74 terms

Perception test I

physiological, environmental stimuli that fall into our sensory system i.e.-light in our eyes
psychological, refers to the multiple complex processes that result in the interpretation of those sensations (perceptual processes) and the end result of the process
the perceptual processes (in order)
environmental stimulus, attended stimulus, stimulus on the receptor, transduction, transmission, processing, perception, recognition, knowledge
environmental stimulus
anything that can be detected in the senses
attended stimulus
stimulus that is being focused on
energy transformed into electrical signal
neural message sent through nervous system to the brain
top-down processing
processing that involves prior knowledge
bottom-up processing
begins with the information received by the receptors from the external environment
psychophysical level
how a person's perception is related to the stimulus in the environment such as the brightness of a lightbulb and how we perceive it
physiological level
involves the bodies physiological reaction to stimulus such as light and how it effects receptors of our senses
absolute threshold
smallest amount of stimulus energy needed for perception to occur
method of limits
presentation of a stimuli that either increases or decreases one step at a time
method of adjustment
active participation by the subject, such as using a dial to adjust the intensity until it's visible to them
response compression
as stimulus intensity increases the response increases but not as rapidly
response expansion
as the stimulus intensity increases, the perceptual response increases more than the intensity
modular organization
different parts of the brain process different types of information
lobes of the brain
parietal, temporal, occipital
parietal lobe
middle of brain, skin senses, touch, temperature, pain
temporal lobe
bottom of brain, hearing
occipital lobe
back of the brain, controls vision
parts of the neuron
cell body, nucleus, dendrites, axon, myelin sheath, nodes of ranvier
resting potential
negative charge inside neuron of -70 mV
action potential
stimulation from environment causes neurons to fire, cell membrane becomes permeable to sodium and potassium at different times
refractory period
1/1000th of a second it takes for the neuron to go back to its resting potential after it fires. it can fire between 500-800 times a second
excitation (depolorization)
makes the electrical potential of the dendrites of the next neuron more positive so the next neuron is more likely to fire
makes the electrical potential of the dendrites more negative so the neuron is less likely to fire
neural circuits
groups of interconnected neurons, ranging from a few to 100's or 1000's of simple linear circuits
specificity coding
all the informations about a stimulus or event is carried in a single neuron
distributed coding
all information about a stimulus or event is carried in all the neurons of a given population
sparse coding
small portion of neurons carry information about a stimulus
receptive fields
area on receptors that influence firing rate of neurons
center-surround receptive field
base rate of firing with no light in area, decrease firing rate with light shining on area burst of firing when light is off
center surround antagonism
on center/off surrounds, light off center/ on surround
electromagnetic spectrum
arrangement of electromagnetic radiation--including radio waves, visible light from the Sun, gamma rays, X rays, ultraviolet waves, infrared waves, and microwaves--according to their wavelengths
visible light
That portion of the electromagnetic spectrum detected as various colors by the human eye, ranging in wavelength from about 380 nm to about 750 nm.
protective layer of eye (white part of eye)
the adjustable opening in the center of the eye through which light enters
transparent, anterior part of the eyeball covering the iris, pupil, and anterior chamber that functions to refract (bend) light to focus a visual image
a transparent optical device used to converge or diverge transmitted light and to form images
lkayer of light receptors and nerve cells that line the back of the eye
absorb light rays and transform them into information that can be transmitted by neurons, rods and cones
middle of the retina
optic nerve
collection of axons that leave the eye
where the optic nerve leaves the eye, brain fills in area we don't see
visual pigment molecules
light sensitive molecules and transforms light into electrical energy
dark adaptation
has two stages, "fast stage"- increase in cone sensitivity (reason we can see after a few minutes in dark and cones are more sensitive)
"slow stage"- due to increase in rod sensitivity, visual system is controlled my whichever receptor is more sensitive first its cones, then rods become more sensitive
pigment regeneration
process of rejoining opsin and retinal, results in retina becoming dark again, happens quickly in dark
types of cells in the retina
bipolar, ganglion, horizontal, amarcrine
synapse with photoreceptors and ganglion cells, attach to both
axons of these cells form the optic nerve, last cells in retina to transmit information
multiple neurons (receptors) synapsing to a single neuron, rods have more convergence on ganglion cells than cones
lateral inhibition
information transmitted laterally to adjacent neurons
lateral geniculate nucleus (LGN)
located in the thalamus, regulates the flow of info, organized in layers, primary visual area, located in the straite cortex
striate cortex
primary visual receiving area
feature detectors
simple cortical cells, complex, end no
neural plasticity
response properties of neurons can be shaped by our experiences
selective rearing (methods with cats and what it shows)
raised cats in an environment with either only verticle lines or only horizontal lines, they were placed in a cylinder with only horizontal or only verticle lines everyday for five months and when the cats who were only exposed to horizontal lines saw a vertical line, they couldn't see it
what pathway
from the straite cortex to the temporal lobe, object identity, also called the ventral pathway
where pathway
straite cortex to parietal lobe, location of objects, dorsal pathway
one function is absent while another one is present, completely seperate, not a one way street
unable to recognize face recognition
study in behavioral effects of brain damage in humans
cell body
mechanism to keep cells alive, includes the nucleus which is responsible for keeping the cell alive and reproduction
receives information from other neurons
sending information, also called a nerve fiber
myelin sheath
layer of protection and nutritive cells around axons, provides nutrients, speed electrical signal prevents electrical currents from getting lost, kinda like insulation
nodes of ranvier
regularly spaced gaps in myelin sheath
simple linear circuits
simple passing off of the imput
converging circuit
many receptors send information to one cell, as more receptors are stimulated, there is a greater response from that target cell
complex circuits
some receptors excite the target cells while others inhibit
grandmother cell
we have certain neurons for responding to different things such as people and places
out number cones 120 mil-6 mil, located in peripheral retina NOT in the center, respond in faint light so are better used in dark
densely packed in fovea, important for seeing fine detail, responsible for color vision