Flashcards in Tutorial week 9: colour Deck (46)
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1
What color do you see when a light passes through both the red filter and the green filter?
yellow
2
what is the problem with colour constancy
a particular wavelength combination reflected from a surface (and the particular combination of excitation in the 3 cone types) can yield experience of different colors in different situations.
3
___________ applies to all sensory systems. it is fundamental to understanding perception and you should make sure you understand it well.
the concept of receptive field
4
______________ is used to describe the part of the sensory surface that an environmental stimulus must impinge upon to make a neuron fire.
receptive field
5
__________ short wavelength
blue
6
_________ longer wavelength
red
7
_________ middle wavelength
green
8
___________ colour is caused by the lightness in the surrounding scene
black
9
_____ and ______ is when colour constancy is achieved
V1 and V4
10
__________ is where the primary visual cortex is located
VI
11
_______ color-coded cells
V4
12
______ cells responding to moving objects
V5
13
Neurons in the visual cortex work the same way, except they respond when there is a light stimulating the ___________.
retina
14
Neurons also have non-spatial ___________________. this describe the type of stimulus necessary to make the neuron work.
tuning characteristics
15
for ____________ it's the same, not all touch neurons respond to the same type of touch: if pressure on a patch of skin makes a neuron in this cortex fire, the same neuron might not respond to changes in temperature.
somatosentation
16
___________ refers to our ability to perceive different objects as always having the same colour independently of where we see them, or in what lighting conditions.
color constancy
17
lighting is __________
artificial
18
_____________ is different from artificial light
sunlight
19
the light reaching us from the atmosphere is ____________
blue
20
colour constancy sometimes discount the ___________ because somehow the variation is discounted.
illuminant
21
what lobe is responsible for vision - the visual cortex.
occipital lobe
22
the cortical processes that provide colour constancy are not well understand, what is known is that some cells found in the first part of the visual cortex - ___________ - are tuned for a certain combination of wavelength of light, more specifically they sum up the different cones excitation with a different weight for each cone. These cells get their input from the ___________.
area V1
photoreceptors
23
In _________cells respond in more complex fashion. in a way that corresponds more to the perceived colour of an object. in other words, cells in ________ have activity that parallels our conscious experience.
area V4
24
inside is to _________ as outside is to ________
artificial light
in bluer natural light
25
What area is tuned for yellow
V4
26
in ___________, the surface appears yellow will reflect lots of long (reddish) and middle (greenish) wavelengths, but not much short (blueish). here, we could find cells that would fire to this combination of reflected light. if the surface is outside, the reflected light will be different, it will contain more short wavelengths because of the blue light and proportionality less long and middle wavelength. in this area, the cells that fired inside will not fire now, different cells will respond, so constancy is NOT apparent. in this area, but it is in V4.
V1
27
What have experiments demonstrated that is critical to colour constancy
wavelength distribution
28
the perceived colour of an object depends on the relative amount it excited in the 3 kinds of cone and the ____________ in each of the 3 come channels
relative brightness
29
humans have 3 types of ________ and that objects in the world reflect light of different ____________
wavelength sensitive photo-receptors
Wavelength
30