Sensation Quiz - AP Psych

Sensation

Process of detecting info from the environment, that meets a certain threshold, and transducing messages for processing (perception) in the brain

Absolute Threshold

Occurs when a stimulus can be detected at least 50% of the time

Signal Detection Theory

A detection depends upon a combo of stimulus intensity, background noise, and a person's physical condition, biases, and level of motivation

Just Noticeable Difference

• The minimal difference needed to notice a stimulus change

• Aka. Difference Threshold

Weber's Law

Two stimuli must differ by a constant minimum percentage (rather than constant amount) to be perceived as different

Sensory Adaptation

• Our diminishing sensitivity to an unchanging stimulus

• Receptors fire less frequently, and the sensation often fades or disappears

• Doesn't affect vision because our eyes are always shifting

Transduction

• The conversion of one form of energy to another

• Transforming stimulus energy into neural messages

Wavelength

• Distance of wave from peak to peak

• Determines hue (color)

Intensity

• Distance from peak to trough

• Determines amplitude (brightness)

Cornea

Protects the eye and bends light to provide focus

pupil

Adjustable opening in the center of the eye

Iris

A ring of muscle that forms the colored portion of the eye at the pupil; 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 images on the retina

• Visual stimuli are focused onto retina by the lens

• When altered it creates nearsightedness and farsightedness

Nearsightedness

Eye condition that makes it difficult to see objects that are far away

Farsightedness

Eye condition that makes it difficult to see objects that are close up

Retina

• photosensitive inner surface of the eye

• Cells in retina capture visual information that is transduced to the brain for processing

Rods

Peripheral retina; detects black, white & gray; movement; peripheral & low light vision

Cones

Near center of retina (fovea); color & detail; daylight & well-lit conditions

Fovea

Central point of focus, made up of cones, greatest visual acuity in bright light

Bipolar Cells

Specialized neurons that connect the rods and cones with the ganglion cells

ganglion Cells

• Specialized neurons that connect to the bipolar cells

• The bundled axons form the optic nerve

Optic Nerve

Carries neural impulses from the eye to the brain

Blind Spot

Point at which the optic nerve leaves the eye creating a "blind spot" because there are no receptor cells located there

• Evidence of incomplete images captured by the retina is demonstrated by the blind spot

• The brain fills in gaps to perceive a relatively complete picture of the world

Blue

Short Wavelength = high frequency

bright colors

Great Amplitude

red

long wavelength = high frequency

dull colors

small amplitude

Young-Helmholz Trichromatic (3-color) theory

• There are 3 primary colors (red, green, & blue) and any color is a combo of these

• Ex. Yellow is a mixture of red and green light

• Monochromatic and Dichromatic Vision

Color Deficiency

Involves damage or irregularities to one or more cone or ganglion cells

Monochromatic Vision

• Can see no color at all

• World consists of different shades of grey ranging from black and white

Dichromatic Vision

One of the three cone cells is absent or not functioning and color is reduced to two dimensions

Color Blindness

Genetic disorder in which people are blind to green or red colors

Opponent-Process

• Theory that opposing retinal processes (red-green, blue-yellow, black-white) enable color vision

• Ex. Some cells are stimulated by green inhibited by red and vice versa

Afterimages

• Results when certain ganglion cells in the retina are activated while others are not

• Ganglion cells involved in this are:

• red-green

• blue-yellow

• black-white

prosopagnosia

• AKA face blindness

• Ability to recognize familiar faces, including one's own face (self-recognition), is impaired

Blindisight

• Someone can perceive the location of an object despite being cortically blind

• The person is unable to visually see images, but somehow some part of the unconscious brain can still perceive them and their locations in space

Sound Waves

• Compressing and expanding air molecules

• Can feel vibrations

Acoustical Transduction

• Conversion of sound waves into neural impulses in the hair cells of the inner ear

Sound Characteristics

• Wavelengths (pitch)

• Amplitudes (loudness)

Frequency

Number of complete wavelengths that pass a point in a given time (ex. per second)

Pitch

A tone's highness or lowness (depends on length)

Amplitude (Loudness)

Amount of energy in a wave, determined by the amplitude

Outer ear

• Pinna

• Auditory Canal

• Ear drum

• The sound waves travel down the auditory canal to the eardrum

Middle Ear

• Hammer (Malleus)

• Anvil (Incus)
  Stirrup (Stapes)

• Bones of the middle ear (the hammer, anvil, stirrup) vibrate with the eardrum

Cochlea

Coiled, bony, fluid-filled tube in the inner ear that transforms sound vibrations to auditory signals

Oval Window

Membrane at end of middle ear and beginning of inner ear

Basilar Membrane

Fibrous membrane in cochlea

place Theory

Different frequencies excite different hair cells at different locations along the basilar membrane

• High: near stirrup

• Lower: near the end of cochlea

Frequency theory

• The basilar membrane vibrates at the same frequency as the sound wave

• The faster the membrane vibrates, the higher the pitch, the slower it vibrates, the lower the pitch

• Neurons can't fire more than 1000x per second

Volley Principle

Neural cells alternate firing. By firing in rapid succession, they can achieve a combined frequency above 1000 waves per second

stereophonic hearing

allows localization of sounds

Hearing Loss

• Conduction hearing loss

• Sensorineural hearing loss

• Hearing difficulties can result from aging and various kinds of damage to auditory structures

Sensorineural hearing loss

• Damage to cochlea's receptor cells or to the auditory nerve

• AKA. Nerve deafness

• Most common

Conduction Hearing Loss

• Damage to the mechanical system that conducts sound waves to cochlea

• Ex. Eardrum or middle ear bones damage