Yeah one photon for one photoreceptor, right. That's actually amazing. And then can you really see that one photon the signal for one cell because measured that. When your perceive the light you just need one photon to activate the one receptive neuron and then of course happen maybe five to six simultaneously different neuron, right. But in any case the mediation it's one cell you need to respond to one single photon. And with this technique they found this Single-Photon Response from the one cell. Look at that here, this is a picture showing the photo recording. Again, such impact the recording [FOREIGN]. And then this is the Single-Photon Response. So this actually is continuous recording, okay. It's just from here, connect here, for the display to show you, the brick, easy for viewing, for the display. And then at different times, you see it equals a interval. Give it a light flash. This light stimulation actually makes the intensity quite low. And average may be just 0.5 photons per flash. And then what you can see is sometimes there's actually no response. Sometimes maybe it is small bumps. Sometimes larger bumps. This larger one you can easily think it's two, a small overlap. This is the quantum response. Look at here. The small one is the Single-Photon Response. The larger one is the two fold photon response. How you can achieve such like 0.5 photons per flash stimulation. We know the light the minimum unit is a photon you cannot just divide the photon into half. [FOREIGN] >> Do you think do you know someone with a question. >> The question is actually how can you, given the light intensity, only have 0.5 photons per flash. [FOREIGN] >> [INAUDIBLE] >> What? >> [INAUDIBLE] >> A mirror. >> [INAUDIBLE]. >> [FOREIGN] [FOREIGN] This kind of fluctuation. [FOREIGN] response [FOREIGN]. Says vesicle transmitter release, right? Is a counter release, right? [FOREIGN] Distribution. [FOREIGN] distribution [FOREIGN]. If you collect all this data like a mixture of this plot. This is actually OK. No response how many times happens, right? And here you can count, of course, this is maybe not enough. You have many, many more recordings. And you make this plot. So at one picoampere here, then you count how many times happen. And then of course then you have two picoampere. And from this you can fit by the [INAUDIBLE] process exactly. That means actually indeed this is the single photon response, okay? Just like here. This is a single, this is actually the response to two photons. [FOREIGN]. If you have a partial distribution, you know the average lambda of the events, the lambda. Just a partial [FOREIGN] function [FOREIGN] lambda. [FOREIGN] Okay? Exactly [FOREIGN] describe the [INAUDIBLE] distribution. Okay, so we talk about actually this single photon response. This only happens in the receptor. [FOREIGN] photo receptor. Because, they [INAUDIBLE] photo receptor actually is very sensitive and then responsible for the [INAUDIBLE] edition. [FOREIGN] Okay. For the cone [FOREIGN]. No, this is a different scenario. [FOREIGN]. They don't have this single photon response. [FOREIGN] So we still have the, rely on the cone for the receptor quite heavily, okay? So because actually in the daytime you want to see the color. You want to see the motion, this all coming from the cone, photo receptors, okay?
