Tripken5/6 Study Guide
Sensation: The process by which sensory receptors (in eye, ear, etc.) receive and are stimulated by stimulus energies from the 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 sense receptors and works up to the brain's processing of the information.
- Top-down-processing: Information processing guided by higher-level processes, such as our expectations.
Absolute Threshold: The minimum stimulation needed to detect a particular stimulus 50% of the time.
Signal Detection Theory: Predicts how and when we detect faint stimuli (dependent on experience, expectations, motivation & fatigue.)
Subliminal Stimulation: Stimulation below one's threshold of conscious awareness. Research reveals a subtle, fleeting effect on thinking, but no effect on behavior.
Difference Threshold: The minimum difference between two stimuli required for detection 50% of the time. It is also called the just noticeable difference or JND.
It is based on Weber's Law: The difference threshold is in proportion to the strength of the original stimulus.
Sensory Adaptation: Our diminishing sensitivity to unchanging stimuli (loud music becomes unnoticeable after several hours…cold water gets warmer the longer you are in it!)
Selective Attention: The focusing of attention on specific stimuli, while ignoring other stimuli (e.g., the cocktail party effect).
Transduction: The transforming of stimulus energies (i.e., light waves, sound waves) into neural impulses.
VISION & LIGHT ENERGY
Wavelength: Distance from the peak of one light or sound wave to the next. Wavelength determines HUE or color in vision and Pitch in audition.
Shorter wavelengths are bluishin color, while longer wavelengths are reddish.
Amplitude: The height of a light or sound wave. It determines brightness in vision and loudness in hearing.
THE EYE
Light waves stimulate rods & cones which synapse to bipolar cells, which synapse to ganglion cells.
The axons of the ganglion cells come together to form the Optic nerves which transmit visual information to the brain.
Blindspot: The area in the retina where the optic nerve leaves the back of eye. No rods or cones are located there, so no vision is possible at that location.
Feature Detectors: Nerve cells in the brain that respond to specific features of a visual stimulus, such as shape, angle, or movement.
Parallel Processing: The ability of the brain to process several aspect of a situation simultaneously.
COLOR VISION
Young-Helmholtz Trichromatic Theory: The theory that the retina contains three different types of cones--one most sensitive to red, one to blue, and one to green--which when stimulated in combination can produce any color.RED, GREEN, & BLUEare the PRIMARY COLORS OF LIGHT WAVES.
Opponent Process Theory: Theory that opposing retinal processes (red-green, yellow-blue, & black-white) enable color vision. For example some cells are stimulated by red while inhibited by green; others are stimulated by yellow, while inhibited by blue. This helps explain afterimages.
Color constancy: Perceiving familiar objects as having consistent color, even if changing illumination alters the wavelength reflected by the object.
AUDITION
Audition: The sense of hearing.
Radio waves / > 30 cm
Microwaves / 1 mm - 30 cm
Infrared / 700 nm - 1 mm
Visible light / 350 nm - 700 nm
Ultraviolet / 10 nm - 350 nm
X-rays / 0.01 nm - 10 nm
Gamma rays / < 0.01 nm
Frequency: The number of complete wavelengths in a given period of time.Frequency determines pitch.
Amplitude: Height of each wavelength--determines loudness.
Sound Localization: Sound waves strike one ear sooner and with more intensity than the other ear. With this information, the brain can determine the location of the sound.
Middle Ear: Chamber between the eardrum and the oval window which contains the ossicles (three tiny bones--hammer, anvil, & stirrup) which concentrate the vibrations of the eardrum.
Inner Ear: Contains the cochlea, semicircular canals, and vestibular sacs.
- Cochlea: a coiled, bony, fluid-filled tube through which sound waves trigger nerve impulses.
- Basilar Membrane: Membrane along the center of the cochlea that contains hair cells (the receptor cells for sound). Axons from the hair cells for the Auditory Nerves, which transmit neural impulses to the brain.
PITCH PERCEPTION
- Place Theory: Theory that the pitch we hear is associated with the place where the basilar membrane is stimulated. Best for explaining high-pitched tones.
- Frequency Theory: Theory that the rate of nerve impulses traveling up the auditory nerve matches the frequency of the tone we are hearing. Best for explaining low-pitched tones.
- Volley Principle: Helps explain in frequency theory how we can hear sounds with a frequency greater than 1000 cycles per second. While some neurons are "recharging" during the refractory period(do you know what this means?), others are firing.
Conduction Deafness: Caused by damage to the structures that conduct soundwaves through the ear (eardrum, ossicles).
Nerve Deafness: Caused by damage to the cochlea's hair cells or the auditory nerve.
TOUCH
Touch or tactile sense involves a mixture of at least 4 distinct skin senses--pressure, warmth, cold, and pain. Only pressure has identifiable sense receptors.
COLD + PRESSURE = WETNESS
COLD + WARMTH = HOT
PAIN
Gate-Control-Theory: Theory that the spinal cord contains a neurological "gate" that blocks pain signals or allows them to pass. The gate is opened by stimulation of small nerve fibers and closed by stimulation of larger fiber or by information coming from the brain
TASTE
Taste is the Gustatory Sense.
- Taste is a CHEMICAL SENSE and consists of the four basic tastes of sweet, sour, bitter, & salty. There may also be a 5th sense called "umami" or a meaty taste.
Each bump on the tongue contains over 200 taste buds.
- Each bud contains a pore that captures food molecules.
- The molecules cause hair-like neurons within the pores to fire.
- Taste Buds reproduce themselves every 2-3 weeks.
Sensory Interaction: The principle that one sense may be influenced by another, as when the smell of food influences its taste.
SMELL
Smell is the Olfactory Sense.
Smell is also a CHEMICAL SENSE.
Very little is known about the olfactory sense.
However, we are able to detect about 10,000 different odors.
Smells are processed in the temporal lobes of the brain and in the LIMBIC SYSTEM, which may explain why certain smells seem to have an emotional component and can trigger memories.
Molecules in the air reach millions of receptor cells in each nasal cavity. These cells send messages to the olfactory bulb and the olfactory nerve which transmits the messages to the brain.
BODY POSITION & MOVEMENT
Kinesthesis: The system for sensing the position and movement of individual body parts. The receptor cells for kinesthesis are found in our muscles, tendons, & joints.
Vestibular Sense: The system that monitors the head's (and thus the body's) position and movement.
- It is our sense of equilibrium.
The semicircular canals and vestibular sacs in the inner ear contain receptors that tell us about our head's position.
The Eye returns!!!!!!!!!!!!!!!!
Pupil: Adjustable opening in the center of the eye through which light passes.
Iris: A ring of muscle tissue that forms the colored part of the eye. It controls the size of the pupil
Lens: The transparent structure behind the pupil that changes shape (called accommodation) to help focus images on the retina.
Visual Acuity: The sharpness of vision.
Nearsightedness: Can see nearby objects more clearly because distant object focus in front of the retina (eyeball may be too long).
Farsightedness: Can see distant objects more clearly because nearby objects focus behind the retina (eyeball may be too short).
Rods & Cones: The receptor cells for vision. Receptor cells are specialized neurons designed, in this case, to transduce light energy into neural impulses.
- Rods: detect black, white, & grey.
- Found mainly in the periphery of the retina.
- More than one rod connects to each bipolar cell.
- Thus, less light energy is necessary for them to cause the bipolar cells to fire.
- Necessary for NIGHT VISION & PERIPHERAL VISION.
Cones: Found mainly in the center (fovea) of the retina. Necessary for COLOR VISION and VISUAL ACUITY.
Perception: The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.
Perceptual Organization
Figure-ground Relationship: Our ability to perceive any object (the figure) as distinct from its surroundings (the ground).
Visual Capture: The tendency for vision to dominate the other senses when conflicting information is being received.
Gestalt Grouping Principles
Gestalt Organizational Principles: Gestalt psychologists emphasize our tendency to integrate individual pieces of information into a meaningful whole. To bring order and form to basic visual sensations, our brains follow certain rules for grouping stimuli together.
1. Proximity: We group nearby objects and belonging together.
2. Similarity: Figures similar to each other (i.e., as in shape or color) are groups together.
3. Continuity: We perceive smooth, continuous patterns rather than discontinuous ones.
4. Connectedness: When the are uniform and linked, we perceive spots, lines, or areas as single units.
5. Closure: We fill in gaps to create complete, whole objects.
Depth Perception
Visual Cliff: A laboratory device for testing depth perception in infants. Even when coaxed, infants are reluctant to venture onto the glass over the cliff.
Binocular Cues: Depth cues that depend on the use of both of our eyes.
1. Retinal Disparity: By comparing the two slightly different images received on each retina, the brain computes the distance of what we are looking at. The greater the disparity (difference) between the two images, the closer the object.
2. Convergence: The extent to which the eyes converge inward when looking at an object. The greater the convergence, the closer the object.
Monocular Cues: Distance cues that require the use of one eye only.
1. Relative Size: If we assume two objects are about the same size, the one that casts the smaller retinal image is perceived as being farther away.
2. Interposition (Overlap): If one object partially blocks another, the one that is partially blocked is perceived to be farther away.
3. Relative Clarity: Because light from distant objects must pass through more atmosphere, we perceive hazy object as being farther away than clear, distinct objects.
4. Texture Gradient: A gradual change from a coarse, distinct texture to a fine, indistinct texture signals increasing distance.
5. Relative Height: We perceive objects higher in our visual field as being further away.
6. Linear Perspective: Parallel lines (such as railroad tracks) appear further away as they converge in the distance.
7. Light & Shadow (relative brightness): Nearby objects reflect more light. Thus, given two identical objects, the dimmer one seems further away.
8. Relative Motion (motion parallax): If while riding in a train you fix your gaze on some object (the fixation point), objects closer than the fixation point appear to be moving backward. The nearer an object is the faster it seems to move. Objects behind the fixation point appear to be moving with you: The farther away the object is from the fixation point, the more slowly it appears to move.
Motion Perception
One way we perceive motion is by knowing that if an object keeps getting bigger, it is probably moving towards us. If an object is shrinking, it is moving away from us.
Phi Phenomenon: When two or more adjacent stationary lights blink on and off in quick succession, we perceive a single light moving. (Lighted signs use this phenomenon).
Stroboscopic Movement: The brain will interpret a rapid series of slightly varying images as continuous movement. By flashing 24 still pictures each second, a motion picture creates perceived movement.
Perceptual Constancies
Perceiving objects as unchanging (having constant lightness, color, shape, and size) even when our retinal images of them change. For example:
Shape Constancy: We perceive the form of familiar objects as constant even when our retinal images of them change.
Size Constancy: We perceive familiar objects to maintain a constant size even when their distance from us changes.
Lightness Constancy: We perceive an object as having a constant lightness even when its illumination varies.
Similarly, Blakemore & Cooper found that kittens whose vision was restricted to only seeing vertical lines during a critical period of development, later could not see horizontal lines.
Perceptual Adaptation: In vision, the ability to adjust to an artificially displaced or even inverted visual field.
Perceptual Set: A mental predisposition to perceive one thing and not another (e.g., seeing the Lock Ness Monster instead of a piece of driftwood because of your beliefs).
Context Effects: Any given stimulus may trigger radically different perceptions depending on the surrounding environment or circumstances. Culture may have a great impact on context and perception.
Human Factors Psychology: A branch of psychology that explores how people and machines interact and how machines and physical environments can be adapted to human behaviors.
Extrasensory Perception (ESP)
The controversial claim that perception can occur apart from sensory input.
Telepathy: Mind to mind communication
Clairvoyance: The sensing of remote events that are presently occurring.
Precognition: The sensing of future events.
Telekinesis (psychokinesis): Ability to affect objects with the power of the mind.
Parapsychologists: Psychologists who study paranormal occurrences, including claims of ESP.
ADDITIOAL NOTES AND SOME ARE REDUNDENT!!
SENSATION AND PERCEPTION
Sensation -Experience of sensory stimulation, the activation or our senses
Perception -Process of creating meaningful patterns from raw sensory information
VISION
Vision is the dominant sense in human beings. Sighted people use vision to gather information about their environment more than any other sense. The process of vision involves several steps.
Step 1: Gathering light
Step 2: Within the eye
Cornea -The transparent protective coating over the front part of the eye
Pupil -small opening in the iris through which light enters the eye.
Iris -colored part of the eye.
Lens -transparent part of the eye inside the pupil that focuses light onto the retina
Retina -lining of the eye containing receptor cells that are sensitive to light
Step 3: Transduction
Transduction –process by which sensory signals are transformed into neural impulses
Receptor cell -Specialized cell that responds to a particular type of energy.
Rods -Receptor cells in the retina responsible for night vision and perception of brightness.
Cones -Receptor cells in the retina responsible for color vision
Fovea -Area of the retina that is the center of the visual field
Optic nerve - The bundle of axons of ganglion cells that carries neural messages from each eye to the brain.
Blind spot - Place on the retina where the axons of all the ganglion cells leave the eye and where there are no receptors Optic chiasm -Point near the base of the brain where some fibers in the optic nerve from each eye cross to the other side of the brain
Step 4: In the Brain - Theories or color vision-
Trichromatic theory -Theory of color vision that holds that all color perception derives from three different color receptors in the retina
Opponent-process theory - Theory of color vision that holds that three sets of color receptors respond in an either/or fashion to determine the color you experience
Colorblindness -Partial or total inability to perceive hues.
Trichromats -People who have normal color vision
Monochromats -People who are totally color blind
Dichromats - People who are blind to either red-green or yellow-blue
HEARING
The ears contain structures for both the sense of hearing and the sense of balance.The eighth cranial nerve (vestibulocochlear nerve made up of the auditory and vestibular nerves) carries nerve impulses for both hearing and balance from the ear to the brain. /
Amplitude – the height of the wave , determines the loudness of the sound, measured in decibels
Frequency - The number of cycles per second in a wave; in sound, the primary determinant of pitch
Hertz (Hz) - Cycles per second; unit of measurement for the frequency of waves
Pitch - Auditory experience corresponding primarily to frequency of sound vibrations, resulting in a higher or lower tone
Decibel -The magnitude of a wave; in sound the primary determinant of loudness of sounds