AP Psych Unit 2 - Sensation and Perception

Sensation

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

Transduction

The process of converting one form of energy to another (sensory stimuli →neural signal)

Transduction (Pathway)

Stimulus →Receptor → Brain → Perception

Absolute Threshold

The minimum amount of stimulus required to detect a particular stimulus, 50% of the time

Difference Threshold / Just Noticeable Difference

The difference minimum between two stimuli required for detection 50% of the time

Signal Detection Theory

Prediction about how and when we detect a faint/background stimulus,thus assuming there is no single absolute threshold and that detection depends on the person

Weber’s Law

To be perceived as different, two stimuli must differ by a constant percentage rather than a constant amount

Sensory Adaptation

Diminished sensitivity as a consequence of constant stimulation or exposure

Synesthesia

One sense is activated and another unrelated sense is activated at the same time

Sensory Interaction

When one sense influences another

Intensity

Determined by the amplitude of a light wave

Hue

Determined by the wavelength of a light wave

Iris

A ring of muscle tissue that forms the colored portion and controls the size of the pupil opening

Lens

The transparent structure behind the pupil that helps focus images in the retina

Cornea

Outer covering of the eye

Pupil

The adjustable hole in the center of the eye

Blind Spot

The point at which the optic nerve leaves the eye, there are no receptors cells

Fovea

Central point of focus

Cones

Track color, centered, low sensitivity in dim light, look at details

Rods

Black and white images, track movement, most common in the eye, periphery images

Ganglion Cells

The axons twine together to form the optic nerve, sends signals to the brain

Bipolar Cells

Chemical reaction →Neural signals, activates the Ganglion cells

Young Helmholtz Trichromatic Theory

Monochromatic & Dichromatic vision, vision in reds, greens, and blues

Opponent Process Theory

Colors are paired, red & green, blue & yellow, black & white, afterimages

Dichromatism

Can’t see reds and greens

Monochromatism

Can only see one color

Prosopagnosia/Face Blindness

The inability to recognize faces, damage to the detectors in the temporal lobe

Blindsight

A condition where a person can respond to a visual stimulus without consciously experiencing it - process visual stimuli while being blind

Pitch

Comes from wavelength and frequency

Loundness

Comes from the amplitude (amp)

Pinna

The outer part of the ear, aims sound into the ear

Ear Canal/ Auditory Canal

Where sound waves travel to reach the eardrum

Ear Drum/ Timpanic Membrane

A layer of tissue that vibrates in response to sound

Ossicles (hammer/anvil/stirrup)

3 smallest bones in the body, transfer the vibration from the eardrum to the oval window

Oval Window/ Cochlea Opening

Where vibrations transfer to the cochlea, causing fluid to move

Cochlea

Sound waves travel through(fluid) to trigger neural impules

Semicircular canals

3 fluid-filled tubes in the inner ear that maintain balance of the body and detect head movements

Sensorineural Deafness

Inability to hear due to damage to the cochlea’s receptor cells or to the nerves, treated with cochlear implants

Conductive Deafness

Deafness due to damage to mechanical elements of the ear(non-cochlea parts), treated with hearing aids

Place Theory

The pitch of a sound we hear is due to activation of specific hair cells on the basiler membrane (like a piano)

Frequency Theory

The entirety of the basiler membrane vibrates in response to sound, and the speed of the vibration is how we perceive pitch

Volley Principle

Groups of auditory nerves fire action potentials slightly out of phase with one another, so a greater frequency of sounds can be analyzed and sent out

Sound Localization

Sound that reaches one ear faster causes use to localize the sound to determine directionality

6 Taste Sensations

Sweet, Sour, Salty, Olegustus, Bitter, Umami

Supertaster

Someone who has more(kinds of) taste buds

4 Basic Touch Sensations

Pain, Pressure, Temperature, Touch

The Purpose of Pain

Pain tells the body that something is wrong and needs to be fixed

Gate-Control Theory

The spinal cord contains gates that act as a buffer between pain and the brain, deciding which signals will pass through

Phantom Limb Sensation

A physical phenomenon of injured nerves sending impulses to a definable brain or spinal cord area, for a limb that no longer exists

3 Methods of Controlling Pain

Painkillers, placebos, distraction

Kinesthesia/Kinesthetic Sense

Sense of our individual body part’s position and movement, receptors in the muscle tissues and joints

Vestibular Sense

Monitors head and body position and sense of balance, receptors in the semicircular canals and vestibular sacs in ears, works with the cerebellum

Sensation

The process by which our sensory receptors and neurons system receive and represent stimulus from our enviornment 

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 sensory receptors and works up to the brain’s integration of sensory information

Top Down Processing

processing guided by higher-level mental processors, constructing perception from lived experiences and expectations

Attention

Awareness of a stimuli

Selective Attention

Foucusing conscious awareness on a particular stimulus

Cocktail Party Effect

The ability to focus one’s attention on a particular stimulus while filtering out a range of other stimuli

Inattentional Blindness

Failing to see visible objects when our attention is focused elsewhere

Change Blindness

Failing to notice changes in the environment

Gestalt Theory

We filter incoming information to construct perceptions, in perception the whole may exceed the sum of its parts

Figure-Ground

The organization of the visual field into objects(figures) that stand out from their surroundings(background) 

Proximity

Group objects that are close together as being part of the same group

Similarity

Objects similar in appearance are perceived as being part of the same group

Continuity

Objects that form a continuous shape are perceived as the same group

Closure

We fill in gaps if we can recognize it

Connectedness

elements tend to be grouped together if they are connected by other elements and viewed as a single unit

Closure

We fill in gaps if we can recognize it

Depth Perception

The perception of 3D objects from 2D images

Retinal Disparity

Compares the retinal images from each eye and computing the distance between two images

Convergence

Coordinated movement of both the eyes so that the image of a single point is formed on corresponding retinal areas

Relative Clarity

Distant objects have less clarity

Relative Size

If we assume two objects are similar in size, we perceive the smaller one as farther away

Texture Gradient/Shading

A sense of depth is produced consistent with assumptions about where the light source is 

Interposition

If one object blocks the position of another it is perceived as closer

Linear Perspective

Parallel lines appear to meet in the distant, the sharper the angle the further the distance

Measure of Apparent Motion

Measure the absolute threshold for detecting motion

Perceptual Constancy

A top-down process that allows for perception of objects to remain unchanging regardless of color, brightness, size, or shape

Stroboscopic Effect

A rapid series of slightly varying images perceived as moving images, such as a flip book

Phi Phenomenon

Illusion of movement created when 2 or more lights next to each other blink on and off

Autokenietic Effect

A stationary point of light appears to move in a dark environment due to small eye movements