Confused about 'staircases'
$begingroup$
Hi I'm currently reading a paper, which contains an experiment I was to re-create - is there any chance someone can explain the staircase to me?
I've had a quick Google - and I haven't really got anywhere - I'm not even sure if this falls under mathematics, if I'm honest. I've tried to break up the text a little, but I'm still super lost on this.
I can reword the question if the detail of the article is unhelpful - I just didn't want to remove something that was actually of importance
... In each trial, one eye was presented with a population of “signal”
dots that all moved in the same direction (left or right).
The other eye was presented with the noise dots that moved in random directions.
The task was to indicate the motion direction of the signal dots. To
measure the threshold number of signal dots required for 79% correct
performance (the motion coherence threshold), the number of signal
dots was varied on a trial-by-trial basis in a three-down, one-up
staircase procedure with a proportional step size of 50% before the
first reversal and 25% thereafter.
The starting point for each staircase was 100 signal dots and 0 noise dots.
When dots were removed from the signal population, they were added to the noise population and vice versa.
Each staircase consisted of six reversals, and the
last five reversals were averaged to estimate threshold. During each
threshold measurement, two staircases were randomly interleaved.
One staircase measured the motion coherence threshold when the signal dots
were presented to the left eye and the other staircase measured the
motion coherence threshold when signal dots were presented to the
right eye.
In each case, the eye that did not see the signal dots saw
the noise dots.
By randomly interleaving the staircases, participants
could not tell which eye had seen the signal and which had seen the
noise as the stimuli were fused. The interleaved staircase
measurements lasted approximately 3 minutes ...
Anyone that has any advice or pointers are greatly welcomed :)
Thanks!
100 - 3 down, 1 up - Proportional step size of 50% before the first reversal
and 25% thereafter.
- 100 > right > right > right > 50 > wrong - is then 75?
- 100 > right > right > right > 50 > right > right> right> 25 > wrong - is then 31.25?
Is this how this works? Is the 25% proportional to the current, or the max?
education
asked Apr 15 '16 at 22:09
OllieOllie
1224
$endgroup$
add a comment |
$begingroup$
Hi I'm currently reading a paper, which contains an experiment I was to re-create - is there any chance someone can explain the staircase to me?
I've had a quick Google - and I haven't really got anywhere - I'm not even sure if this falls under mathematics, if I'm honest. I've tried to break up the text a little, but I'm still super lost on this.
I can reword the question if the detail of the article is unhelpful - I just didn't want to remove something that was actually of importance
... In each trial, one eye was presented with a population of “signal”
dots that all moved in the same direction (left or right).
The other eye was presented with the noise dots that moved in random directions.
The task was to indicate the motion direction of the signal dots. To
measure the threshold number of signal dots required for 79% correct
performance (the motion coherence threshold), the number of signal
dots was varied on a trial-by-trial basis in a three-down, one-up
staircase procedure with a proportional step size of 50% before the
first reversal and 25% thereafter.
The starting point for each staircase was 100 signal dots and 0 noise dots.
When dots were removed from the signal population, they were added to the noise population and vice versa.
Each staircase consisted of six reversals, and the
last five reversals were averaged to estimate threshold. During each
threshold measurement, two staircases were randomly interleaved.
One staircase measured the motion coherence threshold when the signal dots
were presented to the left eye and the other staircase measured the
motion coherence threshold when signal dots were presented to the
right eye.
In each case, the eye that did not see the signal dots saw
the noise dots.
By randomly interleaving the staircases, participants
could not tell which eye had seen the signal and which had seen the
noise as the stimuli were fused. The interleaved staircase
measurements lasted approximately 3 minutes ...
Anyone that has any advice or pointers are greatly welcomed :)
Thanks!
100 - 3 down, 1 up - Proportional step size of 50% before the first reversal
and 25% thereafter.
- 100 > right > right > right > 50 > wrong - is then 75?
- 100 > right > right > right > 50 > right > right> right> 25 > wrong - is then 31.25?
Is this how this works? Is the 25% proportional to the current, or the max?
education
asked Apr 15 '16 at 22:09
OllieOllie
1224
$endgroup$
1
$begingroup$
see en.wikipedia.org/wiki/Psychophysics#Staircase_procedures
$endgroup$
– Rahul
Apr 15 '16 at 22:12
$begingroup$
I saw the wiki and wasn't 100% sure I was on the right track - I think I get it now, the wording has really thrown me :) Thanks! 100 - 3 down, 1 up 100 > r
$endgroup$
– Ollie
Apr 15 '16 at 22:15
add a comment |
$begingroup$
Hi I'm currently reading a paper, which contains an experiment I was to re-create - is there any chance someone can explain the staircase to me?
I've had a quick Google - and I haven't really got anywhere - I'm not even sure if this falls under mathematics, if I'm honest. I've tried to break up the text a little, but I'm still super lost on this.
I can reword the question if the detail of the article is unhelpful - I just didn't want to remove something that was actually of importance
... In each trial, one eye was presented with a population of “signal”
dots that all moved in the same direction (left or right).
The other eye was presented with the noise dots that moved in random directions.
The task was to indicate the motion direction of the signal dots. To
measure the threshold number of signal dots required for 79% correct
performance (the motion coherence threshold), the number of signal
dots was varied on a trial-by-trial basis in a three-down, one-up
staircase procedure with a proportional step size of 50% before the
first reversal and 25% thereafter.
The starting point for each staircase was 100 signal dots and 0 noise dots.
When dots were removed from the signal population, they were added to the noise population and vice versa.
Each staircase consisted of six reversals, and the
last five reversals were averaged to estimate threshold. During each
threshold measurement, two staircases were randomly interleaved.
One staircase measured the motion coherence threshold when the signal dots
were presented to the left eye and the other staircase measured the
motion coherence threshold when signal dots were presented to the
right eye.
In each case, the eye that did not see the signal dots saw
the noise dots.
By randomly interleaving the staircases, participants
could not tell which eye had seen the signal and which had seen the
noise as the stimuli were fused. The interleaved staircase
measurements lasted approximately 3 minutes ...
Anyone that has any advice or pointers are greatly welcomed :)
Thanks!
100 - 3 down, 1 up - Proportional step size of 50% before the first reversal
and 25% thereafter.
- 100 > right > right > right > 50 > wrong - is then 75?
- 100 > right > right > right > 50 > right > right> right> 25 > wrong - is then 31.25?
Is this how this works? Is the 25% proportional to the current, or the max?
education
asked Apr 15 '16 at 22:09
OllieOllie
1224
$endgroup$
Hi I'm currently reading a paper, which contains an experiment I was to re-create - is there any chance someone can explain the staircase to me?
I've had a quick Google - and I haven't really got anywhere - I'm not even sure if this falls under mathematics, if I'm honest. I've tried to break up the text a little, but I'm still super lost on this.
I can reword the question if the detail of the article is unhelpful - I just didn't want to remove something that was actually of importance
... In each trial, one eye was presented with a population of “signal”
dots that all moved in the same direction (left or right).
The other eye was presented with the noise dots that moved in random directions.
The task was to indicate the motion direction of the signal dots. To
measure the threshold number of signal dots required for 79% correct
performance (the motion coherence threshold), the number of signal
dots was varied on a trial-by-trial basis in a three-down, one-up
staircase procedure with a proportional step size of 50% before the
first reversal and 25% thereafter.
The starting point for each staircase was 100 signal dots and 0 noise dots.
When dots were removed from the signal population, they were added to the noise population and vice versa.
Each staircase consisted of six reversals, and the
last five reversals were averaged to estimate threshold. During each
threshold measurement, two staircases were randomly interleaved.
One staircase measured the motion coherence threshold when the signal dots
were presented to the left eye and the other staircase measured the
motion coherence threshold when signal dots were presented to the
right eye.
In each case, the eye that did not see the signal dots saw
the noise dots.
By randomly interleaving the staircases, participants
could not tell which eye had seen the signal and which had seen the
noise as the stimuli were fused. The interleaved staircase
measurements lasted approximately 3 minutes ...
Anyone that has any advice or pointers are greatly welcomed :)
Thanks!
100 - 3 down, 1 up - Proportional step size of 50% before the first reversal
and 25% thereafter.
- 100 > right > right > right > 50 > wrong - is then 75?
- 100 > right > right > right > 50 > right > right> right> 25 > wrong - is then 31.25?
Is this how this works? Is the 25% proportional to the current, or the max?
education
education
asked Apr 15 '16 at 22:09
OllieOllie
1224
asked Apr 15 '16 at 22:09
OllieOllie
1224
edited Apr 15 '16 at 22:22
Ollie
asked Apr 15 '16 at 22:09
OllieOllie
1224
asked Apr 15 '16 at 22:09
OllieOllie
1224
asked Apr 15 '16 at 22:09
OllieOllie
1224
1224
1
$begingroup$
see en.wikipedia.org/wiki/Psychophysics#Staircase_procedures
$endgroup$
– Rahul
Apr 15 '16 at 22:12
$begingroup$
I saw the wiki and wasn't 100% sure I was on the right track - I think I get it now, the wording has really thrown me :) Thanks! 100 - 3 down, 1 up 100 > r
$endgroup$
– Ollie
Apr 15 '16 at 22:15
add a comment |
1
$begingroup$
see en.wikipedia.org/wiki/Psychophysics#Staircase_procedures
$endgroup$
– Rahul
Apr 15 '16 at 22:12
$begingroup$
I saw the wiki and wasn't 100% sure I was on the right track - I think I get it now, the wording has really thrown me :) Thanks! 100 - 3 down, 1 up 100 > r
$endgroup$
– Ollie
Apr 15 '16 at 22:15
1
1
$begingroup$
see en.wikipedia.org/wiki/Psychophysics#Staircase_procedures
$endgroup$
– Rahul
Apr 15 '16 at 22:12
$begingroup$
see en.wikipedia.org/wiki/Psychophysics#Staircase_procedures
$endgroup$
– Rahul
Apr 15 '16 at 22:12
$begingroup$
I saw the wiki and wasn't 100% sure I was on the right track - I think I get it now, the wording has really thrown me :) Thanks! 100 - 3 down, 1 up 100 > r
$endgroup$
– Ollie
Apr 15 '16 at 22:15
$begingroup$
I saw the wiki and wasn't 100% sure I was on the right track - I think I get it now, the wording has really thrown me :) Thanks! 100 - 3 down, 1 up 100 > r
$endgroup$
– Ollie
Apr 15 '16 at 22:15
add a comment |
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1
$begingroup$
see en.wikipedia.org/wiki/Psychophysics#Staircase_procedures
$endgroup$
– Rahul
Apr 15 '16 at 22:12
$begingroup$
I saw the wiki and wasn't 100% sure I was on the right track - I think I get it now, the wording has really thrown me :) Thanks! 100 - 3 down, 1 up 100 > r
$endgroup$
– Ollie
Apr 15 '16 at 22:15