Sensation and Perception Flashcards
Sensation
- conversion of physical, electromagnetic, auditory etc. info to electrical signal in PNS
- performed by receptors
- raw signal
Perception
- making sense of the sensation
- involves analyzing and making sense of signals
Sensory receptors
respond to stimuli and trigger electical signals
Distal stimuli
- originate outside of the body
- part of the outside
- ex. campfire, photon of light
Proximal stimuli
- directly interact and affect sensory receptors
- inform observer of the presence of distal stimuli
- ex. photoreceptor
ganglia
collection of cell body in PNS
photoreceptors
- respond to electromagnetic waves in visible spectrum
hair cells
respond to movement of fluid in the inner ear
nociceptors
respond to painful and noxious stimuli (somatosensation)
Thermoreceptors
respond to t
Osmoreceptors
respond to osmolarity of the blood
Olfactory receptors
respond to volatile receptors
taste receptors
respond to dissolved compounds
thresholds
- min amount of stimulus tat render a difference in perception
- three types: absolute, of conscious perception, difference
Absolute threshold
- min intensity needed for a stimulus to convert into action potential
- threshold only of sensation
- talking about how intense something must be in order to be sensed
Limina
threshold
Threshold of conscious perception
- aka subliminal perception
- perception of stimulus below given threshold
- stimuli reach CNS, but not higher order brain, so stimuli isn’t perceived
Difference threshold
- aka just noticeable difference
- min difference in magnitude b/ two stimuli before one can perceive this difference
Weber’s law
- there’s a const ratio b/ change in stimulus magnitude and the magnitude of the original stimuli
- for higher magnitude stimuli, the actual difference must be larger to produce a jnd
Signal detection theory
- focuses on changes in our perception of the same stimuli depending on internal and external factors
response bias
we tend to respond to the stimulus in particular way due to nonsensory factors
possible outcomes for signal detection experiment trial
- hit: detect stimuli when stimuli present
- miss: didn’t detect stimuli when there was one
- false alarm: detect stimuli when there wasn’t one
- correct negative: didn’t detect stimuli when there wasn’t one
Adaptation
decrease in response to stimuli over time
retina
- back of the eye
- macula (central section) has fovea- the cenermost point that has only cones
- further away from macula: cones decrease, rods increase
- cones - three types, responsible for color vision, effectiv in bright light
- rodes - one type, contains rhodopsin (pigment), night vision
connections b/ rod, cones and optic disc
- bipolar cells: conect rods and cones
- bipolar cells synapse with ganglion cells
- optic nerve: grouping of synapses between ganglions and bipolar cells
Horizontal and amacrine cells
- integrate the signals from ganglion cells
- make edges sharper
R visual field is progected onto
L half of OU retinas
Visual pathways
- Eye>optic nerve>optic chiasm>optic tracts>lateral geniculate nucleus of thalamus>visual radiations (temporal and lateral lobes)>visual cortex
Parallel processing
ability to simultaneously analyze and combine info regarding color, shape and motion
Parvocellular cells
detect shape
can only work with stationary or slow moving objects
Magnocellular cells
- detect motion
- MNEMONICS: M for M (magnocellular=motion)
Intensity of the sound
- corresponds to loudness
- increase intensity= greater amplitude
Outer ear include
pinna (auricle) ear lobe (where we pierce) external auditory canal tympanic membrane (/ b/ middle and outer ear)
middle ear
3 ossicles:
- malleus
- incus
- stapes
connect via eustachian tube to nasal cavity- stabilize P
inner ear
- cochlea (detect sound), vestibule (detects linear acceleration) and semicircular canal (detects rotational acceleration) filled w/ endolymph and perilymph
auditory pathway
cochlea>vestibulocochlear nerve>medial geniculate nucleus>auditory cortex
1) medial vs 2)lateral geniculate nucleus
1) L for light. SEnsory pathway
2) M for music. Auditory pathway
Bottom-Up processing
brain takes individual sensory stimuli and combines them together to create cohesive image
Top-Down processing
- driven by memories and expectations
- brain recognizes the whole object w/t analyzing for specific parts
Perceptual organization
ability to use top-down and bottom-up processing to create a complete picture or idea
Gestalt principles:
we view things as whole
include:
- law of proximity - elements close to one another tend to be grouped together
- law of good continuation - elements that appear to follow in the same pathway tend to be grouped together
- law of similarity - objects that are similar tend to be grouped together
- Law of subjective contour - perceiving contour and shapes that are not actually present in the stimuli
- Law of closure - perceiving things as complete
