Introduction
An aspect of cognitive performance that yields strong between person differences is the ability to manipulate spatial information. One of the most popular tasks to use in measuring individual differences in spatial ability is a mental rotation task introduced by Shepard and Metzler (1971).
Task
In the mental rotation task used here, research participants make judgments about 3-D objects patterned after ones first used by Shepard and Metzler. The objects are either identical (illustrated below by the pair on the left) or mirror image reversals of each other (illustrated below by the pair on the right). In each pair, the object on the left is presented in an upright position and the object on the right is rotated. The research participant's job is to determine as rapidly as possible whether the figures are the same (i.e., a copy that differs only in rotation angle) or different (i.e., mirror image objects). Responses are timed in addition to being judged for correctness. « Return to Top»
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The minimal experiment consists of just 16 trials but participants may choose to conduct 2, 3 , or 4 replications of these 16 trials. On each trial, a different one of the 16 possible object pairs is presented in random order. Eight are identical object pairs and eight are mirror image pairs. The eight in each set are distinguished by their angular discrepancy, which measured clockwise goes from 0o to 315o in 45o steps. While there are 16 possible object pairs, each object pair can occur in one of two versions, as shown by the pairs below both of which are matching pairs with an angular discrepancy of 180o. The version that is used on any one trial is chosen at random. « Return to Top»
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There are two within subject variables to be investigated. One is rotation angle and the other is pair type. A graph like the one below provides a convenient display of the effects of these variables, which can be analyzed for significance using a 2 X 6 repeated measures analysis of variance
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In addition to the within subject effects that were of interest to Shepard and Metzler in their original research, there are between subject variables of interest. One is gender and the other is age. Males typically are faster than females in performing mental rotation and young adults are faster than both children and elderly adults. « Return to Top» |
References
Burnett, S.A. (1986). Sex-related differences in spatial ability: Are they trivial? American Psychologist, 41, 1012-1014.
Cooper, L. A. (1975). Mental rotation of random two-dimensional shapes. Cognitive Psychology, 7, 20-43.
Cooper, L. A. & Shepard, R. N. (1973). Chronometric studies of the rotation of mental images. In W.G. Chase (Ed.), Visual information processing (pp. 75-176). New York: Academic Press.
Linn, M.C. & Petersen, A.C. (1985). Emergence and characterization of sex differences in spatial ability: A meta-analysis. Child Development, 56, 1479-1498.
Shepard, R.N. & Metzler, J. (1971). Mental rotation of three-dimensional objects. Science, 171, 701-703.
Metzler, J. & Shepard, 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 (pp.147-202). Potomac, MD: Lawrence Erlbaum.
Richardson, J. T. E. (1991). Gender differences in
imagery, cognition, and memory. In R.H. Logie & M. Denis (Eds.), Mental images in
human cognition (pp.271-303). Amsterdam: North-Holland.
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Last revised:November 01, 2003 07:01:31 PM
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