Final Exam Flashcards
Computerized tomography (CT)
The use of a device that employs a computer to analyze data obtained by a scanning beam of X-rays to produce a two-dimensional picture of a “slice” through the body.
Magnetic resonance imaging (MRI)
A technique whereby the interior of the body can be accurately imaged; involves the interaction between radio waves and a strong magnetic field.
Diffusion tensor imaging (DTI)
An imaging method that uses a modified MRI scanner to reveal bundles of myelinated axons in the living human brain.
Henry Molaison (H.M.)
As a boy had a bike accident which left him with severe epilepsy
Doctors pinpointed the seizures to his medial left and right temporal lobes
Hippocampus
Amygdala
Part of the entorhinal cortex
Doctors removed the affected tissue (all went well)
However when henry woke up he could only remember his name and his childhood
- Couldn’t form any new memories
Lead to important knowledge about the amygdala and hippocampus in memory formation
His only deficit was in long term memory
Could still form habits like
finding the hospital dining room
Working memory tasks - Repeating a string of numbers
Showed us the difference in types of memory
Leborgne “Tan”
Nicknamed tan because it was the only word he was able to say. Nothing wrong with him, he understood everything and could follow commands
Broca performed an autopsy and found a lesion on the left hemisphere (Broca’s area)
Damage to broca area
People could comprehend everything
No other cognitive deficits
Just can’t talk words or sentences in a meaningful way
Lesion was important for understanding human language
Phineas Gage
1840’s worked blasting rock with gunpowder. Used a tamping iron - set an explosion sending the iron rod through his cheek and top of his head. Was cleaned up and was walking, talking and living independently like before
However he was described as a different person
-Was impatient
-Spoke foul language
Damage to his left frontal lobe told us personality is localised in the frontal lobe
Aphasia
Loss of speech ability
Brain Lesion
Damage to the brain tissue caused by injury, disease and more
Caused by
-strokes
-Traumatic head injuries
-Tumours
Can occur in almost any brain region and be almost any size
Help us learn something new about the human brain
Microelectrode
A very fine electrode, generally used to record activity of individual neurons.
Single-unit recording
Recording of the electrical activity of a single neuron.
Macroelectrode
An electrode used to record the electrical activity of large numbers of neurons in a particular region of the brain; much larger than a microelectrode.
Electroencephalogram (EEG)
An electrical brain potential recorded by placing electrodes on the scalp.
Magnetoencephalography
A procedure that detects groups of synchronously activated neurons by means of the magnetic field induced by their electrical activity; uses an array of superconducting quantum interference devices, or SQUIDs.
2-deoxyglucose (2-DG)
A sugar that enters cells along with glucose but is not metabolized.
Autoradiography
A procedure that locates radioactive substances in a slice of tissue; the radiation exposes a photographic emulsion or a piece of film that covers the tissue.
Fos
A protein produced in the nucleus of a neuron in response to synaptic stimulation.
Functional imaging
A computerized method of detecting metabolic or chemical changes in particular regions of the brain.
Positron emission tomography
(PET)
A functional imaging method that reveals the localization of a radioactive tracer in a living brain.
Functional MRI (fMRI)
A functional imaging method; a modification of the MRI procedure that permits the measurement of regional metabolism in the brain, usually by detecting changes in blood oxygen level.
Transcranial magnetic stimulation
(TMS)
Stimulation of the cerebral cortex by means of magnetic fields produced by passing pulses of electricity through a coil of wire placed next to the skull; interferes with the functions of the brain region that is stimulated.
Optogenetic method
The use of a genetically modified virus to insert light sensitive ion channels into the membrane of particular neurons in the brain; can depolarize or hyperpolarize the neurons when light of the appropriate wavelength is applied.
Genome
The complete set of genes that compose the DNA of a particular species.
Allele
The nature of the particular sequence of base pairs of DNA that constitutes a gene; for example, the genes that code for blue or brown iris pigment are different alleles of a particular gene. (the particular form of an individual gene)
Targeted mutation
A mutated gene produced in the laboratory and inserted into the chromosomes of mice; alters production of a functional protein.
Twin studies
Twin studies provide a powerful method of estimating the influence of heredity on particular traits
Compare monozygotic (identical) and Dizygotic (Fraternal) twins
Twin studies compare the concordance rate for a trait in pairs of monozygotic and dizygotic twins
- If both twins are diagnosed with same condition they are concordant
- If only one is diagnosed they are discordant
If a disorder has a strong genetic basis, the percentage of monozygotic twins who are concordant for the diagnosis will be higher than that for dizygotic twins
Monozygotic twins
have identical genotypes - that is their chromosomes, and the genes they contain, are identical
Dizygotic twins
have a genetic similarity of around 50%
Adoption studies
All behavioural traits are affected to some degree by hereditary factors,
environmental factors (physical, social and biological) and an interaction between these factors
Compare people adopted early in life with biological and adoptive family members
If people strongly resemble biological parents, trait is probably influenced by genetic factors
Genomic studies
Linkage studies
Genome wide association studies
knowledge of the human genome to understand behaviour
Linkage studies
identify families whose members vary in particular trait (presence/absence of huntington’s disease)
Markers = sequences of DNA whose locations are already known
Compare markers across members of the family
Genome wide association studies (GWAS)
Compare all or portions of the genomes of different individuals to determine whether differences in the people’s genomes correlate with the presence or absence of diseases (or other traits)
works well:
- determine variant-trait associations not otherwise known which might have important clinical applications.
- the discovery of new biological mechanisms underlying some conditions.
GWAS data is easy to share, and publicly available data allows for further advancement of knowledge.
Limitations to the use of GWAS
GWAS usually only estimates a modest amount of the heritability of a given trait, meaning it can have limited clinical predictive value.
Correlation does not equal causation - GWAS do not necessarily tell us about causal mechanisms
Future research is needed to further advance the area and discern exactly what the method can (and cannot) achieve.
Sensation
involves cells of the nervous system that are specialised to detect stimuli from the environment
Perception
the conscious experience and interpretation of information from the senses
Visual light
is a narrow band of the spectrum of electromagnetic radiation that receptor cells in our eyes detect
Three dimensions determine the perceived colour of light
Hue = dominant wavelength (Colour)
Saturation = purity of the light being perceived
Brightness = intensity of the electromagnetic energy
hue
One of the perceptual dimensions of color; the dominant wavelength.
brightness
One of the perceptual dimensions of color; intensity.
saturation
One of the perceptual dimensions of color; purity.
sensory transduction
The process by which sensory stimuli are transduced into slow, graded receptor potentials.
sensory receptor
A specialized neuron that detects a particular category of physical events.
receptor potential
A slow, graded electrical potential produced by a receptor cell in response to a physical stimulus.
retina
The neural tissue and photoreceptive cells located on the inner surface of the posterior portion of the eye.
accommodation
Changes in the thickness of the lens of the eye, accomplished by the ciliary muscles, that focus images of near or distant objects on the retina.
rod
One of the receptor cells of the retina; sensitive to light of low intensity.
cone
One of the receptor cells of the retina; maximally sensitive to one of three different wavelengths of light and hence encodes color vision.
photoreceptor
One of the receptor cells of the retina; transduces photic energy into electrical potentials.
fovea
The region of the retina that mediates the most acute vision of birds and higher mammals. Colour sensitive cones constitute the only type of photoreceptor found in the fovea.
optic disk
The location of the exit point from the retina of the fibers of the ganglion cells that form the optic nerve; responsible for the blind spot.
photopigment
A protein dye bonded to retinal, a substance derived from vitamin A; responsible for transduction of visual information.
bipolar cell
A bipolar neuron located in the middle layer of the retina, conveying information from the photoreceptors to the ganglion cells.
rhodopsin
A particular opsin found in rods.
amacrine cell
A neuron in the retina that interconnects adjacent ganglion cells and the inner processes of the bipolar cells.
ganglion cell
A neuron located in the retina that receives visual information from bipolar cells; its axons give rise to the optic nerve.
receptive field
That portion of the visual field in which the presentation of visual stimuli will produce an alteration in the firing rate of a particular neuron.
horizontal cell
A neuron in the retina that interconnects adjacent photoreceptors and the outer processes of the bipolar cells.
lamella
A layer of membrane containing photopigments; found in rods and cones of the retina.
opsin
A class of protein that, together with retinal, constitutes the photopigments.
retinal
A chemical synthesized from vitamin A; joins with an opsin to form a photopigment.
optic chiasm
A cross-shaped connection between the optic nerves, located below the base of the brain, just anterior to the pituitary gland.
transduction
how light is converted into electrochemical messages processed in the visual system
parvocellular layer
One of the four outer layers of neurons in the dorsal lateral geniculate nucleus; transmits information necessary for perception of color and fine details to the primary visual cortex.
vergence movement
The cooperative movement of the eyes, which ensures that the image of an object falls on identical portions of both retinas.
saccadic movement
The rapid, jerky movement of the eyes used in scanning a visual scene.
dorsal stream
A system of interconnected regions of visual cortex involved in the perception of spatial location, beginning with the striate cortex and ending with the posterior parietal cortex.
pursuit movement
The movement that the eyes make to maintain an image of a moving object on the fovea.
magnocellular layer
One of the inner two layers of neurons in the dorsal lateral geniculate nucleus; transmits information necessary for the perception of form, movement, depth, and small differences in brightness to the primary visual cortex.
dorsal lateral geniculate nucleus (LGN)
A group of cell bodies within the lateral geniculate body of the thalamus; receives input from the retina and projects to the primary visual cortex.
optic nerve
Bundles of axons from retinal ganglion cells exit the eye and convey information to the lateral geniculate nucleus.
striate cortex (primary visual cortex, or V1)
The primary visual cortex.
visual pathway
The pathway of visual processing from the retina to the lateral geniculate nucleus to striate and extrastriate cortical regions.
extrastriate cortex (visual association cortex, or V2)
A region of visual association cortex; receives fibers from the striate cortex and from the superior colliculi and projects to the inferior temporal cortex.
koniocellular sublayer
One of the sublayers of neurons in the dorsal lateral geniculate nucleus found ventral to each of the magnocellular and parvocellular layers; transmits information from short-wavelength (“blue”) cones to the primary visual cortex.
ventral stream
A system of interconnected regions of visual cortex involved in the perception of form, beginning with the striate cortex and ending with the inferior temporal cortex.
protanopia
An inherited form of defective color vision in which red and green hues are confused; “red” cones are filled with “green” cone opsin.
deuteranopia
An inherited form of defective color vision in which red and green hues are confused; “green” cones are filled with “red” cone opsin.
tritanopia
An inherited form of defective color vision in which hues with short wavelengths are confused; “blue” cones are either lacking or faulty.
negative afterimage
The image seen after a portion of the retina is exposed to an intense visual stimulus; consists of colors complementary to those of the physical stimulus.
complementary colors
Colors that make white or gray when mixed together.
cerebral achromatopsia
Inability to discriminate among different hues; caused by damage to the visual association cortex.
lateral occipital complex (LOC)
A region of the extrastriate cortex, involved in perception of objects other than people’s bodies and faces.
visual agnosia
Deficits in visual perception in the absence of blindness; caused by brain damage.
fusiform face area (FFA)
A region of the visual association cortex located in the inferior temporal lobe; involved in perception of faces and other complex objects that require expertise to recognize.
prosopagnosia
Failure to recognize particular people by the sight of their faces.