• Background
  • Results


This experiment will allow you to conduct variations of the mental rotations of Cooper (1975) and Metzler and Shepherd (1974). These studies opened up methods for studying the way that we interact with images in our mind, a long neglected area of study.

In this version of the expeirment, you must decide if two stimuli are identical or one is a mirror image of the other one.

Setup Instrutions

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.
Stimulus Type: chose the type of stimulus that you wish to test.
Stimulus Size: the size of the stimuli. For letters and words, this refers to font size for the drawn stimuli it is the proportion of the drawing area allowed. Be careful of overlaps int he middle.
Background Gray Level: the brightness the background behind the word from back to white.
Stimulus Position Horizontal (relative): The distance the stimulus is from the central fixation mark. The larger the number, the farther the two stimuli are from the middle.
Stimulus Position Vertical (relative): The distance the stimuli are from the top of the screen. A value of 0.5 puts the stimuli at the same level as the fixation mark, in the middle of the screen.
Fixation Duration (ms): The duration of the fixation mark before the stimuli are presented.
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.

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.
Number of Rotation Angles (includes 0 and 180): How many different levels of the rotation angle between the two stimuli will be used. The steps are selected in equal intervals and includes angles of 0 (rotated exactly the same) and 180.
Number of Trials/condition: How many trials in each condition. The total number of trials will be this number times the number of angles times 2. The last two is that there are the same number of trials where the stimuli are mirror image and identical.


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 angle difference between the two images. You can look at both reaction time and accuracy. To see your trial-by-trial, press the Show Data button. To see the summary data in text form press the Show Summary button. This data can be copied and saved.


Cooper, L. A. (1975). Mental rotation of random two-dimensional shapes. Cognitive Psychology, 7, 20-43.
Metzler, J. & Shepherd, R. N. (1974). Transformational studies of the internal representation of three-dimensional objects. In R. L. Solso, ed., Theories of cognitive Psychology: The Loyola Symposium. Potomac, MD. Lawrence Earlbaum Associates.

Your Results