Lecture 7 - stimulus recognition Flashcards
1
Q
layers of lateral geniculate nucleus
A
- has 6 layers
- first 2 layers receive input from magnocellular ganglion cells and other 4 receive input from parvocellular ganglion cells
- one layer receives information from consolateral eye other from ipsilateral then consolateral
2
Q
where does nerve fibres of lateral geniculate nucleus project into?
A
project into primary visual cortex for information processing
3
Q
how is the LGN organised?
A
retinotopically
4
Q
two visual pathways in cortex
A
- ventral - object recognition (inferior temporal)
- dorsal - object distance, speed and location (posterior parietal)
5
Q
two key features of cortical structure
A
- layering
- columns (ocular dominance, orientation, direction) and blobs
6
Q
cortical layers
A
- small and large numbers of cell bodies
- always 6 cortical layers
- neurons have different properties and have different functions
7
Q
what is injected for ocular dominance columns in visual cortex
A
- radioactvie proline in on eye
- or inject radioactive glucose in the cortex and stimulate on eye with light
8
Q
ocular dominance column input
A
- receives input only from one eye
- each column receives input from ipsilateral or contralateral eye
9
Q
blobs - processing of colour
A
- stained by cytochrome oxidase
- labelling localised to specific parts of the brain, neurons contain different amounts
- contained in neurons involved with processing information about colour
10
Q
where do blobs receive their input from?
A
from parvocellular cells from LGN
11
Q
columnar orientation in V1 cortex
A
- neurons that respond to different combinations of edges
- some might respond to only horizontal or vertical
12
Q
hypercolumn
A
three types of columns shown together
can process information about the entire space
13
Q
hubel and wiesel experiment
A
- recorded neurons in different parts of cat brain (mainly V1 cortex) whilst car looked at screens showing shapes in differet orientations, moving in different directions
14
Q
result of hubel and wiesel experiment
A
- simple cells respond to a bar orientated in certain direction
- simple cells are localised in layers 4 and 6
15
Q
receptive fields of V1 neurons: simple cells
A
- unlike receptive field in retina and LGN, simple cells have elongated receptive fields
