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The Stroop task is a classic task. In the basic task, you name the color of the stimulus that is presented. In some conditions, the stimulus could be neutral, like a string of x's in this version or the word that is the same color. In these cases, naming the colors are not very difficult. However, in the critical condition, the words are different color words than the color being presented. The effort to not respond to the word makes you slower to respond to the color, and more likely to make an error.

The most common way to explain this outcome is that reading is a more automatic response than naming colors. Automatic processes do not require attention and happen faster than nonautomatic responses. Thus, the response to the word is available faster and interferes with the response to the color.

Setup Instructions

You can adjust several parameters to design your own version of the experments. The settings are discussed below.

Settings for the Stimuli

The stimulus settings include the following:

New Study: when the study has been finished, you can press this button to start a new experiment.
Reset Stimulus: press this button to reset to the default conditions.
Font Size: the size of the letters for the words.
Word Intensity: Adjust the relative intensity of the colors used for the words. The value of 255 is full on and 0 will be black.
Background Gray Level: the brightness the background behind the word from back to white.
Word Position Horizontal (relative): The left/right position of the word relative to the screen width. The lower the value, the more towards the left.
Word Position Random: The position of the word randomly varies from trial to trial. The extent of the variation is determined by the Word Position variable above.
Fixation Duration (ms): The duration of the fixation mark.
Show Fixation Every Trial: If checked, the fixation mark appears before very word.
Trial Delay before Fixation (ms): The duration delay before the fixation mark and between the words.
Stimulus On Till Response: Select to have the stimulus on till the participant responds.
Duration of Stimulus (ms): If the above item is unselected, use this setting to adjust how long the stimulus stays on.
Show Masker: If the word does not stay on till a response is made, choose this item to add a masking stimulus after the word has been removed.
Gap Size: How big is the gap between the end of the masker and the word relative to the height of the screen drawing area.
Masker Duration (ms): The duration of the masking stimulus in milliseconds.

Experimental Method Settings

New Study: when the study has been finished, you can press this button to start a new experiment.
Reset Method: press this button to reset to the default conditions.
Word/Color Relationship: Select those conditions you want to run. Congruent: word and color the same, Incongruent: word and color or different, XXXX Colored: a string of X's, and two scrambld conditions where th middle of the color word is scrambled randomly, these words can be congruent or incongruent with the color (NEW).
Words: The color words, and thus the colors, that will be used.
Number of Trials/condition: How many trials in each condition.


Settings for the Stimuli

Change the settings below to alter the stimulus parameters in this experiment.

Experimental Method Settings

Change the settings below to alter the parameters of the experimental method.

Instructions for Experiment

Below, press the spacebar or the Open Experiment Window button on the screen to open the window where the experiment will run. When this screen opens, press the spacebar or click the "Start" button to begin the experiment. There are instructions above the "Start" button. Read them to know how to perform the experiment. Keep your eyes fixated on the red plus sign in the middle of the screen.

Results Tab

Your data will be presented on the results tab. The x-axis will have the word/color relationship. You can look at both reaction time and accuracy. To download your trial-by-trial, press the Show Data link. To download the summary data press the Show Summary link. This data will be stored in a csv format readable by most spreadsheet and statistical programs.

Your Results