Sensation and Perception

sensation

detection of external stimuli via five senses

bottom-up processing

info about actual stimulus > preconceived notions

perception

organizing and interpreting sensory info

transduction

converting sensory info into signals that the brain can understand

top-down processing

perception based on past experiences

pyschophysics

study of relationships between physical characteristics of stimuli and how the are psychologicalically percieved

absolute threshhold

minimum stimulation needed to detect a particular stimulus 50% of the time

signal detection theory

theory about how we detect a faint stimulus amid background noise (ie. parents hear baby whimper in loud room)

subliminal

below absolute threshhold

difference threshold (just noticeable difference)

it is the smallest detectable difference (minimum volume change needed to hear a difference, or the minimum weight added to a bag that you can feel)

Webers Law

for an average person to perceive a difference two stimuli must differ by a constant proportion, not a constant amount (add 1 lb to 10lb you feel it, at 1 lb to 100 lbs you don’t feel it)

sensory adaptation

diminished sensitivity as a consequence of constant stimulation, allowing us to focus without being distracted by background (except eyes, which are constantly moving) 

McGurk effect

interaction between vision and hearing, if seeing visual component of one sound and auditory component of another, creates third sound

embodied cognition

influence of bodily sensations, gestures, and other states on cognitive preferences and judgements; ie. taking hot shower after being cold, water feels hotter