Sensation/Perception Flashcards
Place Theory
auditory
the closer to the oval window in the ear (base) the higher the frequency (pitch)
the closer to the apex the lower the frequency
Weber’s Law
the just noticeable difference -> smallest difference you can detect 50% of the time
ex: think of comparison of 2 different weights
delta I/I = K
absolute threshold
lowest intensity value a person can detect a stimulus 50% of the time
experimentally found by seeing percentage of time a person accurately detects the stimulus
ex: Sam could hear a fly from across the room, so she has a higher absolute threshold than quinn who is practically deaf
also think of the hearing tests in kindergarten
Sensory Adaptation
adapting to the sensations around you to the point that you don’t notice them anymore
ex: not feeling your watch after a few minutes of wearing it; not being able to detect a weird smell after being there for a while
Mechanoreceptors
detect movement
stimuli: sound waves and touch
ex: hair cells in the ear
chemoreceptors
detect chemicals
stimuli: molecules, solutes
ex: taste buds
Thermoreceptor
detects temperature
stimuli: heat, cold
ex: skin
Photoreceptors
light waves
stimuli: visible light
ex: rods, cones (retina)
Signal Detection Theory
the more stimuli distractions (visual, cognitive, auditory) you add, the lower a person’s correct results to stimuli
external noise: auditory distraction
internal noise: cognitive processing
ex: when I’m studying for MCAT and watson is yelling outside, I become distracted and don’t do as well on thinking through the exam. When you add Kenzie talking and the tv playing, it becomes harder to focus with the extra distractions and the more I get incorrect on my exam.
PET scans
Positron Emission Tomography
uses radioactively labeled glucose to measure brain activity
produces 3D image of the brain showing hypermetabolic and hypometabolic regions
fMRI scans
look at oxygenation levels of the brain
the more oxygen to a specific area means more brain activity
scanner detects the differential properties of oxyhemoglobin and deoxyhemoglobin
feature detection
process by which nervous system sorts through/filters natural stimuli to only pick up on the most relevant stimuli and ignore the others
want to pick up behaviorally relevant cues
feature detector neurons only fire for specific movement, shapes, colors, angles etc
parallel processing
taking in multiple components and applying it to visualize an object
ex: seeing an object containing both movement and color
top-down processing
taking information we already know and applying it to a more generalized situation
ex: when seeing a picture with amino acids, you will automatically think you see all of them even if they aren’t all present because your brain already has that information
bottom-up processing
using sensory information to guide our perception; usually applied to novel experiences
ex: blind taste test
EEG
electroencephalogram
electrodes placed on scalp and connected to an amplifier
measures voltage fluctuations in the brain over time
cannot localize activity to a specific brain area
used to visually see seizures
CT
computerized tomography
computer combines multiple x-rays taken at different angles
measures detailed structure of internal organs and tissues at a single point in time
motion parallax
relative motion
monocular cue (one eye)
objects closer to the observer appear to be moving faster than the background
can perceive depth and motion
retinal disparity
each eye transmits a slightly different picture to the brain
helps infer distance
convergence
the amount the eye turns inward to focus on an object
the closer the object, the more convergence
helps infer distance
phi phenomenon
motion picture effect
optical illusion were still photos are flipped in rapid succession so it appears to be moving
taste aversion
a specific and powerful classical conditioning that occurs when an organism becomes ill after consuming something
only requires one pairing and has a long duration
most likely the organism will never eat the thing again
Gestalt principles
describes how human’s holistically perceive sensory stimuli
similarity
gestalt’s principle
tendency to group together objects that share similar features
- shape, color
common fate
perception that things moving together are grouped together
ex: flock of birds flying in V-formation is perceived as a unit
proximity
gestalt’s principle
perceive things that are physically closer to one another as a group
continuity
gestalt’s principle
tendency to perceive elements as continuing on a smooth path
closure
gestalt’s principle
tendency to see lines that are close together as closed and forming part of a picture
perceptual constancy
perception that an object’s characteristics remain stable even when the object seems to change because the environment was altered
applies to shape, color, brightness, and size
subjective contours
gestalt’s principle
illusions
our mind will fill in gaps to create images based on top-down processing
invariance
gestalt’s principle
objects can be recognized despite slight alterations
can be recognized in different spatial orientations or when it is depicted with dotted rather than solid lines
kinesthetic sense
proprioceptors in muscles, joints, tendons, and skin detect movement and position of body/limbs
kinesthetic input provides awareness of location of parts of the body in space and how they are moving
vestibular sense
maintains balance and orientation
motion sickness arises from conflict between vestibular system and visual input
organs within the inner ear
Otolithic organs
vestibular sense
located within the cochlea of the inner ear
contains utricle and saccule
detect gravity/acceleration
has crystals that attach to hair cells that are pulled when change head position, causing AP to fire
semicircular canals
vestibular sense
senses head rotation
contains anterior, posterior, and lateral semi-circular canals
maintenance of spatial orientation and balance relies on
visual input (provides input on orientation of body)
vestibular input (provides info on motion, equilibrium, and spatial orientation)
somatosensory input (proprioceptors, provide info on location and movement of body in space)
cochlea
located within inner ear
sound processing and transmission of auditory information to the temporal lobe of the brain
Monocular cues
depth cues that can be perceived using one eye only and often rely on comparisons between objects
include: interposition light and shadow texture gradient relative size relative height linear perspective
interposition
type of monocular cue
closer objects will overlap in front of object that are further away
create a sense of depth
light and shadow
monocular cue
highlights and shadows help to give objects the appearance of depth
texture gradient
monocular cue
closer objects are more fine detailed than objects that are further away
relative size
monocular cue
further objects appear smaller than closer objects of the same size
relative height
monocular cue
further objects are perceived at being higher in our line of sight
linear perspective
monocular cue
distances between parallel lines appear narrower as they become further away
stereopsis
perception of depth that arises from having retinas in 2 different locations that create one picture for your brain to process
binocular
convergence
the closer the object is to the observer, the more the eye turns inward to focus on the object
that angle indicated distance from the observer
sensory accommodation - eye
ciliary muscles of the eye alter the shape of the lens
this helps with depth perception - monocular cue
circadian rhythms
cycles in physiological activity that occur over 24 hour interval
align with synthesis and secretion of melatonin from pineal gland -> light dependent process
Ruffinian Endings
respond to pressure on the skin
