The P-chain: relating sentence production and its disorders to comprehension and acquisition

Abstract

This article introduces the P-chain, an emerging framework for theory in psycholinguistics that unifies research on comprehension, production and acquisition. The framework proposes that language processing involves incremental prediction, which is carried out by the production system. Prediction necessarily leads to prediction error, which drives learning, including both adaptive adjustment to the mature language processing system as well as language acquisition. To illustrate the P-chain, we review the Dual-path model of sentence production, a connectionist model that explains structural priming in production and a number of facts about language acquisition. The potential of this and related models for explaining acquired and developmental disorders of sentence production is discussed.

Keywords: aphasia; connectionist models; prediction; psycholinguistics; sentence production; specific language impairment.

Figure 1.

The P-chain framework for psycholinguistics.

Figure 2.

A simple recurrent network model of sequence prediction (based on Cleeremans & McClelland [32]). (a) The network is predicting A or B as the next output, but instead, C is the actual output. This results in prediction error, which drives learning and leads, for example, to an increase in connection weights from units representing the current context to the output for C (b).

Figure 3.

The Dual-path model. Units are represented by small boxes, and connections by lines. All connection weights are learnable, except for the connections between roles (or croles) and concepts (or cconcepts), whose weights are temporary and are set to represent the message. The prefix ‘c’ indicates unit layers that function in comprehension, rather than in production. For further information, see Chang et al. [3].