Towards a New Model of Verbal Monitoring

Abstract

As all human activities, verbal communication is fraught with errors. It is estimated that humans produce around 16,000 words per day, but the word that is selected for production is not always correct and neither is the articulation always flawless. However, to facilitate communication, it is important to limit the number of errors. This is accomplished via the verbal monitoring mechanism. A body of research over the last century has uncovered a number of properties of the mechanisms at work during verbal monitoring. Over a dozen routes for verbal monitoring have been postulated. However, to date a complete account of verbal monitoring does not exist. In the current paper we first outline the properties of verbal monitoring that have been empirically demonstrated. This is followed by a discussion of current verbal monitoring models: the perceptual loop theory, conflict monitoring, the hierarchical state feedback control model, and the forward model theory. Each of these models is evaluated given empirical findings and theoretical considerations. We then outline lacunae of current theories, which we address with a proposal for a new model of verbal monitoring for production and perception, based on conflict monitoring models. Additionally, this novel model suggests a mechanism of how a detected error leads to a correction. The error resolution mechanism proposed in our new model is then tested in a computational model. Finally, we outline the advances and predictions of the model.

Keywords: Action and perception; Auditory word processing; Cognitive Control; Language production; Speech perception.

Figure 1

Self-Monitoring according to the Perceptual Loop Model (Levelt, 1983, 1989).

Figure 2

Self-Monitoring according to the Conflict Monitoring Model (Nozari, Dell & Schwartz, 2011).

Figure 3

The Hierarchical State Feedback (HSFC) Model of Self-Monitoring.

Figure 4

The Forward Model account of Self-Monitoring. Sem is the semantic representation, Syn is the syntactic representation, and Phon is the phonological representation.

Figure 5

Hierarchical Conflict Model for Self- and Other Monitoring. Speech production and perception have separate words and phonemes, which are tightly connected via links. Arrows indicate the direction of processing.

Figure 6

Distributions of conflict at the lexical level (based on the difference between the two nodes with the highest activation) for trials that result in corrects (top panel) and semantic errors (bottom panel). Corrects based on 9,768 trials, semantic errors based on 216 trials.

Figure 7

Panels A and C. Reduction in semantic and all errors for each combination of gain and time steps for criterion values of 4.96 and 5.25 respectively. Negative bars mean that the intervention reduced number of errors. Panels B and D. Proportions of successfully repaired errors for each parameter combination.