PETMAN

Boston Dynamics - the creator of the Big Dog robot - have released a new video of their latest project, PETMAN.



It's come a long way since this prototype version from two years ago. It's certainly a very impressive project, but I'm really curious to see how it behaves off a treadmill...

The Psychology of Fraud

After the Marc Hauser case last year, it might have been reasonable to think that we wouldn't see another scandal hit psychology for a while (although it'd be a slightly better bet that the Hauser story wasn't finished yet).

Alas, that hasn't turned out to be the case, as a highly cited Dutch psychologist - Diederik Stapel - has been found outright falsifying the data for at least thirty papers (some of which were published in journals as highly regarded as Science). What does this mean for social psychology? I don't know; it's not my field, and the Nature article I linked to above quotes Oxford psychologist Miles Hewstone as suggesting that Stapel's work wasn't actually that influential. So the tentative response is; not much.

I can't say I'm optimistic about the effect it will have on the reputation of psychology as a whole, though. The field really needs to figure out some way to improve its public relations; a case in point is this article, which implicitly suggests that both the recent fraud cases and the sheer number of criticisms from within the field threaten to disrupt the "fragile respectability" that psychology has only "recently" earned. Whether that's the case or not, it's pretty clear that psychology desperately needs to improve its image.

The Fourth Online Consciousness Conference

A call for papers is up here.

In celebration of Ada Lovelace day...

I encourage you all to take a look at Maggie Boden's work. Her book The Creative Mind was probably one of the main reasons I moved back to psychology and cognitive science, as opposed to purely being interested in the philosophy of mind.

Need an introduction to artificial intelligence?

Stanford is offering a free course here, taught by Sebastian Thrun and Peter Norvig. Norvig in particular is one of the biggest names in AI - the textbook that he and Stuart Russell wrote, Artificial Intelligence: A Modern Approach, is essentially the classic in the field - (Thrun is also ridiculously highly cited, even if I'm less familiar with his work) and the syllabus for the course looks like it covers a lot of ground.

Registration is open until the 9th of October, with the class actually starting on the 10th of October, so sign up if you're interested!

Jane Austen was a Bayesian

... well, no, she wasn't, actually (as far as I'm aware), although the quirkily named paper Prior and Prejudice [PDF] in August's issue of Nature Neuroscience introduces Bayesian inference by appeal to her work. It's an interesting overview of two studies which appeared in the August and July issues of Nat. Neuroscience, and "create convincing links between psychophysical performance and neuronal representations using the formalism of Bayesian inference"; Fischer and Pena's Owl's Behavior and Neural Representation Predicted by Bayesian inference and Girschick et al.'s Cardinal rules: visual orientation perception reflects knowledge of environmental statistics.

Rats and the "Wave of Death"

Bit of a morbid topic for this post, but an article examining what happens in the brains of decapitated rats recently came to my attention. To be fair to the scientists involved, they're investigating whether euthanasia by decapitation is humane, but the idea still seems somewhat... grim.

Issues of personal queasiness aside, the paper did find something interesting;

Remarkably, after 50 seconds (awake group) or 80 seconds (anesthetized group) following decapitation, a high amplitude slow wave was observed. The EEG before this wave had more power than the signal after the wave. This wave might be due to a simultaneous massive loss of membrane potentials of the neurons. Still functioning ion channels, which keep the membrane potential intact before the wave, might explain the observed power difference.

This "wave of death" is suggested by the authors to reflect "the ultimate border between life and death". The question arises as to whether this wave is irreparably damaging to the cells involved, something which the authors apparently intend upon researching in future.

On a somewhat related note, the authors also argue that conscious brain activity probably vanishes a scant few seconds after decapitation, making the process a reasonably humane method of disposing of unwanted rodents.

A related study, published more recently, develops a computational model to attempt to account for this "wave of death" phenomenon. Of particular note is the end of the paper, where they argue against the wave as a biomarker of clinical death;

Irreversible functional damage due to oxygen and
glucose deprivation most likely occurs from damage to synapses,
rather than from cell death itself. In line with this perhaps
surprising result, cells from neocortical slices from adult human
brain obtained several hours postmortem, can survive for weeks in
vitro. We therefore reject the claim in the paper by van Rijn
et al. that this particular phenomenon can be used clinically to
determine brain death. In fact, this wave does not imply death,
neither of neurons nor of individuals.
In summary, our simulations and the data presented from
experimental physiology show that the ‘‘Wave of Death’’ reflects
the sudden change in membrane potential due to anoxic
depolarization, that is a direct result of the Hodgkin-Huxley
dynamics and ion concentrations. Although the wave is indeed a
typical signature of the final membrane voltage changes of neurons
suffering from severe oxygen and glucose deprivation, it is not a
biomarker for irreversibility.

A pair of pretty interesting papers, all round. Hopefully they'll inspire some fascinating follow-up research.

References:
Rijn CMv, Krijnen H, Menting-Hermeling S, Coenen AML (2011) Decapitation in Rats: Latency to Unconsciousness and the ‘Wave of Death’. PLoS ONE 6(1): e16514. doi:10.1371/journal.pone.0016514

Zandt B-J, ten Haken B, van Dijk JG, van Putten MJAM (2011) Neural Dynamics during Anoxia and the “Wave of Death”. PLoS ONE 6(7): e22127. doi:10.1371/journal.pone.0022127