Friday, 24 January 2014

Perception (information or use?)

When we see the sunrise, do we perceive an illusion? We know that the sun is stationary with respect to the earth yet we say that the sun rises and falls. Are we misinforming ourselves, or, worse still, do we think that the sun presents misleading information? Philosophers talk of “accuracy conditions”, of “illusions” and “elusive appearances” but are these terms really appropriate? Is it even true to say that things present information to our senses? If we take the view that things do indeed present information then we are forced to conclude (though we should probably deny) that the sun presents inaccurate, imprecise or contradictory information about itself.

Many philosophers claim that experience has what they call “content” and this is either rich or sparse depending on your philosophical view. Others disagree. And so they should. The sun doesn’t emanate information and nor do the many surfaces from which its energy in reflected. So, it doesn’t follow that the appearance of the rising sun is inaccurate, elusive, deceptive, illusory etc.

The reason we commonly say that the sun rises and falls is because this has proven again and again to be a useful description of what we see. When some of our specialist needs changed (about 500 years or so ago) we eventually worked out that the sun doesn’t in fact revolve around the earth. Yet we continue to describe it in this way – not because we are misinformed, but because this is the way that continues to be most useful for our earth-bound needs.

So, what do we actually perceive when our portion of the earth turns towards the sun? Well, if you ask philosophers, you’ll get as many answers as you can fit fairies on a pinhead. But perhaps the most revealing way of approaching this issue is by asking what we can usefully do in response to the things that we see. And one of the most useful things we have learnt to do – especially with ungraspable things like the sun - is to represent them.

Perhaps one day it will be obvious that perception isn’t something we gain possession of (content we get) but rather something we are capable of doing. And, of all the things we are capable of purposefully doing, representing is probably the most fundamental.

Monday, 6 January 2014

Representing Neurons

Last year several websites posted articles about the research of David B. Hay and co-researchers (Darren Williams, Daniel Stahl, Richard Wingate) who published a paper investigating the drawing styles of undergraduates, trainee scientists, and leading neuroscience researchers when making drawings of neurons. The following image shows the three sets of drawings. 

The upper line was produced by undergraduate students and shows a close adherence to textbook diagrams whilst the mid line was produced by PhD students and postdoctoral researchers more familiar with neurons under the microscope. The lower line of drawings was produced by expert neuroscientists and shows the greatest variety of approaches to the task.

The research of Hay et al claims that:

“The analysis strongly suggests that a willingness/ability to hybridize extant brain cell knowledge with imaginative conjecture grounded by experience of experimental plausibility gives rise to drawings that are recognized as being ‘expert signatures’ by all classes of participants.”

In other words there was general agreement that the drawings of expert neuroscientists were more “creative,” and on the back of this conclusion various visualization techniques were employed to encourage undergraduate students to be more inventive with their visualisations of neurons. Apparently at the end of this process the drawings of the undergraduates were indistinguishable from the drawings of the experts.

The ability to visualize ideas on paper (and increasingly on screen) is a valuable means of stimulating theories, testing hypotheses and communicating ideas. It is also an important tool in science education - and education in general in fact - because it allows concepts to be digested quickly and efficiently thus optimizing learning and often making it more enjoyable in the process. I’m sure I wasn’t the only child to have wished that physics, biology and chemistry could have involved a lot more drawing and visualization. But what is often missed in the drive towards optimal learning is the value of lateral approaches to concept generation. Students are often treated as inert vessels that need to be crammed full of facts and it is assumed that once these facts have been assimilated that other more lateral skills will emerge of their own accord – or more worryingly - that such skills are superfluous to the advancement of science.

Clearly the work of Hay et al intends to counter such narrow-mindedness and for this reason it should be applauded. Nonetheless, I have several reservations about the way that the study interprets the theory and practice and drawing and the conclusions it makes about creativity in both educational and expert settings.

Different kinds of drawing serve different kinds of purposes and it is vital to understand that these differences have nothing to do with ‘expert signatures.’ When undergraduate students draw neurons the reference material they are given tends to be diagrammatic - usually diagrams in which certain details have been exaggerated in order to make them more informative for a wide variety of applications. When these students draw a neuron they are expected to copy the diagram. Strictly speaking, when a student copies a diagram they produce a predominantly matching representation of the predominantly symbolizing  illustration. So, what they end up with - and few people ever acknowledge this subtle but obvious fact - is a drawing that represents two things simultaneously: a neuron and a diagram of a neuron.  And in either case the strategy of representation is significantly different.

When a PhD student or postdoctoral researcher draws a neuron seen under a microscope they are most likely seeking to produce an image that would be hard to tell apart from the view of the neuron. Even if they are asked to draw a neuron from memory, they are likely to attempt this form of simulating representation. Equally, if their branch of research isn’t concerned with observing neurons under a lens, then it is likely that their drawings will be more like those of an expert neuroscientist, as several of the drawings confirm.

When an expert neuroscientist draws a neuron they are clearly not interested in simulating what neurons look-like. They are probably more interested in how neurons function and their drawings tend to be more schematic because they intend to symbolise what they believe to be salient neuronal processes.

So, when Hay et al ask undergraduate students to experiment with alternative methods of representing neurons they are encouraging different ways of thinking about the features and functions of neurons. This is good. But when they assume that expert drawings are more “creative” they make an important error that is easily exemplified. When a doctor scrawls a prescription, even if it is perfectly legible to the pharmacist, this is no evidence of creative flair and we are right not to seek to encourage aspiring doctors to develop similarly idiosyncratic writing styles. Where information is concerned the style of communication is completely irrelevant. What matters is the purpose.

If experimentation with different forms of representation leads to insights then it is obviously important to exploit this practice. But if the representations produced are uninformative, or worse still if they lead to bad medicine, then there is little point in promoting them, no matter how creative they are claimed to be.

Thanks to James Atherton for posting the link.