This week's session notes - Week 12 (30 October and 1 November 2018)

Hi everyone

So far, our discussion about problem solving and decision making has largely assumed that we have some measure of control over the whole process. After all, most of us can cross a road without being hit by a car, or we can visit a supermarket and return home with enough food to keep us fed for the week. We can also successfully complete tasks such as doing the crossword or filling out a tax return.

However, there are strong indications that we are also highly susceptible to many undue influences which can affect our ability to make sound decisions. These influences may include biases, assumptions and pre-dispositions, some of which we may be aware of and many of which we aren’t.

We should also consider that everything that we know about the world is filtered through our five basic senses. Those incoming sensations are then organised in the brain according to sets of rules. Sometimes, the human mind (and our sensory system) can make it difficult for us to arrive at correct decisions!

To show just how susceptible we can be to subtle influences, we looked at a classic piece of research 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. They then asked some questions about the accident, including a question about the estimated 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 us making correct decisions about situations which we may encounter in every day situations. 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 the things around us and sometimes this leads us to be somewhat 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 in a picture. 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 also contaminate future evidence by reinforcing 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. In these cases, we generally know what to look for and the images weren’t overly surprising as they were so familiar to us. 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, when we observe it from the right angle) and the black triangle which isn’t really there (it ‘appears’ because of the images around it and the assumptions and inferences 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 grey chess board (which are, in fact, the same colour). If you go to the last few slides in the Visual Illusions PowerPoint (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 is, 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 subject 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 (or is it a three-dimensional picture?)

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 population 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 appears to do).

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 or not he also 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 looked at a classic performance by stage magicians Penn and Teller, in which they perform the cups and balls routine (https://www.youtube.com/watch?v=FFq-fn-nSZI). This act involves moving balls from one inverted cup to another and (in typical Pen and Teller style) they tell us 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 watched ‘bar magician’ Smoothini, pulling objects out-of-the-air and making pens disappear and re-appear (https://www.youtube.com/watch?v=ZTy3qG_qInU).

Finally, we 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 we only have a few classes left before the end of the semester. In that time we need to cover off on a few topics which you will need for Assignment 4, so make sure that you don’t miss the opportunity to unlock good marks in this assignment. As mentioned, previously, you will need to do some good-quality independent reading (properly referenced in your assignment) to show what you have learned.

Have a good weekend and I will see you all on Tuesday!

Cheers

Phil