sensations vs perception Flashcards
____________ means taking the physical, electromagnetic, auditory,and other information from our internal and external environent and converting this information into electrical signals in the nervous system
sensation
sensation is performed by receptors in the _________
PNS
____________ refers to processing this information within the CNS in order to make sense of the informations significance
perception
physical objects outside of the body are referred to as ___________
distal stimuli
sensory stimulating byproducts are called __________
proximal stimuli
identify the distal and proximal stimuli of a campfire
distal = physical object = campire
proximal = byproduct = light, crackling, heat
the relationship between the physical nature of stimuli and the sensations and perceptions these stimuli ecoke is studied in the field of _____________
psychophysics
___________ are a collection of neuron cell bodies found outside the CNS
ganglia
___________ respond to electromagnetic waves in the visible spectrum
photoreceptors
*light
___________ respond to preesure or movement
mechanoreceptors
*movement, vibration, hearing, rotational and linear acceleration
___________ respond to painful or noxious smells
nociceptors
*somatosensation
___________ respond to changes in temperature
thermoreceptors
*thermosensation
___________ respond to osmolarity of blood
osmoreceptors
*water homeostasis
___________ respond to voltaile compounds
olfactory receptors
*smells
___________ respond to dissolved compounds
taste receptors
*taste
____________ is the minimum of stimulus energy that is needed to activate a sensory system
absolute threshold
T / F - the absolute threshold is a threhold in perception, not in sensation
false, the absolute threshold is a threhold in sensation, not in perception
absolute threshold is the minimum of stimulus energy that is needed to activate a sensory system
sensation = activates sensory system
if the stimulus is below the absolute potential, what happens?
if it is below the absolute threshold, them the stimulus will not be transduced into an action potential and therefore will never be sent to the CNS
the level of intensity that a stimulus must pass in order to be consciouslt perceived by the brain is the _____________
threshold of conscious perception
if the stimulus is below the threshold of conscious perception, what happens?
stimuus below this threshold arrives at the CNS, but does not reach the high order brain regions that control attention and consciousness
infromation is received by the CNS but does not cross this threshold = subliminal perception
____________ refers to the minimum change in magnitude required for an observer to perceive that two different stimuli are in fact different
difference threshold
the difference threhold is usually reported as a fraction or percent, how is this calculated?
difference between 440 Hz and 443 Hz
divide the chnage in stimilus by the magnitude of the original stimulus
3 Hz (difference) / 440 Hz (original) = 0.68%
explain webers law
difference threholds are proportional and must be computed as percentages
*spiders make WEBS, a high % of people are scared of spiders
what is the signal detection theory?
internal and external factors influence thresholds of sensation and perception
trials in which the signal is presented?
noise trials
trails in which the signal is not presented?
catch trials
four possible outcomes for noise / catch trials?
- hit = subject correctly perceived signal
- miss = subject fails to perceive signal
- false alarm = subject indicates they perceived signal, even though the signal was not presented
- correct negative = subject correctly identifies that no signal was presented
our ability to detect stimulus can change over time through ____________
adaptation
*body tries to focus on the most relevent stimuli
