Unit 4: Sensation & Perception Flashcards
sensation
the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment
perception
the process of organizing and interpreting sensory information, allowing us to recognize important objects and events
sensory receptors
sensory nerve endings that respond to stimuli
bottom-up processing
beginning with the sensory input, the brain attempts to comprehend from there
top-down processing
led by experiences and higher-level processes, we comprehend what our brains are familiar with and what we want to see
selective attention
our tendency to focus on just a particular stimulus among the many that are being received; although we are surrounded by sights and sounds, smells and tastes, we tend to pay attention to only a few at a time
inattentional blindness
failing to see visible objects when our attention is directed elsewhere
cocktail party effect
the ability to focus your attention on one particular voice in hubbub, a great example of selective attention
change blindness
failing to notice changes in the visual environment
transduction
conversion of one form of energy, such as light waves, into another form, like neural impulses that our brain is able to interpret
What is the transduction process?
a. receive sensory information
b. transform the stimulation into neural impulses
c. deliver the neural information to the brain for processing
psychophysics
the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them
absolute threshold
the minimum stimulus energy needed to detect a particular stimulus 50% of the time
signal detection theory
a theory predicting how and when we predict weak signals; this theory assumes that there is no single absolute threshold and that detection depends partly on a person’s experiences and expectations
subliminal
below one’s absolute threshold for conscious awareness
difference threshold
the minimum difference between two stimuli required for detection 50% of the time
priming
the action, often unconsciously, of certain associations, thus predisposing one’s perception, memory, or response
Weber’s law
to be perceived as different, two stimuli must differ by a constant minimum percentage, rather than a constant amount
sensory adaptation
diminished sensitivity as a consequence of constant stimulation
perceptual set
a mental predisposition to perceive one thing and not another; we see what we expect to see
extrasensory perception (ESP)
the controversial claim that awareness can occur partly from sensory input; includes telepathy (mind-to-mind communication), clairvoyance (seeing remote things), and precognition (seeing the future)
parapsychology
the study of paranormal phenomena, including ESP and psychokinesis (the ability of the mind to move objects)
wavelength
the distance from the peak of one light or sound wave to the peak of the next
hue
the dimension of color that is determined by the wavelength of the light; colors like blue, red, green, etc.
intensity
the amount of energy in a light wave or sound wave, which influences what we perceive as brightness or loudness; intensity is determined by the wave’s amplitude
cornea
the eye’s clear, protective outer layer covering the pupil and iris; light enters the eye first through the cornea
pupil
a small adjustable opening in the center of the eye through which light passes
iris
a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening by expanding and contracting over the pupil
lens
the transparent structure behind the pupil that changes shape to help focus images on the retina
retina
the light-sensitive inner surface of the eye, containing the receptor rods and cones + layers of neurons that begin the processing of visual information
accommodation
the process of lens changing its curvature to focus the rays
rods
retinal photoreceptors on the side of the eye that detect black, white, and gray and are sensitive to movement; responsible for peripheral vision
cones
retinal photoreceptors that are concentrated near the center of the retina and function in daylight or in well-lit conditions; detects fine detail and create color sensations