PAST NEUR3001 EXAM PAPERS (note that the course code changed from BIOS3001 in 2011/12)
Candidates should answer THREE questions with at least one being chosen from the Basic section, and at least one chosen from the Advanced section. Credit will be given for imaginative and critical discussion of experimental evidence relevant to the question being answered. Use separate answer books for each question.
1. Describe the main steps in the visual transduction cascade.
2. How is the electroretinogram (ERG) generated and recorded, and what does it tell us?
3. How are the signals from cones processed to generate the receptive fields of retinal ganglion cells?
4. What can visual illusions reveal about brain function?
5. “Form and movement are processed by independent systems in the eye and the brain" Discuss.
6. What can "visual crowding" tell us about spatial vision?
7. How have scientists attempted to clarify the 'neural correlate of consciousness'?
8. What is 'colour'? How does the visual system generate this percept?
9. What factors determine the firing patterns of thalamic relay neurones, and what impact does this have on the transmission of visual information?
10. What are the strengths and weaknesses of current theories of human face recognition?
11. How does motion processing develop in infancy?
12. How are ON responses of ON rod bipolars and Retinal Ganglion cells generated from rod signals under scotopic conditions?
13. Much of what we have learned about reading in patients with vision loss comes from studies that simulate visual impairment. Describe some of the key findings and discuss the advantages and limitations of the simulation approach?
14. What is 'selective visual attention'? Describe what it might involve in neural terms.
Candidates should answer THREE questions with at least one being chosen from Section A, and at least one chosen from Section B. Credit will be given for imaginative and critical discussion of experimental evidence relevant to the question being answered. Be sure to use separate answer books for each question.
1. How does the basic structure of the vertebrate eye vary among species?
2. How is visual acuity measured? What limits it?
3. How does the retina generate distinct ON and OFF responses to light?
4. How are opponent centre-surround receptive fields of retinal ganglion cells formed?
5. What mechanisms underlie our perception of motion?
6. How does it help to understand the workings of visual cortex by defining separate 'areas'?
7. Describe the mechanisms by which the visual system regulates its sensitivity.
8. What's the best way to assess if someone can detect a visual object?
9. What functions might be served by the presence of a visual input to the cerebellum?
10. What factors determine the firing patterns of thalamic relay neurones, and what impact does this have on the transmission of visual information?
11. How is the electroretinogram (ERG) generated and recorded, and what does it tell us?
12. Describe studies of the motion blind patient LM. What do these studied tell us about normal vision?
13. What is the anatomical nature of the magnocellular sub-system within visual cortex and subcortex? What does it permit us to see?
14. Give an account of neural mechanisms associated with either (a) visual attention, OR (b) visual memory.
Answer THREE questions with at least one from Section A, and at least one from Section B.
Use a separate answer book for each question.
1. How does the absorption of a single photon produce a clearly measureable photoreceptor response?
2. How does the human visual system code the shape of objects?
3. How does the output from cone photoreceptors give rise to distinct ON-centre and OFF-centre responses in retinal ganglion cells?
4. How are the rods and the rod retinal pathways optimized for vision at low light levels? What are the limitations of vision mediated by rods?
5. Why is the organisation and function of the visual cortex said to be 'hierarchical'?
6. What do you understand by the term 'neural correlate of consciousness'? Describe two experiments (one human, one non-human) that address this topic and discuss their implications.
7. How is second order motion encoded?
8. What can illusions tell us about how the visual system works? Give specific examples to support your discussion.
9. Why are thresholds a good way of characterising visual performance?
10. What factors determine the firing patterns of thalamic relay neurones, and what impact do they have on the transmission of visual information?
11. What are the main components of the electroretinogram (ERG) and where are they generated?
12. Why is normal colour vision trichromatic at the photoreceptor level? How is colour encoded after the photoreceptors?
13. What is the 'premotor theory' of attention? What experimental evidence supports it?
14. How can parallel streams of processing in the visual system be identified experimentally?
15. Discuss the evidence for direction selectivity in monkey and human vision.
NEUR 3001 Advanced Visual Neuroscience 2014
Answer THREE questions with at least one from Section A, and at least one from Section B.
Use a separate answer book for each question.
1. Describe the steps of the visual transduction cascade. What are the main events at each step and how are they modified by light adaptation?
2. You are an expert witness in a criminal trial and you are conducting a psychophysical experiment to measure the greatest distance at which someone could reliably identify the face of a suspect. Describe the experiment and discuss its strengths and weaknesses.
3. How do we see depth in the visual scene?
4. Ascending visual pathways are found to generate increasingly elaborate response selectivity at higher levels. Citing specific examples, explain how this might be achieved.
5. “All we are hypothesizing is that the activity in V1 does not directly enter awareness” (Crick & Koch, 1995): what experimental evidence has been used to address this issue?
6. Discuss the evidence for, and properties of, direction-selective neurons at different levels of the visual system.
Answer either 7a or 7b.
7a. How does the output from cone photoreceptors give rise to distinct ON-centre /OFF-surround and OFF-centre /ON-surround responses in retinal bipolar cells?
7b. How are achromatic and chromatic signals encoded and processed in the retina?
10. What is the distinction between the ‘dorsal’ and ‘ventral’ streams of visual processing? How early in the visual pathways does this distinction arise?
11. How does the output from rod photoreceptors give rise to distinct ON-centre and OFF-centre responses in retinal ganglion cells under scotopic conditions?
12. Can human visual processing of static scenes be characterised as a Fourier analysis?
13. Area V4 has been a frequent target for studies of attention. Describe two such studies, and what they have contributed to our understanding of neural mechanisms of attention.
14. What are the two types of firing pattern of thalamic relay neurones? Discuss the membrane and synaptic mechanisms that underlie them and how these impact on the transmission of visual information through the thalamus.
15. What can studies of reading performance in people with visual impairments tell us about reading with normal vision?
16. Discuss the factors that limit the development of visual acuity in infancy.
Time allowed: 3 hours
Answer THREE questions with at least one from Section A, and at least one from Section B.
Use a separate answer book for each question.
1. What does Weber’s Law tell us about visual perception, and how would you design an experiment to test whether it applies to judgements of size?
2. Discuss how the anatomy of the vertebrate eye varies across species. Consider those features that are common to all vertebrates, and those that differ. Can the differences be related to the life that the animal leads?
3. How is visual acuity measured? What limits visual acuity?
4. What is an ‘area’ of cortex? How do areas interact in a hierarchical fashion?
5. What is meant by the ‘neural correlate of consciousness’? Discuss in detail how research in this field has exploited the phenomenon of binocular rivalry?
6. Distinguish between short range and long range motion perception?
7. How do the signals from cone photoreceptors give rise to the receptive fields of retinal ganglion cells under photopic conditions?
8. How do visual Illusions inform our understanding of visual processing? Illustrate your answer with six distinct examples.
9. How does the output from rod photoreceptors give rise to distinct ON-centre and OFF-centre responses in retinal ganglion cells under scotopic conditions?
10. Describe the characteristics and of an electro-retinogram (ERG) and how this can be recorded from a mammalian subject. Describe and discuss the experimental evidence for the cellular origins of the different ERG component phases.
11. What is ‘colour’? How does the visual system generate this percept?
12. How has the investigation of neurological patients informed our understanding of the visual processing of motion in the normal brain?
13. Compare and contrast neural visual mechanisms of spatial and feature attention.
14. Why is it important to measure cortical visual field maps using fMRI in human subjects? Describe how this technique is used to characterise such maps.