Sensation and Perception Flashcards
Max Wertheimer
Founder of Gestalt Psychology and the phi phenomenon
Limen
Another word for threshold (e.g., subliminal)
Difference threshold
Would compare a standard stimulus and a comparison stimulus to find the difference threshold
Weber’s Law
What’s important in producing a just-noticeable-difference is not the absolute difference between the two stimulus, but the ratio of them. Change in intensity divided by standard stimulus equals K (K is Weber’s fraction/constant)
Just-noticeable-difference (JND)
One JND needs to be added to or subtracted from a stimulus for a person to say that they notice the difference.
Fechner’s Law
“Sensation increases more slowly as intensity increases”. The purpose of this law is to relate the intensity of the stimulus to the intensity of the sensation.
S.S. Steven’s Power Law
Was an alternative suggestion to Fechner’s law. It also relates the intensity of the stimulus to the intensity of the sensation.
Response bias
The tendency of subjects to respond in a particular way to to non sensory factors.
Receiver operating characteristics (ROC)
Curves employed by many researchers to graphically summarize a subject’s responses on the signal detection experimental (hits, misses, false alarms, correct negatives) by measuring the operating (sensitivity) characteristics of a subject receive signals.
John A. Swets
Refined the use of the ROC curve.
Duplicity (or duplexity) theory of vision
States that the retina contains two kinds of photoreceptors.
True or false: In addition to being used for color vision, they also perceive fine detail
True. This is due to the small number of cones covering onto individual ganglion cells
Nasal fibers
The fibers from the eyes that cross to the opposite side of the brain (e.g., left eye to right brain) in the optic chiasm
Feature detection theory
Certain cells in the cortex are maximally sensitive to certain features of stimuli (simple, complex, hypercomplex)
Illumination
A physical ,objective measure that is simply the amount of light falling on a surface
Brightness
The subjective impression of the intensity of a light stimulus
Rhodopsin
The photopigment of the rod. It is made of a vitamin A derivative called retinal and a protein called opsin.
Dark adaptation
When you adapt to a dark environment, like a move theater. When you first enter you can barely see, but soon your eyes adjust. The initial blindness results from rod bleaching, where rhodopsin is split into retinal and opsin.
Stimulus brightness contrast
A target area of a particular luminance appears brighter when surrounded by a darker stimulus than when surrounded by a lighter stimulus.
Subtractive color mixture
Occurs when we mix pigments (e.g., blue and yellow make green). The mixture of pigments is subtractive.
Additive color mixing
Has to do with LIGHTS. Primary colors here are RBG. Mixing red and green gives yellow.
George Berkely
Listed various cues for depth (e.g., interposition, relative size, linear perspective).