Gaussian variational estimation for multidimensional item response theory

Multidimensional item response theory (MIRT) is widely used in assessment and evaluation of educational and psychological tests. It models the individual response patterns by specifying a functional relationship between individuals' multiple latent traits and their responses to test items. One major challenge in parameter estimation in MIRT is that the likelihood involves intractable multidimensional integrals due to the latent variable structure. Various methods have been proposed that involve either direct numerical approximations to the integrals or Monte Carlo simulations. However, these methods are known to be computationally demanding in high dimensions and rely on sampling data points from a posterior distribution. We propose a new Gaussian variational expectation--maximization (GVEM) algorithm which adopts variational inference to approximate the intractable marginal likelihood by a computationally feasible lower bound. In addition, the proposed algorithm can be applied to assess the dimensionality of the latent traits in an exploratory analysis. Simulation studies are conducted to demonstrate the computational efficiency and estimation precision of the new GVEM algorithm compared to the popular alternative Metropolis–Hastings Robbins–Monro algorithm. In addition, theoretical results are presented to establish the consistency of the estimator from the new GVEM algorithm.     

Task utility and norms for the Preschool Executive Task Assessment (PETA)

Earlier identification of executive deficits in preschool children using an ecological approach would give more scope for intervention. The Preschool Executive Task Assessment (PETA) was developed to resemble an everyday age-appropriate task in order to examine the self-direction and integration of executive functions during a multistep task. It was designed so that performance can be evaluated in a microanalytic way and so individualized feedback and support can be easily communicated. The utility of the PETA was assessed with 166 three-to five-year olds. Results showed improved performance with increasing age and verbal intellectual quotient as well as good task reliability and utility. Evidence for influence of socioeconomic status, gender, and use of self-talk was also observed. Clinical applications and future directions of this novel measure are discussed.     

Executive abilities in children with congenital visual impairment in mid-childhood

The role of vision and vision deprivation in the development of executive function (EF) abilities in childhood is little understood; aspects of EF such as initiative, attention orienting, inhibition, planning and performance monitoring are often measured through visual tasks. Studying the development and integrity of EF abilities in children with congenital visual impairment (VI) may provide important insights into the development of EF and also its possible relationship with vision and non-visual senses. The current study investigates non-visual EF abilities in 18 school-age children of average verbal intelligence with VI of differing levels of severity arising from congenital disorders affecting the eye, retina, or anterior optic nerve. Standard auditory neuropsychological assessments of sustained and divided attention, phonemic, semantic and switching verbal fluency, verbal working memory, and ratings of everyday executive abilities by parents were undertaken. Executive skills were compared to age-matched typically-sighted (TS) typically-developing children and across levels of vision (mild to moderate VI [MVI] or severe to profound VI [SPVI]). The results do not indicate significant differences or deficits on direct assessments of verbal and auditory EF between the groups. However, parent ratings suggest difficulties with everyday executive abilities, with the greatest difficulties in those with SPVI. The findings are discussed as possibly reflecting increased demands of behavioral executive skills for children with VI in everyday situations despite auditory and verbal EF abilities in the typical range for their age. These findings have potential implications for clinical and educational practices.     

Breaking script: Deviations and postevent information in adult memory for a repeated event

Witnesses to industrial incidents may be asked to recall a single instance of a familiar event. This research systematically tested if deviations to what typically occurs and postevent information (PEI) enhanced reporting of an instance of a repeated event. Across 2 experiments, each participant experienced 5 food‐tasting instances; these instances comprised the repeated event. Half of the participants in both Experiments 1 (continuous deviation setting) and 2 (continuous deviation integrated) experienced a deviation to how the third instance occurred. Also, half of the participants in both experiments received PEI about the third instance. All participants demonstrated superior reporting for the first instance of the repeated event. The continuous deviation setting in Experiment 1 enhanced reporting for all 5 instances of the repeated event (general effect). In Experiment 2, participants who received a continuous deviation integrated and PEI demonstrated superior reporting for the first and third instances of the event (targeted effect).     

Cultural differences in distraction processing: influence of context at retrieval

Cultural differences in information processing affect perceptual judgment, attention, and memory. We investigated whether cultural differences in processing patterns, specifically East Asian participants’ tendency to encode holistically, compared to Western tendencies to process analytically, affect performance on an implicit memory test. First, participants completed a 1-back task on pictures with superimposed distracting words. After a delay filled with a computerised Corsi block task, they performed a word fragment task in which some fragments could be completed with the distracting words from the 1-back task. Critically, fragments were presented with the same pictures as previously seen (matched condition), with no pictures (control condition), or with pictures from other trials on the 1-back task (mismatched condition). Non-Asian Canadian participants showed virtually no priming for distraction, independent of the reinstatement of encoding context. East Asian Canadian participants showed superior priming for fragments that had been paired with their original pictures. They did not show evidence of a detriment for the mismatched, relative to control, condition.     

Generalized Information Theory Meets Human Cognition: Introducing a Unified Framework to Model Uncertainty and Information Search

Searching for information is critical in many situations. In medicine, for instance, careful choice of a diagnostic test can help narrow down the range of plausible diseases that the patient might have. In a probabilistic framework, test selection is often modeled by assuming that people's goal is to reduce uncertainty about possible states of the world. In cognitive science, psychology, and medical decision making, Shannon entropy is the most prominent and most widely used model to formalize probabilistic uncertainty and the reduction thereof. However, a variety of alternative entropy metrics (Hartley, Quadratic, Tsallis, Rényi, and more) are popular in the social and the natural sciences, computer science, and philosophy of science. Particular entropy measures have been predominant in particular research areas, and it is often an open issue whether these divergences emerge from different theoretical and practical goals or are merely due to historical accident. Cutting across disciplinary boundaries, we show that several entropy and entropy reduction measures arise as special cases in a unified formalism, the Sharma–Mittal framework. Using mathematical results, computer simulations, and analyses of published behavioral data, we discuss four key questions: How do various entropy models relate to each other? What insights can be obtained by considering diverse entropy models within a unified framework? What is the psychological plausibility of different entropy models? What new questions and insights for research on human information acquisition follow? Our work provides several new pathways for theoretical and empirical research, reconciling apparently conflicting approaches and empirical findings within a comprehensive and unified information‐theoretic formalism.     

Journalism as Model for Civic and Information Literacies

Journalism can serve as a generative disciplinary context for developing civic and information literacies needed to meaningfully participate in an increasingly networked and mediated public sphere. Using interviews with journalists, we developed a cognitive task analysis model, identifying an iterative sequence of production and domain-specific cognitive constructs of journalism expertise. We diagnose common discrepancies between professional practices and typical youth journalism pedagogies, and offer suggestions for teaching participatory politics and civic literacies through journalism.     

The Senses as Signalling Systems

A central goal of the philosophy of perception is to uncover the nature of sensory capacities. Ideally, we would like an account that specifies what conditions need to be met in order for an organism to count as having the capacity to sense or perceive its environment. And, on the assumption that sensory states are the kinds of things that can be accurate or inaccurate, a further goal of the philosophy of perception is to identify the accuracy conditions for sensory states. In this paper I recommend a novel approach to these core issues, one that draws heavily on game-theoretic treatments of signalling in nature. A benefit of the approach is that it helps us to understand why biologists attribute sensory powers to such a diverse range of organisms, including plants, fungi, and algae.