Millisecond Forums

Saving randomized stimuli for reuse

https://forums.millisecond.com/Topic36629.aspx

By lir1995 - 11/14/2024

Hi, 

I have an experiment where I have faces and scenes paired together. The pairing of the two are random, and should be random initially. However, participants will then need to see the same face-scene pair again later in the experiment. For instance, trials 1-4 could be four trial unique pairs, but trials 5-8 should be the repeats of trials 1-4 in a random order. 

How do I save this random pair so that participants can learn these pairings?

Here is code I have so far.

************
Import Faces
************
<item Face>
  / 1 = "Faces/1.jpg"
  / 2 = "Faces/2.jpg"
  / 3 = "Faces/3.jpg"
  / 4 = "Faces/4.jpg"
</item>

*************
Locate Scenes
*************
<include>
/ precondition = [mod(script.subjectid,6) == 1]
/ file = "scene_files_test/all1.txt"
</include>

****************
Picture Elements
****************
<picture face_pictured_2>
/ items = Face
/ position = (27%, 50%)
/ size = (50%, 50%)
</picture>
# one face and one scene next to each other (second part)

<picture scene1_display>
  / items = everything
  / position = (70%, 50%)
  / size = (50%, 50%)
</picture>
#for the scenes in the second part


***************
Creating Trials
***************
<trial Face_and_Scene>
  / stimulustimes = [
   0 = face_pictured_2;
   0 = scene1_display;
  ]
  / timeout = 5000
  / validresponse = ("1", "2", "3")
  / inputdevice = keyboard
</trial>
# one face and one scene next to each other (second part)

***************
Creating Blocks
***************
<block Study>
/ trials = [1-4 = Face_and_Scene]
</block>

Any help is greatly appreciated!!
By Dave - 11/14/2024

lir1995 - 11/14/2024
Hi, 

I have an experiment where I have faces and scenes paired together. The pairing of the two are random, and should be random initially. However, participants will then need to see the same face-scene pair again later in the experiment. For instance, trials 1-4 could be four trial unique pairs, but trials 5-8 should be the repeats of trials 1-4 in a random order. 

How do I save this random pair so that participants can learn these pairings?

Here is code I have so far.

************
Import Faces
************
<item Face>
  / 1 = "Faces/1.jpg"
  / 2 = "Faces/2.jpg"
  / 3 = "Faces/3.jpg"
  / 4 = "Faces/4.jpg"
</item>

*************
Locate Scenes
*************
<include>
/ precondition = [mod(script.subjectid,6) == 1]
/ file = "scene_files_test/all1.txt"
</include>

****************
Picture Elements
****************
<picture face_pictured_2>
/ items = Face
/ position = (27%, 50%)
/ size = (50%, 50%)
</picture>
# one face and one scene next to each other (second part)

<picture scene1_display>
  / items = everything
  / position = (70%, 50%)
  / size = (50%, 50%)
</picture>
#for the scenes in the second part


***************
Creating Trials
***************
<trial Face_and_Scene>
  / stimulustimes = [
   0 = face_pictured_2;
   0 = scene1_display;
  ]
  / timeout = 5000
  / validresponse = ("1", "2", "3")
  / inputdevice = keyboard
</trial>
# one face and one scene next to each other (second part)

***************
Creating Blocks
***************
<block Study>
/ trials = [1-4 = Face_and_Scene]
</block>

Any help is greatly appreciated!!

This question has been asked and answered numerous times. You can find previous examples via search.

See e.g. https://forums.millisecond.com/Topic16276.aspx