Coding of Reaction Times

[Rouge]

Dear Livecode Users,
my last experiment I programmed with livecode a video scene was shown which had to be evaluated after the scene stopped. Within the experiment I manipulated the factor video sceene "freezing":
At the end of each video scene the last frame of the video stopped and was masked or the last frame of the video scene was "freezed" so that the subject could see the last video frame as long as he wanted.
The reaction time from start of video to video evaluation was recorded.
In regard to the reaction times I have two questions:
1. In which which unit are the reaction times stored?

For the condition of masked video scene, the reaction times look quite normel:

1014
1062
3268
3657
572

But for the condition with the "freezed" video frame at the end of each video scene the reaction times look as following:

SUBJECT 1:
1379069904633
1379070193329
1379070164473
1379069815561
1379069768985
1379070283073
1379069926681
1379070261281
1379070314801


SUBJECT 2:
1378973936794
1378974131730
1378973681610
1378974090050
1378974023538
1378973620250
1378973727498
1378974050386

Which leads me to my second question:
Does anybody know how to decode does numbers?

Thank you very very much for your answer! And all the best.

[Klaus]

Hi Rouge,

1. welcome to the forum!

2. I presume you are using a PLAYER object for your videos, right?
In that case the values are the times in the players own timescale.

Use it like this:
the timescale of player xyz -> (native movie-)frames per second
the duration of player xyz/the timescale of player xyz -> the total time in seconds.
Check also "currenttime" in the docs.

Hope you get the picture on how to "translate" your values.


Best

Klaus

[Rouge]

Dear Klaus,

thank you very much for your fast answer and for your welcome .
I am not quite sure, wether I understood your advice right or not.
What do you mean by PLAYER object? - do you mean - as an example - "QuickTimePlayer"? or the length of each video scene?
(Sorry, I am confused right now - maybe the language barrier.)

Best greetings!
Rouge

[Klaus]

Hi Rouge,

how did you play the videos? And how did you "measure" the times?
If you can answer these question, I will be able to answer your questions


Best

Klaus

[Rouge]

Dear Klaus,

a short update helped me to realize: YES I used the Player object for my videos.
Time was measured from Stimulus Onset (Video Start) to Stimulus Evaluation.
That is why I was confused about the regularities in the reaction time of those subjects who were in the condition "freezed video frame" .
Ah - I used the same computer (mac) for all subjects.

Again: Thank you very much for your fast answer!

[[-hh]]

If person 2 was 'measured' starting at
18:56:05 on Thursday, Dec 10, 2013
[on your local hardware clock] then the long numbers are the milliseconds.
Just a presumption.

[dunbarx]

Good thing we have Hermann in our ranks.

Craig

[[-hh]]

Don't scoff at me. I had the idea because I recently tried in my unlimited naivety to convert milliseconds to date items. Since that my brain is not willing to stop the timed delivering of (at about) the current milliseconds.

[By the way: Save the date. In the morning of Sat, Oct 25 2014 we'll arrive at sqrt(2)*10^12 milliseconds.]

[dunbarx]

Scoff??

No way.

Never. Not at least until we reach Skewes' number of seconds.

Craig

[Rouge]

Dear Claus!
Thank you very much for your help!
I am curious: How did you come frome

SUBJECT 2:
1378973936794
1378974131730
1378973681610
1378974090050
1378974023538
1378973620250
1378973727498
1378974050386

to 18:56:05 on Thursday, Dec 10, 2013
[on your local hardware clock] then the long numbers are the milliseconds.
Just a presumption.

?

Do I miss an important point?
Sorry fpr those questions! I am just a real beginner in programming.
Again: Thank you very much for your answer!

[Klaus]

Hi Rogue,

Dear Claus!
Thank you very much for your help!
I am curious: How did you come frome

SUBJECT 2:
1378973936794
...

to 18:56:05 on Thursday, Dec 10, 2013
[on your local hardware clock] then the long numbers are the milliseconds.
Just a presumption.

?

well, THAT was Hermann (-hh)

Since you still not answered my intitial question on HOW you measured the times, I am still not sure
I first thtought that were some times in/from the MOVIE, that's why I asked for the player object.
But seconds or milliseconds actually make more sense now.


Best

Klaus

[[-hh]]

It was just a try, because these numbers are plus/minus in a suitable range of current milliseconds. You get a date from them for example by the following script lines.

Code: Select all

put line 1 of fld "IN" into S
repeat for each line L in S
  put (L div 1000) into L0
  convert L0 to dateItems
  put cr & L0 after T
end repeat
put T into fld "OUT"

What Klaus said, you have to say more, not about your project but simply about the physics of your measurement method so that we can estimate the units: Was it a hardwareClock, a click, an evaluation from the times of a video, ...?

What I'm wondering about is that the numbers are not strictly increasing. Are this somehow *distances* between measurement points?
Then I have no idea, even if these are nanoseconds (you can't seriously measure for an action that takes by itself at thousands of nanoseconds).
Are are a certain number of digits representating a date? Or are they coded to note a certain kind of stimulus?

@Klaus. What I used is that for the rest of the live of a baby born now, that will reach an age of 100 years, the seconds will have 10 digits (more 'exactly': 1*10^9 < the seconds < 5*10^9), and the milliseconds will have 13 digits.