Sensation & Perception

Front 1

Transduction

Back 1

Conversion from one form of energy into another; e.g. sights, sounds, smells into neural impulses to the brain

Front 2

What is the rough distinction between sensation and perception?

Back 2

Sensation: Bottom-up process by which the physical sensory system receives and represents stimuli

Perception: Top-down mental process of organizing and interpreting input

Front 3

Absolute threshold

Back 3

The minimum stimulation needed to detect a particular stimulus 50% of the time

Front 4

Signal detection theory

Back 4

How and when we detect a faint stimulus signal; depends on experience, expectation, motivation, alertness

Front 5

Subliminal

Back 5

Below one's absolute threshold or conscious awareness

Front 6

What 3 factors will make it more likely that you correctly detect a text message?

Back 6

1) Expectation
2) The text message is important
3) Alertness

Front 7

Difference threshold

Back 7

The minimum difference between 2 stimuli half the time

Front 8

Weber's law

Back 8

To perceive a difference, 2 stimuli must differ by a constant proportion

Front 9

Sensory adaptation

Back 9

Diminished sensitivity as a consequence of constant stimulation

Front 10

Perceptual set

Back 10

Top-down processing; mental predisposition to perceive one thing and not another

Front 11

Vision: Wavelength

Back 11

The distance from one peak to the next; determines its hue

Front 12

Vision: Intensity

Back 12

The amount of energy in light waves; influences brightness

Front 13

Vision: Variations in frequency

Back 13

Color

Front 14

Vision: Amplitude size

Back 14

Intensity of color (bright/dull)

Front 15

Feature detectors

Back 15

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

Front 16

Parallel processing

Back 16

The processing of many aspects of a problem simultaneously (vision = color, motion, form, depth); contrary to step-by-step (serial) processing of most computers and of conscious problem solving

Front 17

How do we see?

Back 17

1. Light enters through the cornea (bends light to provide focus)
2. Then the pupil (surrounded and controlled by the iris)
3. The lens (behind the pupil) focuses light rays into an image on the retina (accommodation)
4. Fovea: Retina’s area of central focus
5. Cones: Cluster in and around the fovea; many have direct line to the brain via bipolar cells; colors and details
6. Rods: Share bipolar cells with each other; effective in faint light
7. Then the retina’s millions of receptor cells (rods & cones) convert the light energy into neural impulses (activating bipolar cells) and forward those to the brain via the optic nerve (formed by strands of ganglion cells)

Front 18

Blind spot

Back 18

Located where the optic nerve leaves the eye; no receptor cells

Front 19

Helmholtz's trichromatic theory

Back 19

The retina contains 3 different color receptors (red, green, blue) which, in combination, can produce the perception of any color

Front 20

Opponent-process theory

Back 20

Opposing retinal processes (red-green, yellow-blue, white-black) enable color vision; e.g. some cells are stimulated by green and inhibited by red, while others are vice versa

Front 21

Gestalt psychology

Back 21

"The whole is greater than the sum of its parts."

Front 22

Figure-ground

Back 22

Organization of the visual field into objects (the figures) that stand out from their surroundings (the ground)

Front 23

Grouping

Back 23

Our perceptual tendency to organize stimuli into coherent groups

1. Proximity
2. Continuity
3. Closure

Front 24

Depth perception

Back 24

To see objects in 3D although the images that hits our retinas are 2D; allows us to judge distance

Front 25

Binocular cues

Back 25

Depth cues, such as retinal disparity, that depend on the use of 2 eyes

Front 26

Monocular cues

Back 26

1. Relative height
2. Relative size
3. Relative motion
4. Interposition
5. Linear perspective
6. Light and shadow

Front 27

Retinal disparity

Back 27

By comparing images from the retinas in the 2 eyes, the brain computes distance; the greater the disparity between the 2 images, the closer the object

Front 28

Phi phenomenon

Back 28

An illusion of movement created when 2 or more adjacent lights blink on and off in quick succession

Front 29

Perceptual constancy

Back 29

Perceiving objects as unchanging even as illumination and retinal images change

1. Color constancy
2. Brightness constancy
3. Shape constancy

Front 30

Hearing: Amplitude

Back 30

Loudness

Front 31

Hearing: Length & frequency

Back 31

Pitch (e.g. long wave, low frequency = low pitch)

Front 32

How do we hear?

Back 32

Vibrating air >> moving piston >> fluid waves >> electrical neural impulses >> SOUND!

1. Outer ear: Sound waves are channeled through the auditory canal to the eardrum
2. Middle ear: (Hammer, anvil, stirrup) transmits waves to the cochlea (fluid-filled)
3. Inner ear: Hair cells in the basilar membrane bend and triggers impulses in the nerve cells

Front 33

Sensorineural hearing loss ("nerve deafness")

Back 33

Hearing loss caused by damage to the cochlea’s receptor cells or to the auditory nerves; occurs with age or disease

Front 34

Conduction hearing loss

Back 34

Hearing loss caused by damage to the mechanical system that conducts sound waves to the cochlea; less common

Front 35

Cochlear implant

Back 35

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

Front 36

How do we perceive loudness?

Back 36

The brain can interpret loudness from the number of activated hair cells

Front 37

Helmholtz's place theory

Back 37

We hear different pitches because different sound waves trigger activity at different places along the basilar membrane (HIGH PITCHES)

Front 38

Frequency theory

Back 38

The rate of nerve impulses traveling up the auditory nerve matches the frequency of a tone, thus enable us to sense its pitch (LOW PITCHES)

Front 39

Volley principle

Back 39

Neural cells alternate firing and can achieve a combined frequency above 1000 waves per second (because a single neuron can't fire faster than 1000)

Front 40

Touch sensations (4)

Back 40

Pressure, warmth, cold, pain

Front 41

Nociceptors

Back 41

Sensory receptors that detect hurtful temperatures, pressure, or chemicals (pain)

Front 42

Gate-control theory

Back 42

The spinal cord contains a neurological “gate” that opens and closes upon stimulation; small nerve fibers open & large fibers (or brain-to-spinal-cord messages) close the “gate”

Front 43

Tinnitus

Back 43

Phantom sounds; ringing-in-the-ears sensation

Front 44

Memorable points of pain (2)

Back 44

Peak & end

Front 45

Sensory interaction

Back 45

One sense may influence another (smell influences taste)

Front 46

McGurk effect

Back 46

Mouth "ga" + say "ba" = perceive "da"

Front 47

Embodied cognition

Back 47

The influence of bodily sensations, gestures, and other states on cognitive preferences and judgments; e.g. holding a warm coffee = social warmth

Front 48

Anosmia

Back 48

Inability to smell

Front 49

How do we smell?

Back 49

1. Odors bind to receptors
2. Olfactory receptor cells are activated and send electric signals to the olfactory bulb
3. The signals are relayed via converged axons
4. The signals are transmitted to higher regions of the brain (temporal lobe and the limbic system for memory and emotion)

Front 50

Kinesthesis

Back 50

The system for sensing the position and movement of individual body parts

Front 51

Vestibular sense

Back 51

The sense of body movement and position, including balance