science section 5 - Technology & neuroscience Flashcards
which scientist used early microscopes to see individual neurons in the brain?
santiago ramon y cajal
what was the goal of the brain research through innovative technologies (BRAIN) project?
to give scientists the resources they needed to get a “dynamic picture of the brain in action”
Human connectome project
the largest map of neural circuits structure
perturbing (The brain)
changing something in the brain and seeing how cells in the brain/subject behavior changes in response
lesion studies
damaging part of the brain and seeing how the subject then interacts with the world. still done on animals
paul broca
met a patient with an extreme speech impediment. Broca later did an autopsy on this patient, and found that the patient had a massive lesion in the left side of his brain. led broca to believe that speech and language areas are localized on the left side of the brain.
electrical brain stimulation
implanting an electrode into the brain and stimulating a certain region; led to important treatments such as electroshock therapy
transcranial direct current stimulation (tDCS)
uses a positive and negative electrode on the scalp to change brain activity. stimulation created with this is very small
optogenetics
genetically modifying a neuron to have a ChR2 gene, which manifests as an ion channel that depolarizes in light. in this way, scientists can trigger an action potential just with light and be highly specific about which neuron they’re targeting.
transcranial magnetic stimulation (TMS)
creates an electric field within the cortex, causing neurons in the targeted region to turn “on” or “off”. used to confirm what brain regions correlate to what functions (e.g. if a subject can’t speak when the left side of their brain is “turned off”, then left side must correlate with speaking.)
pro of TMS
can target a small area without spread
con of TMS
can only stimulate brain regions near the surface
intracellular/single-unit recording
implanting an electrode in one neuron and recording changes in membrane potential; hard bc neurons are small
extracellular recording
electrode measures membrane potential from a population of cells, not just one
phrenology
developed by Franz Joseph Gall, who believed you could determine traits and abilities by feeling bumps on a subject’s skull. this pseudoscience was used to justify belief that some people are inferior (e.g. enslaved people in America)
theory of localization
idea that particular areas of the brain have particular jobs to do
electroencephalogram (EEG)
developed by Hans Berger. he originally stuck metal wires directly into brain, but today electrodes are just stuck to the scalp.
whats the EEG used for?
electrodes record electrical impulses of a large population of neurons. Berger used it to show differences between electrical activity of healthy brain vs irregular brain (e.g. one with epilepsy)
dipole
most neurons in an area have similar charges, creating a dipole, an area of positive charge next to an area of negative charge.
Event related potential (ERP :P)
an electrical potential that directly results from a stimulus; ERP experiments record EEG activity at certain times to track neural response to events/stimuli
cons of EEG
only for outermost brain areas, and poor spatial resolution (can’t really pinpoint where in brain certain activity is coming from)
Magnetic resonance field imaging (MRI)
medical imaging technique that produces a strong magnetic field to generate map of inner body
what is the process of an MRI scan?
1.) patient lays inside
2.) strong magnetic pulses align the protons in the patient’s body 3.) until a radio frequency (RF) momentarily disrupts this alignment
4.) the atoms gradually float back into alignment which emits a radio signal that the MRI can measure
what does the magnet component do in an MRI?
generates magnetic field
what do the gradient coils do in an MRI?
allow the scanner to assess where a particular signal is coming from
what do the radio frequency coils do in an MRI?
produce the radio frequency (RF) pulse
deoxygenated
red blood cells not carrying oxygen. these have different magnetic properties from those that are carrying oxygen.
functional MRI (fMRI)
creates maps of what brain areas are active during different activities. if a brain region has oxygenated blood flowing to it, then it is probably related to whatever activity the person is doing. scientists can tell where oxygenated blood is going because it stands out on an MRI scan (remember it has different magnetic properties from deoxygenated blood cells!)
fusiform face area
tiny region in temporal lobe that is very active when person is looking at faces. would not have been discovered without fMRI.
brain computer interface
a system that allows a person to control a device by way of implanted electrodes. still experimental
invasive methods of brain computer interface
any involving brain implants. electrocorticography, local field potentials, multi-unit activity, sing-unit activity.
non-invasive methods of brain computer interface
any surface detectors. EEG, fMRI, near-infrared spectroscopy (NIRS)
computational neuronal modeling
use of computer algorithms or simulator programs to model behavior of neurons and understand their processes. these mimic existing network of neurons in brain.
what can computational neuronal modeling do?
simulate the interactions between multiple neurons in a larger neuronal network
artificial neural networks
give computers the ability to perform tasks that a human would typically do (e.g. a self driving car can spot pedestrians with enough accuracy to avoid them)
deep neural network
neural network that is capable of complex problem solving (e.g. the neural network that beat Europe’s champion at Go in 2015)
computational psychiatry
researchers argue that adding computer algorithms to patient
descriptions and behavioral testing could provide more data about psychiatric patients and
provide clinicians with vital tools to improve diagnosis; fast-growing field
what’s the goal of computational psychiatry?
improve patients’ responses to treatment, improve patients’ adherence to therapeutic drugs, and improve patient outcomes
