Sensation and Perception Flashcards
Sensation
the physical processing of environmental stimuli by the sense organs
Perception
the psychological process of interpreting sensory information
Psychophysics
methods that systematically relate the physical characteristics of a stimulus to an observer’s perception
Gustav Fechner
introduced the concept of a threshold
Absolute Threshold
the smallest amount of stimulation needed for detection by a sense 50% of the time
*this is because perception is gradual
Just Noticeable Difference (JND) Threshold
the minimum difference between two stimuli needed to detect a difference between them 50% of the time
*this is proportional to the size of the original stimuli
Top-down processing
when our perceptions are influenced by our expectations or by our prior knowledge
Bottom-up Processing
when we perceive individual bits of sensory information and use them to construct a more complex message
Signal Detection Theory
response to a stimulus depends on a person’s sensitivity and decision criteria
*e.g. person’s experience, expectations, motivation, level of fatigue, consequence of missing
Sensory Adaptation
diminished sensitivity as a result of constant or recurring stimuli
Selective Attention
focusing on one particular task or event
*gorilla example
Inattentional Blindness
a failure to perceive objects that are not the focus of attention
*gorilla example
*unlike change blindness, you don’t need a pre and post memory
Change Blindness
the failure to detect changes to the visual details of a scene
*mirror example
*there is a before and after
What is the proportion of “hits” and “false alarms” in more dire situations?
You’ll have a higher number of hits and false alarms
*you’re choosing “present” more frequently
What is the proportion of “misses” and “correct rejections” in less dire situations?
You’ll have more misses and correct rejections
*you’re choosing “absent” more frequently
