Three experiments examined whether semantics is activated automatically by testing whether Arabic digits (e.g., 4), number words (e.g., four), and non-number words (e.g., rat) activate semantics in the absence of central attention within the Psychological Refractory Period (PRP) paradigm. In all three experiments, subjects performed colour discriminations as Task 1. In Task 2, subjects performed magnitude comparisons on digits (Experiment 1) and number words (Experiment 2) and size comparisons on animal words (Experiment 3). Task overlap was controlled by varying stimulus onset asynchrony (SOA). A distance effect arose in Task 2 and yielded underadditive effects with decreasing SOA for both digits and number words, consistent with these notations activating semantics in the absence of central attention, or automatically. A distance effect also arose for animal words, but it was additive with SOA, inconsistent with non-number words activating semantics automatically.
Author Keywords: Automaticity, Central attention, Dual-task, Numerical cognition, Semantics, Word recognition