Chapter 4 Sensation & Perception Flashcards
Sensation
Stimulation of sense organ
Perception
Organization, identification and interpretation of sensation
Transduction
Conversion of physical signals from the environment into encoded neural signals sent to the central nervous system
Psychophysics
Methods that measure the strength of a stimulus and the observer’s sensitivity to that stimulus
Absolute Threshold
Minimal intensity needed to just barely detect a stimulus in 50% of the trials
Just Noticeable Difference
Minimal change in a stimulus that can just barely be detected
Weber’s Law
JND of a stimulus is a constant proportion despite variations in intensity
Signal Detection Theory
The response to a stimulus depends on both a person’s sensitivity in the presence of noise and on a person’s decision criterion
Perceptual Sensitivity
How effectively the perceptual system represents sensory events
Sensory Adaptation
Sensitivity to prolonged stimulation tends to decline over time as an organism adapts to current conditions
Visual Acuity
Ability to see fine detail
Length of Light
Determines hue or colour
Amplitude of Light Wave
Determines brightness
Purity
Determines saturation
Retina
Light-sensitive tissue lining the back
Accommodation
Process by which the eye maintains a clear image on the retina
Cones
Detect colour, operate under normal daylight condiitons
Rods
Become active under low-light conditions for night vision
Fovea
An area of the retina where vision is the clearest and there are no rods at all