DirectRT - Experiment Question
I have designed an experiment with my psychology group in studies of visual perception.
The experiment involves using different coloured shapes and reaction times. The design requires that on each trial, two of the stimulus are either the same colour, or a different colour, and are either in certain relationship with anOther image (overlayed, or adjacent to the image). I have designed the experiment with basic variables -
I have files that are named according to their properties, so '123.bmp' means the image with shape 1 (of 4), size 2(of 2) colour 3(of 3).
Certain images appear a set distance (radius) from the centre of the screen. This is an easy algorithm, simply taking the centre coordinate and placing the image either 1 'radius' up, left, down, or right, or 1/root2 radius in a diagonal (45 degree) angle.
however, the position, colour and shape of this object depends on two things: the conditions of the experiment ([B]S[/B]ame colour/shape VS [B]D[/B]ifferent colour/shape ||| and [B]A[/B]djacent VS [B]O[/B]verlayed)
I would normally code this by defining each condition
so that in condition SA, I would have a blue triangle appear in the middle of the screen (random.. could be a yellow circle.. or a blue circle..)
and a second image appear on one of the positions that is distanced from the centre (it is a number/letter that the reaction time task is based on), which is a random placing.
The [B]S[/B] part of the condition means that the third image is also a blue triangle ([B]D[/B] condition would mean that the third image is some other colour/shape)
The [B]A[/B] part of the condition means that the third image appears on a position that is adjacent to the second image ([B]O[/B] condition would mean that it appears at the same position to the second image)
I need to go now but I will be back later.
Essentially I am trying to use randomise conditions, but define certain variables by the random value picked.
A simple result is very complicated - I would type in all possible combinations of colours/shape, and position, for all conditions. This seems like a ridiculously long task, since at minimum we are using 2 or3 colours, 3 or 4 shapes, and there are 8 potential positions on the screen that the images may appear, which means there are 24 different spatial relationships used between the images.
If I can somehow use some normal IF-Then coding, and defining stable variables (eg, define xxx at the start of the trial, and then define yyy in terms of xxx) then I can avoid a lot of hassle?
But yes I will be back later as I am really desperate about finding an answerr.. I am already running late and due to technical difficulties, my Direct Rt experience has been awry
