Chapter 6 Flashcards
Face blindness
Prosopagnosia
What is sensation?
The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment
What is 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
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
Absolute threshold
The minimum stimulation needed to detect a particular stimulus 50% 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 the detection depends partly on a person’s experience, expectations, motivation, and alertness.
All of our senses do what?
1) Receive sensory stimulation, often using specialized receptor cells
2) Transform that stimulation into neural impulses
3) Deliver the neural information to our brain
What is the rough distinction between sensation and perception?
Sensation is the bottom-up process by which the physical sensory system receives and represents stimuli. Perception is the top-down mental process of organizing and interpreting sensory input
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% 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)
Using sound as your example, illustrate the distinctions among these concepts: absolute thresholds, subliminal stimulation, and difference thresholds
Absolute threshold is the minimum stimulation needed to detect a particular sound (such as an approaching bike on the sidewalk behind us) 50% of the time. Subliminal stimulation happens when, without our awareness, our sensory system processes that sound (when it is below our absolute threshold). A difference threshold is the minimum difference needed to distinguish between two sounds
Sensory adaptation
Diminished sensitivity as a consequence of constant stimulation
Perceptual set
A mental predisposition to perceive one thing and not another
When we are constantly exposed to stimulus that does not change, we become less aware of it because our nerve cells fire less frequently
Sensory adaptation
Sensory adaptation allows us to focus on?
Changing stimuli
Context creates an expectation that _________ influences our perception
Top-down (information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations)
This curious phenomenon suggests that the brain can work backward in time to allow a later stimulus to determine how we perceive an earlier one
Context
Our motives also direct our?
Perception of ambiguous images
In the context of sensation and perception, what does it mean to say that “believing is seeing”?
Because of perceptual set, our experiences, assumptions, and expectations sculpt our views of reality
Does perceptual set involve bottom up or top down processing? Why?
Top-down drawing on our experiences, assumptions, and expectations
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
Wavelength
The dimension of color that is determined by the wavelength of light; what we know as the color names blue, green, and so forth
Hue
The amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the waves amplitude
Intensity
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
The process by which the eye’s lens changes shape to focus near or far objects on the retina
Accommodation
Bees can see?
Ultraviolet light
Light enters the eye through the 1)_______, which protects the eye and bends light to provide focus. The light then passes through the 2) ______, a small adjustable opening surrounded by the 3) _______, a colored muscle that controls the size of the pupil by dilating or constricting in response to light intensity and even to inner emotions. Behind the 4) _____ is a transparent 5) ______ that focuses incoming light rays into an image on the 6) ______, a multilayered tissue on the eyeball’s sensitive inner surface
1) Cornea
2) Pupil
3) Iris
4) Pupil
5) Lens
6) Retina
The lens focuses the rays by?
Changing its curvature and thickness, in a process called accommodation
Rods are
Retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when cones don’t respond
Cones are?
Retinal receptor cells that are concentrated near the center of the retina & that function in daylight or in well-lit conditions. The cones detect fine detail and give rise to color sensations
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
Fovea
The central focal point in the retina, around which the eye’s cones cluster
If you could follow a single light energy particle to the back of your eye, you would first make your way through the retina’s outer layer of cells to its buried receptor cells, the
1) ____ and _____. There you would see light energy trigger chemical changes that would spark neural signals, activating nearby 2) ________. These cells in turn would activate the neighboring 3) _________, whose axons twine together like the strands of a rope to form the 4) ________.
1) Rods and cones
2) Bipolar cells
3) Ganglion cells
4) Optic nerve
Rods and cones differ in where they are found and in what they do. Describe the cones
The cones cluster in and around the fovea. Many have their own hotline to the brain, which devotes a large area to input from the fovea. These direct connections preserve the cone’s precise information, making them better able to detect fine details.
- Enables you to perceive color
- In dim light they become ineffectual so you see no colors
Rods and cones differ in where they are found and in what they do. Describe the rods.
The rods do not have a hotline like the cones do; they share bipolar cells with other rods, sending combined messages. Rods predominate in outer regions of our retina.
- Enable black and white vision
- Sensitive to dim light
Rods and cones each provide a special sensitivity
Rods to faint light and cones to detail and color
Pathway from the eyes to the visual cortex
Ganglion axons forming the optic nerve run to the thalamus, where they synapse with neurons that run to the visual cortex
Rods and Cones:
1) Number
2) Location in retina
3) Sensitivity in dim light
4) Color sensitivity
5) Detail sensitivity
1) Cones: 6 million; Rods: 120 million
2) Cones: Center; Rods: Periphery
3) Cones: low; Rods: hight
4) Cones: high; Rods: low
5) Cones: high; Rods: low
Nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement
Feature detectors
What is parallel processing?
The processing of many aspects of a problem simultaneously; the brain’s natural mode of information processing for many functions, including vision. Contrasts with the step-by-step (serial) processing of most computers and of conscious problem solving.
To analyze a visual sense, the brain divides it into subdimensions
Color, motion, form, depth
What is the rapid sequence of events that occurs when you see and recognize a friend?
Light waves reflect off the person and travel into your eye, where the receptor cells in the retina convert the light waves’ energy into neural impulses sent to your brain. Your brain processes the subdimensions of this visual input- including color, depth, movement and form- separately but simultaneously. It interprets this information based on previously stored information and your expectations into a conscious perception of your friend
Young-Helmholtz trichromatic (three color) theory
The theory that the retina contains three different color receptors- one most sensitive to red, one to green, one to blue- which, when stimulated in combination, can produce the perception of any color.
The theory that opposing retinal processes (red-green, yellow-blu, white-black) enable color vision. For example, some cells are stimulated by red and inhibited by green
Opponent-process theory
An organized whole. Gestalt psychologists emphasized our tendency to integrate pieces of information into meaningful wholes
Gestalt
The organization of the visual field into objects (the figures) that stand out from their surroundings (the ground)
Figure-ground
The perceptual tendency to organize stimuli into coherent groups
Grouping
The ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allows us to judge distance
Depth perception
A laboratory device for testing depth perception in infants and young animals
Visual cliff
Depth cues, such as retinal disparity, that depend on the use of two eyes
Binocular cues
A binocular cue for perceiving depth: By comparing images from the retinas in the two eyes, the brain computes distance- the greater the disparity (difference) between the two images, the closer the object
Retinal disparity
Depth cues, such as interposition and linear perspective, available to either eye alone
Monocular cues
How do we normally perceive depth?
We are normally able to perceive depth thanks to the binocular cues that are based on our retinal disparity, and monocular cues including relative height, relative size, interposition, linear perspective, light and shadow, and relative motion
Perceiving objects as unchanging (having consistent color, brightness, shape, and size) even as illumination and retinal images change
Perceptual constancy
Perceiving familiar objects as having consistent color, even if changing illumination alters the wavelengths reflected by the object.
Color constancy
Perception adaptation
In vision, the ability to adjust to an artificially displaced or even inverted visual field
The sense or act of hearing
Audition
Frequency
The number of complete wavelengths that pass a point in a given time (for example, per second)
A tone’s experienced highness or lowness; depends on frequency
Pitch
The chamber between the eardrum and cochlea containing 3 tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on the cochlea’s oval window
Middle ear
Cochlea
A coiled, bony, fluid-filled tube in the inner ear; sound waves traveling through the cochlear fluid trigger nerve impulses
Inner ear
The innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs
Hearing loss caused by damage to the cochlea’s receptor cells or to the auditory nerves; also called nerve deafness
Sensorineural hearing loss
Hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea
Conduction hearing loss
The amplitude of a sound wave determines our perception of?
Loudness
The longer the soundwaves are, the ______ their frequency is and the _________ their pitch
lower, lower
Which theory of pitch perception would best explain a symphony audience’s enjoyment of the high pitched piccolo? How about the low-pitched cello?
Place theory; frequency theory
A device for converting sounds into electrical signal stimulating the auditory nerve through electrodes threaded into the cochlea
Cochlear implant
In hearing, the theory that links the pitch we hear with the place where the cochlea’s membrane is stimulated
Place theory
In hearing, the theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enabling us to sense its pitch
Frequency theory
The theory that the spinal cord contains a neurological “gate” that blocks pain signals or allows them to pass on to the brain. The “gate” is opened by the activity of pain signals traveling up small nerve fibers and is closed by activity in larger fibers or by information coming from the brain
Gate-control theory
The pain circuit
Sensory receptors (nociceptors) respond to potentially damaging stimuli by sending an impulse to the spinal cord, which passes the message to the brain, which interprets the signal as pain.
How does our system for sensing smell differ from our sensory systems for vision, touch, and taste
We have two types of retinal receptors, four basic touch senses, and five taste sensations. But we have no basic smell receptors. Instead different combinations of odor receptors send messages to the brain, enabling us to recognize some 10,000 different smells
The system for sensing the position and movement of individual body parts
Kinesthesis
The sense of your head’s (and thus your body’s) movement and position, including the sense of balance
Vestibular sense
Sensory interaction
The principle that one sense may influence another, as when the smell of food influences its taste
Embodied cognition
The influence of bodily sensations, gestures, and other states on cognitive preferences and judgments
Vision: Source & Receptors
Source: Light waves striking the eye
Receptors: Rods and cones in the retina
Hearing: Source & Receptors
Source: Sound waves striking the outer ear
Receptors: Cochlear hair cells in the inner ear
Touch: Source & Receptors
Source: Pressure, warmth, cold on the skin
Receptors:Skin receptors detect pressure, warmth, cold, and pain
Smell: Source & Receptors
Source: Chemical molecules breathed in through the nose
Receptors: Millions of receptors at top of nasal cavity
Position/movement of body parts- Kinesthesis: Source and Receptors
Source: Any change in position of a body part, interacting with vision
Receptors: Kinesthetic sensors in joints, tendons, and muslces
Position/movement of head- Vestibular sense: Source and Receptors
Source: Movement of fluids in the inner ear causes by head/body movement
Receptors: Hairlike receptors in the semi-circular canals and vestibular sacs
Extrasensory perception (ESP)
The controversial claim that perception can occur apart from sensing input; includes telepathy, clairvoyance, and precognition
The study of paranormal phenomena, including ESP and psychokinesis
Parapsychology
Sensation is to ________ as perception is to __________
bottom up processing; top down processing
The process by which we organize & interpret sensory information is called?
Perception
Subliminal stimuli are?
Below our absolute threshold for conscious awareness
Another term for difference threshold is the?
Just noticeable differences
Weber’s law states that for a difference to be perceived, two stimuli must differ by?
A constant minimum percentage
Sensory adaptation helps us focus on
Important changes in the environment
Our perceptual set influences what we perceive. This mental tendency reflects our
Experiences, assumptions, expectations
The characteristic of light that determines the color we experience, such as blue or green, is
wavelength
The amplitude of a sound wave determines our perception of loudness. The amplitude of a light wave determines our perception of?
Brightness
The cells in the visual cortex that respond to certain lines, edges, and angles, are called
Feature detectors
Two theories together account for color vision. The Young-Helmholtz theory shows that the eye contains _______, and the Hering theory accounts for the nervous system’s having ________
Three types of color receptors; opponent-process cells
In listening to a concert, you attend to the solo instrument and perceive the orchestra as accompaniment. This illustrates the organizing principle of
Figure-ground
Two examples of _______ depth cues are interposition and linear perspective
monocular
In experiments, people have worn glasses that turned their visual fields upside down, after a period of adjustment, they learned to function quite well. This ability is called
Perceptual adaptation
_______ theory explains how we hear high-pitched sounds, and _______ theory explains how we hear low-pitched sounds
place; frequency
The gate-control theory of pain proposes that
Small spinal cord nerve fibers conduct most pain signals, but large-fiber activity can close access to those pain signals
