Modeling the Selective Effects of Slowed-Down Speech in Pronoun Comprehension

In this paper we discuss a computational cognitive model of children’s well-known difficulties with pronoun comprehension (the so-called Delay of Principle B Effect, or DPBE). In this DPBE/ACTR model, Hendriks and Spenader’s Optimality Theoretic account (2005/2006) is implemented in the cognitive architecture ACT-R (cf., Hendriks, Van Rijn, & Valkenier, 2007). Hendriks and Spenader’s OT account attributes the DPBE to children’s inability as hearers to also consider the speaker’s perspective. The cognitive model predicts that children are in principle able to consider the speakers’ perspective but lack the processing efficiency to complete this process within the amount of time available for comprehension. We investigated this prediction of the DPBE/ACT-R model in a psycholinguistic experiment, in which children’s pronoun comprehension at a normal speech rate was compared with their comprehension at a slower speech rate. By slowing down the speech rate, children are given more time for interpretation. Slowed-down speech was found to have a beneficial effect on children’s pronoun comprehension, but only if the child displays a DPBE, thus supporting the hypothesis of the cognitive model.