Sensation & Perception Flashcards
sensation
the physical processing of environmental stimuli by the sense organs
perception
the psychological processing of interpreting sensory information
What is the process of sensation to perception?
stimulus → sensory receptors → transduction → neural impulses → perception
psychophysics
methods that measure the strength of a stimulus and the observer’s sensitivity to that stimulus
Who studied psychophysics?
Gustav Fechner
absolute threshold
the smallest amount of stimulation needed for detection by a sense 50% of the time
True or False:
lower absolute threshold = greater sensitivity
True
True or False:
Perception is an all-or-none phenomenon.
False
happens little by little
difference threshold/
just noticeable difference
the minimum difference between two stimuli needed to detect a difference between them 50% of the time
The more intense the original stimulus, the ___ the amount that needs to be added before a difference is detected.
larger
What is the JND?
original: loud music
change: volume up by 3
high
What is the JND?
original: quiet music
change: volume up by 3
low
top-down processing
when our perceptions are influenced by our expectations or prior knowledge
perception → sensation
bottom-up processing
when we receive individual pieces of sensory information and use them to construct a more complex message
sensation → perception
signal detection theory
a response to a stimulus depends on a person’s sensitivity and decision criteria
stimulus: present
response: present
hit
stimulus: absent
response: present
false alarm
stimulus: present
response: absent
miss
stimulus: absent
response: absent
correct rejection
What is the most favorable response in a high-stakes situation?
false alarms > misses
sensory adaptation
diminished sensitivity as a result of constant or recurring stimuli
What are examples of sensory adaptation?
- wearing perfume
- hearing an air conditioner
- being aware of wearing clothes
selective attention
focusing on one particular task or event over the full picture
inattentional blindness
failure to perceive objects that are not the focus of attention
change blindness
failure to detect changes to the visual details of a scene
cornea
transparent covering of the eye