Week 2 CL - Vision

Question 1

What are the two visual cells in the retina called?

Answer 1

Cones - colour and detail perception
Rods - vision n dim light

Question 2

Describe the process of going from eye to cortex.

Answer 2

reception –> transduction –> coding

Question 3

Explain Zeki’s 1993,2016 Functional Specialisation Theory.

__ and __ - basic ___ processing
__ and __A - Form ____ especially for ___
__ - ______ and shape _____
__ - ___
LOC - ____
___ - Face perception
___ - Face perception

Evaluation -
+
-
-
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Answer 3

FUNCTIONAL SPECIALISATION THEORY ( Zeki 1993,2016)
V1 and V2 – Basic visual processing
V3 and V3A – Form perception, especially of moving stimuli.
V4 – Colour perception and shape perception
V5 ( MT IN HUMANS) – Motion perception.
LOC – Object perception
OFA – Face perception
FFA – Face perception

Evaluation of Zeki functional specialisation theory –
+ Ambitious and extremely influential
theoretical approach
– Visual brain areas less specialised than
assumed theoretically
– Visual brain much more complex than
assumed (e.g., V1 is connected to
at least 50 other brain areas)
– Binding problem remains unresolved -

Question 4

What is the binding problem?(in relation to Zeki)

Answer 4

In relation to Zeki, Given functional specialisation, how is visual information combined and integrated?
Binding visual features together
Binding-by-synchrony hypothesis
Neurons that code difference dimensions start to oscillate in synchrony.
Unclear how and why such synchrony might occur.
Precise synchrony is implausible
One module in the brain codes shape. Another module codes color. How do we bind shape and color information to get a multi-dimensional representation (e.g. purple disk)?

Question 5

What are the ventral and dorsal streams and what are the differences between them?

Answer 5

Ventral Stream – What pathway, vision-for-perception, Allocentric (object-centred), usually consciously aware.

Dorsal Stream – Where pathway, vison-for-action, Egocentric (body centred) coding, usually unconscious.

Question 6

What is dual process theory?

Answer 6

there are three cone classes (red = long-wavelength, green = medium , blue = short.)

Question 7

Within depth perception what are monocular and binocular cues?

Answer 7

Monocular cues – only need one eye to be able to conclude.
Binocular cue – Both eyes, stereopsis enhances depth perception

Question 8

Within the retina where are the cones and where are the rods?

Answer 8

Cones - fovea
Rods - periphery

Question 9

What is the difference between type 1 and type 2 blindsight?

Answer 9

Type 1 Blindsight, no conscious experience Type 2 Blindsight, some awareness.

Question 10

What is in the visual cortex?

Answer 10

The visual cortex is made up of the entire occipital cortex, some temporal and some parietal.

Question 11

What is the main pathway between the eye and the cortex?

Answer 11

Retinagenicular-striate