Psychophysics

Sensation

Stimulation of sensory organs

Perception

Selection, organization, and interpretation of sensory input

Visual agnosia

Inability to recognize objects through sight

Prosopagnosia

Face blindness

Transduction

Converting one form of energy into another that your brain can use

Ex. Vision processes light, lightwaves into brain’s electrochemical language

Psychophysics

How physical stimuli are translated into our psychological experience

Stimulus

Any detectable input from the environment

Threshold

Dividing point between energy levels that do/do not have a detectable effect

Absolute threshold

Minimum stimulus intensity a sense can detect 50% of the time

Difference threshold (JND)

Smallest difference in stimulus intensity that a sense can detect half the time

Weber/Fechner’s Law

To perceive difference, two stimuli must differ by a constant minimum percentage instead of a constant amount

Sensory adaptation

• Gradual decline in sensitivity to prolonged stimulation

• Freedom to focus on informative changes in your environment

• Keeps people tuned into the changes rather than the constants in their sensory input

Selective attention

Filter to focus on what is around you

Change blindness

Failure to notice slight changes around you

Precognition

Foreknowledge of an event

Subliminal perception

Registration of sensory input without conscious awareness (below threshold of detection)

Priming

Being mentally led to a particular outcome or having heightened awareness towards it