Visual perception (Part 1) Flashcards
What are the 2 aspects that help us experience vision?
- Visual sensation
- Visual perception
Define visual sensation
The process of the eye receiving and responding to light
Define visual perception
Interpreting the information
What are the 5 stages of perception (in order)?
- Reception
- Transduction
- Transmission
- Selection
- Organization/ interpretation
Explain the process of reception
Light is captured by sensory receptors in the eye
In order, state the 7 locations of reception
- Cornea
- Aqueous humor
- Pupil
- Lens
- Vitreous humor
- Retina
- Optic nerve
What does the frequency of light waves determine?
Colour
What does a high light wave amplitude mean?
Brighter colours
What are photoreceptors? Where are they located?
Light sensitive cells (rods and cones) located in the retina
What is the different between Rods and Cones?
Rods: don’t detect colour, cylinder shape, peripheral vision, night vision
Cones: Shaped like cones, colour vision
Explain the process of transduction
The conversion of electromagnetic energy to electrochemical (light to action potential)
What is a receptor field?
Small groups of photoreceptors influenced by light to produce neural impulses
What is visual field?
Comprised of many receptor fields
Explain the process of transmission
Sending info from the retina to the primary visual cortex, via the optic nerve
What side of the visual field does the right primary visual cortex
Left
What is the optic chiasm
The cross over point between left and right
Explain the process of selection
The process of differentiating the various components that makeup visual images
What are feature detection neurons?
Detect attributes such as shape, size, orientation and motion
What experimenters gained evidence for the feature detection neuron function? What was their experiment?
Hubel and Wiesel 1979
Examined neuron within the visual cortex of cats under anesthesia to see how they responded to visual attributes
What was Hubel and Wiesel (1979) key findings?
- Found that detector neurons are organized systematically
- Primary visual cortex is developed directly after birth
Explain the process of interpretation
Interpretation of visual stimulus is dependent on DEPTH CUES, VISUAL CONSISTENCIES, PERCEPTUAL SET, CULTURAL CONTEXT
What kind of influence is ‘refractory errors’?
How is it caused?
Biological
Abnormalities in the cornea
What are the 2 main types of refractory errors? Explain them.
- Myopia (short-sidedness - can see close): light is focused on the front of the retina
- Hyperopia (long-sidedness - can see far): light is unfocussed when it hits the retina
What are 4 main types of age-related visual issues? describe them
- Age-related Macular Degeneration (MD)
- Presbyopia: the lens is too loose
- Cataracts: Opacities that cause blur or glare
- Glaucoma: Damaged optic nerve = blind spots
TRUE OR FALSE: Genetics can influence visual perception
TRUE
