MBB1 sensation and perception exam questions

[tun44]

Hi guys, this is really good stuff from everyone, thank you so much.
Here are my answers to some of the missing questions, i am not 100% certain they are accurate, and for Q49) i have 4 sets of solutions, which all might be related.

Please feel free to correct any of them.

Cheers!

49. Synaesthesia is….
*A condition in which one type of sensory stimulation creates perception in another sense.
**A curious condition where there is a mingling of the senses due to cross-wiring in the brain. Hearing a musical note for example might cause a person with synesthesia to see a particular colour; C is red, F sharp is blue. Or perhaps the number 2 is always green and 5 always blue.


***Other people may taste spoken words, for example, on hearing the word 'table' they might taste apricots, whereas ‘book’ tastes like tomato soup and ‘telephone’ tastes like earwax.


****(From Lecture)
The involuntary conjoint perception across two modalities:

- A ‘common’ example is letter/colour
- A more interesting example is sound/colour


47.What critical neural interaction is affected by, among other things, hallucinogenic drugs?
Hallucinogenic drugs directly affect the serotonin receptors(specifically the serotonin receptor subtype, 5-HT2), which is what eventually results in a complex pattern of action potentials and activity.


44. The term “Biological motion” describes…..
The unique visual phenomenon of a moving, animate object.
Often, the stimuli used in biological motion experiments are just a few moving dots that reflect the motion of some key joints of the moving organism.


4. Excitation refers to…….
The cone spectral sensitivities at retinal level are called cone excitations.


5. Sensation refers to…….
The process by which a stimulated receptor (such as the eyes or ears) creates a pattern of neural messages that represent the stimulus in the brain, giving rise to our initial experience of the stimulus. An important idea to remember is that sensation involves converting stimulation (such as a pinprick, a sound, or a flash of light) into a form the brain can understand (neural signals)—much as a cell phone converts an electronic signal into sound waves you can hear.

[tun44]

Oh by the way, has anyone attempted the Learning and Cognition Practice Exam Questions 2012 yet? It has 51 Questions with solutions so all we have to do is circle the correct answer.

[anonymous1]

Thanks for contributing tun44!

i have not began the learning and cognition yet, but i think they'll be alright

[kitkat93]

here are a few that i have done not sure on weather they are right but just what i have taken from the notes
Question 1: Which of the following best describes the platonic view of vision and the world?
-   view of Plato, which I interpret as there being a 'real world' but our mortal senses are only capable of sampling a small subsection of that world - the ‘shadows on a cave wall’ analogy

Question 2: which of the following is the alternate view which is illustrated in the writing of Friedrich Nietzsche
-   View as Construction
-   “The ‘apparent world’ and the ‘true world’ means - ‘the world’ and, ‘nothing’.” Friedrich Nietzsche
Question 3: The world we visually sense is entirely dependent on
The presence and pattern of light reflected off objects
Question 4: Excitation refers to:
An act of irritation or stimulation or of responding to a stimulus, the addition of energy, as the excitation of a molecule by absorption of photons.
Question 5: Sensation refers to...
An impression, or the consciousness of an impression, made upon the central nervous organ, through the medium of a sensory or afferent nerve or one of the organs of sense; a feeling, or state of consciousness, whether agreeable or disagreeable, produced either by an external object (stimulus), or by some change in the internal state of the body.
Question 6: At what stage in the visual pathway is an action potential first generated?
In the ganglion cells of the retina
Question 7: What do L, M and S denote when applied to cones?
Long, Medium and Short Wavelengths
Question 22: Taken as a population, primary visual cortical (v1) neurons have what critical property
-   Represent everything that you are able to see as all visual input to the cortex enters at this point, it still represents the data information in a fairly general way; the output of individual neurones at this level is not yet very specialised.
-   Information is separated from here into the later visual corticals which are more specialised

Question 26: The visual system appears to dissociate motion-signals elicited by eye movements or from retinal movement by:
-   The visual cortex distinguishes between the action motion and the movement of the eye as the cells that signal the movement are incorporated into the signal detection
-   Retinal motion is initially detected by an ensemble of motion detectors
-   This is distinct from motion elicited by eye movements and the system has to deal with and account for both

Question 28: Place theory in hearing refers to...
-   The physical location of stimulation on the basilar membrane signals the frequency of stimulation but in the form of a travelling wave
-   Membrane properties altered physically by outer hair cells
-   The frequency to space mapping on the basilar membrane provides the initial means
of frequency coding (place theory)

Question 30: “Adaptation” refers to...
-   (ophthalmology)
o   The ability of the eye to adjust to various light intensities by regulating the pupil of the quantity of light entering the eye.
-   (neurology)
o   The decline in the frequency of firing of a neuron, particularly of a receptor, to changed, constantly applied environmental conditions
Feel free to correct any answers if they are wrong 
Really need help on 39,48,8, 10 and 12

[foolishangel]

Guys, in regards to the excitation and sensation questions, Simon keeps saying to refer to the Helmholtz and Hering theory- something so do with psychological VS physical theory of contrast

@Kitkat- For qs 48: Subjective, different from others-unique & qs 12: Centre-surround receptive fields which are 2D!

[beckot]

Answers to Q8 may be found here: http://www.icr.org/article/2476/

goes over physiological arguments as to why the photoreceptors should be located beyond the retina and not before it.

  thanks for some of the answers/ reassurance, as many of these are subjective or were not explained

[daphaneng]

here are a few that i have done not sure on weather they are right but just what i have taken from the notes
Question 1: Which of the following best describes the platonic view of vision and the world?
-   view of Plato, which I interpret as there being a 'real world' but our mortal senses are only capable of sampling a small subsection of that world - the ‘shadows on a cave wall’ analogy

Question 2: which of the following is the alternate view which is illustrated in the writing of Friedrich Nietzsche
-   View as Construction
-   “The ‘apparent world’ and the ‘true world’ means - ‘the world’ and, ‘nothing’.” Friedrich Nietzsche
Question 3: The world we visually sense is entirely dependent on
The presence and pattern of light reflected off objects
Question 4: Excitation refers to:
An act of irritation or stimulation or of responding to a stimulus, the addition of energy, as the excitation of a molecule by absorption of photons.
Question 5: Sensation refers to...
An impression, or the consciousness of an impression, made upon the central nervous organ, through the medium of a sensory or afferent nerve or one of the organs of sense; a feeling, or state of consciousness, whether agreeable or disagreeable, produced either by an external object (stimulus), or by some change in the internal state of the body.
Question 6: At what stage in the visual pathway is an action potential first generated?
In the ganglion cells of the retina
Question 7: What do L, M and S denote when applied to cones?
Long, Medium and Short Wavelengths
Question 22: Taken as a population, primary visual cortical (v1) neurons have what critical property
-   Represent everything that you are able to see as all visual input to the cortex enters at this point, it still represents the data information in a fairly general way; the output of individual neurones at this level is not yet very specialised.
-   Information is separated from here into the later visual corticals which are more specialised

Question 26: The visual system appears to dissociate motion-signals elicited by eye movements or from retinal movement by:
-   The visual cortex distinguishes between the action motion and the movement of the eye as the cells that signal the movement are incorporated into the signal detection
-   Retinal motion is initially detected by an ensemble of motion detectors
-   This is distinct from motion elicited by eye movements and the system has to deal with and account for both

Question 28: Place theory in hearing refers to...
-   The physical location of stimulation on the basilar membrane signals the frequency of stimulation but in the form of a travelling wave
-   Membrane properties altered physically by outer hair cells
-   The frequency to space mapping on the basilar membrane provides the initial means
of frequency coding (place theory)

Question 30: “Adaptation” refers to...
-   (ophthalmology)
o   The ability of the eye to adjust to various light intensities by regulating the pupil of the quantity of light entering the eye.
-   (neurology)
o   The decline in the frequency of firing of a neuron, particularly of a receptor, to changed, constantly applied environmental conditions
Feel free to correct any answers if they are wrong 
Really need help on 39,48,8, 10 and 12

You mentioned about question 48? Well...Our experience of reality is subjective and is a produce of our sense. It's the transduction of energy that converts into forms where we can use internally and make sense of it. Reality is not a reflection of the world - but is a constructive process.

Here are some notes to the questions on the  sample paper with references to the lectures


1. Which of the following best describes the Platonic view of vision and the world?
Lecture 13/Commentary 1: Plato claims that there is a ‘real’ world, but our moral senses are only capable of sampling a small subsection of that world

2. Which of the following is the alternative view which is illustrated in the writing of Friedrich Nietzsche?
Lecture 13/Commentary 1: There is no ‘real world,’ only the world in our heads. He claims that each individual’s brain creates the world that we perceive from our input, therefore there is vast variation of interpretations within individuals.. We construct our own reality

3. The world that we visually sense is entirely dependent upon…
Lecture 14/15: The retina is the only contact we have to the external world. At the retina, it works out the colour and brightness of an image, and then adds in form, structure, motion and depth. Using the information given from the retina and a light source, the photoreceptors reconstructs this. As it is a constructive process – everyone interprets thins in different ways. It absorbs photons.

14. The term “Opponency” refers to…
Lecture 15: Human visual system interprets information about colour by processing signals from cones and rods. L for long, M for medium and S for shot, and some wavelengths of light overlap so it’s more efficient for the visual system to record differences between the responses of cone, so it is more efficient for the visual system to record differences between the responses of cones, rather than each type of cones responses. Colour is catergorised as red, yellow, blue or green.


15. Why, when considering the processing of the neural signal, is the actual physical location of any visual neuron other than the photoreceptors, arbitrary?
Commentary 2: The actual physical located of visual neuron doesn’t matter, because all receptive fields in the visual system have some relationship to the same x, y, t space that constitutes the axes of the visual input, but they sit in various places within visual pathway – mostly at the back of the head.

Photoreceptors are our only link to the visual world. Once the photoreceptors have encoded the relevant information, it doesn’t make any difference where that information is processed.

17. What is meant by the term “retinotopic mapping”?
Lecture 19: 2 neuron that receive input from adjacent group of photoreceptors will be adjacent in cortex – xy map of retina early in visual system is maintained throughout. V1, there are columns that contain every neuron you will need for that bit of the world. One specialized in colour, motion, form.


20. The idea of modularity in visual processing refers to…
Lecture 19: More efficient to analyse input in modules in parallel than it is to do it serially. Form, motion, colour and depth are processed separately to some degree. Each area is retiontopically organised – each has a full spatial map of visual field.

21. What reason may you have for questioning the assumption that the LGN is just a relay station for signals traveling from the retina to the cortex?
Lecture 19: There are more connections carrying signals from the cortex back to the LGN than from the LGN to the cortex

22. Taken as a population, primary visual cortical (v1) neurons have what critical property?
Lecture 19: Represents every aspect of the image that we can see, but in a sparse fashion (not very specialized). Receptive fields are selective rudimentary properties of colour, motion, depth and form. From here, information is transmitted to visual corticals that are more specialized.

24. What is red?
Lecture 14: We have a very unique sensation for this very simple visual stimulus. It is uniquely definable in terms of wavelength of photon and something that is impossible to describe what the sensation is – therefore we have created terms to describe it.

28. “Place theory” in hearing refers to…
Lecture 22: The frequency to space mapping on the basilar membrane provides the initial means of frequency coding.

29. “Frequency theory” in hearing refers to…
Lecture 22: The physical location of stimulation on the basilar membrane signals the frequency of stimulation but in the form of a travelling wave – membrane properties altered physically by outer hair cells.

40. The theoretical hierarchy established by David Marr is…
Lecture 19: An informational processing system where there are 3 ways to approach a problem. Define the problem clearly than look for solution, then look for implementation. Do not limit yourself when you might not know everything about the problem.

41. “Retino-cortical expansion” refers to…
Lecture 19: There are more cortical neurons dedicated to figure what’s going on in the visual field.

42. The two most likely kinds of motion detector in the human visual system are called…
Lecture 17: (1) Came from fly and betel psychophysics – capture a fly, stick it on a device and responds by thinking where motion is. (2) Spatiotemporal gradient. Either us humans have the same visual system as flies, or we have both that and spatiotemporal gradient.

47. What critical neural interaction is affected by, among other things, hallucinogenic drugs?
Lecture 21: Hallucinogenic drugs increases the amount of serotonin in the body, which increases cortical activity to reduce the inhibition os signals (therefore a lot of information is entering perception)

And still working my way through these other questions Q8, 10, 12, 19, 22, 25, 27, 31, 32, 33, 34, 35, 39, 43, 45, 50...

[anonymous1]

thanks daphaneng!
hopefully us working  together would mean each of us could get extra time to study on other subjects
I'm still working on the 40-50 questions they were a bit vague, hopefully i can get them up soon

[baka11]

q50 one fish two fish...
red fish blue fish!
(lecture 3)

[anonymous1]

^ well done! 

if anyone has any of the following questions 8, 10, 25, 26, 27, 33, 34, 36-39, 43-46, can they please post them up.

I mean this thread has had like 1350+ views, i'm pretty sure someone has at least one of the above answers and if we have all shared our answers with the rest of you guys, you should do the same instead of just feeding off the thread...

thanks to those who are active contributers!!

[xyling]

I've got these:

8. What reason may you have for expecting the photoreceptors to be physically anchored on the retina despite the observation that this means that there is neural matter between the light source and the photoreceptor?
The presence of a blind spot in the retina due to converging neural material in front of the retina. An inverted retina also allows photoreceptors to receive blood and nutrients from the retinal pigment epithelium which absorbs most of the light not captured by the retina. This inverted retina design also prevents light from being reflected off the back of the eye onto the retina which would degrade the visual image.


10. Orthogonality in the vector representation of signal-coding confers which of the following properties upon that stage of the system?
Orthogonality: a property that allows overlapping stimulus coding eg location and quality. (I think this question needs some context, maybe Simon will ask us to identify orthogonality in the choice?)

25. An attentionally-controlled motion system may allow isolation of a particular aspect of motion. A good example would be how turning our heads, under normal circumstance, doesn't make us dizzy but we are still able to distinguish objects in our field of vision.

26.The visual system appears to dissociate motion-signals elicited by eye-movements or from retinal motion (initially detected by an emsemble of motion detectors) by inflow (relies on feedback from eye movement to account for the effect on retinal motion) and outflow (uses same signal that commands the eye movement and is therefore quicker and possibly more accurate) hypothesis.    

33. A form of parallel processing in the auditory system is implemented in the cochlear nucleus by the divergence of auditory signals received.

34. Information is the perception that our sensory organs create of the outside world ie what we see is translated into information for the brain to process so that we see what we see.

36. One critical similarity between the visual and auditory systems is that they both have the ability to perceive the speed and direction of a moving object such as a car on the streets. Both systems may also interact to coordinate and direct attention to one modality or the other and to control subsequent action. Both systems receive information from the outside world and processes them to allow the formation of our sensation and perception. In both systems, motion processing is not confined to a single 'dorsal' pathway.

37. One critical difference between visual and auditory systems is while the visual system has a set receptive field within the photoreceptors, the auditory system's receptive field is not confined to particular regions of the sensory epithelium such as hair cells in the cochlea.

38.Which two structures or processes exploit the properties of orthogonality in their operation?
Semicircular canal (responsible for spatial recognition ie moving one's head etc); motion detection. (One structure in the ear, one process in the visual system, mutually independent)

39. What aspect of the relationship between the stimulus and the cortical representation is different between vision and audition?
It has yet to be found that audition has a functionally equivalent of area MT as per the visual system. In particular, the functional characteristics that uniquely identify area MT such as a large receptive field and responsiveness to complex second- and third-order motion may not have a equivalent functional equivalent in the auditory modality. (not entirely sure but i did some research and came up with this)

43. The three critical dimensions of vision are x, y, t (the third dimension is reconstructed from a variety of cues but is never explicitly coded in the input eg. Scene outside the window looks different from varying angles); computational, algorithmic and implementational according to David Marr.

44. The term “Biological motion” describes the unique visual phenomenon of a moving, animate object. Often, the stimuli used in biological motion experiments are just a few moving dots that reflect the motion of some key joints of the moving organism. Eg moving dots can form the silhouette of a walking man; a moving animate body is perceived from the movements of a few isolated dots

46. The visual system is sensitive to light, colour, what we see outside.

that leaves 27 and 45. come on guys!

[anonymous1]

Thanks heaps xyling and everyone else who has continued to add to this forum

I have work now, i'll look at 45 and 27 later, if i find the answer i'll post them tomorrow because i won't be back till later at night

anyways Goodluck with exams everyone!

[maimu]

Q45: Interaction between V1 orientation-selective receptive fields follows what ʻlawsʼ?
A simple cell is excited by a bar that follows the orientation of ON
Inhibited by a bar that follows the orientation of OFF. And no change if the bar is oriented across both ON and OFF regions.

I'm not so sure.. But hope it helps.
You guys have done amazing jobs. It really helps my revision.

[anonymous1]

for question 27 i found some links that may be somewhat helpful but i can't find the exact answer

https://docs.google.com/viewer?a=v&q=cache:Ts63QQStgwEJ:119.93.223.179/ScienceDirect/Current%2520Biology/10-01/sdarticle_006.pdf+how+is+spatial+structure+of+natural+textures+processed+by+our+visual+system&hl=en&gl=au&pid=bl&srcid=ADGEESjnSd3vwCOi6OcoGt-hVTb-44KQEVtbFaskMv3Sa-uW6HO--FbkVsdOPTzwFpKvMlYsFSxJlA_4YofwlPWYuWkG5vUdKGkJNOM9xHDjxKq9eVl-eJrcvz50HSXzqurlKnydSa4E&sig=AHIEtbRX-_tEmxwSkUZDqo-H2CsGOpzNRA

http://www.pnas.org/content/107/42/18149.full

I think if we read the above articles it will help us answer the question, better yet it won't be on the exam!

[rebekaha]

My answer to 45 was:  Aligned V1 receptive cells positively interact; orthogonal (perpendicular) V1 cells negatively interact – L8