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___ are electrically charged atoms
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Electrical potential aka voltage:
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PSYC 271 Midterm 2
| Question | Answer |
|---|---|
| ___ are electrically charged atoms | Ions |
| Electrical potential aka voltage: | Difference in the concentration of charges between two solutions |
| Voltage | electrostatic pressure |
| 4 important ions for neural conduction | Na, K, Cl, Calcium |
| 2 ways to measure membrane potentials | Voltmeter, or oscilloscope with electrical stimulator |
| ____ concentration is higher outside of the cell | Na |
| ____ concentration is higher inside the cell | K |
| Na is driven in by both ______ _______ and its _____ _____ (random motion) | electrostatic forces, concentration gradient |
| K is driven _____ by electrostatic forces, and _____ by its concentration gradient | IN, OUT |
| Sodium-potassium pump | active force (ATP) that exchanges 3NA+ inside for 2K outsode |
| EPSP causes ______, and an ______probability of action potential. Ie Na or Ca influx | depolarization, increased |
| IPSP causes _______, and a ________ probability of action potential. Ie Cl influx, K efflux | hyperpolarization, decreased |
| PSPs are _______, and they are transmitted ______ and ______ | graded, decrementally and rapidly |
| In EPSP, it depolarizes the cell membrane (making it _____ ____), bringing it ____ to threshold and making it ____ likely that an action potential will fire | less negative, closer, more |
| IPSP hyperpolarizes the cell membrane (making it ____ ______), bringing it ______ to threshold and making it _____ likely that an action potential will fire | more negative, further, less |
| What is typically needed to cause a neuron to fire? | summation |
| In order to generate an AP, the ______ of _____ must be reached near the axon | threshold of activation |
| Integration of IPSPs and EPSPs must result in a potential of about ______ in order to generate an AP | -65mV |
| 3 examples of spatial summation of PSPs | 2 simultaneous EPSP or IPSP to produce 1 greater one, or teo opposite effects to cancel one another out |
| Temporal summation of PSPs | rapid succession sums a larger PSP |
| Steps in ionic basis of action potentials: | Na channels open, Na rushes in (depolarization), K channels slowly open, K leaves cell (repolarization), Cell becomes hyperpolarized |
| Resting membrane potential: | -70 mV, inside of cell has a negative charge relative to outside of cell |
| Depolarization | membrane potential becomes less negative |
| Threshold | point that voltage gated sodium channels open, AP occurs |
| Repolarization | membrane potential becomes negative again, approaching the resting membrane potential |
| Hyperpolarization: | membrane potential becomes even more negative than the resting membrane potential |
| Refractory periods prevent the _____ movement of APs, limit the rate of firing | backward |
| Absolute refractory period: | impossible to initiate another action potential, 1-2 ms after AP start |
| Relative refractory period: | Threshold less negative than rest, more difficult to initiate another AP (more depolarization necessary) |
| Conduction of action potentials is _____, _____, ______ | active, slower, nondecremental |
| Diffusion of Na+ triggers next ___ ____ | action potential |
| ____ channels tightly packed, creating waves of depolarization | Na |
| Orthodromic conduction is transmission ___ | to |
| Antidromic conduction is transmission | away - can stimulate at axon terminals |
| Nodes of ranvier AKA | saltatory conduction |
| What kinds of axons are the fastest? | Myelinated, larger |
| The Hidgkin-Huxley model of neural conduction is from ____ motor axons, which is _____ than that of ____ _____ neurons | squid, different, mammal cerebral |
| Fo interneurons fire action potentials? | NO |
| Are dendrites able to fire action potentials? | Maybe |
| Mammal cerebral action potentials vary in ____, ______, and ______ | amplitude, duration, frequency |
| Can mammalian cerebral axons fire potentials in the absence ofinput? | Maybe, tonically active |
| Axoaxonic synapses | presynaptic inhibition/facilitation |
| dendrodendritic synapses | bidirectional |
| dendroaxonic synapses | rare |
| axonal main shaft synapses | synapses between axon shafts - parallel side by side, synapse onto other |
| nondirected synapses | common for monoamine neurotransmission - diffuse release of NT |
| Some communication is through ____ _____ between cells | gap junctions |
| _____ appear to modulate neuronal activity within their own domain | Astrocytes, communicate with adjacent ones through gap junctions |
| Where are small-molecule neurotransmitters syntehsized | cytoplasm of axon terminal buttons |
| Small molecule NTs packaging | packaged into synaptic vesicles by golgi complex at terminal button |
| Large molecule neurotransmitter synthesis | in cytoplasm of cell body by ribosomes |
| Packaging of large molecule neurotransmitter | packaged into synaptic vescicles by golgi complex |
| Transport of large molecule neurotransmitter | transported to axon terminal by microtubules |
| A single neuron can typically syntehsize and release one type of ____, one type of ____, or one type of ______ (coexistence) | small, large, each |
| 4 steps to NT release | AP arrives at terminal button, voltage gated calcium channels open, Ca++ enters, vesicles fuse, empty contents via exocytosis |
| Ionotropic receptors AKA ______ or _______ | ligand or NT gated ion channels |
| Ionotropic receptors are ____ acting | Fast |
| Ionotropic receptirs usually have a _____ effect | Transient |
| Depending on the type, Ionotropic receptros can _____ or _____ | depolarize (NA or CA), or hyperpolarize (Cl or K) |
| Metabotropic receptors AKA | G-protein-couples receptors |
| Metabotropic receptors are usually ____ acting | slower |
| Metabotropic receptors have a ____ effect by modifying ___ ____ | lasting, intracellular signalling |
| Presynaptic autoreceptors are activated by _____ in the synapse, generally inhibits the amount of ____ released (braking mechanism_ | neurotransmitter, neurotransmitter |
| Neurotransmitter reuptake | pull NT back up into presynaptic neuron, repackaged and re-sent out |
| Neurotransmitter degradation by enzymes | seek out and destroy neurotransmitters |
| 5 classes of NTs | Amino acids, monoamines, acetylcholine, unconventional neurotransmitters, neuropeptides |
| AA NTs | Fast, typically binding to ionotrppic receptors. Glutamate, GAVA, aspartate, glycine |
| Monoamine NTs | more diffuse, non-directed synapses. Metabotropic receptors with diverse functions, arise in brainstem. Catecholamines, indolamines |
| Ach NTs | acetyl + choline, nicotinic (iono) & muscarinic (meta). Degraded by acetylcholinesterase. Many synapses in ANS |
| What defines something as an unconventional neurotransmitter? | Does not fit into other categories, less understood |
| 2 types of unconventional neurotransmitters | Soluble gases that exist only briefly, endocannabinoids |
| Soluble gases that exist only briefly | NO, CO. Backward/retrograde communication. Neural cytoplasm production, short acting (via membranes) |
| Endocannabinoids | produced on-demand, released from dendrites, inhibit presynaptic neurons. rapidly degraded |
| Neuropeptides are ____ ______ of amino acids | short chains |
| the 5 categories of neuropeptides have a ______ of functions | variety |
| Ex of neuropeptide | Endorphins ie Endogenous opiods, analgesia/reward system |
| Agonists | Facilitate neurotransmitter's effects |
| Antagonists | Reduce neurotransmitter's effects |
| Drugs may impact ___ _____ of the synaptic transmission pathway | Any part |
| Agonist drug effect on synthesis | Increases synthesis of neurotransmitter molecules |
| Antagonistic drug effect on synthesis | Blocks synthesis of NT molecule |
| Agonist drug on breakdown | Increases NT # by destroying degrading enzymes |
| Antagonist drug on breakdown | NT molecules leak from vesicles, destroyed by degrading enzymes |
| Agonist drug on exocytosis | increases NT release from terminal buttons |
| Antagonist drug on exocytosis | Blocks NT release from terminal button |
| Agonist drug on inhibitory feedback | binds to autoreceptors, blocks inhibitory effect on NT release |
| Antagonist drug on inhibitory feedback | activates autoreceptors, inhibits NT release |
| Agonist drug on activation | binds to postsynaptic receptor, activates/increases effect on NT molecule |
| Antagonist drug on activation | receptor blocker, binds to postsynaptic receptors to block NT effect |
| Agonist drug on deactivation | blocks deactivation of NT, blocking degradation or reuptake |
| Antagonist drug on deactivation | Receptor blocker, binds to postsynaptic receptors to block NT effect |
| 3 influential lines of pharmacology research | acetylcholine receptor subtypes, endogenous opioids, antipsychotic drugs |
| Historically, we used to think that each NT had ___ kind of receptor | one |
| Different _____ selective to specific _____ subtypes, exerting different effects despite involving the same NT | drugs, receptor |
| Nicotonic vs Muscarinic acetylcholine receptors: | Different locations, receptor function, and behavioural effects |
| In PNS, nicotinic receptors: | Activation at neuromuscular junction stimulates muscle contraction |
| In PNS, muscarinic receptors: | Activation slows heart and constricts pupils in ANS |
| Ancient Greeks would consume _____ extracts for stomach ailments and pupil dilation | belladonna |
| The PNS releases ______ on _______ receptors within iris sphincter muscles to constrict pupils | Acetylcholine, muscarinic |
| _____, the main active ingredient of belladonna, blocks _____ receptors, blocking Ach effect on pupils | Atropine, muscarinic |
| _______: Extract of certain vines used by South American natives as a paralytic poison for darts in hunting and war | Curare |
| Curare blocks _____ receptors at the neuromuscular junction, causing _____ | nicotinic, paralysis |
| Benefit of using Curare in medical setting | no muscular movement during surgery, but artificial respiration needed |
| Extracted toxin of botulism bacteria | Botox |
| Botox prevents _____ release at the neuromuscular junction, causing paralysis and preventing ____, _____ | acetylcholine, tremors, wrinkles |
| Discovery of the endogenous opioids provided insight into what? | brain mechanisms of pleasure and pain |
| Sticky resin obtained from the seed pods of the opium poppy, used for pleasurable effects | Opium |
| Main active ingredient in Opium is _____, an analgesic | morphine |
| Opiates bind to _____ in the midbrain | PAG |
| Direct injection of opiates in PAG produces _____, so does electrical stimulation | Analgesia |
| Endogenous morphine | Endorphins |
| "in the head" opiates | enkephalins |
| First antipsychotic drugs produced antischizophreic effects, but also _____ _____ symptoms | Parkinsonian-like |
| Parkinson's disease associated with death of what? Where? | dopaminergic neurons, substantia nigra |
| ______ _____, such as cocaine and amphetamines can induce and exacerbate phycosis | Dopamine agonists |
| Dopamine antagonists can _____ psychotic symptoms | reduce |
| What are 2 X-ray based research techniques? | Contrast X-rays and CT scans |
| What are 2 radioactivity based research techniques? | PET and SPECT |
| What are 3 magnetic field-based research techniques? | MRI, DTI, fMRI |
| ______ tissues/objects absorb x-rays more than ___ tissues/objects | Dense, softer |
| Are X rays normally useful for neuroimaging? Why or why not? | NO, brain looks like CSF |
| What are X-rays good for | skull and bone fragments, foreign objects |
| X-rays are _____ and can damage tissue | carcinogenic |
| X-rays give a ____ image of density | 2D |
| Contrast X-rays inject ____-____ dye, which _______ X-rays differently than surrounding tissue into the structure of interest | radio-opaque, absorbs |
| _____ ______ is excellent at imaging blood vessels | Cerebral angiography |
| CT scans are X-rays from ____ _____, allowing for a computation of a _____ image of density | multiple angles, 3D |
| Do CT scans have high or low spatial resolution? | Relatively low |
| Health effects of CT better or worse than X-ray? Why? | Worse, more images taken |
| SPECT measures _____ _____ ____ of a radiolabelled tracer in 3D | local blood flow |
| SPECT radiolabelled tracer continually releases _____ as it decays | positrons |
| Typical examples of radiolabelled tracers used in SPECT | inert gas, or tracers with up to 3 day half lifeintravenously |
| SPECT tracers usually administered _____ | Intravenously |
| SPECT has very _____ temporal resolution | low (minutes) |
| SPECT is excellent for measuring ____ _____ of interest | specific substances |
| What is SPECT used to detect? | Alzheimers - decreased temporal-parietal metabolism |
| PET has the same features as SPECT, except what? | Positron quickly annihilated by free electrons, releasing 2 photons in opposite directions |
| PET tracers have longer or shorter half lives than SPECT? | shorter |
| What is a common radiotracer used for PET? what does it do? | 2-DG, taken up by active NTs (not metabolized) anywhere glucose is taken up |
| Why is PET expensive | Tracer production on site with expensive cyclotron particle accelerator |
| PET tracers are usually administered ____ or ____ | intravenously, inhaled |
| Pet has ____ spatial and temporal resolution than SPECT, but is more expensive | greater |
| Constructed image from measures electromagnatic signals emitted by H atoms as they return to alignment with a strong magnetic field after a radio-frequency burst | MRI |
| MRI has very ____ resolution 3D images | high |
| There is high ____ between white and gray matter in MRIs | contrast |
| What can MRIs be combined with? Examples? | Functional scans: fMRI, EEG, PET |
| Exceptions to MRI safety/non-invasiveness | tattoos, metallic devices, pacemakers |
| uses MRI and echo-planar imagine tech to measure subtle magnetic field fluctuations in a substance of interest | fMRI |
| fMRI, fluctuations of magnetic field reflects what? | Cognitive activity |
| what response does fMRI measure? | BOLD - blood oxygen deoxygenation level dependent |
| What can fMRI be used to detect alongside BOLD? | Cerebral blood flow (CBF), dopamine |
| What technique do both PET and fMRI use? What does this control for? | Paired-image subtraction/ controls for external thought, isolates for actual elucidated response |
| What does functional connectivity analysis measure? | Low frequency fluctuations, regional homegeneity |
| Diffusion Tensor Imaging measures pathways along which ____ _____ rapidly diffuse | water molecules |
| DTI tracts indicate how the brain is _____ | connected |
| fUS imaging | Functional ultrasound |
| fUS imaging uses ultrasouns to measure changes in _____ _____ in particular brain regions | blood volume |
| When a brain region becomes active, blood levels increase there, altering the _____ of ultrasound through that brain region | passage |
| Benefits of fUS | cheap, prtable, useful for those who can't use PET or MRI |
| fUS can create small, permanent _____ at high amplitudes | lesions |
| fMRI signals is a process that occurs many times/second, so signals can be _____ to one another | added |
| The default mode network is _____ _____ throughout the brain | widely distributed |
| What is the default mode network? | Attention to own thoughts, not the outside world. |
| Default mode network is a source of ____ ____, actively unrelated to a task | noise variance |
| fNIRS uses _____-_______ ______ to estimate hemodynamic activity | near-infrared light |
| fNIRS involves measuring changes in _____ and ____________ concentration | oxy- and deoxyhemoglobin |
| Measures electical activity on the scalp and is a reflection of neuronal synchrony | EEG |
| EEG can be used to diagnose _____, as it has excellent ______ resolution, but poor ________ resolution | epilepsy, temporal, spatial |
| EEG measures the ______ of brain waves | frequency |
| How does one increase the spatial resolution of EEG? | Increasing the number of electrodes |
| EEG signalling averages uses __________ to match EEG signals to repeated sensory, cognitive, or behavioural trials | event-related potentials |
| EEG _______ cancels out after a certain amount of trials | randomness |
| Early EEG components are usually related to ______ features (exogenous components) | sensory |
| Later EEG components are usually related to _______ components (endogenous conponents) | cognitive |
| Small waves immediately after click, from sensory nuclei far from recording | Far Field Potentials |
| Measures tiny magnetic fields of the brain created perpendicular to the electrical current | Magnetoencephalography |
| For MEG to be effective, patient must be inside room _____ ____ for magnetic fields, because tech is sensitive to magnetic fields created by other objects | heavily insulated |
| brain electrical currents create _____ _____ _____ | tiny magnetic fields |
| Tiny brain magnetic fields are detected by _____ | coils |
| Pros of MEG | both high temporal and spatial resolution, excellent for primary sensory/motor cortices |
| measures the changing difference in the voltage between two large electrodes placed on the skin above a large muscle | Electromyography |
| What does EMG measure? | level of tension in muscle (spike rate) |
| What is electrooculagraphy (EOG)? | Eye movements recorded by placing 4 electrodes around the eye |
| EOG has been replaced by what? | More sophisticated eye tracking methods |
| The general level of skin conductance associated with a particular situation | Skin Conductance Level |
| A rapid change in skin conductance in response to a particular event | Skin conductance response |
| Example of skin conductance response uses? | Polygraph tests |
| Electrocardiograms measure what | Heart rate |
| Blood pressure is measured via a | sphygmomanometer |
| Measurement of blood/air volume in a body structure ie penis, fingers | Plethysmography |
| Transcranial magnetic stimulation temporarily _________ localized brain function | decreases |
| If behaviour from TMS is disrupted, that means what? | That the deactivated part of the brain is causing the bahaviour |
| Transcranial electrical stimulation _______ brain function by passing ____ _____ through the cortex | altering, electrical current |
| In tES, is the current strong enough to elicit an action potential? | NO, it changes the resting membrane threshold - changing how/when it is activated |
| How does transcranial direct current stimulation work? | excitability increases at anodal electrode |
| Transcranial alternating current stimulation alternates current between ______ | electrodes |
| tACS entrains neurons to fire at a particular ______, based on _____ of stimulation | frequency, strength |
| Transcranial random noise stimulation is the same as tACS, except ______ changes randomly | frequency |
| tRNS has different effects depending on _____ of stimulation | duration |
| Invasive physiological research methods are performed almost exclusively on _____ models | animal |
| Stereotaxic surgery uses stereotaxic ______ and instrument | atlas |
| Stereotaxic surgery allows accurate placement of what? | lesions, probes, electrodes |
| In a _______ lesion, tissue is sucked up into a pipette | aspiration |
| What remains behind following an aspiration lesion? why? | white matter, blood vessels. Higher durability |
| ________-________ lesions occur when high-frequency currents are administered through the tip of an electrode | Radio-frequency |
| What is the primary factor for radio-frequency lesions? | heat |
| Radio frequency lesions everything where? | at tip |
| Knife cut lesions are useful for _____ | tracts |
| Reversible lesions temporarily _______ an area | inactivate |
| examples of reversible lesions | Lidocaine, cold |
| Excitotoxic lesions excite neurons past the point of what? | Survival |
| Excitotoxic lesions spares what? | tracts and blood vessels |
| Chemical lesions produce _____ selective lesions than electrical lesions | more |
| Important to keep in mind that after lesion, deficit may be how the incomplete system _____ ___ that missing piece | compensates for |
| Lesions can give us a false sense of ________ | localization |
| What is a mild kind of lesion? Complete/stronger lesion? | Unilateral, bilateral |
| What kind of stimulation typically has the opposite effect of lesions? | electrical stimulation |
| Intracellular unit recording measures changes in the ___ _____ of a neuron over time, requiring a ______ positioned inside a neuron | membrane potential, microelectrode |
| Why is it nearly impossible to record intracellularly in a freely moving animal? | Hard to keep microelectrode inside neuron |
| Extracellular unit recording places a microelecrode ____ the neuron | near |
| Extracellular unit recording signals a series of _____, which indicate _____ ______ from a nearby neuron | spikes, action potential |
| Spikes of the same ______ are assumed to come from the same neuron | amplitude |
| Multiple-unit recording provides an indication of the _____ ____ _____ of many neurons in the general vicinity of the electrode tip | rate of firing |
| Invasive EEG uses electrodes where? | on the surface of the brain |
| What does invasive EEG provide? | more accurate recordings than normal (scalp) EEG |
| The route of drug administration influences the ____ and _____ to which the drug reaches its site of action | rate, degree |
| Difficulties of oral ingestion in non-human subjects? | need to be able and willing to ingest, may leave some unconsumed |
| Absorption via the digestive tract is _________ | unpredictable |
| Inhalation absorbs drugs through _______ in lungs | capillaries |
| Downsides of inhalation | regulation can be difficult, can damage lungs |
| Absorption through mucous membrane entry points: | nose, mouth, rectum |
| Hypodermic injection bypasses ___ ____ | digestive tract |
| Into peritoneal cavity | Intraperitoneally |
| Under the skin | Subcutaneously |
| Into large muscles | Intramuscularly |
| Into veins, most direct | Intravenously |
| ______ injection is injection into CNS | Central |
| Central injection bypasses digestive tract and ____ ____ _____ | Blood Brain Barrier |
| Into a ventricle to affect the whole brain | Intraventricular |
| Autoradiography measures the location of _______ of interest when the brain is active during an _____ | tracers, event |
| Difference between PET scan and autoradiography | have to kill subjects to get results |
| Cerebral dialysis measures specific substances in _____ | vivo |
| Immunocytochemistry creates ______ for desired protein | antibodies |
| In Situ Hybridization locates __________ sequences in the brain/chromosome | mRNA/DNA |
| Organisms lacking a ______ of interest | gene |
| Replacing one gene with another gene | gene replacement |
| CRISPR/Cas9 edit genes at a particular time of ______- | development |
| Optogenetics is the combination of _______ and _____ methods to achieve gain or loss of function in specific cells of living tissue | genetic, optical |
| Current neurophychological assessments focus more on the ______ of a patient | function |
| Brain scanning is best at _____ _____ or metabolic disturbances, but lack ______ to other problems | gross anatomical, sensitivity |
| Can a single neurophychological test detect all brain damage? | No |
| What is a standard battery of neuropsychological tests? | variety of tests that combine to discriminate between brain-damaged and healthy individuals |
| Problem with the standard battery of neurophychological tests? | Poorly discriminate brain-damaged from psychiatric illness |
| What is the HRB test? | Halstead-Reitan Battery - historically most widely-used |
| HRB Category Test | problem solving using abstract reasoning or hypothesis testing using geometric shapes |
| HRB tactual performance test | placing varied shapes in holes without sight |
| HRB Rhythm test | detect similarities and differences between rhythms |
| HRB speech sounds perception test | match spoken nonsense syllables with written forms |
| HRB finger tapping test | Tap index finger as fast as possible for 10 seconds |
| HRB trail making test | tests visual attention and task switching |
| HRB grip strength | Tests motor difficulties of each hemisphere |
| Customized test batteries are used to measure ________, with more precise tests used in follow-ups | deficits |
| Test batteries are based on ______ ______ of psychological functioning | modern theories |
| Cognitive _____, not just performance is measured in customized test batteries | stragegy |
| 3 tests of the common neuropsychological battery measure what? | Intelligence, memory, language and language lateralization |
| Verbal comprehension scale | general verbal skills including verbal fluency, relies on prior knowledge |
| Perceptual reasoning scale | examines a problem, drawing upon visual motor/spatial skills |
| Working memory scale | hold information so it can be used to solve a problem |
| Processing speed scale | focus attention, quickly scan, discriminate between, and sequentially order visual information |
| How do they measure which hemisphere is dominant for language? | Inject sodium amytal, if subject becomes mute then the hemisphere ipsilateral to injection is dominant |
| What is species common behaviours? | behaviours displayed by virtually all members of a species |
| What do the open field tests and the elevated plus maze test for | anxiety and emotion |
| What are the three measures of emotionality | Activity, thigmotaxis, defecation |
| In the colony-intruder paradigm, rats are placed in a chamber with a _________,_________ rat | larger, dominant |
| How to measure sexual behaviour in female rats | lordosis |
| How to measure sexual behaviour in male rats | Mount to intromission, time to remount after ejeculation |
| 3 views of learning that conditioned taste aversion challenges | step-by-step process, temporal continuity, principle of equipotentiality |
| The morris water maze is used to study _________ ability | spatial |
| conditioned defensive burying is used to study _________ drugs/effects | anti-anxiety |
| pupil size is a compromise between _________ and _________, is regulated by the _________ | sensitivity and acuity, iris |
| The lens focuses light on the _________, in a process called _________ | retina, accomodation |
| When the lens is cylindrical, focus is on a _________ object | near |
| When the lens is flattened, focus is on a _________ object | far |
| Most of what is seen is seen through _________ eyes | both |
| Binocular disparity is greater for _________ things, helps to create _________ _________ | closer, depth perception |
| Predator eye placement | front |
| Prey eye placement | side |
| how many layers in the retina | 5 |
| the fovea has high _________ vision | acuity |
| optic disk involves the _________ spot and _________ | blind, completion |
| Can any species see in absolute darkness? | no, some can see in very little light |
| Wavelength is associated closely with the perception of | colour |
| intensity is closely associated with the perception of | brightness |
| _________ is the turning of the eyes slightly inward when looking at something nearby | convergence |
| In the retina, the cells at the _________ are the first to detect light | back |
| In a sense, the retina is _________ | inside-out |
| Light passes through several _________ layers in the retina before reaching its receptors | cell |
| How many layers are in the retina? | five |
| Receptor layer of the retina | rods and cones |
| horizontal cell layer of retina | lateral communication |
| amacrine cell later of retina | lateral communication |
| The fovea is the _________-_________ area near center of retina | high-acuity |
| The _________ of the ganglion cell later in the fovea reduces _________ from cells between the pupil and the retina | thinning, distortion |
| the optic disk is where axons of _________ ganglion cells penetrate _________, exit eye through optic nerve | retinal, retina |
| the duplexity theory of vision states that cones and rods mediate what? | different kinds of vision |
| cones have _________ (daytime) vision, giving _________ colour information in good lighting | phototopic, high-acuity |
| rods have _________ (night-time) vision, with _________, allowing for low acuity vision in dim light, lacking _________ and colour information | scototpic, high-sensitivity, detail |
| Cones have _________ convergence on retinal ganglion cell cone-fed circuits | low |
| rods have _________ convergence on retinal ganglion cell rod-fed circuits | high |
| only _________ are found at the fovea | cones |
| are cones or rods found in the blind spot? | neither |
| There are different _________ sensitivity curves for photopic and scotopic vision | spectral |
| Quick eye movements (_________) are integrated into a stable perception | saccdes |
| the visual system responds to _________ | change |
| Transduction is the _________ of one form of energy to another | conversion |
| visual transduction is the conversion of _________ to neural signals by visual receptors | light |
| Visual transduction information is transmitted via | inhibition |
| What is the pigment found in rods? | Rhodopsin |
| Rhodospin is a receptor that responds to _________ rather than NTs | light |
| In the dark, rhodopsin Na+ channels are partially _________, (partial _________), _________ glutamate | open, depolarized, releasing |
| When light strikes rhodopsin, Na+ channels _________, rods _________, _________ glutamate | close, hyperpolarize, inhibiting |
| In both eyes, left hits _________ and right hits _________ | right, left |
| Each eye only processes _________ of visual field, contralaterally | half |
| The _________ hemiretina of each eye connects to the _________ lateral geniculate nucleus, | right/left, right/left |
| Magnocellular layers have _________ cell bodies, are the _________ 2 laters of LGN | big, bottom |
| Magnocellular bodies are particularily responsive to _________, input primarily from _________ | movement, rods |
| Parvocellular layers have _________ cell bodies, are the _________ 4 layers of LGN | small, top |
| Parvocellular layers are responsive to _________, _________, _________/_________ objects, and input primarily from cones | colour, detail, still/slow |
| Retinotopic organization of primary visual cortex means that information received at _________ portions of the retina _________ _________ in the striate cortex | adjacent, remains adjacent |
| Edges are points of _________ | contrast |
| Mach bands are _________ striped that the visual system _________ for enhancement | non-existent, creates |
| Mach bands makes edges _________ to see, are a consequence of _________ _________ | easier, lateral inhibition |
| _________ _________ is the area of the visual field within which it is possible for a visual stimulus to influence the firing of a GIVEN neuron | receptive field |
| what was hubel and wiesel's methodology to examine visual fields? | Curare-d a cat, placed extracellular electrode near a neuron, mapped the receptive field |
| In the receptive fields of RGS system neurons, there were _________ seen at all three levels | similarities |
| Receptive fields of _________ area are smaller than those in the periphery | foveal |
| Neuron's receptive fields are _________ in shape, and are _________ (respond to a particular eye) | circular, monocular |
| Many neurons at each level have receptive fields with _________ and _________ areas | excitatory, inhibitory |
| The two patterns of neuronal responding are _________ firing, or _________ followed by off firing | on, inhibition |
| firing responds best to _________ _________ "on" area | fully illuminated |
| firing responds poorly to _________ light | diffuse |
| firing responds to _________ _________ between centers and peripheries of their visual fields | brightness contrast |
| Many cells have receptive fields with a _________-_________ organization | center surround |
| on/off-center neurons have excitatory and inhibitory regions separated by a _________ _________ | circular boundary |
| Most neurons in V1 _________ circular receptive fields | do not have |
| Simple striate cells respond best to _________ of a particular orientation, and are _________ | edges/bars, monocular |
| Complex striate cells respond best to _________ _________ of a particular orientation | moving edges/bars |
| Binocular complex striate cells - over half are _________, the other half display _________ _________ | binocular, ocular dominance |
| End-stopped extrastriate cells respond best to _________ _________ of a particular _________ and orientation | moving edges/bars/corners, length |
| Simple striate cells have _________ receptive fields, with on and off regions that are _________ and _________ sensitive | rectangular, orientation, location |
| all simple striate cells are _________, and send information to _________ cells | monocular, complex |
| Not all visual cortex cells respond to _________ stimuli | previous stimuli |
| Complex striate cells have _________ receptive fields than simple | larger |
| Simple, complex, and end-stopped cells all have a preferred _________ and _________ _________ | orientation, receptive field |
| End-stopped cells fire to _________ _________ of a specific length, or _________ _________/_________ | moving lines, moving corners/angles |
| Ocular dominance columns are _________ vertical columns with the same receptive fields and ocular dominance | functional |
| Is retinotopic organization maintained in ocular dominance columns? | Yes |
| What is the trichromatic theory of colour | 3 types of cone cells, each with a different spectral sensitivity |
| short spectral sensitivity | violet/blue |
| medium spectral sensitivity | green/yellow |
| long spectral sensitivity | orange/red |
| Opponent-process theory of colour processing: | two different classes of cells that encode colour, another to encode brightness |
| which colour processing theory accounts for colour afterimages and colour that cannot appear together? | opponent-process theory |
| Which colour processing theory is correct? | both - colour by cones operates according to componenet theory, while opponent processing is seen at all subsequent levels |
| Colour constancy is the _________ of the same colour despite the change in _________ | perception, wavelength |
| Retinex theory states that colour perception is based on the _________ of light of different wavelengths that a surface reflects | proportion |
| As visual information flows through hierarchy, receptive fields become _________ and respond to ... | larger, more complex and specific stimuli |
| Scotomas are areas of _________ in contralateral visual field due to damage to the _______ _________ cortex | blindness, primary visual |
| Blindsight is a response to visual stimuli outside _________ _________ of "seeing" | conscious awareness |
| what is a possible explanation of blindsight? | island of functional cells within scotoma |
| Lesions in each area of the secondary visual cortex and association cortex result in _________ deficits | specific |
| How many functionally distinct areas have been identified so far in the secondary visual and association cortexes? | 12 |
| What are the two streams of visual processing | Dorsal and ventral streams |
| The dorsal stream is the pathway from _________ to _________ to _________. | primary visual cortex, dorsal prestriate cortex, posterior parietal cortex |
| dorsal stream is the _________ pathway, and for the _________ | where, control of behaviour |
| Ventral stream is the pathway from the _________ to _________ to _________ | primary visual cortex, ventral prestriate cortex, inferotemporal cortex |
| The ventral stream is the _________ pathway, and for the _________ | what, conscious perception of objects |
| Damage to secondary/association cortex may lead to (3) | visual agnosia, prosopagnosia, akinetopsia |
| Visual agnosia is the inability to distinguish between | visual stimuli |
| Prosopagnosia is the inability to distinguish | faces |
| Akinetopsia is a deficiency in the ability to see | movement in a normal, smooth fashion |
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esavoy