Zig Zag Tracking
This task is designed to measure both speed and accuracy of psychomotor performance, allowing assessments of the speed-accuracy trade-off and discrimination between the actions of different drugs on performance. For example, ethanol tends to reduce psychomotor accuracy with little effect on speed, while other impairing drugs, such as benzodiazepines, slow down performance with little effect on accuracy (Tiplady et al., 2003)
The volunteer follows the gray track with a pen as quickly as possible while avoiding the obstacles. The layout of the task is designed to allow easy generation of multiple equivalent versions where repeated use in within-subjects designs is required. This ensures that improvement of performance on the task with practice is minimised, as it not possible to memorise the pattern of obstructions.
The test is intended for use with the Anoto® digital pen, which will allow automatic scoring, and detailed analysis of performance. However even as a manual test with stopwatch scoring, the Zig Zag task is very useful, particularly as multiple equivalent versions are available. The zig zag test has been shown to be sensitive to the effects of alcohol (Tiplady et al., 2004). A starter pack is available including 20 test versions which may be freely copied and used with manual scoring. Click on the link to the left to download this version.