The natural mathematics of behavior analysis

Models that generate event records have very general scope regarding the dimensions of the target behavior that we measure. From a set of predicted event records, we can generate predictions for any dependent variable that we could compute from the event records of our subjects. In this sense, models that generate event records permit us a freely multivariate analysis. To explore this proposition, we conducted a multivariate examination of Catania's Operant Reserve on single VI schedules in transition using a Markov Chain Monte Carlo scheme for Approximate Bayesian Computation. Although we found systematic deviations between our implementation of Catania's Operant Reserve and our observed data (e.g., mismatches in the shape of the interresponse time distributions), the general approach that we have demonstrated represents an avenue for modelling behavior that transcends the typical constraints of algebraic models.     

State‐Trace Analysis: Dissociable Processes in a Connectionist Network?

Some argue the common practice of inferring multiple processes or systems from a dissociation is flawed (Dunn, 2003). One proposed solution is state‐trace analysis (Bamber, 1979), which involves plotting, across two or more conditions of interest, performance measured by either two dependent variables, or two conditions of the same dependent measure. The resulting analysis is considered to provide evidence that either (a) a single process underlies performance (one function is produced) or (b) there is evidence for more than one process (more than one function is produced). This article reports simulations using the simple recurrent network (SRN; Elman, 1990) in which changes to the learning rate produced state‐trace plots with multiple functions. We also report simulations using a single‐layer error‐correcting network that generate plots with a single function. We argue that the presence of different functions on a state‐trace plot does not necessarily support a dual‐system account, at least as typically defined (e.g. two separate autonomous systems competing to control responding); it can also indicate variation in a single parameter within theories generally considered to be single‐system accounts.     

A unified approach for revealing multiple balance recovery strategies

In human balance recovery, different strategies have been proposed with generally overlooked knee motions but extensive focus on the ankle, hip, and step strategies. It is not well understood whether maintaining balance is regulated at the lower “muscular–articular” level of coordinating segment joints or at a higher level of controlling whole body dynamics. Whether balance control is to minimize joint degrees of freedom (DOF) or utilize all the available DOF also remains unclear. This study aimed to use a realistic musculoskeletal human model to identify multiple balance recovery strategies with a single optimization criterion. Movements were driven by neural excitations (which activated muscle force generation) and were assumed to be symmetric. Balance recoveries were simulated with forward-inclined straight body postures as the initial conditions. When the position of the toes was fixed, balance was regained with virtually straight knees and mixed ankle/hip strategies. Under a severely perturbed condition, use of the forward hop strategy after releasing the fixed-toes constraint indicated spontaneous recruitment or suppression of DOF, which mimicked functions of optimally computed CNS commands in humans. The results also indicated that increase/decrease in the number of DOF depends on the imposed perturbation intensity and movement constraints.     

Where should the balance be between “scientist” and “practitioner” in Australian undergraduate psychology?

The scientist—practitioner model of training in psychology has been widely influential in the development of undergraduate curricula in Australia. The model had its origins in post‐war America and has formed the basis for accreditation of psychology courses in Australia since the late 1970s. Recently a reconsideration of the model in Australian undergraduate psychology was argued for, suggesting that the absence of significant practical skills development in most curricula is detrimental to the discipline's graduates and their employers. The authors agree that the need for some practical skills development in undergraduate curricula is becoming increasingly important for psychology. Many of the exemplars of curriculum revision provided, however, are impractical and are unlikely to make significant contributions to Australian programs. There is an urgent need to consider the graduate attributes desired for 3‐year and 4‐year trained psychology graduates who will go on to employment without completing postgraduate study. Curriculum innovation to enhance graduates' employability will flow from this development, and will be likely to incorporate information technology solutions, rather than placement experience. This process is entirely compatible with the scientist—practitioner model of training and education in psychology.     

消化内镜医师培训的现状及计算机模拟训练系统的应用

传统的以患者为基础的消化内镜医师培养模式已不能适应消化内镜的快速发展和病患对内镜操作技术的高要求,通过多媒体和虚拟现实技术建立的计算机辅助的内镜模拟训练系统相对于传统的消化内镜医师培训方式是一个巨大进步,它能帮助初学者较快掌握消化内镜诊疗操作的基本技能,使各级消化内镜培训中心的规范化教学成为可能.但是,模拟内镜训练必须结合实际病例的操作才能巩固从模拟内镜得到的内镜操作技能.本文总结了目前消化内镜医师培训的现状,重点对消化内镜模拟训练系统在内镜医师培训中的作用和存在的问题进行探讨,并提出了自己的观点.     

Photic Stimulation of Young Rats

Zajonc, Harrison, and their colleagues have recently conducted a series of studies demonstrating a positive, monotonic relation between frequency of “mere” exposure and liking for stimuli. Other studies have found either the inverted-U relation or a decrease in liking. It was proposed that an emphasis upon mere exposure may be somewhat misleading, and that a concern with degree of stimulus familiarity might be more fruitful. Conflicting forms of the exposure-liking relation seem to be potentially reconcilable if consideration is given to factors that influence the rate at which stimuli become familiar, or capable of being anticipated and represented in memory.

Two experiments using stimuli and procedures taken from Zajonc (23) yielded a positive, monotonic relation between frequency and liking. A third experiment, designed to produce greater attention to the stimuli and thus hasten familiarization, yielded an inverted-U relation. A fourth experiment used simpler verbal stimuli than the first three. This was designed to result in even faster familiarization. As expected, there was a negative relation between liking and exposure frequency.

The “frequency group” of investigators has explained the monotonic exposure effect in terms of the response competition hypothesis. However, the latter is incapable of handling a nonmonotonic relation. A reasonable alternative seems to be the expectancy arousal hypothesis (5): viz., that liking is maximum for stimuli that arouse moderately strong expectancies of either a “molar” or a “molecular” nature. Previous research (5, 6, 7, 8) has supported this hypothesis, although some of the studies are also amenable to the response competition hypothesis. A further experiment was designed to distinguish between predictions from the response competition and the expectancy arousal hypotheses. The results supported the latter.     

The Cognitive Processes Underlying Risky Choice

In this article, we tested two concepts of decision making: expected utility theory and heuristic choice. In Experiment 1, we applied think‐aloud protocols to investigate violations of expected utility theory. In Experiments 2 to 4, we introduced a new process‐tracing method—called predict‐aloud protocols—that has advantages over previously suggested research methods. Results show the following: (i) people examine information between rather than within gambles; (ii) the priority heuristic emerges as the most frequently used strategy when problems are difficult; and (iii) people check for similarity when problems are easy. Copyright © 2012 John Wiley & Sons, Ltd.     

Toward Training Transformation

This article briefly discusses common themes concerning training transformation shared by articles in this special issue. Themes include: the continuing combat training center revolution, the interplay between theory and practice in military training programs, training as an engineering discipline, the role of training as a contributor to human performance in military operations, the use of training simulations to assess human performance, and data standards. The article emphasizes the need for researchers to better explain and articulate the value and return on investment of training in general and training transformation in particular. Meeting this need will better inform decisions and decision makers in allocating resources to training across the full range of defense requirements.     

Dynamic Simulation and Static Matching for Action Prediction: Evidence From Body Part Priming

Accurately predicting other people's actions may involve two processes: internal real‐time simulation (dynamic updating) and matching recently perceived action images (static matching). Using a priming of body parts, this study aimed to differentiate the two processes. Specifically, participants played a motion‐controlled video game with either their arms or legs. They then observed arm movements of a point‐light actor, which were briefly occluded from view, followed by a static test pose. Participants judged whether this test pose depicted a coherent continuation of the previously seen action (i.e., “action prediction task”). Evidence of dynamic updating was obtained after compatible effector priming (i.e., arms), whereas incompatible effector priming (i.e., legs) indicated static matching. Together, the results support action prediction as engaging two distinct processes, dynamic simulation and static matching, and indicate that their relative contributions depend on contextual factors like compatibility of body parts involved in performed and observed action.     

Universality of the reversal transition in growth phenomena of molecular crystals

ABSTRACT

The fundamental origin of the reversal transition during crystal growth has been investigated by Monte Carlo simulations. Evidence is provided supporting the geometrical nature of the transition, arising from the broken translational invariance at the growth front and the interactions of multipoles of opposed parity. The range of interactions, the details of the force field and model are irrelevant to the occurrence and only determine the functional behaviour of the relevant physical quantities like the localisation of the critical point and the morphology of the phase diagram.