Introduction

Mental rotation is imagining what a stimulus would look like if it would be rotated.

Mental rotation tasks are difficult. In these tasks, you might see three stimuli like in the example figure. The top one is the one that matches only one shown at the bottom. But the matching stimulus is rotated. The participant has to mentally rotate (i.e., imagine what something looks like when it is rotated) one or both stimuli (people can figure out their own strategy, there are multiple strategies possible).

Mental rotation time is defined as the time it takes someone to find out if a stimulus matches another stimulus through mental rotation. It is a well established fact that men and women perform differently on this task.

In this demonstration, we are going to rotate 2 dimensional (2D) stimuli. 2D stimuli are those without depth. Rotating stimuli with depth (3D) is more difficult than rotating 2D stimuli.

About this implementation

rotation

In the above screen shot, you see three two-dimensional stimuli. For this demo, we use 2D stimuli (in part because they are easier to create).

If you wish, you can get 3D datasets online.

The grey stimulus at the top is the one you need to match with one of the red ones. In order to match the grey stimulus, you need to imagine what it looks like when it is rotated. In this example, the right one matches, and thus needs to be clicked (as indicated by the little grey mouse cursor).

In the following demonstration, you will need to find out which two object match each other. You can only do that if you mentally rotate the objects and see which ones match. In this example, the stimuli are 2 dimensional, or 2D. In psychology, the most common mental rotation experiments have stimuli with depth, that is 3D.

  • Note, you can show your response times and copy and paste them to a local file for your own data analysis.

Run the demo

Click here to run a demo of the mental rotation task

Data output file

In PsyToolkit, the data output file is simply a textfile. The save line of the PsyToolkit experiment script determines what is being saved in the data output file. Typically, for each experimental trial, you would have exactly one line in your text file, and each number/word on that line gives you the information you need for your data analysis, such as the condition, response speed, and whether an error was made.

Meaning of the columns in the output datafile. You need this information for your data analysis.

Colum Meaning

1

blockname

2

table row number (that way you can look up exactly which stimulus was presented)

3

location of the correct image (0=left,1=right)

4

the response time (ms)

5

status (1=correct, 2=error, 3=too slow)

PsyToolkit code

Click to expand the PsyToolkit script code (part of zip file below) 
options
  window
  mouse on
  escape
  bitmapdir stimuli

bitmaps
  instructions
  instruction2
  correct
  incorrect
  training
  readyforreal
  thatwasit
  # now the actual stimuli
  target1  
  target2  
  target3  
  target4  
  target5  
  target6  
  target7  
  target8  
  target9  
  target10 
  target11 
  target12 
  target13 
  target14 
  target15 
  correct1  
  correct2  
  correct3  
  correct4  
  correct5  
  correct6  
  correct7  
  correct8  
  correct9  
  correct10 
  correct11 
  correct12 
  correct13 
  correct14 
  correct15 
  wrong1 
  wrong2 
  wrong3 
  wrong4 
  wrong5 
  wrong6 
  wrong7 
  wrong8 
  wrong9 
  wrong10
  wrong11
  wrong12
  wrong13
  wrong14
  wrong15

fonts
  arial 20

# the table contains the objects of each trial. But the exact
# positioning of the screen is determined randomly in the task itself

table rotationtable
  target1  correct1  wrong1
  target2  correct2  wrong2
  target3  correct3  wrong3
  target4  correct4  wrong4
  target5  correct5  wrong5
  target6  correct6  wrong6
  target7  correct7  wrong7
  target8  correct8  wrong8
  target9  correct9  wrong9
  target10 correct10 wrong10
  target11 correct11 wrong11
  target12 correct12 wrong12
  target13 correct13 wrong13
  target14 correct14 wrong14
  target15 correct15 wrong15

task rotate
  table rotationtable
  # the next line is part of randomizing where the correct object
  # will be
  set $x random 0 1  # will the correct one be left (0) or right (1)
  draw off
  show bitmap @1 0 -150
  if $x == 0 # if left, then show the correct one left
   show bitmap @2 -250 150
   show bitmap @3  250 150
  fi
  if $x == 1 # if left, then show the correct one right
   show bitmap @2  250  150
   show bitmap @3  -250 150
  fi
  show bitmap instruction2 300 -200
  draw on # show all bitmaps at the same time
  readmouse l 2 20000
  if STATUS == CORRECT
    show bitmap correct 0 200
  fi
  if STATUS != CORRECT
    show bitmap incorrect 0 200
  fi
  delay 2000
  clear 1 2 3 4 5
  save BLOCKNAME TABLEROW $x RT STATUS

message instructions
message training

block training
  tasklist
    rotate 5 fixed
  end

message readyforreal

block test
  tasklist
    rotate 10 fixed
  end
  feedback
    text align left
    set &PercCorrect perc    ; select c5 == 1
    set &RTCorrect mean c4   ; select c5 == 1
    text -200 -100 &PercCorrect ; prefix "Percentage correct (in second block): "
    text -200    0 &RTCorrect   ; prefix "Average time per puzzle: "
    text -200  100 "Press space to continue."
  end

Download

If you have a PsyToolkit account, you can upload the zipfile directly to your PsyToolkit account. Watch a video on how to do that. If you want to upload the zipfile into your PsyToolkit account, make sure the file is not automatically uncompressed (some browsers, especially Mac Safari, by default uncompress zip files). Read here how to easily deal with this.

Further reading

Shephard, R.N. and Metzler, J. (1971). Mental Rotation of Three-Dimensional Objects. Science, 171, 701-703.

Collins, D.W. and Kimura, D. (1997). A Large Sex Difference on a Two-Dimensional Mental Rotation Task. Behavioral Neuroscience, 111, 845-849.