Lecture 17 Flashcards
What does Dark Adaption refer to?
The progressive improvement in brightness sensitivity in low lighting condition
What happens to Photopigments when exposed to light?
They get depleted
What happens to Photopigments in the dak?
They regenerate more quickly because they are not being used
How long does it take for Cones to adapt?
Cones adapt after 10 mins
How long does it take for Rods to adapt?
30 mins
Why do some people work in red light?
Because rods are insensitive to red wavelengths, so being in that part of the spectrum doesn’t affect those photoreceptors. This means someone working under red light can keep their eyes dark adapted
What did Trichromatic theory emerge from?
Observations that any colour can be created by mixing blue, green, and red. (additive colour theory)
What is the Theory proposed by Trichromatic theory?
That there are 3 types of colour receptors in the retina which correspond to the 3 colours
What actually happens contrary to Trichromatic theory?
All cones can be stimulated by light anywhere between 400-700nm to either colour
What does Opponent-process theory believe about colour interpretation?
It proposed that we have 3 types of cones, each which respond to two different wavelengths
What does Dual process theory do?
Combines elements of trichromatic and opponent process theories
What does Dual Process Theory believe?
We have three cone types that are maximally sensitive to three different wavelength. Opponent processes occur in ganglion cells, neurons in visual cortex
What do Trichromats have?
Normal colour vision
What do Dichromats have?
Deficient in one cone system
What are Monochromats?
People who are sensitive to black-white only
What is the relationship between blue light and melatonin?
Blue light reduces the amount of melatonin produced
What is the flow for neural impulses from the eye?
They flow from the eye to the thalamus and onto the primary visual cortex (occipital lobe)
What are Feature detectors?
Neurons that are tuned to respond most strongly to specific characteristics (e.g. shape, orientation, colour, dpeth, movement)
What is Retinotopy?
Two points that are close together on an image formed in the retina will also be processed in areas of cortex that are close together
What is Somatotopy?
The correspondence of an area of the body to a specific point on the central nervous system
What is Parallel Processing?
Different modules in the brain simultaneously processing information related to properties like colour, movement, shape, and distance
Where does all visual information get sent to?
The visual processing cortex
What occurs in the Visual processing cortex do?
Interprets input looking for meaning based on things like prior experience, memories, knowledge
