Sensation and Perception - Will Flashcards
Define sensations
features of the environment that the brain uses to create meaning
define perception
an understanding of the world made based off of processed stimuli
What is bottom-up processing?
neural processing that starts with the sensation
What is top-down processing?
combining sensation with with our understanding of the world
What are the 3 musts of sensation?
Detection
transduction - translated into a message the brain can understand
transmission - message sent to the brain
What is psychophysics?
The study of the link between characteristics of the physical world and the understanding of them.
Define absolute threshold
It is the minimum amount of stimulation needed for us to notice something 50 percent of the time.
What are the 6 Gestalt principles and briefly describe them.
- Principle of proximity - objects close to each other will be perceived as groups
- Principle of similarity - objects that are physically similar to each other will be grouped together
- Principle of closure - people tend to perceive whole objects when parts are missing
- Principle of good continuation - When people see two crossing lines, they assume they continue.
- Principle of common fate - objects moving together will be perceived as a group
- Principle of figure ground - people instinctively see things as part of the foreground or background
What wavelengths can people typically see?
400-700nm
What determines the hue of a colour?
Wavelength determines it. Longer wavelengths will be on the red side of the spectrum and shorter wavelengths will move towards the purple side.
What determines the brightness of a colour?
The amplitude of the wave.
What is the retina?
The thin layer on the back of the eye that contains photosensitive receptor cells.
What is the cornea?
The front of the eye, the first thing light passes through. It focuses most of the image.
What is the pupil?
The hole in the eye that light can go through. It expands and contracts based off stimuli.
What is the iris?
It is the ring of tissue around the pupil. It contracts and dilates the pupil.
What process is accommodation? What part of the eye does it use?
Accommodation is the lens (the layers of tissue behind the pupil) changing shapes in order to bring them into focus in the retina.
When using close vision, what is the shape of the lens?
Thicker and rounder.
If I have myopia what is the problem with my lens? What can I see well?
Myopia (nearsightedness) mean my eye lenses are too long so I cannot see objects far away.