Go No-go respond moving the mouse

tommasocurro

Hi!

I creating a Go No-go task in which the participants see (Go stimuli) an arrow pointing left or right or (No-go stimuli) a blue arrow and have to respond by moving the mouse to the left or the right for a precise length from a starting point until it reaches a threshold (another physical point on the table where the mouse is): if they don't move the mouse far enough to reach the threshold it is not considered a correct_response but an "attempts".

I'm now using the mousetrap plugin.

The questions are:
1. How is it possible to consider as correct_response only the movement of the mouse that reaches the threshold?
2. Is it possible to measure the movements that do not reach the threshold? These are important for the purpose of the experiment because they are considered as "attempts". If a better way to measure them has already been found please tell!
3. If the participant does not move the mouse at all, it is a correct_response for the No-go stimulus, but an error if the Go stimulus is present.

Thank you for your help,

Tommaso

Pascal

Hi Tommaso,

maybe first a general comment: if participants should move the mouse for a prespecified physical distance on the table, I don't know of a way that would exactly implement this procedure in OpenSesame.

The easiest implementation I could think of that would come somewhat close is the following: define a screen with a start button participants need to click on. Afterwards, reset the mouse cursor to the center of the mouse button. Then, define two buttons that cover the complete area either x pixel to the left or x pixel to the right of the start button. This x pixel distance should be set so that if you move the mouse across the desired physical distance on the table, these amounts of pixel are traveled by the cursor on the screen (for this, I would probably reduce the cursor speed and disable acceleration in the system settings - this has to be done outside of OpenSesame). I have implemented a sketch of such an experiment and attached it to my post.

In order to only consider movements above the threshold, you will probably want to specify a timeout until participants must cover the distance (timeout is 2000ms in the example experiment). If participants do not reach one of the button areas in time their response is recorded as None. I included a script that would set a new variable current_response that contains the response ("left"/"right") or is set to "timeout" if no area is reached (this is easier to work with than None in Python, as None is handled differently than a simple character).

Hope this is a good starting point for your experiment.

Best,

Pascal

Viola

Hi Pascal,

I'm working on a similar project.
I want to check whether the participant did not move at all the mouse after the presentation of a stimulus, or he tried to move the mouse to responde and stopped the movement before reaching the 'response button area'. We wanted to save these in a variable called 'current_response' which will have 3 level:"No_response" if he doesn't move the mouse at all, "attempt" and "left" or "right" depending on the direction of the movement.

Here I attach 2 kind of solutions that I tried but none of them works.

Can you please check them?
Is there another smarter way to do that?

Thank you very much,
Best!

Viola

Pascal

Hi Viola,

if you want to define "attempt" as any movement (even a single pixel) that did not reach one of the buttons within the time limit you can use the initiation_time variable (which will be None if there was no movement in the trial). You can modify your inline script from version_1 in the following way (I also fixed the incorrect variable names):

if var.response_new_mousetrap_response == None:
    if var.initiation_time_new_mousetrap_response == None: 
        var.current_response = "No_Response"
    else:
        var.current_response = "attempt"
else:
    var.current_response = var.response_new_mousetrap_response

Hope this helps!

Best,

Pascal

Viola

Thank you for the reply.
It works correctly this way, but I need to have a small range of pixels that are considered as "No_Response" around the 0 coordinate on the X axis, where the mouse is set at the beginning of each trial. This is for a modified go/no-go task, so very small and unintentional mouse movements should not be considered.
Can you help me?

Thanks a lot
Viola

Pascal

Hi Viola,
how would you like to define this range? e.g., a rectangular area around the start position?
Best,
Pascal

Viola

Yes exactly,
a rectangle or square which at its center is in a coordinate of 0,0 (start position) and extends for a few pixels around it. I still do not know how many pixels in particular, let's say 30 pixels for example.

Pascal

This script would classify everything as no response that is within a rectangle of +/- 30 pixel around the screen center (0,0):

xpos = var.xpos_new_mousetrap_response
ypos = var.ypos_new_mousetrap_response

if var.response_new_mousetrap_response == None:
    if all(abs(x)<30 for x in xpos) and all(abs(y)<30 for y in ypos): 
        var.current_response = "No_Response"
    else:
        var.current_response = "attempt"
else:
    var.current_response = var.response_new_mousetrap_response