ap psych unit 3

Sensation

Bringing in sensory stimuli from the enviornment to the brain

Perception

organizing and interpreting sensory information

Transduction

Converting an environmental energy into a neural impulse

Absolute Threshold

The minimum amount of energy needed to detect the presence of a stimulus 50% of the time

Just Noticeable Difference

The minimum amount of energy needed to detect a change in a stimulus, or the difference between two stimuli

Weber's Law

JND is a fixed proportion of the intensity of the stimulus. The greater initial intensity of a stimulus, the more its going to take to notice a change

Sensory Adaptation

Decline in sensitivity to stimuli that are presented at a constant level (our sensory neurons become less responsive)

Sensory interaction

Occurs when one sense impacts another

Synethesia

"cross-talk" of the senses

Amplitude

Brightness/ intensity

Wavelength

Color/hue

Short Wavelengths

blues

Long Wavelengths

reds

Visual Process

Light wave, cornea, iris, pupil, lens, retina, photoreceptors, bipolar cells, ganglion cells, optic disk, thalamus, occipital lobe.

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

occurs when the lens bends to much. Causes the image to fall in front of the retina

Farsightedness

Occurs when the lens doesn't bend enough. Causes the image to fall in behind the retina

Photoreceptors

sensory receptors for vision-transduction

Cones

Color vision; helps us to see in the daytime/ bright lighting; located in the center if the retina

Fovea

Center of the retina; Highest concentration of cones; greatest visual acuity (detail)

Rods

Detect black, White, and gray; sensitive to movement; more sensitive in dim lighting: located on the outer edge of retina (peripheral vision)

Bipolar Cells

Receive visual signals from photoreceptors (Rods and cones); help see contrast and edges

Ganglion Cells

signals sent from bipolar cells to the ganglion cells bundle together to form the optic nerve

Optic disk and Optic Nerve

the optic nerve leaves the eye at the optic disk

Blindspot

where optic nerve leaves the eye and has no photoreceptors

Feature Detectors

Specialized cells that respond selectively to specific features of more complex stimuli

Parallel Processing

Processing visual information is done simultaneously ( as opposed to serial processing)

Blindsight

a condition in which a person can respond to a visual stimulus without consciously experiencing it

Prosopagnosia

inability to recognize faces

Young-Helmoltz trichromatic (three-color) theory

the theory that the retina contains three different types of receptors with differing sensitivity to diffrent wavelengths that can create all

Color Blindness

Lack one of the 3 ( or more in rare cases) types of cones

Dichromatism

Only 2 cone types are functional

Monochromatism

Only 1 type of cone is functional

Opponent Process Theory

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

Figure-Ground

Figure= the object
Ground= the background or surroundings in which object occurs

Closure

Filling in the gaps to perceive a completed image

Proximity

Objects close to each other are grouped

Similarity

Grouping based on shared characteristics

Perceptual Constancies

Perceiving objects as unchanging ( having consistant color, size, shape, brightness, etc) even as illumination and retinal change

Visual cliff

Depth perception is largley innate visual cliff= apparatus used to test depth perception

Retinal Disparity

Depth perception guided by the different images seen by each eye

Convergence

Sensing the eye converging (turning inward) as they focus on closer objects

Linear Perspective

parallel lines appear to converge with distance

Relative Size

Closer objects appear larger on the retina and further objects appear smaller

Relative Clarity

Objects in the distance appear less clear/ more blurry: objects that are closer appear clear/sharp

Texture Gradient

Close objects appear to have more detail than objects that are further away

Interpostition

Objects that obstruct/block the view of another objects that are seen as closer

Phi Phenomenon

An illusion of movement ( as in a motion picture) experienced when viewing a rapid series of still image

Looming

as an image expands on our retina, we perceive the object as approaching us

Selective Attention

The ability to focus your conscious awareness (attention) on a particular stimulus (while ignoring others)

Cocktail Party Effect

In a crowded environment, we can focus on one conversation while blocking out the rest; however, when your name (or something relevant to you) is said, your attention shifts

Inattentional/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 (understand our world). (external focus)

Top-Down Processing

Using schemas, prior experiences, expectations, context to guide perception (understand our world). (internal focus)
(we make quick assumptions using very little "evidence")

Schemas

mental representations of people, objects, events, ideas, etc.
*created by experience (visual, auditory, emotion, etc)

Perceptual Set & Priming

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

Sound Characteristic

Amplitude
Frequency
Timbre

Psychological Characteristic

Loudness/Intensity
Pitch
Purity

Sensory Processing in the Ear

Perceiving Loudness

The brain interprets loudness from the number of activated hair cells

Perceiving Location

Based on differences in the time & intensity each sound wave enters the ear

Place Theory

Perception of pitch corresponds to the vibration of different portions, or locations/places, along the basilar membrane.

Frequency Theory

Perception of pitch corresponds to the firing rate, or frequency, at which the auditory nerve vibrates.
(best explains low frequency sounds)

Volley Theory

Groups of neurons fire slightly out of phase with one another so that when combined a particular pitch is perceived.

Conduction Deafness

Problems/damage to the three little bones or the tympanic membrane
(May be corrected with hearing aids)

Sensorineural Deafness (Nerve Deafness)

Problems/damage to the cilia (hair cells) 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 exposure to loud sounds

The Gustatory System

Taste (Gustation)

Taste Buds (papillae)

*Papillae/taste buds contain sensory receptors for taste
*There are 4 tastes: sweet, sour, bitter, salty, umami (savory, meaty taste) & oleogustus (unique taste of fat)
*Taste buds are most sensitive to 1 or 2 tastes, & weak to others.

What Other Factors Influence Flavor

Flavor is a combination of what two senses?
Taste & Smell
(Sensory interaction)

Supertasters, Medium Tasters & Nontasters

Supertasters have more taste buds than others

The Olfactory System

Smell (Olfaction)

Sensory Receptors

Cilia (hair cells) in the nose

Olfactory Bulb

Cilia in the nose send signals to the olfactory bulb in the brain. *Does not go through thalamus first. (Part of limbic system)

Pheromones

Odor chemicals that shape the behavior/physiology of animals.

4 types of touch receptors

*Pain, Pressure, Warm & Cold
*Hot = Warm + Cold
*Wetness = Cold + Pressure

Pain

A biopsychosocial approach to understanding pain

Gate-Control Theory of Pain

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

Phantom Limb Sensations

When lacking the normal sensory input from a missing limb, the brain misinterprets and amplifies spontaneous but irrelevant CNS activity.

Vestibular Sense *Balance*

Sensory system providing information about spatial orientation (position of head & body in space) as well as our sense of balance.
*Visual system & inner ear (semicircular canals & vestibular sacs) play a large role

Kinesthetic Sense *Coordination*

Sensory system providing information about where parts of your body are in relationship to each other, providing us with our sense of coordination.

ability to sense the movement of muscles, tendons, and joints)