AP Psychology - Unit 3: Sensation & Perception

Selective Attention

The focusing of conscious awareness on a particular stimulus

Inattentional Blindness

Failing to see visible objects when our attention is directed elsewhere

Change Blindness

Failing to notice changes in our environment

Psychophysics

The study of the relationship between physical characteristics of stimuli and our psychological experience with them

Absolute Threshold

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

Signal Detection Theory

A theory predicting how and when we detect the presence of a faint stimulus amid background stimulation

Subliminal Threshold

When stimuli are below one’s absolute threshold for consciousness awareness

Priming

The activation, often unconsciously, of certain associations, thus predisposing one’s perception, memory, or response

Difference Threshold

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

Weber’s Law

Two stimuli must differ by a constant minimum percentage (rather than a constant amount), to be perceived as different

Sensory Adaptation

Diminished sensitivity as a consequence of constant stimulation

Transduction

Conversion of one form of energy into another

Wavelength

The distance from the peak of one light or sound wave to the peak of the next

Hue

The dimension of color that is determined by the wavelength of light

Intensity

The amount of energy in a light wave or sound wave, which influences what we perceive as brightness or loudness - it is determined by a waves amplitude

Accommodation

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

Rods

Retinal receptors that detect black, white, and gray, and are sensitive to movement - necessary for peripheral and twilight vision

Cones

Retinal receptors that are concentrated near the center of the retina and that function in daylight or in well-lit conditions - they detect fine detail and give rise to color sensations

Blind Spot

The point at which the optic nerve leaves the eye - leaving no receptor cells located there

Fovea

The central focal point in the retina, around which the eye’s cones cluster

Frequency

The number of complete wavelengths that pass a point in a given time

Pitch

A tone’s experienced highness or lowness; depends on frequency

Amplitude

The maximum displacement or distance moved by a point on a wave from its equilibrium position

Kinesthesis

Our movement sense - our system for sensing the position and movement of our body

Vestibular Sense

Our sense of body movement and position that enables our 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 large fibers or by information coming from the brain

Sensory Interaction

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

Figure-Ground

The organization of the visual field into objects that stand out from their surroundings

Perceptual Adaptaion

The ability to adjust to changed sensory input, including an artificially displaced or even inverted visual field

Perceptual Set

A mental predisposition to perceive one thing and not another