methodology Flashcards
what is trephination
-drilling through skull
-one french burial site found 40 trephinated skulls but this was not the cause of death
what is leucotomy
Egas Moniz
-inspired by research on chimps and war victims
-frontal lobe tissue destroyed via hole in skull through eye socket or an alcohol injection to destroy parts of frontal lobe
-predominantly women and first women cured of depression in 1935
-won a nobel prize
what is trans orbital lobotomy
Freeman (inspired by Moniz)
-ice pick through orbital socket
-performed in office takes only a few mins
-1960 Howard Dully received a lobotomy after step mother was tired of his youthful defiance
why do these methods seek to disrupt the frontal lobe
because it can change someone’s personality e.g make them more agreeable and calms them down
what is the stereotaxic apparatus
-great advance in brain study
-used to precisely insert recording electrodes into specific regions
-uses X Y Z coordinates and 3D space
-early 20th century but developed 1947-72
-most widely adopted version invented by Russell Brown
-used to create lesions on animals
-implants electrodes into brain
-either stimulates or records electrical activity
what is neurosurgery
surgical treatment of any part of the NS
-intracranial electroencephalography (iEEG) (electrophysiological monitoring via electrodes placed on surface of skull/brain)
-neural implants (device that connects to brain directly to stimulate, inhibit or record neurons- used to treat strokes etc)
-deep brain stimulation DBS (treats disabling neurological cond. e.g parkinsons)
what is histology
-used more with animals in vivo or in vitro
-study of microanatomy of cells and tissues
-study with humans: after death (remove and fix brain, cut with microtome, immunohistochemical staining)
what are brain lesions
age related white matter disease (wearing away of brain tissue)
-Ischemia: insufficient blood flow to brain, poor O2 supply and cell death
-encephalitis: inflammation of brain tissue due to infection or autoimmune disease
what are the three subsections within brain imaging, recording and stimulating
structural images
functional images
stimulating
what are the methods that produce structural images
computed tomography CT
magnetic resonance imaging MRI
what is MRI
STRUCTURAL
-magnetic fields and pulses of radio frequency
-provides pics of organs/structures
-magnetic fields act on H+ atoms in body and radio frequency disrupts this pattern
-when turned off this change can be detected and reconstructed to images
what is CT
STRUCTURAL
-formally known as CAT scan
-measures density of brain tissue using X rays to generate 3D structure
what are the methods that produce functional images
positron emission tomography PET
functional resonance images FMRI
electroencephalography EEG
magnetoencephalography MEG
what is PET
FUNCTIONAL
-metabolic activity
-radioactive positron (+ charge) emitting substance injected into blood
-positrons collide with electrons in tissues
-images reconstructed from photon detector array
-increases blood flow to active brain areas
-more collisions = more activity
what is FMRI
FUNCTIONAL
-based on MRI
-oxygenated and deoxygenated blood respond differently in magnetic field
-increased demand for O2 causes ratio of oxygenated to deoxygenated blood to increase
-compare resting and task state to infer activity
what is MEG
FUNCTIONAL
-modern development
-measure magnetic potentials generated by brain activity
-sources are superimposed on anatomical images of brain
-direct measure of brain function
what is EEG
FUNCTIONAL
-measurement of electrical activity by electrodes on scalp
-traces are electroencephalograms
-can only detect superficial regions
what are the methods that produce stimulating images
transcranial magnetic stimulation TMS
transcranial direct current stimulation TDCS
what is TMS
STIMULATING
-short bursts of strong magnetic pulse to stimulate electrical currents in brain
-insulated wire coil placed on skull
-cortical regions only (1.5-2.5 cm)
-can activate or suppress activity
what is TDCS
STIMULATING
-for brain injuries or cog. performance
-current between 1 or 2 mA applied to skull via electrodes
-either + anodal/ - cathodal current facilitates depolarisation or hyperpolarisation of neurons
-induces long lasting changes in brain (up to 90 mins)
what is gene manipulation
-used on animals
-before fetus forms genes can be inserted into pregnant mouse to alter DNA
-genes can also be removed e.g monoamine oxidase A knock out mice
hormone manipulation study
Nave 2017
-T gel given to men causing them to make intuitive decisions in reflective tasks
