Virtual ICCM III

Mechanisms of number processing have been of interest to cognitive psychologists for many years. There are multiple competing theories to explain how people form mental represenations of two-digit numbers. Nuerk et al. (2001) proposed a decomposed representation, where the decade and unit digits are processed separately. Primary evidence came from the unit-decade compatibility effect, where comparisons when both unit and decade digits obey the same order relation (e.g., 23 versus 55, where both 2 < 5 and 3 < 5) are faster than trials where the order of digit relations is opposite (e.g., 27 versus 55, where 2 < 5 but 7 > 5). In this study, we used mathematical modeling to perform a decomposition of the unit-decade compatibility effect. We analyzed data from 53 adult observers, each of whom completed a two-digit number comparison task. Each observer’s distribution of RTs (split by compatibility condition) was fit to a diffusion model. We used the EZ-diffusion method (Wagenmakers et al., 2007) to obtain estimates of drift rate and nondecision time for each design cell. The estimates were then compared with a Bayesian paired samples t-test. As expected, compatible trials were faster than incompatible trials. This mean effect manifested almost entirely in the drift rate, which was smaller for incompatible trials than for compatible trials. Critically, the nondecision time did not differ between conditions. This implies that the unit-decade compatibility effect is due entirely to decision-related processes (e.g., stimulus information uptake) but not auxiliary nondecision processes (e.g., encoding, motor preparation, etc.). This work helps to shed light on the locus of the unit decade compatibility effect, and more broadly, on the nature of decomposed processing in numerical cognition.

Analogical reasoning is a core cognitive process. Models have implemented features of analogical reasoning with varied success. Successful models approximate analogical mapping but are not focused on cognitive plausibility. Here, we present and demo an integrated model framework leveraging a component model of analogy (Structure Mapping Engine) to extend a cognitive architecture (ACT-R) for cognitively plausible analogical mapping to inform higher-order cognition.

Temporal binding (TB) is the subjective compression between a voluntary action and its associated outcome. It is regarded as an implicit measure of the sense of agency; however, an underlying mechanism has yet to be agreed upon. Previous research suggests memory as an alternative explanation for TB in two publicly available datasets. Here, we test this idea by implementing a model within the ACT-R cognitive architecture and leveraging its existing memory and time perception mechanisms to simulate participants from these datasets. Our model simulations provide evidence to suggest that memory and time perception mechanisms can explain the pattern of results. Implications for temporal binding and the sense of agency will be discussed.

This paper presents Xyrast, an integrative model of human response processes on the Raven's Matrices family of fluid intelligence tests, and reports on a simulation study addressing its response characteristics and verisimilitude. Xyrast is implemented in the Clarion cognitive architecture and models the influence of response strategy, working memory capacity, and persistence on performance. Simulations suggest that the model captures a wide range of phenomena offering, in some cases, novel explanations for observed results. These findings suggest several avenues for future research.

Psychological distance spaces are the building block of many cognitive models, such as the generalized context model (Nosofsky, 1986) and the similarity-choice model (Luce, 1963; Shepard, 1957). The distance between two stimuli is typically computed based on a multidimensional scaling solution using the Minkowski power metric. This paper proposes a novel method for computing pairwise dissimilarities between stimulus representations that is based on the Kullback-Leibler divergence of response distributions. The method is extended with Sharma-Mittal divergence, and its application and properties are illustrated using a classic set of perceptual identification and categorization data.