Sensation and perception Flashcards
Sensation vs perception
Sensation = sense information gathered from environment (objective)
Perception = brain processing info from senses (subjective/interpretation)
Transduction
Process of sensation to perception
Just noticeable difference
Smallest change in stimulus for you to notice it changed
Weber’s Law
Just noticeable difference is not fixed, is dependent on the amount of stimulus
Absolute threshold
Amount of stimulus needed for just noticeable difference
Signal detection theory
If stimulus exists, you will say it exists. Involves stimulus intensity, noise (environment distraction), response criteria (how confident you have to be to say it exists)
Conservative vs liberal response criteria
Conservative: more likely to say no
Liberal: more likely to say yes
Bottom-up vs Top-down processing theories
Bottom up: our knowledge and understanding is built from our perception
Top-down: our knowledge and understanding influences how we perceive
What is the strongest human sense
Vision
What is the stimulus for vision vs source of experience of vision
Stimulus = light
Source of experience = color
How does amplitude and wavelength of light waves change vision
Amplitude = brightness
Wavelength = shade of color
Cornea
Part of eye that light passes through, mainly for protection
Pupil
Black/hole section of eye
Iris
Colorful part around pupil, muscle that changes pupil shape according to light intensity
Lens
Circular object behind pupil that focuses light, shape changes depending where vision focuses
Retina
Receives focused image from lens, which then is sent to the brain, light reflected onto retina activates rods and cones
Fovea
Region of retina, light projected to fovea is where you see the clearest
Rods
Provide black and white vision, night vision, detecting motion and peripheral vision
Cones
Detect color and fine detail
Bipolar and ganglion cells
Collect info from rods and cones, step 1 of transduction
Blind spot
Entrance of optic nerve
Sclera
White of eyes, mostly unique to humans, not important for vision, used for communication and telling where someone is looking
How many wavelengths and colors can humans recognize
3 wavelengths, 1 million colors
Why does colorblindness happen
Dysfunction in the cones
Optic nerve
Info from retina is sent here, is a blind spot
Optic chiasm
Point where info is split: info from left part of visual field is sent to the right side, and vice versa
Optic tract
In between optic chiasm and thalamus
Primary visual cortex
In occipital lobe, where the actual processing of vision occurs
Simple vs complex vs hypercomplex cells
Types of neurons in primary visual cortex that respond to visual information
Simple: simplistic orientation information
Complex: simplistic orientation information and movement info
Hypercomplex: multiple forms of orientation
Ventral stream
“what” pathway: tells your brain what you’re looking at (occipital to temporal lobe)
Dorsal stream
“where/how” pathway: tells your brain where object is located in environment (occipital to parietal lobe)
Illusory conjunction
Separate features can be blended together, causing you to see things that don’t exist. Happens when briefly shown an image/attention is split between two images
Are depth cues more sensation or perception related
Perception
Binocular cues
Requires both eyes. The larger the difference between the images shown in left/right eye are, the closer an object is to you
Monocular cues
Only requires one eye
Familiar size: when we are familiar with an object, we use it to determine distance by change in size
Linear perspective: parallel lines converge as they move farther from you
Texture gradient: closer things are, the clearer their textures are
Interposition: Closer objects are in front of farther objects
Relative height: Close objects are usually at the bottom of our visual field, far objects at the top
Vision gestalt grouping
Simplicity: we interpret images in the simplest/easiest way we can process w/ our eyes
Our brains create closure and continuity when they are not there
Our brains group together objects based on similarity, proximity, and common fate (objects that move together)
How do amplitude and frequency change sound waves
Higher frequency = higher pitch
Higher amplitude = louder sound
What are the three parts of the ear
Outer ear, middle ear, inner ear
What are the parts of the outer ear
Pinna: fleshy part, shaped to catch sound waves
Auditory canal: sound waves bounce here
Eardrum/tympanic membrane: vibrates based on how sound waves hit it
What are the parts of the middle ear
Ossicles: sit against eardrum and vibrate as it vibrates. made up of hammer, anvil and stirrups. bones pass vibration onto each other
What are the parts of the inner ear
Cochlea: makes up most of inner ear, filled with fluid
Basilar membrane: equivalent of the retina, when fluid in cochlea moves, basilar membrane moves
Hair cells: receptor neurons for hearing
Auditory nerve: sends info from hair cells to brain
Semicircular canals: determines balance based on how cochlea fluid is positioned
Place theory
High frequency sounds peak near cochlea base, low frequency sounds peak near the apex
Temporal/frequency theory
We process sounds based on frequency of firing of hair cells
Sound gestalt grouping
Location: sounds coming from the same place are grouped
Temporal: sounds that start/end at the same time are grouped
Localization
Determining where sound comes from. Uses your pinna: location determined by which ear receives info first
What are the two types of hearing loss
Sensorineural: Hearing loss happens in inner ear, issue with hair cells, common in hearing loss due to age. hearing aid does not help
Conduction: Hearing loss happens in middle ear, oscilles do not vibrate enough. hearing aid helps
Plastic
Ability of somatosensory cortex to change amount of neurons allocated to a certain body part
Phantom limb pain
The false sensation of touch on a lost limb
Where does pain come from
A-DELTA FIBERS: fast, sharp, shooting pain. has a myelin sheath for fast transportation
C FIBERS: dull, throbbing pain
Referred pain
Outer and inner body parts are connected on somatosensory cortex: Inner pain can be felt as outer pain
Haptic perception
Understanding the world via touch (how babies understand the world)
Kinesthesia
Understanding of how your body is positioned
What senses are chemical senses and why
Touch and smell because they involve receptors
What is the only sense directly connected to the forebrain
Smell
Olfactory receptors
In your nose, determine how we sense smells. Humans have 350, and can smell 1 trillion smells
Papillae
Taste buds: each has hundreds of taste receptor neurons, are very quick to be replenished, we lose most of our taste buds by age 20
What are the five primary taste sensations
Salty: associated w/ sodium
Sweet: associated w/ fruits
Sour: associated w/ acidic foods
Bitter: associated w/ vegetables
Umami: associated w/ meat
Synesthesia
Combination/joined sensation of the senses
