Sensation and Perception Flashcards
Absolute Threshold
The minimum amount of a stimulus energy required to activate a sensory system (the amount of a stimulus that an individual can perceive)
Difference Thresholds
How different two stimuli must be before they’re perceived as different
Just Noticeable Difference
Ernest Weber
The amount of change necessary to predict the difference between two stimuli: THIS IS A UNIT OF MEASURE (JND)
Weber’s Law
Ernest Weber
What’s important in producing a just noticeable difference is not the absolute difference between stimuli, it is the ratio
Georg von Békésy
Empirical studies led to traveling wave theory of pitch perception which, at least partially, supported Helmholtz’s place-resonance theory
George Berkeley
Developed a list of depth cues that help us perceive depth
Donald Broadbent
Proposed filter theory of attention (attending to something allows it to be processed further), and that selective attention was all or nothing (disconfirming = Cocktail Party Phenomenon which suggests dichotic listening)
Gustav Fechner
Developed Fechner’s Law, which expresses the relationship between the intensity of the stimulus and the intensity of the sensation
Elanor Gibson and Richard Walk
Developed the visual cliff apparatus, which is used to study the development of depth perception
Hermann von Helmholtz
Developed the Young-Helmholtz trichromatic theory of color vision
Developed place-resonance theory of pitch perception
Ewald Hering
Developed opponent process theory of color vision
James Gibson
Studied depth cues (especially texture gradients) that help us to perceive depth
David Hubel and Torsten Wiesel
Studied feature detection in the visual cortex (using single-cell recording) and discovered simple, complex, and hypercomplex cells
Wolfgang Köhler
Developed theory of isomorphism
Ronald Melzack and Patrick Wall
Proposed gate theory of pain
Stanley Smith Stevens
Developed Steven’s law as an alternative to Fechner’s law
John A. Swets
Refined ROC curves in signal detection theory
Ernest Wever & Charles Bray
Proposed volley theory of pitch perception in response to a criticism of the frequency theory of pitch perception
Robert Yerkes and John Dodson
Developed Yerkes-Dodson Law which states that performance is best at intermediate levels of arousal
Fechner’s Law
Expresses the relation between the intensity of a sensation and the intensity of a stimulus
Steven’s Power Law
Relates intensity of a stimulus to the intensity of the sensation
Signal Detection Theory
The idea that other, nonsensory factors influence what a participant says she senses (i.e. experiences, motives, expectations)
Response Bias (signal detection theory)
Measures how risky the subject is in sensory decision making; based on non-sensory factors (measured by hits, misses, false alarms, correct negatives)
Sensitivity
Feature of signal detection theory that measures how well the subject can sense the stimulus
ROC Curve
Receiver Operating Characteristic Curve
Used to graphically summarize a subject’s responses in a signal detection experiment
Proportion of times a signal is reported when presented and when not presented
Stages of Sensory Information Processing
- Reception
- Transduction
- Electrochemical energy is sent to various projection areas in the brain along various neural pathways and can be processed by the nervous system
Transduction
Translation of physical energy into neural impulses or action potentials
Projection Areas
Brain areas that further analyze sensory input
Cornea
Clear dome-like wondow in front of the eye that gathers and focuses incoming light
Pupil
Hole in the iris that contracts and expands to let less or more light in
Iris
Colored part of the eye. Has involuntary muscles and autonomic nerve fibers. Controls the size of the pupil
Lens
Right behind the iris, helps control the curvature of light entering and focuses near or distant objects on the retina
Retina
In the back of the eye, like a screen - is the image detecting part of the eye. Contains rods and cones
Blind Spot
Where the optic nerve leaves the eye - there are no photoreceptors there
Cones
Photoreceptor dealing with color vision and fine detail. Most effective in bright light. Allows us to see chromatic and achromatic colors. Each cone has its own bipolar cell connection to the brain (“private line”)
Rods
Photoreceptors that only detect achromatic colors (light but no hue). They have low sensitivity to detail and work best in reduced illumination. There are more rods than cones. Rods share a bipolar cell connection to the brain (“party line”)