Mental rotation
Measure whether the time needed to compare two shapes grows with the angle between them, as if one of them were being turned in the mind.
Method
Procedure
- Two shapes made of squares appear side by side.
- The right-hand shape is the left-hand one turned by 0°, 45°, 90°, 135° or 180°; on half of the trials it is also a mirror image.
- Decide whether it is the same shape, turned, or its mirror image.
- There are 30 trials; each display stays for up to 8 seconds.
Responses
- F
- same shape
- J
- mirror image
- Touch
- the Same and Mirror image buttons
Measures
The reaction time on correct trials at each angle, and the slope of reaction time against angle. If people turn a mental image at a steady rate, reaction time should rise in a straight line with the angle, and the slope gives the rate of rotation.
Practice
Six practice trials, at 0°, 90°, 135° and 180°, tell you after each trial whether the shape was the same or a mirror image.
Terms
- Mental rotation: Turning an image of an object in the mind, for example to compare it with another.
- Mirror image: A reversed version of a shape; no rotation within the screen can make it match the original.
- Slope: How much reaction time increases for each additional degree, or each 45°, of rotation.
- Rate of rotation: Degrees turned per second, calculated as 1000 divided by the milliseconds per degree.
- Parietal lobe: The part of the cerebral cortex at the top and back of the head, active during mental rotation.
Experiment
Responses stay in this browser tab. Nothing is stored or sent, and everything is lost when the page is closed or reloaded.
Results
Interpretation
The page reports how much your reaction time rose per 45° and, if the rise was clear, the rate of rotation it implies. A steady rise suggests that you turned the shapes in your mind; a flat line suggests another strategy, such as looking for a distinctive part of the shape.
Comparison with published studies
In the experiment of Shepard and Metzler (1971), with drawings of three-dimensional objects, the time to respond rose linearly with the angle, at a rate of about 60° per second. Your shapes are flat and turn within the plane of the screen, so the two rates are not directly comparable.
Limitations
There are only six trials at each angle. Same and mirror-image trials are combined; many studies analyse same-shape trials only, because the angle on mirror trials is less well defined.
The result comes from one person in one session, on a device whose timing and display are not calibrated. It describes this run, not a stable characteristic of the participant, and a second run could differ by chance alone. Research studies test many participants under controlled conditions and report the average with its variability. The experiment is educational; it is not a test of ability or health.
One row per trial: angle, whether the right-hand shape was a mirror image, your response, reaction time, whether it was correct and whether it was used in the medians (correct and slower than 200 ms). In the file, 1 means yes and 0 means no. The file is created on this device and can be opened in a spreadsheet.
Background
Original findings
Shepard and Metzler (1971) found that the time needed to decide whether two drawings show the same three-dimensional object increases linearly with the angle between them, as if one of the objects were being turned in the mind at a steady rate. This version uses flat shapes turned within the plane of the screen.
Neural basis
A meta-analysis of brain-imaging studies found that mental rotation is accompanied by increased activity in and around the intraparietal sulcus in the parietal lobe and, under some conditions, in motor areas of the frontal lobe (Zacks, 2008).
References
- Shepard, R. N., & Metzler, J. (1971). Mental rotation of three-dimensional objects. Science, 171(3972), 701–703. https://doi.org/10.1126/science.171.3972.701
- Zacks, J. M. (2008). Neuroimaging studies of mental rotation: a meta-analysis and review. Journal of Cognitive Neuroscience, 20(1), 1–19. https://doi.org/10.1162/jocn.2008.20013
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