AP Psychology 1.6 Sensation and Perception

Absolute Threshold

Minimum stimulus energy needed to detect a particular stimulus 50% of the time

Signal Detection Theory

Theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise)

Perception

Process by which our brain organizes and interprets sensory info, enabling us to recognize objects and events as meaningful

Bottom Up Processing

Info processing that begins with sensory receptors and works up to the brain’s integration of sensory info

Top Down Processing

Info processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience

Transduction

Conversion of one form of energy/chemical to another form of energy

Psychophysics

Study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them

Subliminal

Signals below one’s absolute threshold for conscious awareness

Priming

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

Framing

The way on issue is posed; often intentionally/consciously

Difference Threshold

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

Weber’s Law

Principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage, rather than amount

Sensory Adaptation

Diminished sensitivity as a consequence of constant stimulation

Wavelength

Distance from the peak of one light wave to the peak of the next

Hue

Dimension of color that is determined by the wavelength of light

Amplitude

Height of wave

Intensity

Amount of energy in a light wave which influences what we perceive as brightness

Accommodation

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

Myopia

Nearsightedness

Hyperopia

Foresightedness

Young-Helmholtz Trichromatic Theory

Theory that the retina contains three different types of color receptors (red, green, blue), when stimulated in combination, can produce the perception of any color

Opponent Process Theory

Theory that opposing retinal processes (red-green, blue-yellow, white-black) enable color vision

Afterimages

Visual illusion that continues to appear in your vision after the original light or image is gone