chapter 4

Question 1

optic chiasm

Answer 1

• location in the optic tract where the optic nerve from each eye splits in half with nasal retinae crossing over and temporal retinae staying on the same side of the optic tract

Question 2

optic tract

Answer 2

• the optic nerve starting at the optic chiasm and continuing into the brain

Question 3

contralateral representation of visual space

Answer 3

• arrangement whereby the left visual world goes in to the right side of the brain and the right visual world goes to the left side of the brain

Question 4

ipsilateral organization

Answer 4

• same side organization, in the visual system, the temporal retina projects to the same side of the brain

Question 5

lateral geniculate nucleus (LGN)

Answer 5

• bilateral structure (one in each hemisphere) in the thalamus that relays information from the optic nerve to the visual cortex

Question 6

magnocellular layers

Answer 6

• layers of the lateral geniculate nucleus with large cells that receive input from M ganglion cells (parasol retinal ganglion cells)

Question 7

parvocellular layers

Answer 7

• layers of the lateral geniculate nucleus with small cells that receive input from P ganglion cells (midget retinal ganglion cells)

Question 8

koniocellular layers

Answer 8

• layers of the lateral geniculate nucleus with very small cells that recieve input from K ganglion cells (bistratified retinal ganglion cells)

Question 9

magnocellular layers

Answer 9

• layers 1 and 2

Question 10

parvocellular layers

Answer 10

• layers 3-6, smaller

Question 11

koniocellular layers

Answer 11

-6 smallest

Question 12

LGN facts

Answer 12

• each layer receives input from only one eye
• contralateral eye, magnocellular 1, parvocellular 4 6
• ibsilateral eye, magnocellular 2, parvocellular 3 5

Question 13

parvocellular pathway (P pathway)

Answer 13

• characterized by the bistratified retinal ganglion cells and projects to the koniocellular layers of the lateral geniculate nucleus

Question 14

magnocellular pathway (M pathway)

Answer 14

• pathway that starts with parasol retinal ganglion cells and projects to the magnocellular layers of the lateral geniculate nucleus

Question 15

superior colliculusx

Answer 15

• structure located at the top of the brain stem beneath the thalamus
• controls eye movements

Question 16

smooth pursuit eye movements

Answer 16

• voluntary tracking eye movements

Question 17

saccades

Answer 17

• most common and rapid of eye movements
• sudden moves to look from one object to another

Question 18

primary visual cortex, VI, striate cortex area 17

Answer 18

• area of the cerebral cortex that receives input from the lateral geniculate nucleus located in the occipital lobe and responsible for early visual processing

Question 19

retinotopic map

Answer 19

a point by point relation between the retina and V1

Question 20

cortical magnification

Answer 20

• allocation of more space in the cortex to some sensory receptors than to others
• the fovea has a larger cortical area than the periphery

Question 21

cerebral cortex lobes

Answer 21

• frontal lobe
• temporal lobe
• parietal lob
• occipital lobe

Question 22

frontal lobe

Answer 22

• thinking, planning, speaking, motor functions

Question 23

temporal lobe

Answer 23

• memory, language comprehension, auditory perception

Question 24

parietal lobe

Answer 24

• attention, somatosensory perception

Question 25

occipital lobe

Answer 25

• visual cortex, vision

Question 26

cortical magnification

Answer 26

-V1 map is not a exact map
- more space in the cortex devoted to sensory receptors than to others

Question 27

simple cells

Answer 27

• V1 neurons that respond to stimuli with particular orientations to objects within their receptive field
• the preferred orientation of a simple cell is the stimulus orientation that produces the strongest response

Question 28

orientation turning curve

Answer 28

• graph that demonstrates the typical response of a simple cell to stimuli or different orientations

Question 29

complex cells

Answer 29

• neurons in V1 that respond optimally to stimuli with particular orientations
• unlike simple cells, respond to variety of stimuli across locations and to moving stimuli

Question 30

end stopped neurons

Answer 30

• neurons that respond to stimuli that end within the cell’s receptive field

Question 31

ocular dominance column

Answer 31

• column within V1 that is made up of neurons that receive input from only the left eye or only the right eye

Question 32

orientation column

Answer 32

• a column within V1 that is made up of neurons with similar responses to the orientation of a shape presented to those neurons

Question 33

blobs

Answer 33

• group of neurons within V1 that are sensitive to color

Question 34

interblobs

Answer 34

• groups of neurons that are sensitive to orientation in vision