Exam 2 Review (11/3) Flashcards
Sensation
the detection of physical energy by sense organs (by cells in eye, nose, ear, skin, and tongue)
Transduction
Conversion of stimulus to electrical signal
Perception
the brain’s interpretation of raw sensory input
What do sensation and perception do?
Sensation gathers info from the external world, and perception helps us make sense of the info
Absolute threshold
the smallest amount of stimulus we can detect at least 50% of the time
Just noticeable difference (JND)
the smallest change we can detect in stimulus strength
Sensory adaption
a decrease in the noticeability of a stimulus over time
- happens at the sensory receptor level (e.g. candle scent)
True or False: our perceptual experience is a direct translation of sensory input
- False
We use more than just sensory input to make sense of the world
perception = sensory input+past perceptions+context+guesses
we need this, partly, bc the sensory input isn’t always clear or complete
Signal-to-noise ratio
sometimes the stimulus is unclear so our brain makes its best guess
Perceptual constancy
the process by which we perceive stimuli consistently across varying conditions
Shape constancy
where an object is perceived as having the same shape when viewed at different angles (e.g. door)
Color constancy
our ability to perceive colors as relatively constant over varying illuminations (light sources)
Visible light
wavelength: 400nm - 700 nm of light
Pupil
a hole that allows light into the eye
Iris
colored part, muscle that controls pupil
Cornea
outside covering that helps protect and focus light
lens
a disc that focuses light on the back of the eye
- lens inverts the image as it focuses it
Retina
membrane on the back of the eye containing sensory receptors
Optic nerve
transmits visual signals to the rest of the brain
Fovea
area of the retina where light is focused
Why care about fovea?
light focused on the fovea controls how well you see
Myopia
nearsighted: light focuses too soon
Hyperopia
farsighted: light focuses too late
Visual System
- the eye
- photoreceptors
- color vision