Cognition Laboratory Experiments

John H. Krantz, Hanover College,






Mental Imagery


Decision Making


Statistical Concepts

Hanover College
Psychology Department

Instructions for the
Lexical Deicsion Experiment


When you click on the link below, you will be presented with the experiment setup screen.  On this screen will be the variables you can set to define your condition.  Here is a list of the variables and their settings.  Not all variables will be visible all the time.  Only those variables appropriate to the stimulus and other settings will be shown.  So changing some values may alter what is shown on the setup screen.

Variable Settings
Number of Times to Repeat Each Stimulus Set How many times each item in a stimulus set will be repeated. Trial will be times repeated*number of items in stimulus set.
Target Type

The type of priming stimulus used:

  • Categories: how conceptually related is the priming stimulus to the word to be responded to.
  • Positive Words
  • Negative Words
Check boxes to the right of Target Type These are the conditions of priming stimulus to be responded to. Check those conditions you wish to use. Default will have all conditions checked.
Font Size The size of the font for the words from 11 to 64 point values.
Delay before Prime The duration of the blank interval prior to the priming stimulus from 0 to 5000 msec.
Duration of Priming Stimulus The time the priming stimulus is presented, from 20 to 5000 msec.
Interstimulus Interval The time between the prime and the actual stimulus, from 0 to 5000 msec.
Duration of Target Stumulus The time during with the target stimulus is visible, from 50 to 5000 msec.

After you have finished making your settings, press the Done button at the bottom of the screen.  The Lexical Decision experiment screen will then be presented. 

Press the space bar to begin the experiment.  A fixation mark will appear for the indicated time.  There there will a word or picture presented briefly. This is the prime and no response if required. After the interstimulus interval will be presented the target stimulus. Your task is to quickly and accurately indicate if the stimulus is a word or nonword. You may respond by pressing either the buttons at the botton of the screen or the F or W keys for words or the J or N keys for nonwords.

At the end of the experiment, your results will be presented.  The results are the reaction time and accuracy for each of the condtions of prime responding to both a word and a nonword. There should be little difference in reaciton time and accuracy for the nonword conditions but they are separated out by prime condition just in case.  You can also get your trial by trial results.  Closing your results window(s) will take you back to the setup window so you can run another experiment.

Click here to start the experiment.