Workload capacity spaces: A unified methodology for response time measures of efficiency as workload is varied

Abstract

Increasing the number of available sources of information may impair or facilitate performance, depending on the capacity of the processing system. Tests performed on response time distributions are proving to be useful tools in determining the workload capacity (as well as other properties) of cognitive systems. In this article, we develop a framework and relevant mathematical formulae that represent different capacity assays (Miller's race model bound, Grice's bound, and Townsend's capacity coefficient) in the same space. The new space allows a direct comparison between the distinct bounds and the capacity coefficient values and helps explicate the relationships among the different measures. An analogous common space is proposed for the AND paradigm, relating the capacity index to the Colonius-Vorberg bounds. We illustrate the effectiveness of the unified spaces by presenting data from two simulated models (standard parallel, coactive) and a prototypical visual detection experiment. A conversion table for the unified spaces is provided.

Composite faces are not processed holistically: evidence from the Garner and redundant target paradigms

“…The third analysis was dedicated to the capacity coefficient (Townsend & Nozawa, 1995). Using the unified methodology developed by Townsend and Eidels (2011), the three capacity measures: the capacity coefficient, the Miller's, and Grice's bounds, were presented within a single space. All analyses were performed separately per observer and alignment condition.…”

“…Figure 4 depicts the capacity coefficient C OR (t), along with the Miller's and Grice's bounds. These measures are presented for each observer and alignment condition within a common unified capacity space (Townsend & Eidels, 2011). The unified space enables a comparison of the different indexes values.…”

“…The system factorial technology (SFT), which has been developed by Townsend and his colleagues over the last couple of decades (Houpt et al, 2013;Townsend & Nozawa, 1995;Townsend & Wenger, 2004;Townsend & Eidels, 2011;Townsend & Altieri, 2012) provides such a model. SFT is a rigorous theory of information processing in OR and AND redundant target designs.…”

“…This has rendered comparison challenging. Townsend and Eidels (2011) have developed a unified framework that allows one to present the three measures within the same space. Here I present the relevant formulas.…”

“…Application of the redundant target task to composite faces is a novel contribution of the present study. Augmented by allied methodologies and recent formal advancements (Townsend & Nozawa, 1995;Townsend & Wenger, 2004;Townsend & Eidels, 2011), the redundant target task can serve as a powerful means for probing the separate but interrelated characteristics of workload capacity and independence in rate in the processing of composite faces.…”