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BNS 107 Week 5
Research Methods and Ethics in Neuroscience
Term | Definition |
---|---|
Experimental study | researchers introduce an intervention and study the effects. Experimental studies are usually randomized, meaning the subjects are grouped by chance. |
Independent variable | Things that can be controlled by the researcher |
Golgi stain | randomly stains entire neurons, only 5% of neurons take up the stain |
Nissl stain | Only stains the cell bodies of neurons |
Electron microscope | pass beams of electrons through a thin slice of tissue onto a detector, high resolution, magnifies objects up to 250,000 times. Can reveal objects in 3D. Very powerful and very expensive. |
Ablation | involves the removal of brain tissue. This can be done in several ways. |
Computed tomography (CT/CAT scan) | dye is injected into the blood and a series of x-rays is made from different angles; the images reflect the density of blood vessels in each area. A computer combines the x-rays. It is fast, but it uses dyes and x-rays. |
Positron emission tomography (PET scan) | Inject radioactive substances into the bloodstream which is taken up by active parts of the brain. It is able to track activity in the brain. It's expensive, requires sophisticated staff, must be near a cyclotron, relatively slow. |
Transcranial magnetic stimulation (TMS) | uses a noninvasive magnetic field and permits excitation or inhibition of brain regions in order to see how that will affect the body. |
Family Studies | determine how strongly a characteristic is shared among family members. Hereditary and environment are confounded, people who share genes also share the same environment |
Twin studies | assess how similar twins are in some characteristics. Used to see how important genetics are in defining a trait. |
Fabrication | (faking results) is more serious than plagiarism because it introduces erroneous information into the body of scientific knowledge |
Gene therapy | Type of genetic engineering, used to help genetic illnesses and diseases to prevent or slow the symptoms. |
Correlational study | The researcher determines whether two variables change together but does not manipulate either variable in order to see if there is a relationship between the two. |
Myelin stain | stains myelin surrounding axons of neurons |
Light microscopy | uses light in order to magnify certain objects. Cell bodies, dendrites, axons, and large organelles in neurons are all able to be seen. There is limited capability due to the nature of the light. |
Electroencephalography (EEG) | records the electrical activity of the brain through the scalp using multiple electrodes. Has good temporal resolution and poor spatial resolution (it doesn’t tell us what areas of the brain are most active). Best used to detect changes in arousal. |
Lesioning | damages neural tissue with heat, electrical current, neurotoxins, or by severing connections. Reversible lesions can be produced by chilling an area or by applying certain chemicals. |
Magnetic resonance imaging (MRI) | scans work by measuring the radio frequency waves emitted by the hydrogen atoms when they are subjected to a strong magnetic field. They provide a more detailed view of the brain, they are reasonably fast, inexpensive and even portable. |
Functional MRI (fMRI) | Measures brain activation by detecting the increase in oxygen levels in active structures Advantages: activity measurement, good spatial resolution and speed, no radioactive substances Disadvantages: expensive, very slow |
Adoption studies | allow us to measure the child’s similarity to their biological parents and their adoptive parents.Adoption studies are referred to as natural experiments; they are not true experiments because adoption cannot be manipulated. |
Concordance rate | A useful measure for identifying genetic influence in disorders. The frequency that relatives share a characteristic. |
What is the difference between experimental and correlational studies? | In an experimental design, you manipulate an independent variable and measure its effect on a dependent variable. In a correlational design, you measure variables without manipulating any of them. |
What are the major staining techniques used in neuroscience research? | Myelin stain, Nissl stain, Golgi stain. |
What are the differences between light and electron microscopy? | One uses light to magnify and the other uses electrons. |
What are the major neuroimaging techniques? | MRI, fMRI, CT, PET, EEG |
Stereotaxic instrument | used to place an electrode or other device at a precise location in the brain |
stereotaxic atlas | shows the location of key structures on images of a series of brain sections |
Dependent variable | things that result from independent variables and what is often documented in research studies. |