Psychology 12 Intro to Sensation Hwk Review p Vocabulary Practice

Psychophysics… The study of the relationship between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them.

Absolute Threshold The minimum stimulation needed to detect a particular stimulus 50% pf the time

Signal Detection Theory A theory that predicts how and when we detect the presence of a faint stimulus (‘signal’) amid background stimulation (‘noise’). This theory assumes that there is no single absolute threshold and that detection depends partly on a person’s experience, motivation, and fatigue levels.

Subliminal Below one’s absolute threshold for conscious awareness. In 1956 controversy erupted over a false report that NJ movie audiences were unwittingly being influenced by subliminal flashed messages to DRINK COCA-COLA and EAT POPCORN. Disney Movie’s claim to also have these ‘subliminal’ messages in them too (not proven)

Difference Threshold The minimum difference that a person can detect between 2 stimuli. This is also called the ‘Just Noticeable Difference’ (jnd)

Weber’s Law The principle that, to perceive their difference, two stimuli must differ by a constant minimum percentage (rather than a constant amount) Ex: If a price of a chocolate bar goes up.25 cents, we may notice if you are a regular chocolate bar eater. If a car goes up $4,000 dollars we may not realize because the price of new cars is already so high.

Sensory Adaptation Diminished sensitivity as a consequence of constant stimulation. Ex: you walk into a room that has a smell, but a few minutes later you do not smell it anymore.