Comprehension and processing of the universal quantifier in children, adolescents and adults.

Quantifier spreading (Q-spreading), children's incorrect falsification of a universally-quantified sentence based on an 'extra-object' picture, may persist beyond childhood, and children adhere to Q-spreading without changing responses throughout testing. We examined the error patterns across wider age groups (aged 4-79) with a picture-sentence verification eye-tracking task. We also examined whether prosodic emphasis affects their comprehension and processing of universally-quantified sentences. Whereas adults' comprehension was ceiling, children/adolescents (aged 4-17) showed various comprehension patterns, splitting into: 'Adult-like responders' (consistently adult-like), 'Q-spreaders' (consistently showing Q-spreading), and 'Switchers' (shifted from Q-spreading to adult-like). While adults rarely looked at the extra-object, 'Q-spreaders' showed frequent looks throughout testing, and both 'Switchers' and 'Adult-like responders' exhibited reduced looks to the extra-object, suggesting that avoidance and correction of Q-spreading requires inhibition of the visual attention to the extra-object. The effect of prosodic emphasis on eye movement emerged later for children/adolescents than adults.