Unit Three: Sensation and 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 higher-level mental processes, as when we construct perceptions drawing on our experience and expectations
Selective attention
the focusing of conscious awareness on a particular stimulus
Inattentional blindness
failing to see visible objects when our attention is directed elsewhere
Change blindness
failing to notice changes in the environment
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 + Scientist
the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them
Gustov Fechner- absolute thresholds
Absolute thresholds
the minimum stimulation needed to detect a particular stimulus 50 percent of the time
Signal detection theory
a theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise). Assumes there is no single absolute threshold and that detection depends partly on a 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
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
Absolute threshold for vision
Candle 30 miles away
Absolute threshold for hearing
Watch 20ft away
Absolute threshold for taste
Tsp of sugar in 2 gallons of water
Absolute threshold for smell
Drop of perfume in small 3bed apartment
Absolute threshold for touch
Bee’s wing on cheek from one centimeter away
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
Telepathy
Mind to mind
Clairvoyance
Perceiving remote events
Precognition
Perceiving future events
Psychokinesis
Mind over matter
Hubel and Wiesel
Ind. cells in the brain determine ind. things (lines vs shapes) called feature detectors
Wavelength
the distance from the peak of one light or sound wave to the peak of the next. Electromagnetic wavelengths vary from the short blips of cosmic rays to the long pulses of radio transmission
Hue
the dimension of color that is determined by the wavelength of light; what we know as the color 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
Cornea + water under
protects the eye and bends light to provide focus, aqueous humor
Pupil
the adjustable opening in the center of the eye through which light enters
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
Lens + jelly behind
the transparent structure behind the pupil that changes shape to help focus images on the retina, vitreous humor
Retina
the light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information
Accommodation
(1) in sensation and perception, the process by which the eye’s lens changes shape to focus near or far objects on the retina
(2) in developmental psychology, adapting our current understandings (schemas) to incorporate new information
Rods
retinal receptors that detect black, white, and gray; necessary for peripheral (they are away from he fovea) and twilight vision, when cones don’t respond. They share bipolar cells and there are more of them then cones
Cones
retinal receptor cells that are concentrated near the center of the retina (fovea) and that function in daylight or in well-lit conditions. The cones detect fine detail and give rise to color sensations. They have their own bipolar cells and there is less of them.
Optic nerve
the nerve that carries neural impulses from the eye to the brain
Blind spot + other name
the point at which the optic nerve leaves the eye, creating a “blind” spot because no receptor cells are located there, optic disk
Fovea
the central focal point in the retina, around which the eye’s cones cluster
Feature detectors and scientists
nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement (Hubel and Wiesel)