chapter 3 Flashcards
what is sensation?
when our senses react to stimuli
what is perception?
to understand and analyze through our senses
what is stimulus?
Energy that produces a response in a sense organ.
what is psychophysics?
The study of the relationship between the physical aspects of stimuli and our psychological experience of them.
What is the absolute threshold?
smallest amount of a stimulus we can detect
what is the difference threshold?
minimal difference needed to detect a stimulus change (JND)
what is sensory adaptation?
adapting to when our sensory receptors have been exposed to stimuli for a long time
when does sensory adaptation happen?
Happens when people become familiar to a stimulus and change their frame of reference
what does our brain do to stimulation?
our brain mentally turns down the volume
what does sensory adaptation prevent us from doing?
having to continuously respond to unimportant
information
what is selective attention?
a process that allows a person to select and focus on particular input for further processing whole simultaneously suppressing irrelevant information
what is inattention blindness?
the failure to noice a fully visible but unexpected object because attention was engaged on another task
what does vision start with?
Starts with light, the physical energy that stimulates the eye
what is light?
electromagnetic energy that moves in waves. Measured in wavelengths
what does the size of the wave correspond to?
to different types of energy
what is the visual spectrum?
the range of wavelengths that humans are sensitive to (its small).
what are rods?
more numerous and more sensitive to light, enable us to see in dim light, however, we compromise our color vision and fine detail.
what are cones?
allow us to see in color and fine detail, most sensitive in brightly lit conditions
what is dark adaptation?
the phenomenon of adjusting to dim light after being in bright light.
what is feature detection?
The activation of neurons in the cortex by visual stimuli of specific shapes or patterns. Found that some cells are activated only by lines of a particular width, shape or orientation.
what is Trichromatic theory of colour vision?
color perception results from mixing three distinct color systems (red, green, and blue)
what does the trichromatic theory of colour vision suggest?
that there are three kinds of cones in the retina
what is perception of colour influenced by?
by the relative strength with each of the three kinds of cones activated
Talks about colour blindness
what is the opponent process theory of colour vision?
The theory that receptor cells for colour are linked in pairs, working in opposition to each other.
what is sound?
movement of air molecules in a particular wave pattern.
sounds arriving at the outer ear in the form of wave like vibrations are funnelled into where?
the auditory canal (leads to the eardrum)
what do sound waves vary in?
length (wavelength)
height (amplitude): distinguish between loud and soft sounds
what are low frequencies translated into?
into a sound that is very low in pitch
what is the lowest frequency that humans are capable of hearing?
20 cycles per second
how many separate smells can we detect?
10,000
what are the four tastes?
sweet, sour, salty and bitter
do taste buds replace themselves?
Replace every 10 days because we would lose our ability to taste after we burn our tongues
what do skin senses involve?
touch (or pressure), temperature, and pain. Operate through nerve receptor cells
are skin senses evenly distributed throughout the body?
no
what are illusions?
false or misleading perceptions help scientists study the processes of perception (e.g., the horizontal-vertical illusion)
selection involves which three factors?
Selective Attention
Feature Detectors
Habituation
what is organization (understanding perception)?
assembling of information into patterns that help us understand the world
what do we organize sensor information in terms of?
Form
Constancy
Depth
Color
what are the different things of form perception?
figure and ground, proximity, continuity, closure, similarity, simplicity
what is proximity?
we perceive elements that are closer together as grouped together. We tend to see pairs of dots rather than a row of single dots
what is closure?
we usually group elements to form enclosed or complete figures rather than open ones
what is simplicity?
we perceive it in the most basic, straightforward matter that we can
what is top down processing?
Perception that is guided by higher-level knowledge, experience, expectations, and motivations.
what is bottom up processing?
Perception that consists of the progression of recognizing and processing information from individual components of a stimuli and moving to the perception of the whole.
what does bottom up processing let us process?
the fundamental characteristics of stimuli
what is figure ground?
is the most fundamental principal of gestalt psychology
what is the essential point of gestalt?
gestalt is that in perception the whole is different from the sum of its parts
what is perceptual constancy?
The phenomenon in which physical objects are perceived as unvarying and consistent despite changes in their appearance or in the physical environment.
what are the four best known constancies?
size, shape, colour, brightness
what we believe can affect what?
what we perceive
what can influence perceptions of sensory information?
emotions (fear)
we are more likely to perceive what?
something when we need it
what is depth perception?
from 2d-3d
what is binocular disparity?
the difference in the images seen by the left eye and the right eye
what does depth perception involve?
both binocular (two eyes) and monocular (one eye) cues.
what is motion parallax?
: is the change in position of an object on the retina caused by the movement of your body relative to the object
what are the two binocular cues for depth?
Retinal disparity
Convergence
what are the six monocular depth cues?
linear perspective, interposition, relative size, texture gradient, aeiral perspective, light and shadow
what is linear perspective?
estimating distance, allowing the two dimensional image on the retina to record the three dimensional world (parallel lines, think of a road)
what is relative size?
if two objects are the same size, the one that makes a smaller image on the retina is farther away than is the one that provides a larger image
what is texture gradient
provides information about distance because the details of things that are far away are less distinct
what is perceptual adaptation?
brain adapts to changed environments
what is perceptual set?
readiness to perceive in a particular manner, based on expectations
what is frame of reference?
based on the context of the situation
what is aerial perspective?
Objects that are farther away seem to be blurred or slightly hazy due to the atmosphere
what is interposition?
When one object overlaps another, the object that is partially obscured is perceived as being farther away
what is light and shadow?
Objects that are darkened and obscured may appear further off in the distance than those that are brightly lit
what is perceptual constancy?
is theperceptionof an object or quality as constant even though oursensationof the object changes
what is shape constancy?
Regardless of changes to an object’s orientation (such as a door opening), the shape of the object is perceived the same
what is brightness constancy?
Light-colored things look light, even in dimly lit surroundings. Dark-colored things look dark, even on the brightest days
what is colour constancy?
Color constancy is the tendency of objects to appear the same color even under changing illumination (eg: yellow banana in sunlight vs. our kitchen with the lights off)
How Do People Distinguish Between Figure and Ground?
size, contract, blurriness and separation
what is weber law?
when talking about difference thresholds there is a constant proportion of intensity of an initial stimulus that causes the difference.
