Science lessons from 8 year old children

[Cross posted from Talking Teaching]

Ed Yong in Not Exactly Rocket science alerted me to an article published in Biological Letters Biology Letters from the Royal Society. I will not discuss the content of the article, Ed Yong has (as usual) done a wonderful job. I would like instead to share the ‘concept’ of the article.

The article reports on some research that shows that bumble-bees use both colour and spatial relationship in their foraging behaviour. But enough about that. What is unique about this article is that the research was conducted by a group of school children. It is also unique in that it is written by a group of school children (in their language). And the icing on the cake are the figures: pencil coloured; no fancy graphic software.

This is, in my opinion, authentic teaching at its best. And authentic learning. And while we are at it, authentic publishing.

So what have I learned from this group of children? That, as they say, science is fun. And that teaching science, whatever the student age group, can be made fun and authentic and can get children motivated.

The background reads:

Although the historical context of any study is of course important, including references in this instance would be disingenuous for two reasons. First, given the way scientific data are naturally reported, the relevant information is simply inaccessible to the literate ability of 8- to 10-year-old children, and second, the true motivation for any scientific study (at least one of integrity) is one’s own curiosity, which for the children was not inspired by the scientific literature, but their own observations of the world.

I could not agree more. I love biology because I ‘played’ with biology as a child. I was fortunate enough to have a father who never answered my question with ‘I don’t know’ without following that up with ‘but lets try to find out’. As a child my father valued my questions and my curiosity, more so about things he didn’t have an answer for. And I will always be grateful to him for that. For my teachers, well, that was a different issue: rather annoying having a pupil in the class that just refused to overcome the ‘why?’ stage.

And these children have been given a great gift by being it let known that their thoughts and ideas have value. And that, once that barriers that have to do with the specific language of the scientific literature are withdrawn, their ideas and thoughts can bring about new knowledge.

These children will also grow up having learned a few fundamental things about science: How an idea is brought into shape, how scientific questions are narrowed, and the hard work and discipline that is needed to see an experiment through. Oh yes, and that no matter how good an idea may be, reviewers may still reject your grant.

None of this they could have learned from a science textbook.

The editors of the Royal Society should also be commended for not requiring that the manuscript adjust to the traditional publishing formats and allowing the authentic voice of the children to come through. This paper should become obligatory reading in science classes. If nothing else, children will recognise their own voices and curiosity in the reading, and, who knows, other groups of children with innovative teachers may teach us (adult scientists) another thing or two.

Citation:
P. S. Blackawton, S. Airzee, A. Allen, S. Baker, A. Berrow, C. Blair, M. Churchill, J. Coles, R. F.-J. Cumming, L. Fraquelli, C. Hackford, A. Hinton Mellor1, M. Hutchcroft, B. Ireland, D. Jewsbury, A. Littlejohns, G. M. Littlejohns, M. Lotto, J. McKeown, A. O’Toole, H. Richards, L. Robbins-Davey, S. Roblyn, H. Rodwell-Lynn, D. Schenck, J. Springer, A. Wishy, T. Rodwell-Lynn, D. Strudwick and R. B. Lotto (2010) Blackawton bees. Biology Letters DOI:10.1098/rsbl.2010.1056

For fireflies, getting the girl requires team work

Imagine you drive into a motel in Gatlinburg TN, and see behind an open room door 2 guys setting up cameras pointing at the beds while two young women peek from the parking lot. Well, if it was in the mid ’90′s it might have been Drs Moiseff and Copeland setting up the equipment before venturing into Elkmont in the Smoky Mountains to study the local fireflies. (And one of the two women would have been me.)

Andy Moiseff and Jon Copeland started studying the population of fireflies in the Smoky Mountains National Park after learning from Lynn Faust, who had grown up in the area, that they produced their flashes in a synchronous pattern.

Image courtesy of Andy Moiseff

In the species they are studying (Photinus carolinus) the males produce a series or bursts of rhythmic flashes that are followed by a ‘quiet period’. But what is particularly interesting about this species is that nearby males do this in synchrony with each other. If you stand in the dark forest, what you see is groups of lightning bugs beating their lights together in the dark night pumping light into the forest in one of nature’s most beautiful displays.

Females flash in a slightly different manner and, as far as I know, they don’t do it synchronously either with other females nor with the males. One interesting thing in Elkmont is that there are several species of fireflies, and you can pretty much tell them apart by their flashing patterns. But as useful as this is for us biologists (since it avoids having to go through extensive testing for species determination), the question still remained of whether the flashing patterns played a biological role.

And this is what Moiseff and Copeland addressed in their latest study published in Science. They put females in a room where LEDs controlled by a computer simulated individual male fireflies. The LEDs were made to flash with different degrees of synchronisation and they looked at the responses of the females. They found that while the females responded to synchronous flashes of the LEDs, they really didn’t seem to respond when the flashes were not synchronous. Even more, they responded better to many LEDs but not much to a single one. What this means, is that if you are a male of Photinus carolinus, you better play nice with your mates if you want to get the girl.

What *I* want to know is how this behaviour is wired in the brain. At first hand, this seems like a rather complex behaviour, but in essence all that it seems to require is a series of if/then computations, which should not be too hard to build (at least not from an ‘electronic circuit’ point of view). But Bjoern Brembs reminded me of a basic concept in neuroscience: brains are evolved circuits, not engineered circuits. So, Andy and Jon, how *do* they do it?

Original article: Moiseff, A., & Copeland, J. (2010). Firefly Synchrony: A Behavioral Strategy to Minimize Visual Clutter Science, 329 (5988), 181-181 DOI: 10.1126/science.1190421

Brain day, bigger, longer, uncut

If you have been paying attention, you might have been hearing a rise in stories related to brains in the media (I will be blogging about some of them soon). This is because this has been Brain Awareness Week. My first (ever) post on a blog (now defunct and reborn here) was indeed one describing my last year’s experience organizing for the 3^rd time the Open Brain Day at the University of Auckland.

A year has gone by, and I am sitting at this year’s Brain Day that is being held at the Business School’s Owen Glenn Building at the University of Auckland. This year we are also celebrating the launch of the Centre of Brain Research, which launched towards the end of last year, finally replacing the Auckland Neuroscience Network.

For the first time, I can look at the day without the pressure of running after a myriad of details. And this year we are bigger, longer and uncut. (Well, the latter not so true since we have some cut brains to show you what they look like on the inside).

If you have come to brain open days before, check it out again. If you haven’t then this would be a great time to start.

[Open] Science Sunday – 28.2.10

I am not sure why, but this week appeared to be filled with news about science to share. All of these are brought to you by the magic of Open Access or the efforts of people in the web to make science accesible to everyone.

I would normally not include articles published in Nature here, but this week David Winter from The Atavism pointed me to this one: “Complete Khoisan and Bantu genomes from southern Africa” by Stephan C. Schuster and a group of collaborators. The authors open their paper stating that

“The genetic structure of the indigenous hunter-gatherer peoples of southern Africa, the oldest known lineage of modern human, is important for understanding human diversity.”

The study has been published under a creative commons licence (http://creativecommons.org/licenses/by-nc-sa/3.0/) and the data has also been released here. I dont know whether Nature will ever move to a full Open Access format, but I think it is worth acknowledging that at least some of their material is made available withouth a subscription. To read a full review of the article, you can visit David Winter’s blog.

PLoS One (which yes is a  fully Open Access journal) published an article on the cognition behind spontaneous string pulling in New Caledonian Crows, by Alex Taylor, Felipe Medina, Jennifer Holzhaider, Lindsay Hearne, Gavin Hunt, and Russell D. Gray. New Caledonian crows are better known for their ability to manufacture tools both from materials that they would normally find in the environment as well as some they would not. New Caledonian crows can solve rather complex puzzles, and for the most part, it has been assumed that this reflected some ‘higher’ cognitive ability that require building a cognitive scenario and imagination. In this study, the authors subjected crows to a series of tests, and conclude that:

Our findings here raise the possibility that string pulling is based on operant conditioning mediated by a perceptual-motor feedback cycle rather than on ‘insight’ or causal knowledge of string ‘connectivity’.

As usual, things are not so black and white. You can read the details of the study on the PLoS One site, and Wired Science has a great review by Brandon Keim on the paper.

And, if you are looking for interesting blogs filled with science nerd content, then this is the best time to find them.

The finalists for best of Research Blogging are out and there is no shortage of interesting stuff to look into. Also out is the Open Laboratory 2009. This is a great collection of science blog posts that is really worth your money. So go on now, go get yourself a copy…

The Open Laboratory 2009

And if all that geekiness was still not enough, then you are in luck.

Next week will see Global Ignite Week: Ignite talks in 65 cities and 5 continents (and yes, there is one in Wellington on Tuesday). Ignites are a great presentation format (well, unless you are a speaker since they are really really hard to do well!).  If you have not heard one before, there are plenty on YouTube Ignite Channel.

If you cannot make it to Wellington, then Auckland will be having on Thursday another Late at the Museum, this time on innovate science. I know, I am now sounding like a tourist guide.

One more (an last). If you want to know everything there is to know about <ahem!> me :), thanks to the magic of Bora Zivkovic and The Blog Around the Clock, now you can. There should be a warning or disclaimer before I lead you to this link.

Full Disclaimer: I am an academic editor for PLoS One and I collaborate with the group behind the New Caledonian Crow Study

Getting up to speed with sound localisation

Funny how we are really good, for the most part, at knowing where sounds are coming from. And it is funny since the ear provides the brain with no direct information about the actual relationship in space of different sound sources. Instead, the brain makes use of what happens to the sound as it reaches both ears by virtue of, well, being a sound wave and that we have two ears separated in space.

Imagine a sound coming from the front, the sound will arrive to the two ears at the same time. But if it is coming from the right it will arrive to the right ear first, and to the left ear a wee later. This ‘time difference‘ will depend on the speed of sound in air and how far apart our ears are. Even more, as the sound source moves from the far right to the front of the head those time differences will become smaller and smaller, until they are zero at the front. If one could put one microphone in each ear, one could reliably predict where the sound comes from by measuring that time difference. And this is exactly what a group of neurons in the brain does.

Easy enough? Not quite.

The way the brain works is that things on the left side of our body are mapped on the right side of our brains, and things on the right side of our bodies are mapped on the left side of our brains. So the ‘time comparison’ neurons on the right side of the brain deal mainly with sound from coming from the left (and neurons dealing with the sound from the right are on the left side of the brain). But to do the time comparison these neurons need to get the information from both ears, not just from only one side!

Figure 1 (by Kubke CC-BY)

This raises this conundrum: the neural path that the information from the left ear needs to travel to get to the same (left) side of the brain will inevitably be shorter than the path travelled by information coming from the other side of the head. So how does the brain overcome this mis-match?

And here is where having paid attention at school during the  “two trains travelling at the same speed leave two different stations blah blah blah” math problem finally pays off. When a sound comes from the front, the information arrives to each of the ears at the same time. The information also arrives to the first station in the brain (nucleus magnocellularis) at the same time. But time comparison neurons need information from both ears, and the path that the information needs to travel from the right side to the time comparison neurons in nucleus laminaris on the left side (red arrow in figure 1) is longer than the path from the same side (blue arrow in figure 1).

However, when you look into an actual brain, things are not so straight-forward (sorry for the pun). The axons from nucleus magnocellularis that go to the time comparison neurons on the same side of the brain take a rather roundabout route (as in figure 2). And for long we assumed that such roundabout way was enough to make signals from the left and right sides to arrive at about the same time.

Figure 2 (by Kubke CC-BY)

Easy enough? Not quite

When Seidl, Rubel and Harris actually measured the length of the axons (red and blue) they found that there was no way that the information could arrive at about the same time and that the system could not work in the biological range. But this problem could be overcome (back to the old school problem) by having the two trains (action potentials rather) travel at different speeds. And this is something that neurons in the brain can relatively easily do in two ways: One is to change the girth or diameter of the axon. The other is to regulate how they are myelinated. Myelin forms a discontinuous insulating wrap around the axon, which is interrupted at what is called the Nodes of Ranvier. The closer the Nodes of Ranvier are, the slower the action potential travels down the axon.

What the group found was that both axon diameter and myelination pattern were different in the direct (blue) and crossed (red) axons. When they now calculated how long it would take for the action potential from both sides to reach the time comparison neurons in nucleus laminaris, adjusting speed for the differences in the two axons, they found that yup, that pretty much solved the problem.

Easy enough? Quite

Like the authors say:

The regulation of these axonal parameters within individual axons seems quite remarkable from a cell biological point of view, but it is not unprecedented.

But remarkable indeed, considering that this regulation needs to adjust to a very high degree of temporal precision. I have always used the train analogy when I lecture about sound localisation, and always assumed equal speed on both sides. Seidl, Rubel and Harris’ work means I will have to redo my slides to incorporate differences in speed. Hope my students don’t end up hating me!

Seidl, A., Rubel, E., & Harris, D. (2010). Mechanisms for Adjusting Interaural Time Differences to Achieve Binaural Coincidence Detection Journal of Neuroscience, 30 (1), 70-80 DOI: 10.1523/JNEUROSCI.3464-09.2010