Hi,
I am doing an experiment that consists of participants being presented with 4 images, and then an advert appearing for a few m/s and then disappearing. The location and colour of this advert (which is coded as an image) is random.
I have 2 questions about this.
1. How can I code the data to show which location and colour was shown to the participant, so I know what they saw, when looking at the collected data?
2. At the moment, I have coded the positions of the advert by having 4 <picture> elements and their position being defined as shown below:
<picture adverttopleft>
/items = newsign
/select = 1
/ position = (30,45)
/ size = (20%,20%)
</picture>
Is this the best way of doing this, or is there a way to code the image to be positioned randomly in 1 of 4 locations? .
I have coded the trials for one colour of advert (see example of trial code below, this is 1 of 10), but I want to add 3 more variations of the colour of the advert. Would it be best to have a trial per colour and then a block that includes the 4 trials (that have each of the four colours of advert)? OR is there a way of randomising the colour and position of the advert within one trial?
<trial trial1>
/ontrialbegin = [values.condition = "C1 Raincoat"]
/ontrialbegin = [values.currentsoa = list.SOAS_all.nextvalue]
/ontrialbegin = [values.soa_remaining = values.currentsoa]
/stimulustimes = [1000 = background;
1000 = fixation;
2000 = eraser;
2001 = picture.c1_TL, picture.c1_TR, picture.c1_BL, picture.c1_BR;
2500 = noreplace (picture.advertbottomleft,picture.advertbottomright, picture.adverttopleft,
picture.adverttopright);
2650 = picture.c1_TL, picture.c1_TR, picture.c1_BL, picture.c1_BR;]
/beginresponsetime = (2500+ values.soa_remaining)
/inputdevice=mouse
/validresponse=(picture.c1_TL, picture.c1_TR, picture.c1_BL, picture.c1_BR)
/correctresponse = (picture.advertbottomleft,picture.advertbottomright, picture.adverttopleft,
picture.adverttopright)
/ontrialend = [if (trial.trial1.correct)
{values.countcorrect +=1;
values.sumrt += trial.trial1.latency}]
/ontrialend = [values.x=trial.trial1.responsex;values.y=trial.trial1.responsey]
/recorddata = true
I hope these questions are clear and that someone can help me!
Many thanks in advance.