PSYCH 104 - General Concepts

Sensation

Stimulation of sense organs

Perception

Selection, organization and interpretation of sensory input

Transduction

Process where sensations are translated into electrochemical transmission

Psychophysics

Study of how physical stimuli are translated into psychological experience

Stimulus

Any input from the environment that is detectable

Absolute Threshold

Regarding the specific type of sensory input: the minimum stimulation amt. that any organism can detect

Arbitrarily

Stimulus intensity is detected only 50% of the time

Just Noticeable Difference (JND)

Smallest difference in the amount of stimulation that a specific sense can detect (reword)

Difference threshold

Weber’s Law

The size of a JND is constant (Weber Fraction) in proportion to the initial stimulus’ size

The constants differ solely depending on the type of stimulus

Scaling

Tendency to measure on absolute scales

Everything is relative in perception → No absolute scales

Fechner’s Law

Subjective sensation in proportion to logarithims of stimulus intensity

Signal-Detection Theory

The detection of stimuli that involves decision and sensory processes

Subliminal Perception

Registering sensory input without our conscious awareness

James Vicary (1957)

Influence our behaviour in some situations

Sensory Adaptation

Gradual decline of sensitivity due to prolonged stimulation

Adaptive process → aware of environmental changes compared to constants