UNIT #3 Sensation And Perception Essential Q and V (P.1) 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 info, enabling us to recognize meaningful objects and events
Absolute threshold
The minimum stimulation needed to detect a particular stimuli 50% of the time
Difference threshold
The minimum difference between two stimuli required for detection 50% of the time. We experience the difference threshold as a just noticeable difference
Retina
The light-sensitive inner surface of the eye, contains the receptor rods and cones plus layers of neurons that begin the processing of visual info
Rods
Retinal receptor that detect black, white and gray ; necessary for peripheral and twilight fusion 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 detail and give rise to colour sensations
Fovea
The central focal point in the retina, around which the eyes’s cones cluster
Optic Nerve
The nerve that carries neural impulses from the eye to the brain
Blind spot
The point at which the optic nerve leaves the eye, creating a “blind spot” because no receptor cells are located there
Middle ear
The chambers between the eardrum and cochlea containing three time bones (hammer, anvil and stirrup) that concentrate the vibrations of the eardrums on the cochlea’s oval window
Ear drum
The eardrum is a thin flap of skin that is stretched right like a drum and vibrates when the sound hits it. These vibrations move the tiny bones of the middle ear then to the inner ear and send messages
Cochlea
A coiled, bony fluid-filled tube in the inner ear ; sound waves traveling through the cochlear fluid trigger nerve impulses
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
Bottom-Up processing
Analysis that begins with the sensory receptors and works up to the brain’s integration of sensory info
Top-Down processing
Info processing guides by higher-level mental processes as when we construct perceptions drawing on our experience and expectations
Colour constancy
Perceiving familiar objects as having consistent colour, even if changing illumination alters wavelengths reflected by the object.
Selective attention
The focusing of conscious awareness of a particular stimulus
Inattentional blindness
Failing to see visible objects when our attention is directed elsewhere
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 relationships between the physical characteristics of stimuli such as their intensity and our psychological experience
Signal detection theory
A theory predicting how and when we detect the presence of a faint stimulus amid background stimulation. Assumes that there is no single absolute threshold and that detection depends partly on a personals experience, expectations, motivation and alertness
Subliminal
Below ones absolute threshold for conscious awareness
Priming
The activation, often unconsciously of certain associations thus predisposing one’s perception, memory or response
Sensory adaptation
Diminished sensitivity as a consequence of constant stimulation
Perceptual set
A mental predisposition to perceive one thing and not another
Extrasensory perception (ESP)
The controversial claim that perception can occur apart from sensory input ; includes telepathy, clairvoyance and precognition
Parapsychology
The study of paranormal phenomena including ESP and psychokinesis
Wave length
The distance from the peak or one light or sound wave to the peak or the next. Electromagnetic stimulation age lengths vary from the short blips of cosmic rays to the long pulses of radio transmissions
Hue
The dimension of colour that is determined by the wavelength of light; what we know as the colour names blue green and so forth
Intensity
The amount of energy in a light or sound wave which we perceive as brightness or loudness as determined by the wave’s amplitude
Pupil
The adjustable opening in the center 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 of the pupil opening.
Lens
The transparent structure behind the pupil that changes shape to help focus images on the retina
Accommodation
The process by which the eye’s lens changes shape to focus near or far objects on the retina
Feature detectors
Nerve cells in the brain that respond to specific features of the stimulus such as shape, angle or movement
