Spatial attention in encoding letter combinations
Reading requires the correct identification of letters and letter positions within words. Selectiveattention is, therefore, required to select chunks of the text for sequential processing. Despite theextensive literature on visual attention, the well known effects of spatial cues in simpleperceptual tasks cannot inform us about the role of attention in a task as complex as reading.Here, we systematically manipulate spatial attention in a multi-letter processing task tounderstand the effects of spatial cues on letter encoding in typical adults. Overall, endogenous(voluntary) cue benefits were larger than exogenous (involuntary). We show that cue benefitsare greater in the left than in the right visual field; and larger for the most crowded letterpositions. Endogenous valid cues reduced errors due to confusing letter positions more thanmisidentifications, specifically for the most crowded letter positions. Therefore, shiftingendogenous attention along a line of text is likely an important mechanism to alleviate theeffects of crowding on letters within words. Our results help set the premise for buildingtheories for how specific mechanisms of attention support reading development in children.Understanding the link between reading development and attention mechanisms has farreaching implications in the remediation for children with reading disabilities.