Term test 2 Flashcards
Psychophysics
states that sensation is the stimulation of sense organs and perception is organizing these stimulations
ophthalmology
study of eye structure and function
audiology
science concerned with hearing
neurology
study of nervous system
sensation
process of receiving stimuli and transforming them into action potentials. Refers to raw material of experience.
what do sensory systems have in common
- specialized receptor cells
- transduction
- multiple subsystems
what do they do
the specialized receptor cells are what allow the sensory systems to receive/detect the stimulus, and then transduction takes place which is when the stimulus is converted to action potentials that relay information to the brain. The information travels to the cerebral cortex and each sensory has its own multiple subsystems.
perception
The process of organizing and interpreting sensory information so that it makes sense. Refers to the experience itself.
bottom up
taking in information from the environment and interpreting it
top-down
applying already known observations or interpretations to make sense of what is happening
do sensation and perception improve a species’ chance of survival?
yes
afferent nerves
bring information from the world to the brain
main categories of sensory organs
- photoreceptors: detect light
- mechanoreceptors: detect pressure and vibration
- chemoreception: detects chemical stimuli
what is synaesthesia?
an experience in which one sense induces an experience in another sense
what organ do sensory organs go through?
the thalamus
thresholds
the minimum amount of stimulus that a sensory system requires for activation. It is the point at which an individual detects a stimulus 50% of the time.
JND (just-noticeable difference)
the minimum difference in which a difference in the stimulation is noticeable
Weber
noted that the JND is a fraction of the original stimulus. His principle is that two stimuli must be differ by a constant proportion to be perceived as different
noise
given to any distracting stimuli for the senses
subliminal perception
refers to the detection of information below the level of conscious awareness
difference threshold
smallest difference in stimulation required to discriminate one stimulus from another 50% of the time
signal detection theory
focuses on decision-making about stimuli under conditions of uncertainty
signal detection theory has 2 main components
- information acquisition
- criterion
2 important factors in perceiving stimuli
- attention
- perceptual set
attention
process of focusing awareness on a specific aspect of environment
perceptual set
predisposition to perceive something in a particular way
sensory adaptation
the ability of a sensory system to adjust to changes
visual system
the sensory system that detects light and three of the 4 cortical lobes are involved
why is vision important
It allows us to detect prey and color, if we look back in time individuals were able to survive if they were able to detect their prey and when picking foods they needed to know whether something was spoiled or rotten and they could do that by looking at the color. these are important for human survival.
why is light detection useful?
because light travels extremely fast and in a straight line, and light interacts with surfaces in the environment
EM spectrum
white light is what we see. The wavelength is one peak to another peak and it gives the color. The height of the wave is the amplitude and it gives the intensity. The purity determines the saturation.
3 parts of eye
- sclera: the white part of the eye that protects us
- iris: colored part of eye
- pupil: black part of eye, at night it dilates to bring in more light and in bright conditions it becomes smaller to let less light in.
2 structures that bring an image into focus
- cornea: keeps in eye water (aqueous humor)
- lens: transparent disk-like structure
these two work together to bend light just enough to focus it at the back of the eye, the cornea does the bending and the lens fine tunes it
Fovea
allows us to see fine details, is in the center of the retina
Retina
where EM waves are recorded, has rods that are sensitive to movement but not fine detail, has cones that are used for color perception and small details
optic nerve
bundle of axons of ganglion cells
where does light travel to?
the retina to impinge on photoreceptors at the back of the eye, and it bleaches a pigment, this causes action potentials in ganglion cells
blindspot
an area that has no cones or rods
optic chiasm
point where optic nerves separate, this causes things we see in our left side get processed in the right side of the brain and vice versa
feature detectors
neurons in the brains visual system that respond to particular features of a stimulus
primary visual pathway
includes eye, retina, occipital, temporal and parietal lobe
secondary visual pathway
includes lens, pupil, and retina
parallel processing
the simultaneous distribution of information across different neural pathways, this is why sensory information is processed quickly.
binding
bringing together what is processed by different pathways, this is what allows us to visualize things
trichromatic theory
color perception is produced by 3 types of cone receptors in the retina. we detect red, blue, and green wavelengths and these are combined to see other colors. this could not account for negative color afterimages. colorblindness supports this theory
opponent-process theory
cells in the visual system respond to red-green and blue-yellow colors. a given cell might be excited by red but inhibited by green
figure-ground relationship
principle by which we organize the perceptual field into stimuli that stand out and those that are left over
gestalt psychology
school of thought interested in how people organize their perceptions according to certain patterns
3 main principles of gestalt
- closure: when we view disconnected figures we fill in the space.
- proximity: when we view objects near each other we see them as one.
- similarity: when we view objects similar to each other we see them as one.
depth perception
ability to perceive objects in 3D and their distance from us
2 cues to see depth
- binocular
- monocular
binocular
derive from images in the left and right eyes, convergence is apart of these depth cues, if an object is near our pupils might move closer together
monocular
same as binocular but only requires one eye.
what takes on role of detecting movement
brain
apparent movement
when we perceive something s moving when it is stationary
perceptual consistency
recognition that objects are constant even though sensory input about them is changing
3 types of perceptual consistency
- size stays the same
- shape stays the same
- color stays the same
sound waves
vibrations that travel through the air
amplitude
decibels
wavelength
frequency
purity
timbre
ear divided into three parts
- outer ear
- middle ear
- inner ear
outer ear
consists of pinna and eardrum
middle ear
consists of hammer, anvil, and stirrup. sound vibrates through them and they send the sound to the fluid-filled inner ear
inner ear
the cochlea, oval window, and basilar membrane. converts sound waves to neural impulses to send to the brain, the stirrup is connected to the oval window which is a membrane that transmits sound to cochlea
basilar membrane
has hair cells that create action potentials that the brain perceives as sound
theories explaining hearing
- place theory
- frequency theory
place theory
states that each frequency produces vibrations at a particular spot on the basilar membrane. explains high-frequency sounds but not low-frequency sounds
frequency theory
states that the perception of sound frequency depends on how often the auditory nerves fire. this theory had a limitation which was that a single neuron had a maximum firing rate of 1000 times per second.
volley principle
states that a cluster of nerve cells can fire neural impulses in rapid succession, producing a volley of impulses
biggest sensory system
skin, it has receptors for touch, temperature, and pain, which form the cutaneous senses, it detects mechanical energy
thermoreceptors
sensory nerve endings under the skin that respond to temperature changes
pain receptors
they have a much higher threshold for firing than receptors for temperature
fast pathway of pain
connected to myelinated fibers that are connected to thalamus
slow pathway of pain
connected to unmyelinated fibred that transmit pain through limbic system
endorphins
involved in turning pain signals on and off
gustatory system
taste
taste buds
bumps on our tongue called papillae contain them, they get replaced every 2 weeks