Vision

Question 1

What is the “where” in the visual procession

Answer 1

• Parieto-occipital association cortex
• analyzes motions and spatial relationship between objects
• analyzes motion and spatial relationship between body and visual stimuli

Question 2

Describe the “what” in visual processing

Answer 2

• occipitotemporal association cortex
• analyzes form
• colors, faces, letters etc

Question 3

Describe the process and muscles involved in Horizontal Eye Movements

Answer 3

• Muscles: Lateral rectus & medial rectus
• Abducens goes to the contralateral Oculomotor Nu via MLF-> Synapse with CN 3 -> Medial Rectus on Contralateral Side

-CN6 goes to ipsilateral side for lateral rectus

Question 4

What does the Paramedian Pontine Reticular Formation do? (PPRF)

Answer 4

Helps CN6 project appropriate amount of information for the horizontal movements

Question 5

If you look left: which eye ABD and ADD?

Answer 5

Left eye ABD and Right eye ADD

-both of these are happening at the same time because of the MLF

Question 6

Describe Vertical Eye Movements and what muscles are involved?

Answer 6

• Muscles: Superior Rectus, Inferior Rectus, Superopr Oblique & Inferior Oblique
• Trochlear & Oculomotor Nu interconnected through MLF
• going to protect all areas and Rostral MB Reticular Formation

Question 7

Describes Saccades

Answer 7

Rapid, voluntary eye movements that function to bring targets of interest into field of view

• 700 degrees/s
• vision temporarily suppressed during saccadic eye movements

Question 8

Describe Smooth Pursuit

Answer 8

Slow following of a visual target while allowing for a stable viewing of moving targets

• 100 degrees/s
• can be voluntary or involuntary

Question 9

Describe Vergence

Answer 9

Maintained fused fixation by both eyes as target move towards or away from the individual

• very slow in order to maintain visual acuity
• 20 degrees/s

Question 10

Describe the Accommodation Response

Answer 10

Occurs when visual object moves from far to near
-pupillary constriction + accommodation of lens ciliary muscle + convergence of eyes by EOMs

-Retinal Cells —> Primary Visual Cortex in occipital lobe —> visual ass. Cortex —> Sup. Colliculus & Pretecal Area —> Oculomotor Nu & Edinger-Westphalia Nu —> EOMs, len’ sphincter msucles and ciliary ganglion

Question 11

Describe the Frontal Eye Fields function and location (in regards to cortical control of EOMs)

Answer 11

Generate contralateral saccades via connections to contra PPRF
-found in junction of sup. Frontal sulcus & pretectal sulcus

Question 12

Describe Parieto-occipito-temporal cortex (in regards to cortical control of EOMs)

Answer 12

Generate Ipsilateral smooth pursuit via connections with vestibular nuclei, cerebellum and PPRF

Question 13

Describe BG (in regards to cortical control of EOMs)

Answer 13

Oculomotor Loop