AP Psychology Chapter 6: Sensation & Perception

(Middle Ear) Hammer

The main cavity of the ear; between the eardrum and the inner ear.

Difference Threshold

The minimum difference between two stimuli required for detection 50 percent of the time. We experience the difference threshold as just noticeable difference. (JND)

Absolute Thresholds

The minimum stimulation needed to detect a stimulus 50 percent of the time.

Optic Nerve

The nerve that carries neural impulses from the eye to the brain.

Cornea

The part of the eye which protects the eye and bends light to provide focus.

How do we locate sounds?

The placement of our ears allows us to enjoy stereophonic ("three-dimensional hearing)

Blind Spot

The point at which the optic nerve leaves the eye, creating a "blind" spot because no receptor cells are located there.

Cochlea [KOHK-lee-uh]

A coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses.

Cochlear Implant

A device for converting sounds in to electrical signals and stimulating the auditory nerve through electrodes threaded in the cochlea.

Ganglion Cell

A large nerve cell.

Iris

A ring of muscle tissue that forms the colored portion of the eye through which light enters.

Subliminal Messages

A subliminal message is a signal or message that is embedded in another medium, designed to pass below the normal limits of the human mind's perception. These messages are unrecognizable by the conscious mind, but in certain situations can affect the subconscious mind, and can negatively or positively influence subsequent later thoughts, behaviors, actions, attitudes, belief systems, and value systems.

What do we mean by bottom-up processing and top-down processing?

Bottom-Up Processing: Suggests that we attend to or perceive elements by starting with the smaller, more fine details of that entity and then building upward until we have a solid representation of that object or event.

Transduction

Conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, smells, into neural impulses our brains can interpret.

Sensory Adaptation

Diminished sensitivity as a consequence of constant stimulation.

Frequency/Pitch

Frequency: The number of complete wavelengths that pass a point in a given time (for example, per second).

Sensorineural Hearing Loss

Hearing loss caused by damage to the cochlea's receptor cells or to the auditory nerves; also called nerve deafness.

Conduction Deafness

Hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea.

Frequency 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.

Volley Principle

Like soldiers who can alternate firing so that some can shoot while others reload, neural cells can alternate firing. By firing in rapid succession, they can achieve a combined frequency above 1000 waves per second.

Subliminal

Literally "below threshold". Below one's absolute threshold for conscious awareness.

Color Blindness

Most people with color-deficient vision are not actually "colorblind. They simply lack functioning red- or green-sensitive cones, or sometimes both.

Visual Cortex/Feature Detectors (Hubel and Weisel)

Nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement.

(Middle Ear) Stirrup

One of the three ossicles in the middle ear.

Rods & Cones

Rods: Retinal receptors that detect black, white, and gray; necessary for peripheral and twilight vision, when comes 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 comes detect fine detail and give rise to color sensation.

What are sensation and perception?

Sensation: How we feel towards the information we perceive. Perception: The process of organizing and interpreting sensory information, allowing us to recognize meaningful objects and events.

Priming

The activation, often unconsciously, of certain associations, thus predisposing one's perception, memory, or response.

Pupil

The adjustable opening in the center of the eye through which light enters.

Saturation/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.

(Outer Ear) Auditory Canal

The auditory canal leads from the opening of the external ear to the eardrum.

Fovea

The central focal point in the retina, around which the eye's cones cluster.

Prosopagnosia

The inability to recognize faces; face blindness.

Inner Ear

The innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs.

Sensation

The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.

Accomodation

The process by which the eye's lens changes shape to focus near or far objects on the retina.

Perception

The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.

Audition

The sense or act of hearing.

Electromagnetic Spectrum

The spectrum ranges from gamma rays as short as the diameter of an atom to radio waves over a mile long.The narrow band of wavelengths visible to the human eye (shown enlarged) extends from the shorter waves of blue-violet light to the longer waves of red light.

Amplitude/Loudness

The strength or amplitude, of sound waves determines their loudness,

Opponent-Process Theory

The theory that opposing retinal processes (red-green, yellow-blue, white-black) enable color vision. For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green.

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.

Visual Afterimages

When you stare at a picture of a green square for a while and then look at a white sheet of paper, you see red, green's opponent color.

(Outer Ear) Ear Drum

A membrane of the middle ear that vibrates in response to sound waves; the tympanic membrane.

Bipolar Cell

A neuron having two processes.

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 level of fatigue.

Amplitude

A wave's height. (Amplitude is shown by the height of the wave).

Place Theory

In hearing, the theory that links the pitch we hear with the place where the cochlea's membrane is stimulated.

Parallel vs. Serial Processing/Blindsight

Parallel Processing (What our brains do): 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. Serial Processing (What computers do ): Step by step problem solving; gathering information only one piece at a time. Blindsight: Those who have experienced a stroke or surgery damage to their brain's visual cortex have experienced blindsight, which is a localized area of blindness in part of their field of vision.

(Middle Ear) Anvil

The anvil shaped small bone is one of three ossicles in the middle ear.

Middle Ear

The chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, and stirrup) that concentrate the vibrations of the eardrum on the cochleas oval window.

Hue

The dimension of color that is determined by the wavelength of light; what we know as the color names green, blue, and so forth.

Wavelength

The distance from the peak of one light or sound wave to the peak of the next.

(Outer Ear) Pinna

The external part of the ear in humans and other mammals.

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).

Psychophysics

The study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them.

Lens

The transparent structure behind the pupil that changes shape to help focus images on the retina.

Purity/Timbre

The type of sound something makes in comparison to anything else producing the same pitch at the same loudness. Nails on a chalkboard and a violin may play the same pitch at the same loudness, but typically the violin is preferred.