2 Sensation and Perception Flashcards
sensation
transduction
conversion of physical, electromagnetic, auditory, and other information from internal/external environment to electrical signals in nervous system
perception
processing of sensory information to make sense of its significance
sensory receptors
neurons that respond to stimuli and trigger electrical signals
distal stimuli
originate outside body (ex. photons)
proximal stimuli
directly interact with and affect sensory receptors
inform observer about presence of distal stimuli
ganglia
collections of neuron cell bodies found outside the central nervous system
stimuli
travel to receptors –> ganglia (via transduction) –> electrochemical energy along neural pathways –> various projection areas in brain for further analysis (perception)
photoreceptors
sight (electromagnetic waves in visible spectrum)
hair cells
respond to movement of inner ear structures’ fluid
hearing, rotational and linear acceleration
nociceptors
respond to painful/noxious stimuli
somatosensation
thermoreceptors
respond to changes in temperature
thermosensation
osmoreceptors
respond to osmolarity of blood
water homeostasis
olfactory receptors
respond to volatile compounds
smell
taste receptors
respond to dissolved
taste
threshold
minimum amount of stimulus that renders a difference in perception
“limina”
good example of perception
absolute threshold
minimum of stimulus energy needed to activate and sensory system
sensation NOT perception
subliminal perception
perception of a stimulus below a given a threshold
“threshold of conscious perception”
difference threshold
“just-noticeable difference”
minimum difference in magnitude between 2 stimuli before one can perceive the difference
Weber’s Law
there is a constant ration between the change in stimulus magnitude needed to produce JND and the magnitude of the original stimulus
higher magnitude of stimulus needs larger difference to produce JND
signal detection theory
focuses on the changes in our perception of the same stimuli depending on both internal (psychological) and external (environmental) context
response bias
tendency of subjects to systematically respond to a stimulus in a certain way due to nonsensory factors
adaptation
our detection of a stimulus can change over time both physiological (sensory) and psychological (perceptual)
rods
functional; light & dark
cones
bright light; 3 wavelengths (blue(short), green, red(long))