Millisecond Forums

Flicker Paradigm

https://forums.millisecond.com/Topic22847.aspx

By lovecanines - 11/10/2017

Hi all, 
The script provides three change types.
Is there a way to provide a test with only one change type?
For example: let's say I only want to test pictures with item present or absent but not changes in colors or locations. 

Thanks.
Gal
By Dave - 11/13/2017

lovecanines - Friday, November 10, 2017
Hi all, 
The script provides three change types.
Is there a way to provide a test with only one change type?
For example: let's say I only want to test pictures with item present or absent but not changes in colors or locations. 

Thanks.
Gal

> Is there a way to provide a test with only one change type?

Yes. The change types are sampled from <list> elements:

Note: selects randomly without replacement a trial sequence presenting stimuli with location (1), presence/absence (2) or color changes
=> each change type trial sequence is selected equally often
<list changetype_Mixed>
/items = (1, 2, 3)
/poolsize = parameters.max_numberoftrials
/replace = false
/resetinterval = 1
</list>

***********************************
Test Lists: BLOCKED design
***********************************

Note: selects randomly without replacement a trial sequence presenting stimuli with location (1), presence/absence (2) or color changes
=> each change type trial sequence is selected equally often
<list changetype_Blocked>
/items = (1, 2, 3)
/poolsize = parameters.max_numberoftrials/2
/replace = false
/resetinterval = 1
</list>

You can eliminate the change types you don't want from the <list>s' /items.