Flashcards
Optic neural coding - HSC 350
Cards in this deck (44)
- 1What does opponent-process coding explain?Our perception of hues
- 2In colour-opponent P-ganglion cells, response to one wavelength in the receptive field center is ______ by showing another wavelength in the receptive field aroundcancelled
- 3The lack of colour opponency in ____ cells is because both the center and the surround receptive fields recieve input from _____ ____ _____ type of coneM; more than one
- 4M retinal ganglion cells have _____ receptive fields, ____ axon conduction velocities, respond _____ to visual stimuli _____ transmit info about colour. What are the critical functions of M ganglion cells?large; fast; transiently; cannot; high temporal resolution, ie. location, speed and direction of rapidly moving object
- 5P retinal ganglion cells have _____ receptive fields, ____ axon conduction velocities, respond _____ to visual stimuli _____ transmit info about colour. What are the critical functions of P ganglion cells?small; slow; sustained; can; high spatial resolution, i.e. detailed analysis of the shape, colour, and size of objects
- 6What is the most important cause of negative afterimages?Adaptation in the rate of firing if retinal ganglion cells
- 7when ganglion cells are excited or inhibited for a prolonged period of time, they later show a _______ effect, firing _____ or _____ than normalrebound; faster; slower
- 8Which cells are the only cells to leave the retina?ganglion cells
- 9What is the retinofugal projection?Optic nerve, optic chiasm, optic tract
- 10Binocular field of view consists of two symmetrical _____ _______visual hemifields
- 11Left visual hemifield > nasal retina left eye and ____ retina _____ eye > ____ optic tracttemporal; R; R
- 12RIght visual hemifield > nasal retina right eye and ____ retina _____ eye > ____ optic tracttemporal; L; L
- 13Anything that hits the _____ retina crosses over in the optic chiasm and gets processed in the contralateral side of the brainnasal
- 14Anything that hits the _____ retina does not cross over in the optic chiasm and gets processed in the ipsilateral side of the braintemporal
- 15What does the superior colliculus do?orients movements of the head and eyes
- 16What does the pretectum do?reflex control of pupil and lens
- 17What does the hypothalamus do?regulation of circadian rythyms
- 18The stimulated eye recieves the ____ response, while the unstimulated eye receives the ______ responsedirect; consensual
- 19A direct response in the left eye without a consensual response in the right eye suggests a problem with the ______ to the right eyevisceral motor outflow
- 20Failure to elicit a response to stimulation (direct or indirect) of the left eye if both eyes response normally to stimulation of the right eye suggests damage to _____ _____from left eyesensory input
- 21What is the Edingerwestphal nucleus responsible for?pupil dilation/ constriction of both eyes
- 22What is the pathway of retinal ganglion cells that mediates conscious visual perception?1. optic tract 2. LGN 3. Optic radiation 4. primary visual cortex
- 23The LGN contains ___ major cell layers. ( ___ magnocellular, ___ parvocellular)6; 2; 4
- 24each of the 6 layers of the LGN receives projections exclusively from either the _____ or ______ retina, so that individual geniculate neurons are ______, driven by either the left or right eye but not bothipsilateral; contralateral; monocular
- 25P type retinal ganglion cells project exclusively to the _______ LGN; M type retinal ganglion cells project exclusively to the _______ LGNparvocellular; magnocellular
- 26The retinotopic representation is _____ in the LGN projection to V1preserved
- 27posterior regions in the fovea are represented more ____ in the striate cortex, upper visual field is ______ the calcarine sulcus, lower visual field is _______ calcarine sulcus. Hemifields are mapped onto the ______ side of the brainanterior; below; above; contralateral
- 28What are scotomas?small visual field deficits
- 29What are anopsias?large visual field deficits (prefixes indicate the region of damage)
- 306 layers of the striate cortex; Magnocellular LGN neurons project to layer ______, parvocellular LGN neurons project to layer _______4C (IVC); 4B (IVB)
- 31what is ocular dominance?Neurons with similar ocular preference
- 32Mixing of the pathways from the two eyes first occurs in the _______striate cortex
- 33When does binocularity happen?When signals from the two eyes are combined at the cellular level in the striate cortex; provides basis for stereopsis (depth sensation)
- 34When does binocular disparity happen?When disparity between the two eye views of objects nearer or father than the fixation point is interpreted as depth
- 35What do cortical far cells do?discharge to disparities beyond the plane of fixation
- 36What do near cells do?respond to disparities in front of the plane of fixiation
- 37What is preferred orientation?The orientation to which a cell is most responsive to
- 38Other cortical neurons are sensitive to the _____ or _____ of an object in the visual fieldlength; direction
- 39orientation-selective neurons are thought to be specialized for the analysis of _______object shape
- 40What does the dorsal stream of the visual area process?"where"; spatial aspects of vision, anaylsis of motion, positional relationships between objects in the scene, direction-selective neurons
- 41What is akinetopsia?inability to perceive motion
- 42What does the ventral stream process?high resolution from vision and object resolution
- 43What is prosopagnosia?inability to recognize faces
- 44What are the 2 extreme hypotheses on how neurons encode visual percepts?1. Schemas that rely on an implicit representation over a very broad and distributed population of neurons
2. Schemas based on the explicit representations by highly selective 'grandmother' neurons; brian has a separate neuron to detect and represent every object
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- Flashcards on Optic neural coding - HSC 350, created by Suh Dude on 21/02/2015.
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