ch 5-6

contrast x-ray technique

involves injecting into one compartment of the body a substance that obsorbs x-ray either less than or more than the surrounding tissue

then the substance heightens the constrast between the compartment and surrounding tissue

cerebral angiography

type of contrast x-ray technique

uses the infusion of a radiopaque dye into a cerebral artery to visualize the cerebral circulatory system

they are useful for localizing vascular damage as well as tumors

computed tomography (CT)

computer-assisted x-ray procedure that can be used to visualize the brain and other internal structures

x-ray tube (projecting x-ray beams to the head) and an x-ray detector rotate around the head taking individual x-ray photos as they rotate and are then combined to provide 3D representations of the brain

positron emission tomography (PET)

images of brain activity rather than brain structure

fluorodeoxyglucose(FDG) is injected in the carotid artery to be presented in the scan

each scan is an image of levels of radioactivity in various parts of one horiozntal level of brain

ligands

thorugh injecting radioactively labeled, researchers cna identify the distribution of molecules in the brain

magnetic resonance imegining (MRI)

structural brain-imaging procedure in which HD images are constructed from the measurement of radio-frequency waves that hydrogen atoms emit as they align with a powerful magnetic field

spatial resolution

MRI provides high…

ability to detect differences in spatial location, an MRI can produce 3D diagnosis

functional MRI (FMRI)

images representing the increase in oxygen flow in the blood to activate area of the brain

bold signal

blood-oxygen-level-dependent signal

signals recorded by FMRI

temporal resolution

FMRI has poor of this, meaning its poor at specifying the timing of neural events

diffusion tensor imagining

method of identifying pathway along which water molecules diffuse

provides imaging of major tracts, thus information about the connectomes(connections among structure)

transcranial magnetic stimulation (TMS)

technique that stimulates an area of the cortex by applying an electrical current through two electrodes placed directly on the scalp while assessing the effects on stimulation on cognition and behavior

electroencephalograohy

involves attaching electrodes to the scalp using an *EEG*

reflects the sum of electrical events including action potentials, postsynaptic potentials, and signals from the skin, muscles, blood and eyes

bc EEG waves decrease in amplitude as they spread, it is usual to record it from many sites of the skull simultaneously

event-related potentials (ERRPs)

psychological event that accompany EEG waves

sensory evoke potential

type of event-related potential which is the change in the cortical EEG signalelicited by momentary presentation of sensory stimulus

signal averaging

signal is the part of any recording that is of interest, the noise is the part that isnt

sensory evoke potentials are often hard to detect, thus can reduce the noise of the background EEG

P300 wave

positive wave that occur 300 milliseconds after a stimulus that has meaning for subject

far-field potential

small waves that are not influenced by meaning of stimulus bc they originate far in sensory muclei of the brain stem

magnetoencephalography (MEG)

measures changes in magnetic field on the surface of scalp that are produced by changes in underlying patterns of neural activity

muscle tension

different tension levels of muscle can indicate psychological arousal

electromyography

measures muscle tension using an electromyogram (EMG) that is recorded though 2 electrodes that are taped on surface of the skin over muscle of interest

electrooculography

records eye movement using an electrooculogram (EOG) that is recorded though electrodes placed around the eye

based on the fact that steady potential difference exists between the front and back of the eyeball

skin conductance level (SCL)

measures of general level of skin conductance thats associated with particular situation

skin conductance response (SCR)

measure of temporary, faster changes in skin conductance that are associated with discrete experiences

electrocardiogram (ECG)

records electrical signals associated with each heartbeat though electrodes places on the chest

average resting heart rate around 70bpm

blood pressure

measuring arterial blood pressure involves a measurement of peak pressure during periods of heart contraction, the systoles

and a measurement of minimum pressure during relaxation, diastoles

hypertension

chronic blood pressure more than 140/90mmHg

plethysmography

various techniques for measuring changes in blood volume of particular part of body

stereotaxic surgery

means by which experimental devices are precisely positioned in depth of brain, repuires an atlas to provide directions and an instrument to get there

stereotaxic atlas

used to locate brain structures by series of individual maps, each representing a single, two-dimensional frontal brain slice

bregma

point on the top of skull where two major sutures intersect

stereotaxic instrument

consisted of head holder that holds each subject’s brain in prescribed positions and orientations, and an electrode holder that holds the device

aspiration

lesions are made in an area of cortical tissue that accessible

reversible lesions

methods for temporarily eliminating the activity in particular area of brain while test are being conducted

produced by cooling the target structure or using anesthetics

advantage is that the same subject can be repeatedly tested in lesion and control conditions

unilateral lesions

restricted to one half of brain

milder than bilateral lesions, involving both sides of brain

although most experiments are bilateral

intracellular unit recording

records the membrane potential from one neuron as it fires

extracellular unit recording

records the electrical distribance that is created each time an adjacent neuron vires

microelectrodes in places in extracellular fluid next neuron

doent provide info on neuron’s membrane potential

multiple unit recording

small electrode records the action potential og many nearby neurons, then combined though an integrating circuit

invasive EEG recording

large implanted electrode that picks up general charges in electrical brain activity

cannula

drugs can be administered though a tube

intragastrically

injected into stomach

intraperitoneally

injected hypodermically into peritoneal cavity of abdomen

intramuscularly

large muscle

subcutaneously

fatty tissue beneath the skin

intravenously

into large surface vein

neurotoxins

neural poison

can make up for more selective lesions, having a likeness for certain components of nervous system

autoradiography

the slices

entails placing an animal that’s been injected with 2-DT to engage in an activity of interest, followed by killing the subject and removing and slicing its brain

cerebral dialysis

measures the extracellular concentration of specific neurochemicals

immunocytochemisrty

produre for locating particular neuroproteins in the brain by labeling their antibodies with dye or radioactive elements and then exposing slices of brain tissue to the labeled antibodies

can be used to locate neurotransmitters by binding to their enzymes

in situ hybridization

another technique for locating peptides and other proteins in the brain

gene knockout technique

produres for creating organisms that lack a particular gene under investigation

gene replacement technique

inserting pathological genes from human cells into other animals like mice

transgenic mice

mice containing genetic material of other species

gene fluorescent protein (GFP)

protein that exhibits bright green fluorescence when exposed to blue light

brainbow

pathway of neural axons could be traced to their destination

opsins

light sensitive ion channels that are found in cell membrane of certain bacteria and algae

optogenetics

inserting an opsin gene into type of neuron, so that a neuroscientist could use light to hyperpolarize or depolarize neurons

wechsler adult intelligence scale (WAIS)

first neuropscyhological assessment bc knowing a patient IQ can help neuropsychologists interpret the results of subsequent test and draw inferences about dysfunctions from the pattern of deficits on 15 subtests of the WAIS

digit span

used of short-term memory

token test

20 tokens of two shapes, two sizes, and five colors are placed in front of the patient where they listen to instructions from an examiner, and then read the instructions aloud and follow them

sodium amytal test

injecting anesthetic sodium amytal into either left or right carotid artery in the neck, which temporarily anesthetizes the ipsilateral (same-side) hemisphere while leaving the contralateral (opposite-side) hemisphere largely unaffected

tests for language function are administered while the ipsilateral hemisphere is anesthetized. Later, its repeated on the other side of the brain

dichotic listening test

three digits are presented on each ear at the same time, and then they are asked to report as many of the 6 digits as possible

repetition priming test

used to study patients that display severe deficits in explicit memory(patient aware of) but nothing in implicit memory(unconscious memory)

phonology

sound of language

syntax

grammer of language

semantics

meaning of language

wisconsin card scoring test

component of many customized test batteries bc performance on its sensitive to frontal lobe

cognitive neuroscience

complex cognitive process results from combined activity of simple cognitive processes called constituent cognitive processes

each constituent cognitive process is mediated by neural activity in a particular area of the brain

paired image subtraction technique

obtaining functional brain iamges during several different cognitive tasks

default mode

interpretation of difference images thats complicated by the fact that theres substantial brain activity when humans sit quiet and let their minds wander

mean difference image

emphasizes area of activity that are common to many volunteers and de-emphasizes areas of activity that are peculiar to a few of them

species common behaviour

displayed by virtually all members of species, or at least by all those of te same age and sex

open field test

subjects being placed in large chamber and its activity being recorded

thigmotaxic

fearful rats rarely venture away from walls of the test chamber and rarely egage in acitivities like grooming

colony intruder paradigm

when the behaviour of dominant male are considered to be aggressive and those of hapless intruder, defensive

elevated plus maze

used to study the anxiolytic (anxiety reducing) effects of drugs

lordosis

if the female is receptive to male’s mount

intromission

when male inserts his penis into female’s vagina

lordosis quotient

proportion of mounts that elicit lordosis

pavlovian conditioning paradigm

experimenter pairs an initially neutral stimulus called a conditional stimulus with an unconditional stimulus, a stimulus that elicits an unconditional response

operant conditioning paradigm

rate at which a particular voluntary response is emitted is increased by reinforcement or decreased by punishment

self-stimulation paradigm

widely used opent conditioning paradigm

pleasure centers

structures in the brain that support self-stimulation have been

conditioned taste aversion

avoidance response that develops to tastes of food whose consumption has been followed by illness

radial arm maze

used to study special abilties in maze of an array of arms, each arm containing a food cup that may or may not baited

morris water maze

studies the special abilities of rats, by replacing rats in a circular, featureless pool of cool milky water in which they must swim until they discover the scape platform

light

waves of electromahnetic energy between 390-769 nanometers in lenght

irises

amount of light reaching the retinas is regulated by donut-shped tissue, which give our eyes their colour

pupil

hole in the iris, light enters the though it

sensitivity

ability to detect the presence of dimly lit (bulanık) objects

acuity

ability to see details of objects

pupil size

in response to changes in illumination represents a comprimise between sensitivity and acuity

ciliary muscles

tension on the ligaments holding each lens in place is adjusted by it when we direct our gaze

refract

ciliary muscles increases the ability of lenses to bend light and bring close objects into sharp focus

when focusing on distant objects, the lens is flattened

accommodation

process of adjusting the configuration of the lenses to bring images into focus on the retina

binocular disparity

difference in position of the same image on the two retinas

grater for close objects than for distant objects

lateral communiation

amacrine cells and horizontal cells are specialized for communication across major channels of sensory input

fovea

indentation at the center of retina that is specialized for high acuity vision

only includes cons

surface interpolation

process by which we percive surface

visual system extracts info about th edges and from it infers the appearance of large surface

cones and rods

two types of receptors in human eye

high light levels and low light levels

produce a visual signal and saturated