I have a simple experiment which should run like this:
- prime (picture of a face presented for specified time, no response required)
- mask (a Chinese ideograph to be rated by the participant. Moves back to cue once response made).
- Inter trial interval (ITI)
I have 40 face primes (each of which MUST be presented per participant) thus 40 trials in effect.
I need each participant to ‘see’ every face prime BUT the order in which they are presented should be randomised per participant.
I’ve tried creating 1 trial which uses two stim lists with items selected from the corresponding folders; one for faces and one for the ideographs. However, some items from the faces folder are being repeated (it doesn’t matter if this is the case with the ideographs) meaning that not all 40 faces are being shown per participant, despite checking the ‘randomise per participant’ box in the block editor.
I have since created 40 trials linked uniquely to each face prime set up as a unique event (thus 40 trials,each linked to 1 face event (selecting 'same file every time) plus cue, Chinese ideograph and ITI. Still getting repeats of the face events.
I have tried adding code values to each face event (presented, ‘yes’ or ‘no’, set to no.). In the feedback tab I have specified that code values should be changed to ‘yes’ always after the event and the remaining events in the trial should be presented. I have then requested that trials should be limited to those marked as ‘no’ in the block editor as well as that the number of events should be 40.
I hope this makes sense - basically I need participants to see all 40 face primes once, with no repeats. How can I achieve this? I have spent too many hours on this!