Hirsch - Eye Movements

Question 1

acuity falls off with

Answer 1

eccentricity in visual space

Question 2

calcified amygdala

Answer 2

focus on nose area where emotion is less expressed; has hard time knowing facial expression. When directed, performance increases

Question 3

eye musces

Answer 3

superior rectus
medial rectus
lateral rectus
inferior rectus

superior oblique
inferior oblique

Question 4

eye muscles responsible for horizontal movement

Answer 4

lateral rectus - abdution away from the nose

medial rectus - adduction towards the nose

Question 5

eye muscles responsible for vertical movement

Answer 5

superior rectus - elevation

inferior rectus - depression

Question 6

eye muscles responsible for torsional move

ents

Answer 6

superior oblique - intorsion

inferior oblique - extorsion

Question 7

innervation of the extraocular muscles

Answer 7

1. oculomotor nucleus-Midbrain -via Cranial nerve III (ipsilaterally)–> inferior rectus, inferior oblique, medial rectus, superior rectus
2. abducens nucleus-Pons -via Cranial nerve VI (ipsilateral) –> lateral rectus
3. Trochlear nucleus-Caudal midbrain - via Cranial nerve IV (contralateral) –> superior oblique

Question 8

Types of eye movements

1. direct gaze to target of interest OR track targets as they move

Answer 8

—> saccades, smooth pursuit, optokinetic nystagmus

Question 9

Types of eye movements

2. Help align fovea of each eye on the target of interest * when distances between each eye and target are different

Answer 9

–> disconjugate vs. conjugate movement; eyes moving in different directions; vergence movement

Question 10

Types of eye movements

3. movement that compensate for head movement to keep the target of interest centered on the fovea

Answer 10

vestibulo-ocular movements

Question 11

saccade cannot stop once started

Answer 11

very fast

Question 12

neural firing during movement and at rest

Answer 12

when moving; intense fire

when stretched less intense yet steady fire

Question 13

moving eye to the right

Answer 13

Right Paramedian Pontine Reticular Formation (PPRF) => right abducens nucleus =====>

1. => abducens or 6th nerve (excitatory; contracts) => right lateral rectus (ipsilateral)
2. => medial longitudinal fasciculus (axon of internuclear neurons) => left oculomotor nucleus (contralateral) => oculomotor or 3rd nerve => left medial rectus

Question 14

know picture in 13/19

Answer 14

pineal gland
superior colliculus
inferior colliculus
trochlear nerve
fourth ventricle
pulvinar of thalamus
superior cerebellar peduncle

Question 15

visual and motor maps in superior colliculus

Answer 15

cartesian map of visual space in the colliculus

Question 16

dorsal midbrain OR PARINAUD syndrome

Answer 16

1. caused by a tumor of the pineal gland or multiple sclerosis or vascular lesions
2. compresses the superior colliculi
3. paralysis of UPWARD gaze

• not clear if ONLY superior colliculi involved
  == center for vertical eye movements (rostral interstitial nucleus) lies just rostral to the superior colliculli and could be involved

Question 17

cortical control of eye movements

Answer 17

primary motor cortex

frontal eye field (parietal cortex) -> superior colliculus (midbrain) -> PPRF - horizontal gaze center (pons)

Question 18

Damage to only Superior colliculus

Answer 18

impede ability to make rapid saccades

*short - but not long term - loss in ability to make saccades

Question 19

Damage to pnly Frontal Eye Fields

Answer 19

impairs ability to make voluntary movements away from a salient stimulus OR towards remembered positions
*short - but not long term - loss in ability to make saccades

Question 20

Damage to both Superior colliculus and frontal eye fields

Answer 20

permanent loss of ability to make saccade

Question 21

Frontal eye fields

Answer 21

attentional regulation of neural activity

attention==> hard fire