contours and forms Flashcards
what is the visual pathway?
eye –> LGN –> primary visual cortex
what is LGN
lateral geniculate nucleus
what are the two components of the receptive field of ganglion cells?
an excitatory centre; shine light turns cell on
an inhibitory surround; shine light turns cell off
how does sensitivity to orientation woek?
one cell detects one orientation in one position, but we have millions of cells detecting orientations from different positions; chopping images into maneagable pieces
what is heirarchical processing in V1:
simple cells to complex cells;
what are complex cells sensitive for?
rough position on the retina, orientation of edge, size/width of edge and movement within receptor field
what are hypercomplex cells sensitive for?
rough position on retina, orientation of edge, size and length
what happens to images in V1?
broken into edges; different orientations, positions and scales
what is orientation in columns?
as u go through depth of cortex, cells in different positions respond to either vertical or horizontal bars
what is gestalts grouping principle for perceptual organisation?
similarity, proximity, closure, good continuation and common fate
what is V2?
visual cortex 2
what is V1?
visual cortex 1
what are v2 cells selective for?
good continuity and closure
