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, enabling us to recognize meaningful objects and events
bottom-up processing
analysis that begins with the sensory receptors and works up to the brain’s integration of sensory information
top-down processing
information processing guided by hight-level mental processes, as when we construct perceptions drawing on our experience and expectations
transduction
conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brain can interpret
psychophysics
the study of relationship 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 percent of the time
signal detection theory
a theory predicting how and when we dent the presence of faint stimulus (signal) amid background stimulation (noise). Assumes there is no single absolute threshold and that detection depends partly on person’s experience, expectations, motivation and alertness
subliminal
below one’s absolute threshold for conscious awareness
priming
the activation, often unconsciously, of certain associations, thus predisposing one’s perception, memory, or response
difference threshold
the minimum difference between two stimuli required for detection 50 percent of the time. We experience the difference threshold as a just noticeable difference (or jnd)
weber’s law
the principle that, 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
wave length
the distance from the peak of one light or sound wave to the peak of the next. Electromagnetic wavelengths vary from short blips of cosmic rays to the long pulses of radio transmission
hue
the dimension of colour that is determined by the wavelengths of light; what we know as the colour names blue, green and so forth
intensity
the amount of energy in a light wave or sound wave, which influences what we precede as brightness or loudness. Intensity is determined by wave’s amplitude (height)
pupil
the adjustable opening in the centre of the eye through which light enters
iris
a ring of muscle tissue that forms the coloured portion of the eye around the pupil and controls the size if the pupil opening
tens
the transparent structure behind the pupil that changed shape to help focus images on the retina
retina
the light-senstive inner surface of the eye, containing the receptors rods and cones plus layer if neurons that begin the process if visual information
accommodation
the process by which the eye’s lens changes she to focus near or far objects on the retina
rods
retinal receptors that detection black, white and grey; necessary for peripheral and twilight vision, when cones don’t respond
cones
retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. the cones detect fine deal and give rise to colour sensation
optic nerve
the nerve that carries neural impulses from the eye to the brain