Sensation and PerceptionSensation and Perception
• Detection and interpretation of stimuli so that we can understand and adapt to the world
• Essential to thinking, emotions, and behavior
• Imagine if you had NO senses
SENSESSENSES
• Detect and analyze stimuli through SENSORY RECEPTORS
• These are specialized neurons that transform stimuli into neural responses
• This is called transduction (see p. 90)
SENSORY THRESHOLDSSENSORY THRESHOLDS
• Absolute Threshold: Smallest strength of a stimulus you can detect 50% of the time
• Examples: candle flame 30 miles away on a dark night, one drop of perfume in a 3-room apartment
SENSORY THRESHOLDSSENSORY THRESHOLDS
• Difference Threshold: smallest possible difference between 2 stimuli that can be noticed 50% of the time
• AKA “Just noticeable difference”• Varies depending on the relation to original
stimulus—it is in constant proportion to the size of the original stimulus
• If the original stimulus was very intense, it will take more of a new stimulus to notice a difference
SENSORY ADAPTATIONSENSORY ADAPTATION
• Senses get used to a prolonged stimulus—they become less responsive to a constant stimulus
• Experience of sensation is relative to the duration of the exposure
• Sensory receptors are best at responding to new and different stimuli—so that we can quickly notice new or changing stimuli and react to it
PERCEPTIONPERCEPTION
• Your interpretation and organization of the world: making sense of the sensations
• Perception depends on sensations, but also on psychological activities like memories, expectations, familiarity, etc.