I'm having difficulty with what I feel should be a pretty simple problem to solve. I would like for participants to be able to respond to a picture by selecting one of eight other pictures (all displayed simultaneously). Basically, it's a multiple choice question with pictures as both question and answers. Each trial will display the stimulus picture and the response picture options. There will be 36 stimulus pictures to respond to, each with 8 response pictures unique to that stimulus. I can accomplish this easily with the trials feature.
However, I also need to allow participants to navigate forward and backward through these pages and to change previous answers if they so desire (thus they need to be able to see what they have previously selected). There is one correct answer (picture) for each displayed stimulus picture. Responses for each item are not required and the participant should be able to skip ahead without answering if they choose to do so. The surveypage elements combined with radiobuttons seem to work well for this. However, since the response pictures aren't numbered and I can't seem to set the buttons to correspond to the pictures instead of text, I am having problems.
Also, the whole experiment needs to have a time limit where the current responses for each trial at the end of the time limit are recorded whether or not they have had a chance to get through all the questions.
Any help is greatly appreciated. Thank you.