Monday, 2 July 2018

Do dogs recognise emotions in photos of humans?

Nearly 150 years ago, Charles Darwin sent photographs of actors expressing various emotions to missionaries far and wide. He wanted to know whether the natives correctly identified the emotions expressed in European faces.

Now, 150 years later, Italian veterinary scientists working on animal behaviour and bioethics asked the same question, with a variation: do dogs recognise anger, fear, happiness, sadness, surprise, and disgust as well emotionally neutral faces when they see photographs?

By Rcramer1413 via Wikimedia Commons

Seems they do. And what’s more, they turn their head towards right (for left hemisphere processing) when they see surprise expressed in a photograph – whereas they turn to their right (for right hemisphere processing) when the photograph expresses other emotions.

Why?

I am not sure about the reasons they give. It appears that it could be a misinterpretation by dogs. Smiling without vocalisation that signal happiness is often mistaken by dogs as snarling too, they say. Do you think they are right? Take a look at the paper published online in Learning & Behavior  -Orienting asymmetries and physiological reactivity in dogs’ response to human emotional faces



Anyway, do you respond to the pictures above left, and here right, differently? (It is the same picture, but flipped horizontally).

Which one do you emotionally respond to, as a dog lover? The picture on the left or the one on the right?

Learning & Behavior https://doi.org/10.3758/s13420-018-0325-2

Wednesday, 11 April 2018

How Many Connections does a Neuron Make in the Brain?

You may find estimates in many neurobiology text books. But has anybody really counted them?

Not really. Estimates are estimates.

But now there is a technique to actually count the number of connections. There is a paper in a recent issue of Nature, that spells out a technique. Whole brain fluorescence-based axonal tracing and high throughput DNA sequencing of genetically barcoded neurons.

The scientists, some of them with unpronounceable names, have delineated the projection patterns of 591 individual neurons in the mouse primary visual cortex using the technique.

Nature 556: 51–56 (05 April 2018), doi:10.1038/nature26159

Some time ago, when I saw a paper that achieved single cell RNA sequencing to come to the conclusion that there are 11 distinct neuronal populations in the dorsal root of the spinal chord, I knew something like this is bound to happen.

Like the Genome project, this is going to throw up such large amounts of data that it will keep the computer programmers busy for some time. And it will take even more time to make some reasonable sense of the data. But this is indeed, a historical beginning. It is even more exciting than the earlier techniques that gave this image by removing all the fats from the brain leaving a protein skeleton:


Image by Thomas Schultz

Friday, 17 February 2017

A a larger brain surface before 12 months of age puts you at risk for autism

Scientists from more than 20 different institutions examined more than 300 infants. And came to the conclusion that hyperexpansion of the brain surface area, between 6 and 12 months of age, before brain volume overgrowth, usually observed between 12 and 24 months, is a early clue for detecting autism.
Early brain development in infants at high risk for autism spectrum disorder, Nature, 542, 348–351 (2017)

Wednesday, 11 January 2017

A quick glance at Indian science. Every fortnight.

It will soon be an year since we started the column titled Science Last Fortnight in Current Science. And we are now in a position to increase the activity to a new height.
We want the world to know what Indian scientists are doing now. The present is more glorious than the past.
Please take a look at the column. Tell us what you think of it.
Here is the link to the column: http://www.currentscience.ac.in/Volumes/111/12/1895.pdf

Monday, 1 August 2016

Climate causes correlations

Climate science has been getting some unwanted attention these days. Like the hoo-haa about HIV, in this case too, people are learning to be less sensationalist. When examining primary principles, one comes across quite a few studies that encourage us to pay heed to the need to be cautious lest one confuses correlations with causes. A recent paper by Sze Ling Ho and Thomas Laepple in Nature Geoscience is yet another in the series.

Surface temperatures of the seas and vast oceans of the planet play a big role in the climate change calculations. To model climate change, scientists use a proxy temperature index, TEX H 86, derived from the relationship between archaeal lipids and temperature. But use of this proxy in the climate model leads to unexplainable warm polar sea surface temperatures in Eocene - about 50 million years ago. This has been a bee in the bonnet for many climate scientists.

Now, this paper comes as a consolation and a cause for further worry. TEX may not be a good proxy for surface temperatures. But it is still very useful, since it is actually measuring subsurface temperatures.

If that does not worry climate researchers who insist that they see climate warming in the future, I see it only as a reflection of Tony Blair's "conviction" about weapons of mass destruction in Iraq.
Nature Geoscience 9, 606–610 (2016)doi:10.1038/ngeo2763

Climate causes correlations

Climate science has been getting some unwanted attention these days. Like the hoo-haa about HIV, in this case too, people are learning to be less sensationalist. When examining primary principles, one comes across quite a few studies that encourage us to pay heed to the need to be cautious lest one confuses correlations with causes. A recent paper by Sze Ling Ho and Thomas Laepple in Nature Geoscience is yet another in the series.

Surface temperatures of the seas and vast oceans of the planet play a big role in the climate change calculations. To model climate change, scientists use an proxy temperature index, TEX H 86 derived from the relationship between archaeal lipids and temperature. But use of this proxy in the climate model leads to unexplainable warm polar sea surface temperatures in Eocene - about 50 million year ago. This has been a bee in the bonnet of many climate scientists.

Now, the paper comes as a consolation and a cause for further worry. TEX may not be a good proxy for surface temperatures. But it is still very useful, since it is actually measuring subsurface temperatures.

If that does not cause worry to climate researchers who insist that they see climate warming in the future, I see it only as a a reflection of Tony Blair's "conviction" about weapons of mass destruction in Iraq.
Nature Geoscience 9, 606–610 (2016)doi:10.1038/ngeo2763

Friday, 22 April 2016

Sleep-Wake Cycles: Magnanimity of Magnesium

All of us know how the sleep-wake cycles work in us: behind our eyes, just below where the optic nerve from the eyes cross, there is the pituitary gland that has melatonin which increases and decreases in response to light and makes us sleepy or awake. Right?

Wrong. Circadian rhythms are found even in plants that do not have eyes or pituitary. Circa means about, dian refers to day. The clock that is inbuilt in living creatures has fascinated biologists and in the last few years we have seen discoveries of a large number of clock genes. So it is not the nervous system that is responsible for the daily cycles, but the clock genes, right?

Wrong. Says a paper in yesterday's Nature. Behind the evolution of clock genes, behind the evolution of pituitary, is the magic of magnesium.

The daily pendulum of human and algal cells, separated by more than a billion years of evolution, swing in response to intracellular magnesium. The element is needed in modest and meagre amounts, and is critical for life: magnesium is a cofactor in all ATP dependent processes. In other words, metabolic energy yo-yos with magnesium. And that sets the pattern for the evolution of clock genes, the evolution of the nervous system with a pituitary that releases melatonin...

The magnanimity of the modest magnesium!