Chapter 3- Sensation and Perception Flashcards
Sensation
an electro chemical signal/stimulus that is picked up by sensory receptors
Transduction
when energy from the physical world is converted into an electro chemical signal/ a sensation that is sent to our brain
Perception
the brain selecting, organizing and interpreting the stimulus
Psychophysics
studying the mind’s relation to the physical world
absolute threshold
amount of energy needed to detect a stimulus (50% of the time)
Difference threshold
just noticeable difference
webers law
in order for us to detect a change, we must detect the ratio of the initial stimulus
Signal Detection Theory
a stimulus needs to be intense to be able to detect it
ex:) crowded room you look for someone and shout their name but they still won’t look at you, you whistle (the whistle is loud and a higher octave to pick up) and you are noticed
Sensory adaptation
senses can adjust to different stimuli in an environment and forget that stimulus is there
ex: you get used to wearing jewelry bc your body gets used to it
Wavelengths
distance between the peaks of each wave of energy
Hue
physical property of light (the color that we interpret from wavelengths)
Amplitude
how we experience brightness of color (400-700 nanometers)
Purity/Saturation
whiteness is added to a color making it pure
rods
takes in light to see, helps see basic stuff at night (120 million) evenly distributed in periphery
cones
perceives color, clarity/details, does NOT work in the dark (6 million), scattered in periphery
Foeva
clearest, sharpest vision (only cones in fovea and densely packed)
“We won’t have this FOREVA”
retinal ganglion cells
Makes up the optic nerve which is connected to the eye and brain
optic nerve
carries neural signals from eye to brain to be processed
(made of retinal ganglion cells)
blind spots
Where there is no photoreceptors and our brain cannot make sense of the visual world
where does color exist?
in our minds
blue wavelengths are
short
green wavelengths are
medium
red wavelengths are
long
opponent process theory
green competes w red
yellow competes w blue
black competes w white
left visual field
hits left side of both eyeballs and travels to optin chaism and crosses over to the right hemisphere
right visual field
hits the right side of both eyeballs and travels to optic chasm and crosses over to the left hemisphere
area vi
primary visual cortex, stritate cortex is used to see shapes, edges (outlines)
David Hubel
What we see and process from the ganglion cells in the retina is categorized into several categories(Color, movement, etc.)
Torsten Wiesel
discovered feature (orienation, direction) detectors, groups of neurons in visual cortex that responds to different types of visual stimuli
parallel processing
perceiving many aspects on an object at once
ex:) when you see an object, you see its form, its color, how small it is, its texture, etc.
blindsight
blindness in part of the visual field due to damage to the primary visual cortex
Ventral pathway
object recognition
dorsal pathway
where and how to get the object
“Shark (dorsal) getting to a fish”
gestalt psychology
humans tend to perceive visual info by grouping objects together and perceiving whole shapes and not individual parts
closure
sees images as complete objects
continuity
seeing intersecting lines as a pattern, not the lines individually
similarity
seeing objects that are similar as part of a pattern
proximity
viewing things that are close together as a group
linear perspective
depth perceition where converging paralell lines mean distance
relative size
smaller objects are farther away
relative height
taller objects are further away
texture gradient
closer something is, the more clearly and defined it is. the further away, the more blurry
interposition
object obstruction shows what is closer and further from you
simplicity
mind interprets the most simple thing it can
Ames room
the world isn’t how we see it, perception and perspective is everything
change blindness
people are really bad at detecting visual changes
inattentional blindness
not noticing things when they aren’t the focus of attention
area MT
part of the brain that processes movement/motion
pitch
physical property of sound (high or low frequencies)
Loudness
intensity/amplitude of a sound
cochlea
where transduction occurs in the ear to detect sound, looks like a snail
basil membrane
fluid that vibrates the hair cells in the cochlea to detect sound
hair cells
specialized neurons that are used to process hearing
Area A1
part of temporal lobe of the brain, helps perceive sound
Left hemisphere
processes language
Place Code Theory
higher frequencies are processed closer to eardrum, lower frequencies are processed further from ear drum
temporal code theory
we determine the frequency of a sound by how fast the neuron fires
gate control theory
when pain signals are blocked by touch cells
ex:) bash your shin in a coffee table and it hurts really bad, by rubbing it your blocking pain signals and replacing them with touch signals
myelinated pain
immediate pain, right after harmed
unmyelinated pain
slower pain signals that reminds you to not use that injury or it will not heal
