Psychology 304: Brain and Behaviour Lecture 31

1

Psychology 304: Brain and Behaviour

Lecture 31

2

Exam: December 7th, 20113:30-6:00 PM, CIRS 1250

• The exam will include 30 multiple choice questions (1 point each), 4 definitions (2 points each), and 5-6 short answer questions (2-6 points each, totaling 22 points).

• The exam is worth 25% of your final grade.

• The exam will be scored out of 60 points.

• The exam is not cumulative. It will cover the contents of Chapters 7-10 and all accompanying lecture material.

3

• Please arrive on time to facilitate rapid distribution of the exams.

• Bring a pencil, eraser, pen, and your student ID to the exam.

• All electronic devices must be put away before the start of the exam.

• Bags and backpacks should be left at the front of the room. Please do not bring valuables to the exam.

• Hats (e.g., baseball caps) should not be worn during the exam.

4

Reminder

I will hold additional office hours in preparation for the December exam:

Monday, December 5: 2:30 - 4:30 Tuesday, December 6: 1:30-3:30

5

3. I will hold additional office hours in preparation for the final exam:

Tuesday, December 6: 10:30 - 12:30 Wednesday, December 7: 12:30-2:30

6

1. What is the structure of the eye and where are the receptors for light? (continued)

2. How is information about light relayed to the brain?

The Visual System

3. What are the major areas of the brain that are associated with the perception of light?

7

By the end of today’s class, you should be able to:

1. explain how an action potential is generated in the retinal cells of the visual system.

2. review the pathway by which visual information is transmitted from receptors to the brain.

3. identify the locations and functions of the primary cortex, secondary cortex, and association areas for the visual system.

8

What is the structure of the eye and where are the receptors for light? (continued)

9Generation of an Action Potential in the Retina

10

How is information about light relayed to the brain?

• Visual information is relayed to the brain via many pathways. The largest and most studied visual

pathway is the retina-geniculate-striate pathway.

• Within this pathway is the optic chiasm: at this point, axons from the nasal halves of the retinas “cross over” and ascend to the dorsal lateral geniculate nucleus (LGN) of the thalamus. Thus, each hemisphere

receives information from the contralateral visual field.

11Retina-Geniculate-Striate Pathway

12Retina-Geniculate-Striate Pathway

13

• The LGN contains six layers of neurons. The inner two layers are called magnocellular layers, and the outer four layers are called parvocellular layers.

• The parvocellular neurons are most responsive to color, fine pattern details, and stationary objects and receive the bulk of their input from cones.

• The magnocellular neurons are most responsive to movement and receive the bulk of their input from rods.

14Layers of the LGN

Magnocellular

15

What are the major areas of the brain that are associated with the perception of light?

• The thalamic neurons that receive visual information subsequently project the information to the primary visual cortex (V1).

16Primary Visual Cortex

17Primary Visual Cortex

18

• The primary visual cortex is organized into functional vertical columns (i.e., ocular dominance slabs, orientation columns).

• The retina-geniculate-striate pathway is characterized by retinotopic organization.

19Ocular Dominance Slabs and Orientation Columns

20

• Information received by the primary visual cortex is segregated into distinct pathways that project to areas of the secondary visual cortex and, then, the association visual cortex.

• Two main pathways from the primary visual cortex have been identified: The dorsal stream and the ventral stream. The dorsal stream is associated with location and movement; the ventral stream is associated with identification.

21The Dorsal and Ventral Streams

22

VI: Location, orientation, colour

V2: Form, relays information

V3: Form

V4: Colour, form, concentric, radial stimuli

Inferior temporal area: Form, pattern recognition

V5, Medial temporal area: Motion perception

Prefrontal cortex: Facial recognition

23

1. What is the structure of the eye and where are the receptors for light? (continued)

2. How is information about light relayed to the brain?

The Visual System

3. What are the major areas of the brain that are associated with the perception of light?

24

Psychology 304: Brain and Behaviour, Term 1

Research MethodsNeuroanatomyNeurophysiologyNeurotransmittersNeuropharmacologyHormonesNervous system developmentTouchHearingVestibular perceptionTasteSmellVision