appsy unit 3 CED

Sensation

Sensation

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

Perception

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

Bottom-Up Processing

Analysis that begins with the sense receptors & works up to the brain’s integration of sensory information. You begin by examining small details & piece them together into a larger picture.

Top-Down Processing

Information processing guided by higher-level mental processes. As when we construct perceptions drawing on our experience & expectations.

Depth Perception

the ability to see objects in three dimensions although the images that strike the retina are

Visual Cliff

a laboratory device for testing depth perception in infants and young animals

Gestalt

an organised whole. These psychologists emphasised our tendency to integrate pieces of information into meaningful wholes

Proximity

Objects close together will be viewed together visually

Closure

The brain is good at filling in gaps to create a whole.

Similarity

Two items that share attributes will be visually grouped together.

Continuity

A line will always appear to continue traveling in the same way.

Figure & Ground

Sometimes, the blank space is just as important as the filled space.

Absolute Threshold

the minimum stimulation needed to detect a particular stimulus 50 percent of the time. Example: If you can hear a firetruck before your brother, your absolute threshold is lower for sound than your brothers

Difference Threshold

the minimum difference between two stimuli required for detection 50 percent of the time. We experience this as a just noticeable difference.Example: being able to hear when the volume of a sound gets louder

Signal Detection Theory

a theory predicting how and when we detect the presence of a faint stimulus amid background stimulation. Assumes that there is no absolute threshold and that detection depends partly on a person's experience, expectations, motivation, and alertness

Sensory Adaptation

diminished sensitivity as a consequence of constant stimulation. Example: you don’t notice the feeling of your underwear over time

Transduction

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

Gustav Fechner

founder of psychophysics

Psychophysics

study of the relationship between stimuli and our responses to them

Weber’s Law

To perceive as different, 2 stimuli must differ by a constant minimum percentage.

David Hubel and Torsten Wiese

received a Nobel Prize for their work on Feature Detectors.

Feature Detectors

Cells in the visual cortex of the brain that respond selectively to specific features of complex stimuli. Detects: Edges, Angles, Length, & Movement

Parallel Processing

Processing of several aspects of a problem simultaneously (motion, depth, color, and form)

Context Effects

States that the context (environmental factors) that surrounds an event effects how an event is perceived and remembered. Is this a B or is this a 13? All depends on the context --- if you are perceiving it as a letter or a number

Perceptual set

a tendency to perceive or notice some aspects of the available sensory data and ignore others.  

Schemas

Mental filters or maps that organise our information about the world are called - they can impact our perceptual sets

Assimilate

interpreting one’s new experience in terms of one’s existing schema. Example: see tiger for the first time and call it a cat

Accommodate

adapting one’s current understanding to incorporate new information Example: see differences between tiger and cat and know difference

Selective Attention

the focusing of conscious awareness on a particular stimulus

The Cocktail Party Effect 

Phenomenon of being able to focus one's auditory attention on a particular stimulus while filtering out a range of other stimuli

Sensory Habituation

our perception of sensations is particularly due to how focused we are on them

Inattentional Blindness

Failing to see visible objects when our attention is directed elsewhere.

Change Blindness

Failing to notice change in the environment around us

Choice Blindness

Failing to notice a change in a previously selected item

Cornea

Clear, curved bulge in front of eyeball.  It protects and COVERS the eye.

Iris

Muscle that expands and contracts to change the size of the opening (pupil) for light.

Lens

Transparent structure behind pupil in eye that changes shape to focus images on retina.

Retina

Contains sensory receptors that process visual information and sends it to the brain. (Transduction occurs here)

Fovea

Located in the retina, contains a concentration of cones that provides the clearest vision of all.

Optic Nerve

Carries the impulses from the retina to the brain to interpret them as images.

Accommodation

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

Rods

detect black, white & gray, peripheral retina, twilight or low light

Cones

detect fine detail & color vision, near center of retina (fovea), daylight or well-lit conditions 

Blindspot

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

Bipolar Cells

transmit signals from the photoreceptors to the ganglion cells

Ganglion Cells

are neurons that relay information from the retina to the brain via the optic nerve.

Young-Helmholtz trichromatic 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

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

Hue

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

Color blindness

inability to perceive color differences

Myopia

nearsightedness (good near vision)

Presbyopia

farsightedness (good distance vision)

Astigmatism

cornea is irregularly shaped (blurry vision)

Glaucoma

damage to the optic nerve and destroyed vision

Synesthesia

condition in which one sense (for example, hearing) is simultaneously perceived as if by one or more additional senses such as sight. Another form joins objects such as letters, shapes, numbers or people's names with a sensory perception such as smell, color or flavor.

Perceptual constancy

our ability and need to perceive objects as unchanging even as changes may occur in distance, point of view, and illumination

Color Constancy

Perception that the color of an object remains the same even if lighting conditions change

Size Constancy

Tendency for the brain to perceive objects as the same apparent size regardless of their distance from us

Shape Constancy

Our viewing angle changes or an object rotates and we still perceive the object as staying the same shape

Lightness Constancy

Occurs when our perception of the whiteness, blackness, or grayness of objects remains constant no matter how much the illumination has changed

Binocular Cues

depth cues, such as retinal disparity, that depend on the use of two eyes

Retinal Disparity

a binocular cue for perceiving depth: by comparing images from the retinas in the two eyes, the brain computes distance - the greater the disparity between the two images, the closer the object

Convergence

When two eyes move inward (towards the nose) to see near objects and outward (away from the nose) to see faraway objects.  More convergence – closer the object

Monocular Cues

depth cues, such as interposition and linear perspective, available to either eye alone

Relative Size

If two objects are similar in size, we perceive the one that casts a smaller retinal image to be farther away.

Interposition

Objects that occlude (block) other objects tend to be perceived as closer.

Relative Clarity

Because light from distant objects passes through more light than closer objects, we perceive hazy

Relative Height

We perceive objects that are higher in our field of vision to be farther away than those that are lower. Objects to be farther away than those objects that appear sharp and clear.

Relative motion

Objects closer to a fixation point move faster and in the opposing direction to those objects that are farther away from a fixation point, moving slower and in the same direction. 

Linear Perspective

Parallel lines, such as railroad tracks, appear to converge in the distance. The more the lines converge, the greater their perceived distance.

Light and Shadow

Nearby objects reflect more light into our eyes than more distant objects. Given two identical objects, the dimmer one appears to be farther away.

Texture Gradient

Indistinct (fine) texture signals an increasing distance.  Less detail shows closeness, finer and denser is further away

Audition

the biological process by which our ears process sound waves

Frequency (pitch)

Dimension of frequency determined by wavelength of sound. 

Intensity (loudness)

Amount of energy in a wave determined by amplitude relates to perceived loudness. 

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 cochlea's oval window

Cochlea

(SNAIL) a coiled, bony, fluid-filled tube in the inner ear; sound waves traveling through the cochlear fluid trigger nerve impulses (Transduction occurs here)

Inner Ear

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

Sensorineural Hearing Loss

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

Cochlear Implant

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

Conduction Hearing Loss

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

Place Theory

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

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

Taste

sensations are transduced by taste cells located in bunches called taste buds. They are found throughout the entire mouth but are most highly concentrated on the tongue, the major sensory organ of the gustatory system.

Olfaction

is the sense of smell. Odors first interact with receptor proteins associated with hairs in the nose. The hairs convey information to the brain's olfactory bulbs, located on the underside of the brain. Certain smells can invoke memory

Sensory Interaction

the principle that one sense may influence another, as when the smell of food influences its taste

Kinesthesia

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

Vestibular Sense

the sense of body movement and position, including the sense of balance

Gate-Control Theory

the theory that the spinal cord contains a neurological "gate" that blocks pain signals or allows them to pass on to the brain. The "gate" is opened by the activity of pain signals traveling up small nerve fibers and is closed by activity in larger fibers or by information coming from the brain

Ernst Weber

Creator of Weber’s law

subliminal messages

a hidden visual or auditory message that the brain acknowledges or perceives but does not process. Because the message is so hidden or small, the brain does not process it, but the brain does perceive it.

pitch theory

explains how humans perceive and interpret the sensation of pitch. It refers to the subjective perception of the frequency of a sound, i.e., how high or low a sound is perceived to be.