AP Psychology Unit 3 Vocab Sensation/Perception

Sensation

Sensation

Bringing in stimuli from the environment (to the brain)

Perception

Organization & interpretation of sensory information

Synesthesia

"Cross Talk" of the senses.

Absolute Threshold

the minimum amount of energy needed to detect the presence of a stimulus (one factor)

Just-noticeable difference (JND)

minimum amount of energy needed to detect change in the intensity of a stimulus (notice the difference)

Weber's law

JND is a fixed proportion (%) of the intensity of the stimulus(as the initial intensity increases, the JND will also increase

Signal detection theory

Theory predicting our ability to detect if a stimulus "signal" is present (accuracy) amid background noise and the factors that influence it

SDT; Hit

the subject responded affirmative when a signal was present

SDT; Miss

Stimulus is present but no response

SDT; False Alarm

Stimulus is not present yet there is a response

SDT; Correct Rejection

No Stimulus present and no response

Factors that influence detection/response criterion

1. Noise - Random Neural firings(distractions) 2.Physical Ability (sensitivity)

2. Expectations

3. Where attention is directed

4. Willingness/relevance (response Criterion)

Subliminal Perception

Processing information without awareness Subliminal Stimuli-below threshold (unaware)

Priming

Occurs when exposure to a stimulus (Consciously or Unconsciously) influences perception

Sensory Adaptation

Decline in sensitivity to stimulus that are presented at a constant level.

Transduction

converting energy into neural impulses Steps: Sensory Stimuli from the environment, Accessory structure, transduction at sensory receptors, Thalamus(except smell), Appropriate part of the cerebral cortex

Temporal Code

Changes in neuron activity, rates, or timing

Spatial Code

Physical location of neural activity

Amplitude

Brightness/Sensitivity

Wavelength

Color/Hue

Purity

Saturation

Visual process

Light Wave - Cornea(outer protective layer) - Iris + Pupil (colored muscle that adjusts pupil) - Lens(Focuses images on retina) - Image is inverted onto retina - Retina(transduction) - Photoreceptors(responsible for transduction) - Bipolar Cells - Ganglion Cells - Bundle together to form optic nerve - optic disk(blind spot) - Thalamus - Occipital lobe(visual cortex)

Accommodation

The ability of the lens to bend light rays in order to focus the image (based on the objects location) on the retina

Nearsightedness(myopia)

occurs when the lens bends too much. The image falls in front of the retina. Can see near

Farsightedness(hyperopia)

Occurs when the lens doesn't bend too much or enough. The image falls behind retina. Able to see far.

Photoreceptors(on the retina)

sensory receptors for vision ~ responsible for transduction

Cones(type of photoreceptor)

Color vision; help us see in daytime/brighter light; located on center of retina

Fovea

Center of retina; contains highest concentration of cones; greatest visual activity(detail)

Rods(type of photoreceptor)

Black & White (&shades of gray); help us see in dark/dim light; locates on the outside of the retina, so they are responsible for peripheral vision

Bipolar Cells

Receive visual signals from photoreceptors(rods & cones); help see contrast & edges

Ganglion Cells

Signals sent from bipolar cells to the ganglion cells. Axons of the ganglion cells bundle together to form the optic nerve

Optic Disk & Optic nerve

The optic nerve leaves the eye at the optic disk

Blindspot

Where optic nerve leaves the eye, there are no rods & cones; which creates a blind spot

Optic Chiasm

Location where the optic nerve of each eye crosses over to the other hemisphere of the brain

Lateral Geniculate Nucleus

A specific place in the Thalamus that processes visual information *Signal now goes to the visual cortex in the Occipital

Feature Detectors

Specialized cells that respond selectively to specific features of more complex stimuli (edges, lines, angles)

Parallel Processing

processing visual information is done simultaneously (as opposite to senial processing).

Prosopagnosia

Visual agnosia-The inability to recognize objects The inability to recognize human faces(face blindness)

Additive Color Mixing

Light: as you mix light waves together the color gets lighter; all together=White

Subtractive Color Mixing

Paints: as you mix colors together the color gets darker; all together=Black

Young-Helmholtz Trichromatic theory

There are three types of receptors(cones) with differing sensitivities to different wavelengths that can create all colors; Red, Green, Blue

Color Blindness

Lack of one of the three (or more in rare cases) types of cones. Care able to discriminate fewer colors than other people. Few people are void of all cones. Supports the YHT theory of color vision

Opponent process theory

Color perception is determined by the activity of 3 opponent systems; yellow-blue, red-green, black-white

Afterimages

an image continuing to appear in one's vision after the exposure to the original image has ceased. Supports the OP theory of color vision

Figure ground processing

Organization of the visual field into objects that stand out from their surroundings. Attention.

Perceptual Set

The tendency to perceive stimulus in a particular way (guided by prior experiences, expectations, surroundings, context, current mood, etc.)

Inattentional blindness & Change blindness

Failure to see visible objects or events(or a change in one's environment) because one's attention is focused elsewhere(or we've stopped processing due to top-down processing.)

Bottom -up processing

Using details/features/characteristics of a stimulus to guide perception

Top-down processing

Using prior experiences, expectations, context, to guide perception(little evidence)

Gestalt Principles

Grouping

GP; Proximity

Objects closer to each other are grouped together

GP; Closure

Filling in the gaps to perceive a completed image

GP; Similarity

Grouping based on like characteristics

GP; Simplicity

We tend to perceive the simplest form of a stimulus

GP; Continuity

Continuous Lines

(GP) common region

Grouping by boundaries

Visual Cliff

The apparatus used to test depth perception in infants

Binocular Depth Cues

2 eyes

BDC; Retinal (binocular) disparity

Depth perception guided by the different Images seen by each eye (the larger the disparity, the closer the object is perceived).

Convergence

sensing the eyes converging toward each other as they focus on closer objects

Monocular depth cues

1 eye

Linear perspective

Parallel line "converge" in the distance

Texture gradient

More detail = closer

Interposition

Closer objects partially block (overlap) objects further away

Relative Size

Larger on retina = closer

Height in the plane

Near objects = lower in visual field

Light & Shadow

3d

Motion Parallax

Objects closer to us speed across our visual field more quickly than objects farther away

Phi Phenomenon/Stroboscopic motion

Illusion of movement created by presenting visual stimuli in rapid succession

Looming

As image expand on our retina we perceive the object as approaching us

Perceptual Constancies (Size, Shape, Brightness)

Tendency to experience a stable perception despite changing sensory input.

Sound; Amplitude

Loudness/Intensity/volume (decibles)

Sound; Wavelenght

Pitch(hertz)

Sound; Purity

Timbre(unique quality of sound)

Sensory Processing in the ear

Sound wave > Pinna (outer ear)~ Accessory structure for audition > Ear Canal > Tympanic membrane(ear drum~vibrations occur) > 3 little bones (malleus-Hammer, Incus-anun, Stapes-Strip) > Oval Window > Cochlear *where transduction occurs > Basilar Membrane lined w/ cilia hairs *responsible for transduction(sensory receptors) > Auditory Nerve > Thalamus > Temporal Lobe(auditory cortex)

Place Theory

Perception of pitch corresponds to the vibration of different portions, or locations/places, along the basilar membrane. [Spatial Code]. High-Frequency Sounds

Frequency Theory

Perception of pitch corresponds to the firing rate, or frequency, at which the basilar membrane vibrates (or firing rates of neurons of the auditory nerve) [Temporal Code]. Low frequency sounds

Conduction Deafness

Problems/damage to the three little bones or the tympanic membrane. (may e corrected with hearing aids)

Sensorineural Deafness

Problems/damage to the cilia(haircells) or auditory nerve. (may be corrected with a cochlear or auditory nerve implant). This is the type of hearing loss that results from too much loud noise.

Gustation/Taste buds(papillae)

*Papillae/taste buds contain sensory receptors for taste *There are 4 tastes; Sweet/Sours/Bitter/Salty *Taste Buds are most sensitive to 1 or 2 tastes & weak to others.

Olfaction + Sensory Receptors

Detection of smell. Cilia choir cells in the nose.

Olfactory Bulb

Cilia in the nose send signals to the olfactory bulb in the brain. *Does not go through Thalamus. (part of timbre system.)

Vomeronasal organ

Part of the nose that detects pheromones

Pheromones

Chemicals that shape the behavior/physiology of animals

Somatosensory system/3 types of touch receptors

Pressure, Pain, Temperature

A-Delta Fibers(Fast Pathway)

Carry quick, localized, sharp pain signals

C-Fibers(Slow Pathway)

Carry chronic(longer lasting), dull, less-localized, aches & burning pain signals

Gate Control Theory

Pain can be blocked at the spinal cord. Other sensory information, aside from the pain signals, can take over the pain pathway.

Analgesia

The inability to feel pain(when pain should be present)

Analgesies

Something that blocks pain signals from being sent to the brain

Vestibular Sense (Balance)

Sensory system providing info about spatial orientation (position of head & body in space) as well as our sense of balance

Kinesthesia (Coordination)

Sensory System providing info about where parts of your body are in relationship to each other, sense of coordination.