Simple games as dynamic, coupled systems: randomness and other emergent properties

From a game theory perspective the ability to generate random behaviors is critical. However, psychological studies have consistently found that individuals are poor at behaving randomly. In this paper we investigated the possibility that the randomness mechanism lies not within the individual players but in the interaction between the players. Provided that players are influenced by their opponent’s past behavior, their relationship may constitute a state of reciprocal causation [Cognitive Science 21 (1998) 461], in which each player simultaneously affects and is affected by the other player. The result of this would be a dynamic, coupled system. Using neural networks to represent the individual players in a game of paper, rock, and scissors, a model of this process was developed and shown to be capable of generating chaos-like behaviors as an emergent property. In addition, it was found that by manipulating the control parameters of the model, corresponding to the amount of working memory and the perceived values of different outcomes, that the game could be biased in favor of one player over the other, an outcome not predicted by game theory. Human data was collected and the results show that the model accurately describes human behavior. The results and the model are discussed in light of recent theoretical advances in dynamic systems theory and cognition.     

Adaptation to continuous perturbation of balance: progressive reduction of postural muscle activity with invariant or increasing oscillations of the center of mass depending on perturbation frequency and vision conditions

We investigated the adaptation of balancing behavior during a continuous, predictable perturbation of stance consisting of 3-min backward and forward horizontal sinusoidal oscillations of the support base. Two visual conditions (eyes-open, EO; eyes-closed, EC) and two oscillation frequencies (LF, 0.2 Hz; HF, 0.6 Hz) were used. Center of Mass (CoM) and Center of Pressure (CoP) oscillations and EMG of Soleus (Sol) and Tibialis Anterior (TA) were recorded. The time course of each variable was estimated through an exponential model. An adaptation index allowed comparison of the degree of adaptation of different variables. Muscle activity pattern was initially prominent under the more challenging conditions (HF, EC and EO; LF, EC) and diminished progressively to reach a steady state. At HF, the behavior of CoM and CoP was almost invariant. The time-constant of EMG adaptation was shorter for TA than for Sol. With EC, the adaptation index showed a larger decay in the TA than Sol activity at the end of the balancing trial, pointing to a different role of the two muscles in the adaptation process. At LF, CoM and CoP oscillations increased during the balancing trial to match the platform translations. This occurred regardless of the different EMG patterns under EO and EC. Contrary to CoM and CoP, the adaptation of the muscle activities had a similar time-course at both HF and LF, in spite of the two frequencies implying a different number of oscillation cycles. During adaptation, under critical balancing conditions (HF), postural muscle activity is tuned to that sufficient for keeping CoM within narrow limits. On the contrary, at LF, when vision permits, a similar decreasing pattern of muscle activity parallels a progressive increase in CoM oscillation amplitude, and the adaptive balancing behavior shifts from the initially reactive behavior to one of passive riding the platform. Adaptive balance control would rely on on-line computation of risk of falling and sensory inflow, while minimizing balance challenge and muscle effort. The results from this study contribute to the understanding of plasticity of the balance control mechanisms under posture-challenging conditions.     

A dynamic context model of interactive behavior

A dynamic context model of interactive behavior was developed to explain results from two experiments that tested the effects of interaction costs on encoding strategies, cognitive representations, and response selection processes in a decision-making and a judgment task. The model assumes that the dynamic context defined by the mixes of internal and external representations and processes are sensitive to the interaction cost imposed by the task environment. The model predicts that changes in the dynamic context may lead to systematic biases in cognitive representations and processes that eventually influence decision-making and judgment outcomes. Consistent with the predictions by the model, results from the experiments showed that as interaction costs increased, encoding strategies and cognitive representations shifted from perception-based to memory-based. Memory-based comparisons of the stimuli enhanced the similarity and dominance effects, and led to stronger systematic biases in response outcomes in a choice task. However, in a judgment task, memory-based representations enhanced only the dominance effects. Results suggested that systematic response biases in the dominance context were caused by biases in the cognitive representations of the stimuli, but response biases in the similarity context were caused by biases in the comparison process induced by the choice task. Results suggest that changes in interaction costs not only change whether information was assessed from the external world or from memory but also introduce systematic biases in the cognitive representation of the information, which act as biased inputs to the subsequent decision-making and judgment processes. Results are consistent with the idea of interactive cognition, which proposes that representations and processes are contingent on the dynamic context defined by the information flow between the external task environment and internal cognition.     

Preschoolers' use of dynamic facial, bodily, and vocal cues to emotion

In daily experience, children have access to a variety of cues to others’ emotions, including face, voice, and body posture. Determining which cues they use at which ages will help to reveal how the ability to recognize emotions develops. For happiness, sadness, anger, and fear, preschoolers (3-5 years, N = 144) were asked to label the emotion conveyed by dynamic cues in four cue conditions. The Face-only, Body Posture-only, and Multi-cue (face, body, and voice) conditions all were well recognized (M > 70%). In the Voice-only condition, recognition of sadness was high (72%), but recognition of the three other emotions was significantly lower (34%).     

The thalamic dynamic core theory of conscious experience

I propose that primary conscious awareness arises from synchronized activity in dendrites of neurons in dorsal thalamic nuclei, mediated particularly by inhibitory interactions with thalamic reticular neurons. In support, I offer four evidential pillars: (1) consciousness is restricted to the results of cortical computations; (2) thalamus is the common locus of action of brain injury in vegetative state and of general anesthetics; (3) the anatomy and physiology of the thalamus imply a central role in consciousness; (4) neural synchronization is a neural correlate of consciousness.     

Complex problem solving — More than reasoning?

This study investigates the internal structure and construct validity of Complex Problem Solving (CPS), which is measured by a Multiple-Item-Approach. It is tested, if (a) three facets of CPS - rule identification (adequateness of strategies), rule knowledge (generated knowledge) and rule application (ability to control a system) - can be empirically distinguished, how (b) reasoning is related to these CPS-facets and if (c) CPS shows incremental validity in predicting school grade point average (GPA) beyond reasoning. N = 222 university students completed MicroDYN, a computer-based CPS test and Ravens Advanced Progressive Matrices. Analysis including structural equation models showed that a 2-dimensionsal model of CPS including rule knowledge and rule application fitted the data best. Furthermore, reasoning predicted performance in rule application only indirectly through its influence on rule knowledge indicating that learning during system exploration is a prerequisite for controlling a system successfully. Finally, CPS explained variance in GPA even beyond reasoning, showing incremental validity of CPS. Thus, CPS measures important aspects of academic performance not assessed by reasoning and should be considered when predicting real life criteria such as GPA.     

Dynamics of identity development and separation–individuation in parent–child relationships during adolescence and emerging adulthood – A conceptual integration

Identity development and separation–individuation in parent–child relationships are widely perceived as related tasks of psychosocial maturation. However, a dynamic, developmental perspective that explains how intra-personal change in identity evolves from transactions between parents and children is not sufficiently represented in the literature. In this article, a selective literature review of psychological approaches to identity development and separation–individuation is presented with a focus on how the role of parents has been covered by approaches to identity development and on how general mechanisms of identity change could be filled with content by processes of separation–individuation. Afterwards, dynamics of identity development and separation–individuation are integrated based on the conceptualization of parents and children as two interrelated identity systems. Specifically, it is illustrated how interpersonal differences in long-term related changes in identity formation, identity evaluation, autonomy, and separateness and attachment between parents and children, could be explained by parent–child transactions in the transition between childhood and adolescence and between adolescence and emerging adulthood. Finally, implications of an integrative perspective for future empirical research are discussed.     

Contributions of dynamic systems theory to cognitive development

We examine the contributions of dynamic systems theory to the field of cognitive development, focusing on modeling using dynamic neural fields. After introducing central concepts of dynamic field theory (DFT), we probe empirical predictions and findings around two examples—the DFT of infant perseverative reaching that explains Piaget's A-not-B error and the DFT of spatial memory that explain changes in spatial cognition in early development. Review of the literature around these examples reveals that computational modeling is having an impact on empirical research in cognitive development; however, this impact does not extend to neural and clinical research. Moreover, there is a tendency for researchers to interpret models narrowly, anchoring them to specific tasks. We conclude on an optimistic note, encouraging both theoreticians and experimentalists to work toward a more theory-driven future.     

An Exploration of Rapists' Motivations as Illustrated by Their Crime Scene Actions: Is the Gender of the Victim an Influential Factor?

An aim of this paper was to examine if the rapist's motivations of anger and power as inferred from rape crime scene behaviours differentiates between rape victim genders. In addition, it was sought to analyse the resistance strategies employed by rape victims to investigate whether gender influences victim–offender behavioural interactions. A sample of 24 female and 12 male rape victims aged from 13 to 39 years were analysed. The data were extracted from the US National Crime Survey, which contained 12 reported cases of male rape. It was hypothesised that the theme of power would be evident from the rapists' behaviour as illustrated by the crime scene actions and victim–offender interaction. Smallest Space Analysis, a multi‐dimensional scaling technique, was employed to identify the themes present in the perpetration of rape. The crime scene actions illustrated several distinctions relating to the theme of power present in the offender's motives irrespective of the victim's gender. An additional finding was that victim resistance strategies differentiated between male and female rape victims. Copyright © 2014 John Wiley & Sons, Ltd.     

A dynamic view of cultural influence: A review

Static models of culture's influence have given way to a dynamic view, which identifies not only differences across cultures in people's judgments and decisions, but also the situations and conditions in which these differences do or do not appear. Theory and evidence developed from a cognitive psychological perspective underlie this dynamic approach, including research emerging from the “dynamic constructivist” and “situated cognition” models. In the present review, we focus on findings that confirm the utility of this cognitively oriented approach, and briefly discuss the advantages and complementary nature of the “social collective” and neuroscience approaches to understanding culture.