Chapter 3: Neural Processing Flashcards
Chevreul illusion
percieved light and dark bands at the border
Hermann grid
ghostlike grey circles in the borders of a black grid
staircase illusion
another name of the chevreul illusion because the gradient is like a staircase
lateral inhibition
inhibition that is transmitted across the retina
mach bands
light and dark bands created at fuzzy borders
ommatidia
(hartline, wagner, ratliff) small structures with a lens that is located directly over a single receptor
define lateral inhibition and describe research demonstrating the phenomenon
lateral inhibition is that the cells surroudning are supressed when they are all stimulated
discussion lateral inhibition accounts and issues for 3 perceptual phenomena
accounts for mach bands, hermaans square and the chevreul illusion
area v1
another name for the striate cortex, called this because it is the first visual recieving area
center-surround anatagonism
small light in the center increase the firing, but as it gets bigger and covers the entire are including it inhibitory the firing rate decreased
center surround organization
showed that neural processing could result in neurons that responsded best to specific patters of illumination
center-surround receptive field
showed that neural processing could result in neurons that responsded best to specific patters of illumination, hubel and wiesel showed how nirons at higher levels of the visual sustem become tines to respond best to more and more specific kinds of stimuil
complex cells
respond only when a correctly oriented bar of light moves across an entire receptive field
end-stopped cells
fire to moving lines of a specific length, corners, angles or bars of a particular length, moving in a particular direction
excitatory area
stimulating with light increase firing
excitatory center, inhibitory surround
light inside increases, light outside decreases firing
inhibitory area
stimulating with light decreases firing
inhibitory center, excitator surround
light inside decreases, light outside increases firing
lateral geniculate nucleus
signals go here before the occipital lobe
oreientation tuning curve
the relationship betwee orientation and firing
receptive field
the region of the retina that must recieve illumination in order to obatin a response in any goven fiber
simple cortical cell
cells with a side by side receptive fields , responds best to vertical bars
striate cortex
visual recieving area, called this because it has a striped appearance when viewed in cross section
superior colliculus
another area that reciees some signals from the eye, aother visual recieving area wit hthe occipital lobe
visual recieving area
where the signals come in
identify receptive field and the techniques to map them
flashing lights on receptors in the retina to understand how the neurons respond to the light
function of the lgn and the difference beween cortical, complex, and end-stopped cortical cells
cortical - simple, side by side, vertical bars
complex - moving vertical bars in a certain direction
end-stopped - moving in a direction, corners etc (most complex)
contrast threshold
the minimum intensity difference between two adjacetnt bards that can be detected
experience dependent plasticity
feature detectors
simple, complex, and eng-stopeed cells, called this because they response to specific features of a stimululs
neural plasticity
the response properties of neurons can ne shaped by perceptual experience
selective adaptation
ex. when you initially show a vertical line, the neuron starts firing like craxy, but with repeated showing, ithey start to adapt and fire less to vertical lines
selective rearing
if an animal was reared in an environemn that contains only certain types of stimuli, then neurons that respond to these stimuli will become more prevalent
method used for selective adaptation to orientation and discuss how the phenomena is related to feature detectors
you have more feature detectors for the features you encounter more often, we encounter vertical and horizontal lines more than oblique lines in nature etc
contextual modulation
stimulating outside of the receptive field
inferotemporal cortex
Gross, found that the neurons here respond to complex stimuli, higher level neurons
population coding
the representation of a particular object by the patern of firing of a large number of neurons
sensory coding
the sesnory code refers to how nerons represent various characteristics of the enviornment
sparse coding
an object is is represented by a pattern of firing of only a small group of nerons with a majority fo neurons remaining silent
specificity coding
the firing of a neuron that only responds to only that object
contrast specificity coding, distrivuted coding and sparse coding
discuss flexible receptive fields and explain context modulation
