Working memory and arithmetic calculation in children: the contributory roles of processing speed, short-term memory, and reading

The cognitive underpinnings of arithmetic calculation in children are noted to involve working memory; however, cognitive processes related to arithmetic calculation and working memory suggest that this relationship is more complex than stated previously. The purpose of this investigation was to examine the relative contributions of processing speed, short-term memory, working memory, and reading to arithmetic calculation in children. Results suggested four important findings. First, processing speed emerged as a significant contributor of arithmetic calculation only in relation to age-related differences in the general sample. Second, processing speed and short-term memory did not eliminate the contribution of working memory to arithmetic calculation. Third, individual working memory components--verbal working memory and visual-spatial working memory--each contributed unique variance to arithmetic calculation in the presence of all other variables. Fourth, a full model indicated that chronological age remained a significant contributor to arithmetic calculation in the presence of significant contributions from all other variables. Results are discussed in terms of directions for future research on working memory in arithmetic calculation.     

A microgenetic study of insightful problem solving

An eight-session microgenetic study of acquisition of an insightful problem-solving strategy was conducted. A total of 35 second graders who did not use this insightful strategy initially were assigned to two groups that differed in the frequency of problems likely to facilitate discovery and generalization of the strategy. Children in the facilitative problems group discovered the insightful strategy earlier, used it more often subsequently, and transferred it more often to novel problems than did those in the nonfacilitative problems group. Children generally discovered the insightful strategy on the most facilitative items and extended it progressively to items on which its advantages were smaller but still substantial. The results indicate that experience outside the experimental situation, as well as experience inside the experimental situation, influences use of new strategies.     

Test of a Level of Aspiration model of group decision making: Non-obvious group preference reversal due to an irrelevant alternative

We conducted two experiments that investigated a non-obvious prediction of a Level of Aspiration (LOA) model of group decision making. In both experiments, groups chose among three alternatives, A, B, and C, with C always being least preferred by all of the group members. In each experiment, by manipulating the nature of alternative C, we created two conditions differing in whether only A or only B was acceptable to all members. In support of the LOA model, groups tended to choose the alternative acceptable to all members, even when (Experiment 2) a majority of members most preferred a different alternative. Implications of the results for the LOA model are discussed in the context of social choice theory.     

Measurement by subjective estimation: Testing for separable representations

Studying how individuals compare two given quantitative stimuli, say d₁ and d₂, is a fundamental problem. One very common way to address it is through ratio estimation, that is to ask individuals not to give values to d₁ and d₂, but rather to give their estimates of the ratio p=d₁/d₂. Several psychophysical theories (the best known being Stevens’ power-law) claim that this ratio cannot be known directly and that there are cognitive distortions on the apprehension of the different quantities. These theories result in the so-called separable representations [Luce, R. D. (2002). A psychophysical theory of intensity proportions, joint presentations, and matches. Psychological Review, 109, 520–532; Narens, L. (1996). A theory of ratio magnitude estimation. Journal of Mathematical Psychology, 40, 109–788], which include Stevens’ model as a special case. In this paper we propose a general statistical framework that allows for testing in a rigorous way whether the separable representation theory is grounded or not. We conclude in favor of it, but reject Stevens’ model. As a byproduct, we provide estimates of the psychophysical functions of interest.     

A fast numerical algorithm for the estimation of diffusion model parameters

In this paper, we describe a new algorithmic approach for parameter estimation in Ratcliff's [(1978). A theory of memory retrieval. Psychological Review, 85 (2), 59-108] diffusion model. This problem, especially if inter-trial variabilities of parameters are included in the model, is computationally very expensive; the parameter estimation procedure often takes a long time even with today's high-speed computers. The algorithm described here makes the calculation of the cumulative distribution functions for predicted process durations computationally much less expensive. This improvement is achieved by solving the Kolmogorov backward equation numerically instead of employing the previously used closed form solution. Additionally, the algorithm can determine the optimum fit for one of the model parameters (the starting point z) directly, thereby reducing the dimension of the parameter search space by one. The resulting method is shown to be notably faster than the standard (closed-form solution) method for parameter estimation.     

Speech Perception: Cognitive Foundations and Cortical Implementation

ABSTRACT— Speech perception includes, minimally, the set of computations that transform continuously varying acoustic signals into linguistic representations that can be used for subsequent processing. The auditory and motor subroutines of this complex perceptual process are executed in a network of brain areas organized in ventral and dorsal parallel pathways, performing sound-to-meaning and sound-to-motor mappings, respectively. Research on speech using neurobiological techniques argues against narrow motor or auditory theories. To account for the range of cognitive and neural attributes, integrative computational models seem promising.     

Strategy generalization across orientation tasks: testing a computational cognitive model

Humans use their spatial information processing abilities flexibly to facilitate problem solving and decision making in a variety of tasks. This article explores the question of whether a general strategy can be adapted for performing two different spatial orientation tasks by testing the predictions of a computational cognitive model. Human performance was measured on an orientation task requiring participants to identify the location of a target either on a map (find-on-map) or within an egocentric view of a space (find-in-scene). A general strategy instantiated in a computational cognitive model of the find-on-map task, based on the results from Gunzelmann and Anderson (2006) , was adapted to perform both tasks and used to generate performance predictions for a new study. The qualitative fit of the model to the human data supports the view that participants were able to tailor a general strategy to the requirements of particular spatial tasks. The quantitative differences between the predictions of the model and the performance of human participants in the new experiment expose individual differences in sample populations. The model provides a means of accounting for those differences and a framework for understanding how human spatial abilities are applied to naturalistic spatial tasks that involve reasoning with maps.     

When and how do differences matter? An exploration of perceived similarity in teams

In this paper, we directly assess perceived similarity—the degree to which members view themselves as having few differences—because we want to understand when teams notice diversity on various member characteristics and how they interpret it. Our results indicate social category diversity was related to initial estimates of both perceived social category similarity (SCS) and perceived work style similarity (WSS). And, whereas perceived SCS did not change over time, perceived WSS decreased significantly over the period of our study. We suggest this change in perceived WSS can be explained by an information-processing/decision-making framework. We found informational diversity was positively related to conflict in teams, and in turn conflict was negatively related to subsequent estimates of perceived WSS. However, informational diversity was positively related to information sharing in teams, which in turn was positively related to subsequent estimates of perceived WSS. Finally, these updated estimates of perceived WSS affected subgroup formation and team process effectiveness. We discuss how our research explores the subjective experience of diversity by team members, provides a dynamic view of the relationship between diversity and team outcomes, and informs emerging theory about the activation of faultlines in teams.     

Expectation confirmation: An examination of three competing models

We discuss three theoretical models from met expectations research in the fields of organizational behavior and consumer psychology. Based on the fundamental arguments in the models, we term these models: disconfirmation, ideal point, and experiences only. We present three-dimensional graphical and analytical representations of the models, with satisfaction being a function of expectations and experiences. We tested the models in the context of a new information system implementation in an organization, with expectations, experiences, and system satisfaction measured for both ease of use and usefulness, the focal constructs of the Technology Acceptance Model (TAM). We found that an experiences only model in which expectations had no measurable effect best explained the data for ease of use. The results for usefulness indicated a modified version of the experiences only model in which the positive effect of experiences becomes slightly stronger—i.e., more positive—as expectations increase.     

Recall of details never experienced: Effects of age,repetition, and semantic cues

To test theoretical predictions about the role of meaning connections in false memory, the effects of semantic cues and list repetition on children's false memories were evaluated across early childhood to mid-adolescence using the Deese–Roediger–McDermott (DRM) paradigm. True recall and false recall increased from 7 to 13 years. Study list repetition increased true recall of list words with the magnitude of this effect largest in the older children and adolescents. Repetition reduced false recall of critical lures in all age groups. Consistent with theoretical predictions, false recall of critical lures increased when children were informed of the thematic gist of each list prior to study.