Topic 2: Sight and Visual pathways

Question 1

What is a receptive field?

Answer 1

A region in the sensory periphery within which stimuli can influence the electrical activity of sensory cells

Question 2

When do photoreceptors send signals to retinal ganglion cells?

Answer 2

Photoreceptors respond when light falls on their receptive field, sending action potentials to the retinal ganglion cells, whose axon forms the optic nerve

Question 3

Retinal ganglion cells divide into two groups …

Answer 3

1. On centre - where light falling in the middle of the donut sends a signal
2. Off centre -where light falling in the surround sends a signal

Question 4

Where do on centre cells connect to?

Answer 4

They connect directly to a small (less than 10) group of photoreceptors

Question 5

How does each type of light affect the on centre ganglion cell?
1. No light
2. Centre light
3. Donut light
4. Full light

Answer 5

1. Resting action potentials
2. Strong output
3. No output
4. Resting action potentials

Question 6

What do retinal ganglion cells ONLY detect and process?

Answer 6

Edges

Question 7

How do retinal ganglion cells cause simultaneous contrast type illusions?

Answer 7

The on-centre cell looking at the left side with the dark background, will not be so inhibited (because there is less light to activate the off-surround) and the bar will look lighter than it really is.
The on-centre cell looking at the right side with the light background, will be inhibited (because there is more light to activate the off-surround) and the bar will look darker than it really is.

Question 8

Retina -> LGN > V1, V2, V3
What goes ABOVE this?
What or where pathway?
Dorsal or ventral pathway?

Answer 8

The Where / Dorsal pathway

Question 9

Retina -> LGN > V1, V2, V3
What goes BELOW this?
What or where pathway?
Dorsal or ventral pathway?

Answer 9

The What / Ventral pathway

Question 10

Retina -> LGN > V1, V2, V3
Name the things in the Dorsal pathway

Answer 10

STS

V5/MT V6 V7 MST

Question 11

Retina -> LGN > V1, V2, V3
Name the things in the Ventral pathway

Answer 11

V4 V8 LOC

OFA FFA PPA

Question 12

What is processed in the Dorsal pathway?

Answer 12

• Motion
• 3D shape
• Events
• Sequences
• Emotions

Question 13

What is processed in the Ventral pathway?

Answer 13

• Outline
• Colour
• Form
• Faces
• Objects

Question 14

What do these abbreviations from the Dorsal pathway stand for?
1. MST
2. STS

Answer 14

1. Medial Superior Temporal area
2. Superior Temporal Sulcus

Remember: they both have superior and temporal in it

Question 15

What do these abbreviations for the Ventral pathway stand for?
1. LOC
2. OFA
3. FFA
4. PPA

Answer 15

1. Lateral Occipital Complex
2. Occipital Face Area
3. Fusiform Face Area
4. Parahippocampal Place Area