Sensation Flashcards
Transduction
Outside stimuli becoming neural activity
Sensory receptors
Receive stem by energy instead of neurotransmitters
Jnd
Smallest noticeable difference 50% of the time. Different between two stimuli has to be same percentage of change each time
Absolute Threshold
Lowest level of stimuli person can detect 50% of the time
Subliminal
Stimuli below threshold
Habituation
Hearing but not paying attention. Sensory receptors are responding but brain not signaling. Learned effect.
Sensory Adaptation
Receptor cells become less responsive to unchanging stimuli. Physiological effect.
Light waves
Amplitude: brightness
Length of wave: Color
Saturation is determined if other waves are mixed in
Parts of eye
Retnia, cornea, aqueous humor, pupil, iris, rods, cones
How does light pass through eye
light enters by bouncing off. Enters through pupil, goes through retina that has rods and cones that make the light signals
Cornea
Surface of eye, protects eye
iris and pupil
Pupil is hole into eye, iris is the ‘lens’ that focuses the hole to get more or less light
Retnia
Final step, has ganglion, bipolar, and rods plus cones
Rods
and cells make light into signals, send it to bipolar and then to ganglion. In periphery.
Cones
Fine detail and color
Trichromatic theory
red green and blue cones where colors correspond to amount of light each receives
Afterimages
Visual sensation that stays for a short time when original stimuli is removed
opponenT-proCeSSTheory
mind can only register the presence of one color of a pair at a time because the two colors oppose one another. The same kind of cell that activates when you see red will deactivate in green light, and the cells that activate in green light will deactivate when you see red. This explains why you can’t see yellowish-blue or reddish-green.
How is sound perceived?
Vibrations/waves in the molecules in the air
Soundwaves
Amplitude is volume, length is pitch
Parts of the ear
Outer Ear
Middle Ear
Inner Ear
Outer Ear
Pinna funnels sound waves from outside to inside, where they enter auditory canal that leads to eardrum
Middle Ear
3 bones in middle ear behind eardrum (hammer, anvil, stirrup). The stirrup causes the membrane covering the inner ear too pen
Inner Ear
Cochlea has a basilar membrane fluid that vibrates organ of the corti
Organ of the corti
Has hairs that receive sound and sends messages through auditors nerves
Place theory (pitch)
Pitch a Pearson hears is based on where the hair cells on corti are located
only works above 1k hz
Frequency theory (pitch)
Pitch is related to how fast basilar membrane vibrates, only works up to 1k hz
Volley principle
Groups of neurons take turns sending msg to the brain for 1000 kz each,
How does taste work
Taste receptors receive molecules that fit into receptors like a lock, which is sent to gustatory cortex
texture is in soma-sensory core
How does smell work
Outer part of nose sucks in molecules of scent and transduces odor at top of olafactory passage
Lens
Focuses light in the eye to make a sharper image
What is somesthetic sense?
“Body sense”
Feel, motion, pain, and balance
Olfactory receptor cells
Have cilia that project into cavity
Receptors send signals from molecules of scent
Olfactory bulb
On top of sinus cavity right under frontal lobes
Signals are sent to bulb bypassing thalamus and then sent to higher cortical areas
Types of skin sensory receptors
Pacinian corpusles: Just below the skin, changes in pressure
Free Nerve Endings: Pressure, temp, pain
Viceral Pain: In organs and somatic pain that reminds of damage
Gate control theory
pain signals must pass through ‘gate’ in spinal cord
Stim of pain receptor cells releases substance P that activates other neurons, brain interprets info and opens or closes gate
Kinesthetic sense
Muscles, tendons, and joints so you know what and where your body is doing/is
Vestibular sense
Inner ear
Crystals suspended in fluid vibrate based on motion and tell you how you’re moving
Size constancy
Interpret object always being the same size even if it looks tiny in the distance
Shape constancy
Shape of object is the same even if seen at a different angle (coin on side is still round)
Brightness constancy
Even when darker the difference reflected from objects previously seen in lighter room is still the same ratio
Gesalt principles
Figure ground: Objects all exist on a background
Proximity: Objects that are close together are in group
Similarity: Similar objects are part of a group
Closure: Tendancy to connect figures that are incomplete (making a face out of a few lines)
Continuity: Percieve things as simply as possible
Contiguity: Two things that happen close together in time are percieved as related
Depth perception
Ability to see things in 3D
Monocular and binocular cues
Monocular cues
Linear perspection: paralell converging lines are gradually getting further away
Relative Size: When certain objects appear smaller or larger we assume they’re closer or farther away
Overlap: Thing overlapping other must be in front
Aerial perspective: Fuzzier means further away
Accomodation: Eye lens changes to see things further away, brain notices and tells you they must be in distance
Binocular cues
Convergence: Eyes cross or widen to see objects close or far, brain uses this as distance cue
Binocular dispairty: eyes don’t see exact same image, overlapping pic gives depth
Fovea
Small part of Retnia that has vision stuff
