Chapter 5 Sensation and Perception - Please Do Not Alter Review List

The stimulation of the sense organs.

Selection, Organization, and interpretation of sensory input.

The study of how physical stimuli are translated into psychological experience.

Information in the environment that is picked up by the receptors in our nervous system.

Begins with a detectable stimulus

The lowest intensity at which a stimulus can be detected correctly 50% of the time. Fechner is credited for this finding
Lower the threshold = Greater the sensitivity

JND- Just noticeable difference. The minimal amount of stimulus needed to be increased enough to be judged as different from the original.

The difference threshold or JND (Just noticeable difference ) is directly proportional to the magnitude of the stimulus with which the comparison is being made .

The fraction of something that has to be changed in order for one to recognize something has changed.
Weight 1/50

• 100 lbs. then 101 will not be recognizable
• 100 and 102 will be recognizable (1/50)

The diminishing sensitivity to a constant stimulus over time. The skill has survival value because it allows brain to focus on new stimuli.

Stimuli that are so weak that the cannot be perceived consciously although registered by our senses.

Subliminal stimuli have little effect on behaviour and small effect on attitudes. Problem mitigated

The eardrum

The brain detects a sound is louder by : -greater sound waves-vibrations in basilar membrane-greater bending of hair cells-more neurotransmitter substance is released-certain cells respond only to very loud sounds

Nerve impulses sent to the brain match the frequency of the sound. Only useful for frequencies under 1000 Hz.