8

Condition characterized by excessive and abnormally patterned brain activity

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Single Dissociation

Back 9

Participants being selectively impaired on only one of the two memory tests. When two groups are each tested on two tasks, a between group difference is apparently in only one task

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Double Dissociation

Back 10

Identifies whether two cognitive functions are independent of each other, something a single association can’t do

Front 11

Callosotomy or split brain procedure

Back 11

Procedure in which the fibres of the corpus callosum are severed. The two hemispheres are disconnected

Front 12

Deep Brain Stimulation (DBS)

Back 12

Technique in which electrodes are implanted in the basal ganglia. Devices produce continuous electrical signals that stimulate neural activity

Front 13

Pharmacological Studies

Back 13

Involve the administration of agonist drugs, those that have a similar structure to a neurotransmitter and mimic its action, or antagonist drugs, those that bind to the receptors and block or dampen neurotransmission

Front 14

Transcranial Magnetic Stimulation (TMS) mechanism

Back 14

Non-invasive method used to stimulate neurons in the intact human brain. A quick electrical current is generated over a targeted region. This causes a magnetic field that causes the neurons in the underlying region to discharge

Front 15

Transcranial Direct Current Stimulation (tDCS)

Back 15

Non-invasive method in which a low voltage electrical current is created across the brain by applying two electrodes to the scalp. (Depolarizes neurons at the anodal end, while hyperpolarizing neurons at the anodal end)

Front 16

Knock-out procedure

Back 16

specific genes are manipulated so that they are no longer present or expressed

Front 17

CT/CAT Scans

Back 17

Non-invasive neuroimaging method that provides images of internal structures such as the brain. It is an advanced version of the conventional X-ray. Former allows a 3-D image to be made, while the latter compressed the image into 2-D

Front 18

MRI

Back 18

A neuroimaging technique that exploits the magnetic properties of organic tissue. Certain atoms are sensitive to magnetic forces (due to # of protons + neutrons) and their orientation can be altered by the presence of a strong magnetic field. A radio frequency causes the alignment of the atoms to be messed up. When it is stopped, the atoms realign again, which gives off a radio frequency signal that is picked up by detectors. Structural MRI measures the variations in the density of hydrogen while fMRI measures the the changes over time in the signal intensity of the target atom.

Front 19

DTI

Back 19

a neuroimaging technique employed using an MRI scanner that allows white matter pathways in the brain to be imaged. (Isotropic: diffusion of water occurs in all directions. Anisotropic: restricted diffusion of water→ water diffusing in only one direction→ ex: down the axon)

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Neurophysiology

Back 20

the study of the physiological process by the nervous system. Characterizing the activity of the nervous system by both chemical and electrical methods

Front 21

Single-Cell Recording

Back 21

Neurophysiological method used to monitor the activity of individual neurons. IT requires a small recording electrode either inside a cell or (more typically) near the outer membrane of a neuron). Electrode measures electrical potentials

Front 22

Receptive Field

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The area of external space within which a stimulus that must be presented in order to activate the cell

Front 23

Retinotopy

Back 23

topographic representation in the nervous system that reflects spatial properties of the environment in an eye-based reference frame

Front 24

Cochleotopy

Back 24

topographic representation in the nervous system that reflects frequency properties of sound in a hearing reference frame

Front 25

Multiunit recording

Back 25

A physiological procedure in which an array of electrodes is inserted in the brain such that the activity of many cells can be recorded simultaneously

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Single-cell Recording

Back 26

recording electrical activity of single neuron (patch-clamp electrophysiology usually)

Front 27

Electroencephalography

Back 27

measured non-invasive electrical activity throughout the brain, usually an average - requires reference anode (usually at base of mastoid bone).

Front 28

Event-related Potential (def'n, notation)

Back 28

evoked response from a stimulus, seen a brain activity. Notation used is N100 (for Negative, relative to initial and 100 ms delay), etc. Used to diagnose diseases (such as MS), where time to response (ERP) is tested. Best used for time-course of cognition rather than localizing functional areas of brain.

Front 29

Time-frequency Analysis

Back 29

characterizes two-dimensional EEG signals (amplitude + frequency). Allows for amplitude rather than solely frequency to be used to characterize changes in EEG signal (often related to ERPs)

Front 30

Magnetoencephalography

Back 30

Similar to EEG but uses magnetic fields (perpendicular to electrical signal) to detect electrical activity in the brain. Requires anti-magnetic chamber since it is very sensitive. Can only detect flow that is parallel to surface of skull - usually detects sulci based neurons because of this.

Front 31

Electrocorticogram

Back 31

EEG but invasive. Used on animals (or humans during nsgy only)

Front 32

Positron Emission Tomography

Back 32

measures variations in blood flow. Requires radioactive tracer (O15 usually) which is monitored via x-ray machine. Due to radioactivity only certain # of studies can be done/patient - leads to problems with case studies and doing follow-up hypotheses.

Front 33

Regional Cerebral Blood Flow

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localized change within blood volume in a certain region of the brain

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Voxel

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3D volume of the brain (5-10 mm^3) => used in MRI

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PiB

Back 35

Biomarker used to characterize beta-amyloid plaque buildup using PET scan

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BOLD

Back 36

ratio of oxygenated:deoxygenated blood - this measure is dependent on the blood oxygen level of the brain region in question

Front 37

Block Design Experiment

Back 37

experiment where patient is given alternating stimulus/task over a “block” of time (usually PET studies or fMRI studies)

Front 38

Event-Related Design

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BOLD response being linked to specific events (usually done with fMRI only since fMRI can detect immediate changes over seconds rather than the required minutes for PET)

Front 39

block design experiment

Back 39

An experiment where a participant performs a task (or is presented a stimulus) and their neural activity is recorded and integrated during this “block” of time. It may be later compared to other “blocks” of time that have been recorded while the participant performs either the same, different or no task/stimulus.

Front 40

event-related design

Back 40

A paradigm used in fMRI studies where the BOLD response across experimental trials is linked to specific events such as the onset of a movement or the presentation of a stimulus. This design is obtained by averaging over repetitions of these events as metabolic changes to any single event are harder to detect.

Front 41

functional connectivity

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When data from an fMRI study can be used to ask whether the activation changes in one brain area are correlated with activation changes in another brain area. It can be used to describe networks associated with particular cognitive operations and the relationships among nodes within those networks

Front 42

brain graph

Back 42

A visual model of brain organization and the connections within some part of the nervous system. The model is made up of nodes, which are the neural elements, and edges, which are the connections between neural elements

Front 43

Optogenetics

Back 43

when an opsin protein (transmembrane protein that changes conformation in response to light, opening a channel) is artificially spliced into a neuron of interest to fire an AP... good for finding function of certain regions

Front 44

infarct

Back 44

necrotic region of brain tissue

Front 45

2 types of stroke

Back 45

1) Ischemic: foreign matter blocking artery

2) Hemmorhagic: blood vessel bursts

Front 46

thrombus vs embolus

Back 46

T: foreign matter blocking vessel at it's origin

E: foreign matter (like fatty tissue) breaks off and travels thru bloodstream, blocking somewhere downstream (i.e. in a capillary)

Front 47

common symptoms after CHI

Back 47

- memory difficulties

- difficulty in abstract thinking

- distractibility

- loss of mental speed

- easily fatigued

Front 48

in Glasgow Coma Scale, a (higher/ lower?) score indicates unconsciousness

Back 48

LOWER

<9 total score is considered SEVERE head injury (25% of returning to normal f(x))

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coma

Back 49

no evidence of awareness, can't communicate, doesn't open eyes, no sleep-wake cycle

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vegetative state

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same as coma, but shows a sleep-wake cycle (sometimes eyes open but unaware)

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minimally conscious state

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capable of awareness and purposeful action but only intermittently

Front 52

locked-in syndrome

Back 52

cortical f(x) and awareness are normal but brainstem injury prevents almost all motor output... communicates w/ eye movements

Front 53

disorders of consciousness (4)

Back 53

1) coma

2) vegetative state

3) minimally conscious state

4) locked-in syndrome

Front 54

TBI increases risk of (3)

Back 54

1) post-traumatic epilepsy

2) future head injuries

3) Alzheimer's disease (2-3x)

Front 55

Classification of tumors (3)

Back 55

1) Gliomas

2) Meningiomas

3) Metastatic tumors (form somewhere else)

Front 56

3 types of seizures (& brief characterization)

Back 56

1) Grand mal (lose consciousness and fall => rhythmic jerking)

2) Petit mal (lose consciousness and don't fall... looks like they're spacing our => 10s)

3) complex partial (smell burnt toast? lol)

Front 57

subtraction principle

Back 57

used in PET

- assume that the two comparisons tasks differ in only ONE KEY COMPONENT