chapter 3 Flashcards
What is sensation?
An involuntary process but which our senses receive information from the environment
Occurs when a receptor cell is stimulated
What is perception?
Higher order processing of sensory information which is in part dependent upon previous knowledge
What is top down processing?
strategy of information processing and knowledge ordering, starting first with the high-level aspects and then working your way down to the fine details.
An example of this would be recognizing someone you know.
What is bottom up processing?
strategy of information processing and knowledge ordering, known as “small chunk” processing and suggests that we attend to or perceive elements by starting with the smaller, more fine details of that element and then building upward until we have a solid representation of it in our minds.
An example of this would be trying to figure out something diferent about someone you know.
What is psychophysics?
In psychology, the study of relationships between physical stimuli and resulting sensations/mental states.
What is Just Noticeable Difference?
The size of the of the difference in a stimulus characteristics needed for a person to detect a difference between two stimuli or a change in a single stimulus.
What is Difference Threshold?
is the minimum difference in stimulation that a person can detect 50 percent of the time
What is Weber’s Law?
A constant percentage of magnitude change is necessary to detect a difference - calculated to be about 5%
What is Absolute Threshold?
The magnitude of the stimulus needed, on average, for an observer to detect it half the time it is present.
What is the stroop affect?
test that demonstrates interference in task reaction time. This particular test uses words that name colors, but then print those names in a color different from the one being named. For example, the word “Blue” may be written in red. When asked to read these words aloud, a mental conflict occurs between the task of reading the word and identifying the color and requires more mental effort to actually perform the task itself.
What is the signal detection theory?
What people detect signals in some situations but not in others? (Sensativity - too faint to notice, Bias-how vitaly important is it to detect the signal correctly)
Signal is always embeded in noise
What is attention as it relates to awareness?
The focus on particular information
What is selective attention?
Particular object, quality or event for detaited analysis. purposely focusing your conscious awareness onto a specific stimulus.
What is light energy called and how is it measured?
Photons! And it’s measured by:
Amplitude: the height of the waves in a light waveor sound wave
Frequency: The number of light wavesor sound waves that move past a given point per second
Wavelength: The distance between the arrival of peaks of a light wave or sound wave
What light wave length (in nanometers) can the human eye detect?
400-700nm
What are rods?
very sensative to light, allow us to see shades of grey, white and black
each eye contains 100-120 million rods
gross detail, night/low light vision
What are cones?
not as sensative to light, but allow us to see color
each eye contains 5-6 million cones
fine details and daytime light
What is transduction?
When the eye converts electromagnetic energy that is light into neural impulses/signals.
What is accomodation?
Adomatic adjustment the eye makes to see at particular distances
What is dark adaption?
Process that leads to increased sensativity to light after being in the dark
what does the pupil do?
regulates light
what does the iris do?
contains the muscles that contract the eye
what does the cornea do?
protects the eye from injury
what is the retina?
sheet of tissue at the back of the eye, containing receptor cells that convert light to neural signnals
what is the fovea?
area of retina with the highest density of cones and highest resolution
what is the optic nerve?
axons of ganglion cells are gathered into a single large cord
what are ganglion cells?
collect signal from retina and pass to optic nerve
Why do we see color
evolution, neded to see edible fods, better survival
What are the properties of color?
Hue: Differing wavelengths produce different colors
Satuation: Purity of input (amount of white mixed in)
Lightness: amplitude of waves
What is the trichromatic theory?
the eye has 3 kinds of color sensors. Cones detect specific wavelenth s and blend together to product colors
What is the opponent process theory?
in some pairs of color, the presences of one color inhibits our sensing the other color in the same location on the retina (complementary colors)
What is after image?
image left being by previous perception
What are opponent cells
respond to one colors from a pair at a time and inhibit sensing the other color form the pair
what is color blindness?
can’t distinguish between one or more hues from each other, or can’t see hues all together. Some people can’t see the a particular wave length etc
Most of the time it’s genetic and from birth
What is figure in perceptual organization?
A set of perceptual characteristics (such as shape, color and texture) that correspond to an object
What is ground in perceptual organization?
The background
Describe the gestalt principles
Proximity: objects near one another are grouped together as a perceptual unit
Continuity: Visual characteristic that fall along a smooth curve or a straight line tend to be grouped together.
Similarity: similar items tend to be grouped together including by lightness, orientation, size
Closure: fill in missing parts of a shape
Good form: visual characteristics that form a single shape are grouped together
What are bionocular cues?
cues to distance when both eyes are working together
What is retinal disparity?
The difference between the images striking the retinas of the two eyes; also called binocular disparity