Can perceiving letters of the alphabet cause spatial shifts of attention?

There is an association between number or letter perception and response preference with faster left-hand responses for small numbers and faster right-hand responses for large numbers. Involuntary shifts of attention to the left or right visual field were shown to occur when stimuli with a strong meaning appear in the visual field. We investigated whether perceiving letters of the alphabet can induce such a shift of attention. The results suggest that the spatial component of letters might not be as strong as that of the numbers, and it probably takes longer for letter perception to induce shifts of attention.