Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Visual Path & Percep
Lec 3: Perception Lec 4: Visual System Readings: Sacks & McCloskey
| Question | Answer |
|---|---|
| Perception | the means by which info acquired from the environment via the sense organs is transformed into experiences |
| stages in perception | distal stimulus > proximal stimulus > percept |
| distal stimulus | the thing at a distance from you in the world you are trying to perceive |
| proximal stimulus | the pattern that the distal stimulus projects on to our sensory organs |
| percept | our mental representation |
| lack of correspondence | when the percept does not correspond to the distal stimulus |
| paradoxical correspondance | when the proximal stimulus does not correspond to the distal stimulus, but the percept does |
| perceptual constancy | our perception of an objects features remains constant even when viewpoint (and proximal stimulus) changes |
| size constancy | perception of size doesn't change with distance |
| color constancy | perception of color doesn't change with light |
| shape constancy | perception of shape doesn't change with angle |
| Direct perception (stimulus theory) | environment provided all necessary cues our brains are pre-wired to pick up cues stimulus information is almost always unambiguous |
| constructivism | perception uses data from the world and our prior knowledge and expectations sensory information is often ambiguous (must rely on knowledge/expectations) |
| bottom-up processing | processing that is driven by the external stimulus, rather than internal knowledge |
| direct perception claims that perception is purely | ...bottom-up |
| top-down processing | processing that is driven by knowledge & expectations |
| constructivism claims that perception is | both a bottom-up and top-down process |
| depth perception | the distal stimulus is 3D but the proximal stimulus on the retina is 2D yet the perceptual experience is 3D |
| depth perception is an example of | ...paradoxical correspondance |
| examples of monocular depth cues are | linear perspective, shape, relative size, interposition, shadows, accommodation |
| monocular depth cues | can see depth cues with only 1 eye |
| examples of binocular depth cues are | retinal disparity |
| interposition | if something is close to you it will obstruct our view of what is behind it |
| binocular depth clues | can see depth cues with both eyes |
| ganglion cell layer is comprised of | ... ganglion cells |
| bipolar cell layer is comprised of | ... amacrine cells, bipolar cells, horizontal cells |
| photoreceptor layer is comprised of | photoreceptors (rods and cones) |
| rods and cones are | photoreceptors |
| rods detect | brightness |
| cones detect | colors |
| what kind of reaction takes place inside photoreceptors when exposed to light | photo-chemical reaction |
| cones are concentrated in the | ... fovea |
| color vision problems are because what photoreceptor isn't working properly | cones |
| electrical potential is | the potential to do work |
| threshold | potential must get above a threshold level for neuron to fire |
| firing | generating an action potential |
| all-or-none | action potential always has the same strength. either you get all of if (if above threshold) or none of it |
| propagation | once past threshold, active process (ion pumping) propagates action potential down axon |
| refractory period | short period after firing before neuron can fire again. used to restore the neuron back to resting state & "recode" ions |
| neural transmission | when one neuron fires it can cause neighboring cells to fire or prevent them from doing so so signal can move from one cell to another |
| neurons communicate by sending neurotransmitters across synapses which is triggered by | an action potential when it reaches an axon's end |
| neural transmission is | electrochemical |
| neural transmission involves | an electrical action potential within cells and a chemical neurotransmitter between cells |
| when neurotransmitter is released into synapses | it binds to receptors on target neuron |
| excitatory neurotransmitters | increases the potential & brings it closer to firing |
| inhibitory neurotransmitters | decreases the potential & keeps it from firing |
| summation | if combined effects at all synapses take potential across axon above threshold, then neuron will fire an action potential |
| on-center, off-surround cells | turns on when light is in the center, and turns off when light is surrounding the center |
| off-center, on-surround | turns off when light is in the center & turns on when light is in the surrounding area |
| center-surround organization | are antagonistic & tend to cancel each other out |
| functions of center-surround organization | point detection, edge detection, light-on-dark or dark-on-light |
| lateral geniculate | composed of magnocellular & parvocellular cell layers |
| magnocellular cells | have a transient response (lasting only a short period of time) and large receptive field, and track movement/location |
| parvocellular cells | have a sustained response (maintained at length without interruption or weakening), small receptive field and track patterns/color/form |
| functions of a simple cell | responds to a bar of light, specific orientation, specific retinal position |
| functions of a complex cell | edges, movement, responds to bars of light that are moving |
| hypercomplex cells responds to | very specific shapes, corners, gaps |
| edge detection | edges in images correspond to edges of real-life objects, offer depth cues, allow parts of 3D objects to be identified |
| dorsal "where" pathway | goes from the occipital lobe to parietal lobe |
| ventral "what” pathway | goes from occipital lobe to temporal lobe |
| positron emission tomography | mental activity leads to neural activity which causes blood flow, which leads to more radioactive tracer and more positrons emitted |
| a spatial (where) task should activate | occipital and parietal regions |
| an object (what) task should activate | occipital and temporal regions |
| there is not a grandmother cell | a neuron that has a very specific receptive cell that only fires when you are hearing/seeing/thinking of your grandma |
| the sacks reading described Dr. P who | could not recognize faces & would often mistake inanimate objects as being people, could not see the whole picture only details, difficulties with lefties & visual field deficits, could not make a cognitive judgement but could produce cognitive hypotheses |
| McCloskey reading focused on A.H. a | women with impairment in localizing objects from vision severe/drastic impairment when asked to reach for objects in her visual field reached for objects with ballistic movement impairment in up/down & left/right localization |
| ballistic movement | without changing direction in mid movement |
| the ability to identify objects even when mislocalizing them | adds to evidence that location & identity are processed separately in the visual system |
| errors in a reflection across a vertical/horizontal axis suggests | that visual location representations have multiple components & some may be correct while others are incorrect |
| transient subsystem | specialized for processing rapidly changing visual stimuli |
| sustained subsystem | specialized for processing steady, long-duration, stationary stimuli |
| visual allochiria | an object present in 1 visual half-field is perceived at the corresponding point in the opposite half-field |
| visual allochiria is a rare symptom associated with | parietal or Pareto-occipital pathology |
| if an illusory image is palinoptic then it is | persisting after stimulus was no longer in view |
| in visual disorientation a person | can recognize objects even when can't localize the objects |
| visual disorientation doesn't have a | reflection across a vertical/horizontal axis |
| visual allochiria & disorientation can occur | with acquired brain damage |
| if visual representations are inaccurate in capturing properties | people will see a different visual scene than the real scene |
Created by:
kzegelien2005
Popular Psychology sets