SD429: TMA-4

The final TMA.

Three questions.
The first one is the big one though, as it has 50% of the marks. We have to write an essay, of no more than 1500 words(!) on mechanoreceptors and their use in proprioception. Also it needs to include body image and body schema. I don't like essays much. This seems to have been reflected in my marks, although I think I made a fair stab at it.

Question 2 - we look at some images of rat glomeruli, when labelled with radioactive substances, and look at the uptake when exposed to three compounds. We have to comment on the similarity and differences in the compounds, the patterns shown in the glomeruli, and then bring it together by saying whats happening here with known mechanisms of odourant coding. I found this one a bit difficult to answer well. Not really sure what was being looked for outside of the obvious.

Question 3 - pain - and how Ibuprofen, codeine and amitriptyline work, where they work and what side effects they have.

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SD329: Book 4 - Touch and Pain, Smell and Taste, Integrating the senses

The last book contains the final three blocks of the course.

The first block (block 5) is about touch and pain.
It starts by looking in detail at touch and the various sense receptors used to detect touch, pressure, and so on.
Then it looks at the integrated perception of touch, and how it is perceived. This is followed by the sense of proprioception - which is how you know where your arms and legs etc are without actually looking at them.
Its an important sense, as a video of someone who lost it shows, they are unable to walk or even sit in some cases.
Finally we look at pain, how it is sensed, how its passed and what various drugs can do to stop pain.

Smell and taste are block 6, and it seems there is still a lot to learn about the exact mechanisms that work here. It starts by looking at smell and how the structure of molecules and the sense of smell don't always seem to be correlated. Then there are the usual nerve pathways to consider, and theories on how exactly smell works etc.
Taste is similar in a way but much less complex as there are only 4-5 basic tastes.
Then a quick bit on combined taste/smell.

Then finally a rather short block on the integration of the senses. Things covered include the focus of attention and connection between sight and sound, and things like motion sickness.

Phew - another course that I've read to the end of.

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SD329 - TMA3

Course work 3. Three questions.

Question 1 is the biggest. In this we have to perform a home experiment, and then write it up as a proper experimental write up. The subject is the Pulfrich effect, which is an oddity in visual processing. You view a pendulum in this case or other moving thing using both eyes, but with one eye slightly obscured by a filter making the scene less bright. The brain interprets the slight lag in a similar way to seeing things moving in 3-d, so the pendulum which is swinging back and forth in front of the subject, starts to apparently take on a elliptical path moving closer and further away at the peak swing. What's more you can measure this using a pointer stick and work out where apparently the object comes to its closest point. From all this it is possible using a bit of trig to work out what this means in the delay in neural processing.  Myself and my daughter set this up one Sunday morning as my variation on the experiment was to see if the difference in ages affected the processing speed.

I used a tin of beans attached to the curtain rail, and a handy dog as backdrop. We were supplied with

Anyway - the experiment went ok, and the write up too. 1500 words or so with references and so on.

Question 2 is a short essay for the layman, describing visual processing contrasting bottom up and top down processing. This wasn't too bad, after the marathon first question.

Question 3 was much easier for me anyway - it was about focal lengths and whether a person was short sighted or not, and what was the nearest distance they could observe etc. Some basic maths and a few definitions.

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SD329: Book 3 Vision

On to the most complex of the topics - Vision.

To begin with it starts with an examination of light. What light is and how it is composed, and then how the eye interprets if. Looking at the science of colour and intensity. Colour is very much a product of how our eye perceives it, and we all see it slightly differently.

The continues by looking at the eye itself, the structure and function of the bits. All the bits that bring the image into focus, including some rather detailed physics of how the cornea is transparent despite being made of proteins. Also something about visual defects such as short and long sightedness, then onto the retina, colour vision movement and adaptation. There is a lot of processing done in the retina itself, to aid things like edge detection, colour constancy and other things - its a big topic.

After that we follow the signals from the retina to the visual cortex, taking in such structures as the optical chiasma, the lateral geniculate nucleus and ending up at the visual cortex.

Then its a case of looking (NPI) at visual processing, how we recognise shapes, scenes and people, including a whole chapter on recognition of writing. Lots of theories and experiments, but still it seems little in the way of solidly understood detail.

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SD329: TMA-2

The second coursework. I haven't finished book 3/block 4 - vision - its a pretty big subject as you might imagine.

So - what's in TMA-2?
Q1 is a research questions. It starts by asking "Can regular drug intake or exposure to chemicals increase the risk of hearing loss?". In particular drugs such as aspirin, paracetamol and the like. Can regular taking of these affect hearing? We are given a paper where there is a claim to that effect. We have to do lots of internet searching to find articles for and against the position, and to determine what we think about each source - how trustworthy it is etc.
There are three parts to the question focused around the two sub questions

1. Is there a proven link between use of either painkillers and hearing loss?
2. Is there any evidence that a particular group within the general population is more at risk or that a particular drug or chemical is any more, or less, risky?
We first have to compile our bibliography of information, together with criticism of the sources.
Then we have to argue to each of the sub question above
Finally we have to describe our search strategy - how we found the items, what we searched for etc.

For question 2, we have to write a summary of one of the detailed chapters in the hearing section. So condensing several pages and diagrams into 400 words.

Question 3 is about hearing directly. First we have to define pitch and intensity. Then we have to describe how both pitch and intensity are encoded, with two possible mechanisms for each.

I found this TMA somewhat easier, although the first question is quite open ended, depending on how much searching you want to do.
Anyway, much happier with the mark for this one, more up to my usual standard.

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SD329: TMA-1

Time for the first piece of coursework.

There are three questions on this.
It starts with the first question - where we have to write a brief essay (600 words) on the structure and function of the neuron. It's been a while since I had to write an essay, but the format comes back to me. We have to mention things like dendrites, axons, neurotransmitters and so on. All in just 600 words. It appears conciseness is a virtue in this course.

Question 2 is a bit about sensory inputs, and how they are detected, encoded and received. We also have to describe lateral inhibition.

In question 3 we are given a paper to read all about the McGurk effect, which you can see an example of here. There is a lot of detail in the paper, and several images of brains. We are asked a number of detailed questions on the scope of the paper and the results. By the end of this, I'm beginning to find I no longer wish to hear or see the McGurk effect again!

Anyway, first TMA posted, and a rather poor score for me. If we had a cat I would probably kick it.

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