Van Horn And McManus Circle Marking Task

Marion Tapley and Phil Bryden published, in 1985, an easy and practical test of performance differences between the right and the left hand (Tapley & Bryden, 1985). It was characterised by its simplicity, consisting merely of a series of printed circles on a piece of paper, with the participant being required merely, with each hand in turn and in twenty seconds, to use a pencil to put a dot in as many of the circles as possible.  Particularly important was that the distribution was almost entirely bimodal, with no overlap between those who were better with their right hand and those who were better with their left hand.

As a part of his PhD thesis (Van Horn, 1992), which I supervised, Jack Van Horn and I developed an extension of the Tapley and Bryden task which involved four different levels of difficulty, the circles being graded in size. In addition we used a felt-tip pen that left a clear mark on the paper (to detect when the mark was outside the limits of the circle). The pen had a diameter of 2 mms, which allowed the calculation of an index of difficulty, based on the approach of Hicks.

The document shows pages from Jack Van Horn's thesis, and in particular shows the title page, the four test sheets used, with their different diameter circles (10 mms, 5.5 mms, 3.3 mms and 2.5 mms). The centres of the circles are 15 mms apart.  Results are shown separately for right- and left-handers and it can be seen that the number of circles marked decreases linearly with task difficulty, at an equal rate in dominant and non-dominant hands. Intriguingly the absolute difference remains constant, and as a result the laterality index increases steeply as the task becomes more difficult.



Reference List

Tapley, S. M. & Bryden, M. P. (1985). A group test for the assessment of performance between the hands. Neuropsychologia, 23, 215-221.
Van Horn, J. D. (1992). Brain structural abnormality and laterality in schizophrenia. University College London: Unpublished PhD thesis.