Dean Radin - harmless pseudo-psientist.

They were retrieved immediately before the pictures were displayed in all experiments.

You are not listening: That doesn't mean that the pictures necessarily will be retrieved from the hard disk.

But - if you insist that the pictures were retrieved immediately from the hard disk every time, do you agree that there is a possible leak, yes or no?

Can you explain what a "calm" picture is? What is an "emotional" picture?

And can you answer the questions the first time they are put to you, instead of avoiding them?
 
That doesn't mean that the pictures necessarily will be retrieved from the hard disk.

What I'm assuming (and you seem to know more about this than me), is that any noise related to the computer retrieving the image from RAM or the HD is confined to the period immediately before presentation of the image.

Is there reason to think that the image is retrieved during the presentiment analysis period? I know that you have described various ways in which the image can be retrieved but is there any reason to think that these processes would happen at any time other than immediately before presentation of the image?
 
What I'm assuming (and you seem to know more about this than me), is that any noise related to the computer retrieving the image from RAM or the HD is confined to the period immediately before presentation of the image.

Is there reason to think that the image is retrieved during the presentiment analysis period? I know that you have described various ways in which the image can be retrieved but is there any reason to think that these processes would happen at any time other than immediately before presentation of the image?

David, stop.

I have described some of the many factors that could give clues to the participants in the experiments. You can keep talking about how this could not be the case (even though you clearly have no idea what you are talking about), or you could admit that there could be a leak.

It really hurts you to admit that there could be a leak, doesn't it?
 
Would all the problems not be solved simply by having the computer and hard disk in another room than the monitor and keyboard?
 
I have described some of the many factors that could give clues to the participants in the experiments. You can keep talking about how this could not be the case...

How could image retrieval, by any of the methods you previously mentioned, cause leakage if the retrieval happened after the presentiment analysis period?
 
Would all the problems not be solved simply by having the computer and hard disk in another room than the monitor and keyboard?

It would. That it wasn't only shows just how incompetent Radin is.

How could image retrieval, by any of the methods you previously mentioned, cause leakage if the retrieval happened after the presentiment analysis period?

But you don't know when the image was retrieved and how.

You still cling to straws here.

Do you think that Radin is incompetent since he didn't move the computer and hard disk in another room?
 
But you don't know when the image was retrieved and how.

Going by what the paper says, the image was retrieved after the presentiment analysis period (see p254, fig 1., p260, p262 p264 and p268). Are you saying that there's a possibility it wasn't? If so, how?
 
Going by what the paper says, the image was retrieved after the presentiment analysis period (see p254, fig 1., p260, p262 p264 and p268). Are you saying that there's a possibility it wasn't? If so, how?

Pay attention: How and when the image was retrieved from the hard disk.

Do you still deny this is a possible leak?

Do you think that Radin is incompetent since he didn't move the computer and hard disk in another room?

Don't talk about something else. Don't talk around these issues. Just answer the questions.

As hard as it clearly is.
 
Rather than effects that cancel each other out (then tend to all go in the same direction, after all), I'm thinking that most of the time there is little effect and occasionally there is a large effect. The residual effect of seeing an emotional photo is twice as likely to be subsequently associated with a calm photo as with an emotional photo (although the way the analysis is set up, the subject may be equally likely to be placed in the 'calm' or 'emotional' group, since the 'emotional' group contains subjects exposed to calm photos). If the occasional presence of a large effect is distributed unevenly between the two groups, then it will lead to a tiny, inconsistent, but sometimes significant, difference in the averages between the two groups (which is what we see with the different studies). I'd be interested in seeing what happens if you take this into account.

I've been trying to get my head around this and I think I agree with you. But there's another complication I can see.

It appears that the analysis described in the paper, starting p256, is an analysis that he applied to every experimental data set for the purposes of consistency, even though the experiments were done on separate occasions and analysed by different methods independently. It says that the entire trial set of each experiment was sorted according to pre-assessed emotionality ratings for each trial photo and then split in half, so that the lower half was "calm" and the upper half was "emotional". However someone selected twice as many calm photos to be included in the experiments when they were originally performed. The paper doesn't say how this original decision was made, whether it was purely subjective or based on more quantitative methods. We can assume that this 2:1 ratio did reflect a real difference in valence and arousal.

So this means that the emotional half of each data set in the 2004 paper probably contain trials where the photos were originally regarded as "calm" according to some unknown criteria.

Would this affect your argument in any way?

I think I need to go away and think about what you said some more. It's an excellent point though and I agree it could potentially exlpain the results.
 
Linda, can you explain the bolded section. I'm not sure I understand what you mean by "may equally likely to be placed in the 'calm' or 'emotional' group"?

The trials were simply divided into two groups based on the ranking for the photo (top half and bottom half), so there is an equal chance of being in either group. The bottom half contains photos considered 'emotional', but it also contains photos considered 'calm' because more photos in the database (as far as I can tell) were 'calm'.

Linda
 
Would all the problems not be solved simply by having the computer and hard disk in another room than the monitor and keyboard?

If it's true that the images were retrieved after the PS period and immediately prior to display then there is no problem. There is zero potential for leakage.

Previously I misunderstood and thought that the disk access was prior to the PS period on at least one of the experiments. It turns out this is not so.
 
I've been trying to get my head around this and I think I agree with you. But there's another complication I can see.

It appears that the analysis described in the paper, starting p256, is an analysis that he applied to every experimental data set for the purposes of consistency, even though the experiments were done on separate occasions and analysed by different methods independently. It says that the entire trial set of each experiment was sorted according to pre-assessed emotionality ratings for each trial photo and then split in half, so that the lower half was "calm" and the upper half was "emotional". However someone selected twice as many calm photos to be included in the experiments when they were originally performed. The paper doesn't say how this original decision was made, whether it was purely subjective or based on more quantitative methods. We can assume that this 2:1 ratio did reflect a real difference in valence and arousal.

So this means that the emotional half of each data set in the 2004 paper probably contain trials where the photos were originally regarded as "calm" according to some unknown criteria.

Would this affect your argument in any way?

I think I need to go away and think about what you said some more. It's an excellent point though and I agree it could potentially exlpain the results.

I was taking this into consideration. It's a subtle bias (but the effect, when it does show up, is so tiny that all it needs is a subtle bias) and I need to do some Monte Carlo sims to develop the idea and do a better job of explaining it.

Linda
 
I was taking this into consideration. It's a subtle bias (but the effect, when it does show up, is so tiny that all it needs is a subtle bias) and I need to do some Monte Carlo sims to develop the idea and do a better job of explaining it.

Linda

Please let us know the results of those Monte Carlo's if you get round to doing them! :)
 
It is going to be difficult to analyse Radin’s results using this paper alone. On is left to guess, and then point to potential errors as a likely indicator of the quality of the trials or results. Ok, here is my 2 cent's worth of trying to unravel nonsense and trivia. He may not exploit all of the potential sources.

Referring to fig 2. of Experiment 1
If the author is correct, then he need not collect any data beyond the 0sec line. It could be argued that the subject need never see the photo because it is only the anticipation, or presentiment, of that photo that is of interest. If the photo must be shown, there is no need to record data beyond the end of the photo display period (t=3) and still no reason to process data beyond t=0

I think that Radin needs to record and include the biggest emotional signal he can get, so as to best exploit the artifacts that produce the result. (For this reason, any spurious sounds that may influence the response, even after the lead-in, may be considered as leakage.)

The SCL is obtained in a vague and contrived manner. Radin speaks of clamping, but does not define what that means. In fact very little detail is given regarding this critical issue. How does the end of that trace get back to the beginning? Surely there is a simpler method?

After recording the SCL to the end of the display period (t=3s)the remaining data could be dumped, and the SCL instrument zeroed so that the reference SCL for each run is that value recorded at the time the button is pressed. The incremental change over time is simply and directly referred to that initial value. Why not?

In the first experiment, the sampling rate is 5/sec. To avoid aliasing, the input to the A/D converter must not exceed 2.5Hz. The delay and transient response of this filter will depend upon the precise design, which of course, is not given. It may well be that the profile of Fig 2 has as much to to do with the filter characteristics than skin resistance.

I suspect that Radin fiddles with the lead-in and relaxation periods around the fixed points of image time and filter response, until he gets what he wants. Later, there will be plenty of parametric variables to play with. The linearity of the SCL, A/D linearity, quantization error.....
The J&J 1330 SCL datalogger has been superseded, but what information there is on the newer 1330-C2 model, is scant. (I have e-mailed) It does not look like the equipment is certified.

I think that the way the SCL is measured and processed is critical. It seems that a big finish for emotional photos is of benefit to him.
I wonder if he does not also gain a boost from the way subjects react after the image has passed. The subject is only 2 foot from the monitor, and staring at a small 6x3 photo for 8 seconds (5 seconds lead-in and 3 seconds display). That in itself is odd (why not full screen?) and I expect, rather uncomfortable.

The emotional images are harsher than the calm photos, putting more ‘strain’ on the subject. The subject may recoil back more after the emotional photos, than the calm, resulting perhaps in a change in the SCL after the fact (when it will not be seen as significant). There is no mention of controlling the subject’s movements, nor is it more than superficially considered.

A single trial lasts 18sec, with 40 images per session making a total of 12minutes, yet Radin reports that they may last 30mins. What happens to the downtime? The researcher is behind a screen, but presumably within earshot. Could it be that by obtaining auditory clues from the subject, the process is interrupted - ostensibly to let the subject relax - but has another motive?
Maybe after being halted, the subject behaves according to a pattern that may be of advantage to the researchers.


1. The paper states that no sound (apart from the HD) comes from the PC or the monitor, but does not say how this is qualified. If it is by ear alone, that could well be a problem. The line frequency of a CRT monitor is >16KHz. Even in early adulthood, high frequency loss is quite common, so what was inaudible to the researchers may not be to some subjects.
Monitor noise mat not help the subject guess the target, but if the sound accompanies only some photos, this may influence the subject’s response. In fact, in one of Radin’s lamentable lectures, he alludes to a connection between presentiment and the colour-phi experiments that demonstrate an unexpected phenomenological response to closely-spaced sensory inputs. If that’s the case, then he is at least careless of his own ideas.

2. The HD is an older machine, and will certainly have a slower and noisier disk than we have now.(Because Radin mentions it, I presume that it could be heard in this case). If this does not affect the randomization, then the sound may still have an effect as explained above. If the file is retrieved ‘just before’ the image is shown, then time to display will vary with the seek time, access time, location on disk and file size; as may the subject’s response to it. Also, unless Radin has taken precautions to synchronize the sampling - each 200mS apart - this additional delay could produce a considerable, and certainly variable, timing error. When in doubt, get rid if the source of the problem, something which Radin does not do.

3. There is no mention at all of protection against mains-borne noise in the first test. (In later experiments a UPS is installed, but it is only an assumption that filtering is fitted or effective.). Motors and fans could be a source of interference. The room is air-conditioned, so there is at least one possible source. (Electrical noise is mentioned, but turning off the lights was deemed to be an adequate solution. Well, close enough for a pseudo's.)

3. There are no precautions taken to ensure that the SCL does not pick up interference from the monitor, either through the wires or subject’s body. The input impedance of the SCL datalogger is very high. Even if the signal is low-pass filtered, input rectification could occur unless suitable filters are fitted at the input itself. Given that the presentiment effect is said to be difficult to measure, I would have thought a Faraday shield helpful, if not essential.

5. Some trouble has been given to selecting the photo for emotional response, but not for say, brightness. Why is this not a factor in the response? Surely the photos should be selected by the same means as the experiment, rather than by external review.

6. Software and hardware have not been certified, nor controls locked, nor is the equipment traceable. Independent verification would be difficult. Ah, well the frontiers of science need not bother with such trifles.

Baron,
I cannot agree that Radin is being hard done by. I think he gets more voice than he deserves. His experimental work is quite obviously sloppy. He is economical with the truth, and data. In one lecture, he blatantly took Dennett out of context regarding the colour phi experiments. :mad: Dennett doesn't do woo, and everybody knows it except maybe Radin's intended audience.

I have looked into Radin's work. He is published, gives lectures, writes books gets on the TV. Some have even repeated variants of his experiments.
He really is beleaguered, isn't he? Such a hard grind. In between (paid?)lectures and conventions, he has to assemble some off-the-shelf equipment now and again, for an experiment or woo, er, two.
 
A really simple explanation for the results is the SCL logging equipment was not reliably synchronized to the PC control system. Now that would be funny.
 
Read post #228.

Stop feigning ignorance, David.

A remember a lecturer of mine once saying that if someone doesn't understand your argument then its more likely to be your fault for not explaining clearly rather than the other person not being capable of understanding the argument.

I've read post 228 and I can't understand what your point is. Surely, the method of retrieval is irrelevant if the retrieval happens after the presentiment period. Are you saying that there is a possibility the retrieval happens during the presentiment period? If so, how? I can't see that information in post 228
 
A remember a lecturer of mine once saying that if someone doesn't understand your argument then its more likely to be your fault for not explaining clearly rather than the other person not being capable of understanding the argument.

I've read post 228 and I can't understand what your point is. Surely, the method of retrieval is irrelevant if the retrieval happens after the presentiment period. Are you saying that there is a possibility the retrieval happens during the presentiment period? If so, how? I can't see that information in post 228

What, exactly, in post #228 don't you understand?
 
No, no, no.
First of all, two different images of the same dimensions - say, 1024x768 - can be of vastly different size, and therefore take very noticeable different time to retrieve. A very complex JPG of a train can be many, many times bigger than a simple JPG of a blue sky with few clouds.

They can indeed be of different size, although different levels of compression can have a greater effect than complexity.

However, it is of no relevance whatsoever to the experiment. We can see this by examining what difference it might make ~

Let's say the images differ hugely in size:

Image 1: 50K
Image 2: 500K

(I'm being generous as the image dimensions mentioned are very unlikely to differ so much in size)

Assuming a similar level of fragmentation, for obvious reasons, let's say I2 will take approximately 10X longer to retrieve than I1.

Taking the rough HD speed for a 486 (3600rpm est.) - again I'm being generous, this is the slowest PC he used - it can be said that I1 image would take approximately 0.002 seconds and I1 0.02 seconds.

Therefore, in instance 1, we have the 3 second presentiment time + 0.002 seconds retrieval afterward the presentiment time has finished.

In instance 2 we have the 3 second presentiment time + 0.02 seconds retrieval afterward the presentiment time has finished.

How can that possibly make a difference to anything?

Firstly, it's happened after the presentiment data has been recorded.

Secondly it's such a trifling time span that it's not even worth considering.

Will waiting for 3.002 seconds to see the image cause a myraid of false positives when waiting 3 seconds will not? What nonsense.

Second, it is by far not certain that the computer accesses the hard disk for the pictures every time - it can also retrieve them from cache, either on the hard disk or from RAM.

So what?

Third, the program can access the pictures in many ways: It can force-read bit-by-bit on the hard disk, or it can read ahead before the experiment starts and have them ready in the memory (RAM). Even so, it still doesn't necessarily ensure that the pictures stay in RAM.

So what? It makes no difference.

Whenever a computer is involved in an experimental setup, there is every reason to look deep into the possibilities of influencing the experiment.

Done that, no issue.
 
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