Michael R Peters

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The available versions of the Vandenberg and Kuse (1978) Mental Rotations Test (MRT) have physically deteriorated because only copies of copies are available. We report results from a redrawn version of the MRT and for alternate versions of the test. Males perform better than females, and students drawn from the physical sciences perform better than(More)
The strongest sex differences on any cognitive task, favoring men, are found for tasks that require the mental rotation of three-dimensional objects. A number of studies have explored functional brain activation during mental rotation tasks, and sex differences have been noted in some. However, in these studies there was a substantial confounding factor(More)
Hemodynamic responses were measured applying functional magnetic resonance imaging in two professional piano players and two carefully matched non-musician control subjects during the performance of self-paced bimanual and unimanual tapping tasks. The bimanual tasks were chosen because they resemble typical movements pianists have to generate during piano(More)
In an Internet study unrelated to handedness, 134,317 female and 120,783 male participants answered a graded question as to which hand they preferred for writing. This allowed determination of hand preference patterns across 7 ethnic groups. Sex differences in left-handedness were found in 4 ethnic groups, favoring males, while no significant sex(More)
We used self-reported direct finger measurements from 255,116 participants in a BBC Internet survey to investigate the measurement of 2D:4D ratios and their association with sex, ethnicity, and sexual orientation. We found significant sex differences such that males had lower 2D:4D than females and the effect size of the sex differences was greatest for(More)
When brain size is compared across taxonomic levels, there is a clear relation between body parameters and brain size. It is generally stated that the correlation between brain size and body parameters becomes very small at the species level (Aboitiz, 1996), but this is not the case for Homo sapiens where there is a strong correlation between brain size and(More)
Functional magnetic resonance tomography (fMRI) analysis of unimanual and bimanual sequential movements in righthanders showed the following effects. First, a rate-dependent activation of the somato-motor cortex was confirmed, with faster movement rates producing higher activation both in terms of signal intensity and number of activated voxels. Second, the(More)
In accounting for the well-established sex differences on mental rotation tasks that involve cube stimuli of the Shepard and Metzler (Shepard & Metzler, 1971) kind, performance factors are frequently invoked. Three studies are presented that examine performance factors. In Study 1, analyses of the performance of a large number of subjects (n=1765) that(More)
Empirical evidence is provided which shows that handedness questionnaires should: (a) comprise items that cover skilled and unskilled activities; (b) be sufficiently long to capture a ''mass effect'' of variability in lateral preferences over a range of items; and (c) allow graded answer options for individual items rather than forced left/right choices.(More)
In spite of the reduced level of experimental control, this large scale study brought some clarity into the relation between mental rotation task (MRT) performance and a number of variables where contradictory associations had previously been reported in the literature. Clear sex differences in MRT were observed for a sample of 134,317 men and 120,783(More)