Ch. 4: Sensation and Perception

Sensation

stimulation of a sense organ; registration of light, sound, pressure, odour, or taste as parts of the body interacts with the physical world

Perception

interpretation of a sensation

Transduction

sensors in the body convert physical signals from the environment into encoded neural signals sent to the CNS

Sensory adaptation

sensitivity to prolonged stimulation tends to decline over time as an organism adapts to current(unchanging) conditions; stronger response changes in stimulation than to constant stimulation

Psychophysics

methods that systematically relate the physical characteristics of a stimulus to an observer’s perception

Absolute threshold

minimal intensity needed to just barely detect a stimulus(50% mark on graph); increasing intensity = frequent stimulus detection

Just noticeable difference (JND) threshold

minimal change in a stimulus that can just barely be detected

Weber’s law threshold

the smallest noticeable difference between two stimuli is a constant ratio of the original stimulus; ex: adding 0.05kg vs. 0.2 kg

Signal detection theory (SDT)

how individuals perceive and respond to signals (stimuli) in the presence of noise or uncertainty

Selective attention

perceiving only what’s currently relevant

Multitasking

involves paying attention to more than one stimulus at the same time, fMRI studies show decreases in brain areas while multitasking