Basic concepts of Sensation and Perception
Weber's Law
The size of the difference threshold is greater for heavier objects than for lighter ones. This BEST illustrates:
Psychophysics
the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them
Perception
the top-down process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events
Sensory adaptation
Barbara stubbed her toe last night. It hurts and all day today she has been aware of her toe. She says, "This is so weird. I usually don't think about my toe." Barbara is describing:
signal detection theory
Dennis, a nurse, notes that some parents of asthmatic children respond to very small changes in their children's breathing and seek care accordingly. However, other parents do not notice the same small changes. This type of difference in reaction to stimuli is BEST explained by:
top down processing
Interpreting new sensory information within the framework of a past memory illustrates:
perceptual set
Once John learned of Sara's past history of being an abuse victim, he began to view her cautious behavior around men as more self-protective rather than rude. This BEST illustrates the impact of:
signal detection theory
Two Transportation Security Administration officers are scanning bags at the airport. One of the officers lets a bag go through, but the other officer yells, "Wait, didn't you see that?" Why one officer saw a weapon and the other did not is BEST explained by
perceptual set
When people look at a photograph of an adult-child pair and are told that the two individuals are parent and child, the people tend to say the pair looks more alike than people who are told the pair is unrelated. This is MOST likely due to:
perceptual set
a mental predisposition to perceive one thing and not another
signal detection theory
a theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise). Assumes there is no single absolute threshold and that detection depends partly on a person's experience, expectations, motivation, and alertness.
bottom-up processing
analysis that begins with the sensory receptors and works up to the brain's integration of sensory information
subliminal stimulation
below one's absolute threshold for conscious awareness
Transduction
conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brains can interpret.
sensory adaptation
diminished sensitivity as a consequence of constant stimulation
top-down processing
information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations
sensory receptors
sensory nerve endings that respond to stimuli by developing action potentials
Sensation
the bottom-up process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment
difference threshold
the minimum difference between two stimuli required for detection 50 percent of the time.
absolute threshold
the minimum stimulation needed to detect a particular stimulus 50 percent of the time
Weber's Law
the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount)