luse
New Member
Posts: 1
|
Post by luse on Mar 5, 2021 8:43:17 GMT
Hi everyone, - I'm coding a task that requires a fast presentation of a visual stimulus (60 milliseconds). Considering that I'll be using the web-based version of psytoolkit, do you think it's possible to get stimulus presentations that are consistently close to this measure?
- Using the timestamp command as shown in the piece of code below, would I be able to estimate the "real" stimulus presentation timing (in order to eliminate trials in which there is a significant discrepancy), or is this a fallacious method?
.... timestamp myFirstTimeStamp
show bitmap @1
delay 60
clear -1
timestamp mySecondTimeStamp
set $my_difference timestamp-diff myFirstTimeStamp mySecondTimeStamp
save $my_difference ....
Thank you.
|
|
|
|
Post by matia on Mar 5, 2021 21:35:41 GMT
Dear luse, it is best to try out for yourself.
I have done a simulation with your data (using my images). here's the code, you can play around with it. task search
timestamp myFirstTimeStamp
keys space
show bitmap rekl1 -128 -96
delay 25
timestamp m2
show bitmap rekl2 128 -96
delay 50
timestamp m3
show bitmap rekl3 -128 96
delay 75
timestamp m4
show bitmap rekl4 128 96
delay 100
timestamp m5
show bitmap rekl1 -394 -288
delay 125
timestamp m6
show bitmap rekl2 -394 -96
delay 150
timestamp m7
show bitmap rekl3 -394 96
delay 172
timestamp m8
show bitmap rekl4 -394 288
delay 200
timestamp m9
show bitmap rekl1 -128 -288
delay 245
timestamp m10
show bitmap rekl2 -128 288
delay 300
timestamp m11
show bitmap rekl3 128 -288
delay 300
timestamp m12
show bitmap rekl4 128 288
delay 1
timestamp m13
show bitmap rekl1 394 -288
show bitmap rekl2 394 -96
show bitmap rekl3 394 96
show bitmap rekl4 394 288
clear 1 16
set $bla2 timestamp-diff myFirstTimeStamp m2
set $bla3 timestamp-diff m2 m3
set $bla4 timestamp-diff m3 m4
set $bla5 timestamp-diff m4 m5
set $bla6 timestamp-diff m5 m6
set $bla7 timestamp-diff m6 m7
set $bla8 timestamp-diff m7 m8
set $bla9 timestamp-diff m8 m9
set $bla10 timestamp-diff m9 m10
set $bla11 timestamp-diff m10 m11
set $bla12 timestamp-diff m11 m12
save $bla2 $bla3 $bla4 $bla5 $bla6 $bla7 $bla8 $bla9 $bla10 $bla11 $bla12
block block1
tasklist
search 10 all_before_repeat
end  So, as You can see, the deviation is negligible and probably due to the internet, or the size of the images I used (each had 60KB). You can also check papers that validated the Psytoolkit. You cannot miss them since they pop-out when you enter the web-based login 
Best, Matia
|
|
|
|
Post by leon826 on Mar 28, 2021 18:53:08 GMT
Hi, I have a problem with running an experiment. It´s a SRTT and I have build trials of 12 elements (4 fingers) which are repeating. After tapping 12 times the screen refreshes and acts like it blinks. Is it possible to build it like a loop, so one cannot see that it´s actually is are 12 finger trial?
kind regards
Leon
|
|
