Chapter 3.1 & 3.2 Flashcards
perception
a mental process that brings understanding to what one sees
transduction
transformation of one form of information into another
absolute threshold
the amount of stimulation needed for something to be detected
difference threshold
the smallest amount that something can be changed and a difference can be detected half the time
weber’s law
the concept that the size of the “Just Noticeable Difference” is proportional to the intensity of the stimulus; the JND is large when the intensity is high and small when the intensity is low
signal detection theory
explains how we detect signals consisting of stimulation affecting our senses. Sensation is a judgement that the sensory system makes about the incoming stimulation that usually occurs outside of consciousness. This also takes the observer characteristics into account
sensory adaptation
loss of responsiveness in receptor cells after stimulation has remained unchanged for a while, as when a swimmer becomes adapted to the temperature of the water
retina
the thin light-sensitive area at the back of the eyeball containing million of photoreceptors and other nerve cells
photoreceptors
light-sensitive neurons in the retina that convert light energy to neural impulses; light does not get past these
rods
photoreceptors that are especially sensitive to dim light but not to colors…125 million in the retina
cones
photoreceptors that are especially sensitive to colors but no dim light…7 million in the retina
fovea
tiny area of sharpest vision in the very center of the retina
optic nerve
the bundle of neurons that carry that carry visual information from the retina to the brain
blind spot
the point where the optic nerve exits the eye and where no photoreceptors exist, creating a point which cannot be seen
brightness
a psychological sensation caused by the intensity (amplitude) of light waves
color
also called hue; it is not a property of the external world but only a sensation that is created in the brain using the information sent from the retina
electromagnetic spectrum
entire range of electromagnetic energy including radio waves, x-rays, microwaves, and visible light
visible spectrum
the tiny part of the electromagnetic spectrum in which our eyes are sensitive
trichromatic theory
the idea that colors are sensed by three different types of cones sensitive to light in the red, green, and blue wavelengths; explains earliest stage of color sensation
opponent-process theory
the idea that cells in the visual system process colors in complimentary pairs (red/green or yellow/blue); explains color sensation from bipolar cells onward
afterimages
sensations that linger after the stimulus has been removed; most are negative, appearing in reversed colors
color blindness
a genetic disorder that prevents a person from discriminating color; most common form is red-green
frequency
the number of cycles completed by a wave in a second (width of the wave)
amplitude
the physical strength of the wave (height of the wave)
tympanic membrane
eardrum
cochlea
primary organ of healing; coiled tube in inner ear where sound waves are transduced into neural messages
basilar membrane
thin strip of tissue sensitive to the vibrations in the cochlea that contains hair cells connected to neurons; when the hair cells vibrate, transduction occurs
pitch
sensory characteristic of sound produced by frequency of the sound wave (width of wave)
loudness
sensory characteristic of sound produced by loudness of the sound wave (height of wave)
timbre
quality of the sound derived from the wave’s complexity
vestibular sense
the sense of body orientation in respect to gravity; associated with the inner ear
kinesthetic sense
the sense of body position and movement of body parts in relation to each other
pheremones
chemical signals released by organisms to communicate with other members of their species; human use is unclear
olfaction
the sense of smell
gustation
the sense of taste
skin senses
sensory systems for processing touch, warmth, cold, texture, and pain
synesthesia
mixing of the sensations across the senses; numbers are colors, tastes like a shape
gate-control theory
explanation for pain control that proposes that we have a “neural gate” that can, under certain circumstances, block incoming pain signals
placebo
substances that appear to be a drug but are not; sugar pills
placebo effect
the response to a placebo caused by thinking it is a real drug
