Trajectories emerging from discrete versus continuous processing models in phonological competitor tasks: A commentary on Spivey, Grosjean, and Knoblich (2005).

Abstract

M. J. Spivey, M. Grosjean, and G. Knoblich showed that in a phonological competitor task, participants' mouse cursor movements showed more curvature toward the competitor item when the competitor and target were phonologically similar than when the competitor and target were phonologically dissimilar. Spivey et al. interpreted this result as evidence for continuous cascading of information during the processing of spoken words. Here we show that the results of Spivey et al.need not be ascribed to continuous speech processing. Instead, their results can be ascribed to discrete processing of speech, provided one appeals to an already supported model of motor control that asserts that switching movements from 1 target to another relies on superposition of the 2nd movement onto the 1st. The latter process is a continuous cascade, a fact that indirectly strengthens the plausibility of continuous cascade models. However, the fact that we can simulate the results of Spivey et al.with a continuous motor output model and a discrete perceptual model shows that the implications of Spivey et al.'s experiment are less clear than these authors supposed.

Analyzing spatial data from mouse tracker methodology: An entropic approach

“…The overall dynamics of the movement is largely due to the two fast movements (ξ = 2.94, 91 %) with only a motor pause for the competing category (ζ 1 = 0.28, 9 %; ζ 2 = 0, 0 %). This profile is an example of a movement path composed by two discrete sub-movements separated by a pause (e.g., see: Hwang et al, 2005;van der Wel, Eder, Mitchel, Walsh, & Rosenbaum, 2009), which is difficult to reconcile with the assumption of continuous movement trajectories assumed by some of the DGA interpretations (e.g., see: J. Freeman, Dale, & Farmer, 2011).…”

Degree of certainty modulates anticipatory processes in real time.

“…Hence, it might also be interesting for future research within the field of decision making to pay more attention to individual differences. Finally, we speculate that these individual differences are correlated with personality-related factors, such as, for example, sensation seeking (Zuckerman, 1979) and state/trait anxiety (Spielberger, 1985). Specifically, one might expect discrete guessing to be associated with high sensation seeking/low anxiety and holding back and, to a lower degree, one might expect equal parallel attraction behavior to be associated with low sensation seeking/high anxiety.…”

The Cat is on the Mat. or is it a Dog? Dynamic Competition in Perceptual Decision Making

“…To explain these findings, several researchers have developed dynamical models that incorporate competitive processes. For example, [40] implemented a dynamic competitive model of choice that successfully explains the results of a "phonological competitor" task [41] (but see [42] for an alternative explanation that consider perception as a serial rather than parallel process).…”