ABSTRACT
The writing of normal script, mirror script and inverted scripts with either hand is recorded in lefthanders and righthanders. Ten lefthanders writing with their right hand and 10 lefthanders writing with their left hand are compared to 10 righthanders writing with their right hand. Mirror script implies right-left reversal, and inverted script up-down reversal of writing.
When writing with their inexperienced hand, most subjects show a preference for mirror script. This facilitation of mirror script with the opposite hand is called “mirror script transfer,” acquired by the writing of normal script with the experienced hand.
All lefthanders and many righthanders write mirror script faster with their left hand than with their right hand. The strongest mirror transfer occurs for the left hand of lefthanders who normally write with their right hand. This may be related to their predominant control of language by the right cerebral hemisphere. Since mirror writing with the opposite, inexperienced hand may be transferred via the corpus callosum, the mirror transfer from the left to the right cerebral hemisphere may contribute to the recognition of script. Lefthanders trained to write with their left hand have the weakest mirror transfer for their right hand, probably because language and writing are both coordinated by their right hemisphere.
Learning improves minor and inverted scripts and often shortens the writing time for untrained scripts by one half within the first week of daily training. The slower the inexperienced script originally was, the greater the practice effect. A superior learning of mirror script versus inverted script by mirror-script transfer is not apparent from our results. The rapid learning of inverted script with practice is compared to Kohler's studies of learned responses to inverted vision.
