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Comment by ACow_Adonis | Hacker News Reader

Am I the only HN reader whose bullshit detector has gone off and, admittedly without reading the study at this stage (I will attempt to do so when I get home), thinks this has all the hallmarks of future non-reproducible results?

A photon? Really?

Extraordinary claims require extraordinary evidence...and to me that's a pretty extraordinary claim. And yet when I read the report it sounds like a probability based argument from a group of 3?

ESP trials all over again anyone?

I mean, as scientists, I feel we should be cynical/skeptical...

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You can also see it this way:

There exist (∃) some detectors which are also human males. These three males have been statistically proven to detect single hit photons at a rate greater than chance. Yes, you are right, this doesn't suggest all humans or even most humans (discounting the blind and individuals with poor sight) can detect single photons, but they certainly have characterized these three individuals.

It's reasonable to be skeptical, but it is even more reasonable to evaluate a peer-reviewed publication in one of the most rigorous subfields of psychology (sensation & perception) after having read at least its abstract, ideally the whole paper.

Especially when papers before it have established that at most only a few photons were needed for perception. The very first line is:

"Landmark experiments by Hecht and colleagues in the 1940s established that dark-adapted human subjects are capable of reporting light signals as low as a few photons (~5–7)."

Looking around, http://onlinelibrary.wiley.com/doi/10.1113/jphysiol.1979.sp0... is a 1979 paper showing that a toad retina can respond to a single photon.

The claim from this new paper doesn't seem that extraordinary given what's been known for decades.

I'm probably about as cynical--at least about other people's data--as they come, but this seems pretty plausible to me.

It's been known for a while that humans can detect <SMALLNUM> of photons. I think people have looked at the fine structure of a rod and determined that it should have very high quantum efficiency. Finally, direct measurements of the electrical activity of individual (isolated) rod cells suggests that they do respond to single photons.

However, the intact retina has some "normalization" circuitry, which might wash out the signal from a single rod. Even if it makes it out of the eye, the signal has to pass through a lot of cortical processing before the subject consciously perceives it, so these results are a little surprising. However, there is some data suggesting that rats can detect the activity of a single cell in somatosensory cortex (Houwelling and Brect, 2007)[1], so it seems possible.

In summary, it doesn't seem totally outlandish based on what we already knew but...replications are good.

[1] http://www.nature.com/nature/journal/v451/n7174/full/nature0...

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