Today’s session (28 August 2017)

Hi everyone

I started today with a few housekeeping matters.

Firstly, I reminded the class that Assignment 1 is due next Friday, 8 September. Please email your assignment to me and also hand in a hard copy at the admin office in E block.

While you are handing in the hardcopy of your assignment, please take another good look at the Great Jellybean Challenge jar. I will need each student to give me a figure for how many jellybeans are in the jar. You can weigh, measure, shake and worry the jar to your heart’s content BUT you are not allowed to open it or take it out of the office. Go back to the earlier session notes to see different methods that you can use to work out how many jellybeans are in the jar. The winner of the Great Jellybean Challenge will be announced in class on Monday 25 September, just before the term break.

I also mentioned that next Monday is a self-directed learning day for the class. I won’t be here that day, so you can use the PSDM session as you see fit, working on Assignment 1 or other work that you need to complete.

Finally, I asked if anyone had tried peeling a banana or identifying heuristics which they might have used during the week. If you haven’t done this yet then please try both in the coming week.

Following these housekeeping matters, I turned our attention to an interview with Bruno Lemke from Nelson Marlborough Institute of Technology about climate change (Too hot to host? Climate change hangs over future Olympics http://www.radionz.co.nz/national/programmes/ninetonoon/audio/201812815/too-hot-to-host-climate-change-hangs-over-future-olympics). Lemke’s basic premise is that climate change trends indicated that it will soon be too dangerous to hold the Summer Olympics in the northern hemisphere. Increasing summer temperatures would put athletes in danger of sun stroke, prickly heat and a range of other temperature induced maladies.

This interview was interesting for two reasons. Firstly, as a problem in its own right: What are some of the possible solutions which we could put in place to keep the Summer Olympics without endangering competitors?

Some of the possible off-the-cuff answers might include greater use of climate controlled indoor venues (such as enclosed stadia), holding events at cooler parts of the day (which might impact on TV viewing arrangements), greater use of temperature control clothing, holding the games in cooler northern cities (e.g. Helsinki) or holding the games in the southern hemisphere (e.g. the Sydney Olympics in 2000, held in the southern spring).

The interview was also interesting because the scientist let slip that because of the predominance of climate change stories in the media it was difficult to get his own research in front of the public. His solution to the problem was to link his findings about climate change to a 2016 current media event (i.e. the Olympics) and to present his research as an Olympics-related story. A very clever way to get media coverage on National Radio!

We then took a look at ways in which the human mind (and sensory system) can sometimes make it difficult for us to arrive at correct decisions.

We started by talking about a classic piece of work done by Loftus and Palmer in 1974. These two researchers showed their test subjects a short film clip of two cars involved in an accident. Then they asked some questions about the accident, including a question about the speed of the vehicles when the accident occurred. Loftus and Palmer varied the question by changing the verb from ‘smashed’ to other words such as ‘collided’, ‘bumped’ or ‘contacted’.

Just by changing this one variable, Loftus and Palmer could influence the estimates of speed that people gave them. The mean estimates of speed were highest in the “smashed” condition (40.8 mph) and lowest in the “contacted” group (31.8 mph).

Obviously, this has huge implications for eye witness testimony in court cases as well as for making correct decisions about situations which we may encounter every day. Research such as this suggests that we can be influenced in very subtle ways without being aware of it (more about this below). You might like to read a bit more about this area of research (including some more up-to-date stuff) as part of your own readings.

We then looked at situations in which our brains can be conflicted over the correct response that we should give. We already know that we use short-cuts to help us to make sense of things and sometimes this leads us to be imprecise about what we see and say. For instance, we might say that we see a vase when all that we are actually seeing is a two dimensional representation of a vase. Normally this isn’t too much of a problem as we expect other people to ‘know what we mean’.

More significantly, conflicting information can lead to incorrect conclusions and it may contaminate future evidence through biases, assumptions, presumptions and distorted perspectives.

To see how these conflicts work in action, we looked at a series of pictures of ambiguous scenes. The first few pictures were well-known examples of double images such as the black-and-white face profile / vase image and the picture of the old / young woman. We generally know what to look for and the images weren’t overly surprising as they were so familiar. Most people in the class had no difficulty in resolving the conflicts as they were ‘in’ on the visual jokes.

We then moved on to some less-well-known examples such as the headland which looks like a horse’s head (or rather, it has a shape which reminds us of a horse’s head) and the black triangle which isn’t really there (it ‘appears’ because of the images around it and the assumptions which we make, as a result).

Returning again to more familiar examples, we looked at some shapes which appear to be different sizes, mainly due to perspective cues which fool our brains. In reality, we are trying to apply sets of logical rules about three-dimensional perspective to two-dimensional representations.

We also looked at a couple of examples where it takes an extraordinary amount of will-power to force ourselves to reject the evidence that our eyes and brain have gathered. Two good examples of this include the two rectangles which appear to be of different size and the contrasting colour squares on the chess board (which are, in fact, the same colour). If you go to the last few slides in the Visual Illusions PowerPoint (under Session 5 in Moodle), then you can click on the relevant parts of both images and drag them around to make comparisons.

We also looked at some photo illusions (non-Photoshopped!) which again challenged our visual expectations. These images included the brightly-coloured parrot (which was, in fact, a woman in body paint) and the tiny-man-and-giant-dog in the Ames Room. Read up about the Ames Room this week, if you are interested, as there is a question on this in Assignment 4.

We then looked at some amazing two-dimensional drawings (again, using forced perspective) which create the illusion of being three-dimensional. These include waterfalls, rapids and bottomless pits drawn onto streets and also a combined scene of an artist working on his own two-dimensional picture.

Finally, we took a look at the infamous dress which went viral on the internet a few years ago. Most of the class seemed to opt for black-and-blue but others saw it as gold-and-white. With all this in mind, we have to ask ourselves how much of the sensory evidence that we see and accept is really what we think it is?

We then took another short break and when we came back we pursued this line-of-thought a bit further. I suggested to you that while it can be quite unnerving to see how fallible we can be in some situations, it is also amazing how marvellous we can be in other situations. Despite the drawbacks of some short-cut strategies that we use, we have still managed to achieve all the good things that we have today (such as technology and medicine) as well as some massive problems still to be solved (such as booming populations and climate issues).

Some people even have the capacity to far exceed what we normally expect to be the limitations of human abilities, and this raises questions about whether we might be able to engineer better solutions by manipulating human abilities in some way. As an example of this, we had a quick look at Scott Flansberg (https://www.youtube.com/watch?v=NgIICQvhqMc) who is recognised as the world record holder as a human calculator. Quiet amazing! Scott has also devised a mathematics system which he believes can help other people to make calculations quicker (although not in the same way that he naturally does).

We also looked at the way that some people can combine brain and body to achieve amazing feats of dexterity. Richard Turner, for instance, has quite extraordinary abilities to feel, recall and manipulate cards despite being blind (https://www.youtube.com/watch?v=aKfmzu6kqQk). This is based on years of skill development (although it is interesting to speculate whether he has a natural aptitude which helps in this skill development).

Returning to our central theme of whether we can rely on our senses, we then turned our attention to people who combine skills with benevolent deception. In this case, we are talking about stage magic performances where the objective is to amaze us (rather than to prey on human credulity).

We began with a classic performance by Penn and Teller, in which they perform the cups and balls routine. This act involves moving balls from one inverted cup to another and (in typical Pen and Teller style) they tell you exactly how it is done while still fooling the viewer through sleight-of-hand and misdirection. This performance shows that it isn’t always easy to make correct judgements even when the viewer knows what to look for.

We also looked at a few clips of British performer Derren Brown. Brown is an illusionist and mentalist who uses a combination of techniques to perform ‘mind-reading’ tricks and mental manipulations. He also has a few card tricks up his sleeve and we saw him fool Stephen Fry with an amazing mental / illusion trick (https://www.youtube.com/watch?v=QI5-NDiY7IM#t=170.473343). Brown also performed a neat trick involving a random supermarket purchase (https://www.youtube.com/watch?v=UR81VZXVR6U).

Remember that next Monday I am away, so our class on 4 September will be a self-directed study session. You will be free to work on your assignments and to review the work that we have done so far. D101 will be available, as usual, so please make use of it at this time.

Cheers

Phil