Flashcards in Tutorial week 9: colour Deck (46)
What color do you see when a light passes through both the red filter and the green filter?
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.
___________ 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
______________ is used to describe the part of the sensory surface that an environmental stimulus must impinge upon to make a neuron fire.
__________ short wavelength
_________ longer wavelength
_________ middle wavelength
___________ colour is caused by the lightness in the surrounding scene
_____ and ______ is when colour constancy is achieved
V1 and V4
__________ is where the primary visual cortex is located
_______ color-coded cells
______ cells responding to moving objects
Neurons in the visual cortex work the same way, except they respond when there is a light stimulating the ___________.
Neurons also have non-spatial ___________________. this describe the type of stimulus necessary to make the neuron work.
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.
___________ 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.
lighting is __________
_____________ is different from artificial light
the light reaching us from the atmosphere is ____________
colour constancy sometimes discount the ___________ because somehow the variation is discounted.
what lobe is responsible for vision - the visual cortex.
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 ___________.
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.
inside is to _________ as outside is to ________
in bluer natural light
What area is tuned for yellow
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.
What have experiments demonstrated that is critical to colour constancy
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
humans have 3 types of ________ and that objects in the world reflect light of different ____________
wavelength sensitive photo-receptors