Directional scanning effect and strength of reading habit in picture naming and recall.

The present research examined directional scanning effects (DSE) as a function of reading habit strength among right handers. A picture array naming and recall task was administered to three groups of child readers--unidirectional right-to-left readers of Arabic, unidirectional left-to-right readers of Kannada, and bidirectional readers of Urdu and English--and one group of Urdu illiterate adults. The results showed a right-to-left DSE in the Arabic and Urdu readers. In the latter group the strength of the scanning effect decreased with greater schooling in English. No R-L effect was observed in the Kannada readers or in the Urdu illiterates. These results extend prior research in documenting an "invasion" of culturally acquired reading scan habits onto a nonlinguistic domain. It is suggested that directional scanning effects be controlled or else directly examined in future laterality research involving nonlinguistic stimuli.