Hi, all,
I am very new to PsychToolbox (and more specifically to measuring reaction times) -- thanks in advance for your help! I have coded a program in MATLAB to administer a novel psychological task, and I would like to collect fairly accurate reaction time measurements -- I've installed PsychToolbox onto a laptop for this purpose and would like to integrate its timing features into my program. Since I'm so new to this, I thought I would ask your opinions/advice (the experts) on whether there are problems with how I am going about this.
The task presents participants with social dilemmas and then asks them to make judgments in response to the dilemmas:
1) Their preferred choice, with choices represented as two different buttons.
2) Emotion ratings, chosen by clicking somewhere along 7-point axes.
3) Implicit choice preference measured using a brief implicit association task (BIAT), which looks for correct key presses.
For the first reaction time measure, I am using "time0 = GetSecs;" following presentation of the stimulus item/storing gui data, and then "rxn_time = GetSecs - time0" is the first line of code in the callback functions for both buttons.
For the second measure, I store time0 the same way, and compute rxn_time in the first line of code in the WindowButtonDownFcn callback function.
For the third measure, I store time0 immediately after setting the text to which the participant responds to 'Visible', and I compute rxn_time in the first line of code in the KeyPressFcn callback function.
I would appreciate any criticisms of my approach and feedback on how to improve. Thanks so very much!
Best wishes,
Cliff
Cliff Workman
PhD Student in Psychology
University of Manchester
I am very new to PsychToolbox (and more specifically to measuring reaction times) -- thanks in advance for your help! I have coded a program in MATLAB to administer a novel psychological task, and I would like to collect fairly accurate reaction time measurements -- I've installed PsychToolbox onto a laptop for this purpose and would like to integrate its timing features into my program. Since I'm so new to this, I thought I would ask your opinions/advice (the experts) on whether there are problems with how I am going about this.
The task presents participants with social dilemmas and then asks them to make judgments in response to the dilemmas:
1) Their preferred choice, with choices represented as two different buttons.
2) Emotion ratings, chosen by clicking somewhere along 7-point axes.
3) Implicit choice preference measured using a brief implicit association task (BIAT), which looks for correct key presses.
For the first reaction time measure, I am using "time0 = GetSecs;" following presentation of the stimulus item/storing gui data, and then "rxn_time = GetSecs - time0" is the first line of code in the callback functions for both buttons.
For the second measure, I store time0 the same way, and compute rxn_time in the first line of code in the WindowButtonDownFcn callback function.
For the third measure, I store time0 immediately after setting the text to which the participant responds to 'Visible', and I compute rxn_time in the first line of code in the KeyPressFcn callback function.
I would appreciate any criticisms of my approach and feedback on how to improve. Thanks so very much!
Best wishes,
Cliff
Cliff Workman
PhD Student in Psychology
University of Manchester