Download 2.7 notes

Unit II Lesson 7
The ABCs of Sensation
What is Sensation?
• Process where various forms of
outside stimuli become neural
signals in the brain
– Transduction:
• Converting outside stimuli into neural
activity
– Sensory receptors
• Specialized neurons
• Stimulated by energy
Sensory Thresholds
• Weber’s Law: Difference Threshold
– Just noticeable difference (jnd)
• Smallest difference between two stimuli
detectable 50 percent of the time
• Absolute Threshold
– Lowest level of stimulation energy needed to detect
a stimulus 50 percent of the time
Subliminal Sensation
• Subliminal stimuli
– Stimuli below the level of conscious awareness
• Strong enough to activate the sensory receptors
but not strong enough for conscious awareness
• Subliminal perception
– Subliminal stimuli act upon the unconscious
mind, influencing behavior
– Scientific evidence suggests subliminal
perception does not work in advertising
– We do, however, process stimuli
unconsciously
Habituation and Sensory
Adaptation
• Habituation
– Lower centers of the brain filter sensory
stimulation
– "Ignores" or prevents conscious
attention to unchanging stimuli
• Sensory adaptation
– Sensory receptor cells become less
responsive unchanging stimulus
• Microsaccades
– Constant movement of eyes
– Prevents sensory adaptation