Moving to higher ground: The dynamic field theory and the dynamics of visual cognition

In the present report, we describe a new dynamic field theory that captures the dynamics of visuo-spatial cognition. This theory grew out of the dynamic systems approach to motor control and development, and is grounded in neural principles. The initial application of dynamic field theory to issues in visuo-spatial cognition extended concepts of the motor approach to decision making in a sensori-motor context, and, more recently, to the dynamics of spatial cognition. Here we extend these concepts still further to address topics in visual cognition, including visual working memory for non-spatial object properties, the processes that underlie change detection, and the ‘binding problem’ in vision. In each case, we demonstrate that the general principles of the dynamic field approach can unify findings in the literature and generate novel predictions. We contend that the application of these concepts to visual cognition avoids the pitfalls of reductionist approaches in cognitive science, and points toward a formal integration of brains, bodies, and behavior.     

The Live Outdoor Webcams and the Construction of Virtual Geography

The live outdoor webcam seems inseparable from the mid-1990s’ popular proliferation of the Internet. Combining a well-known medium, i.e. the photograph, with a new one, i.e. the Internet, the live outdoor webcam seems in the rear-view mirror to have contributed significantly to the popular perception of the Internet as a globally distended and thus “geographical” medium. Moreover, due to its role in the NASA Triana mission, the never-realised flagship of the Clinton–Gore administration’s Digital Earth project, the live webcam seemed to play an important part in the construction of what leading geographers coined a “virtual geography”—the geography of the Internet, and the networked geography—that sought to establish itself as a new field of study during the late 1990s. In order to substantiate for this interpretation, I would like in the first part of this article to identify a number of basic characteristics of the outdoor webcam and, in the second, to analyse and discuss two papers written by leading scholars in the field; papers which have been important in the assessment of the impact of the Internet and geographical information systems (GIS) before the scientific community as well as policy makers within technological innovation and the public sector.

Cognitive Deficits in the Early Stages of Alzheimer's Disease

ABSTRACT— Evidence from longitudinal, experimental, and neuroimaging studies converge to indicate that psychological functions other than episodic memory are affected very early in the course of Alzheimer's disease and, indeed, may predate or influence the apparent memory deficits. Changes in personality and difficulty in executive function, especially in terms of attentional and inhibitory control, are especially prominent. Deficits in other types of memory (i.e., semantic memory, conditioning) can also be detected in the early stages of the disease. It is time to update existing diagnostic criteria for this form of dementia in terms of current knowledge of multiple and interacting brain systems.     

When good theories make bad predictions

Chaos-related obstructions to predictability have been used to challenge accounts of theory validation based on the agreement between theoretical predictions and experimental data (Rueger & Sharp, 1996. The British Journal for the Philosophy of Science, 47, 93–112; Koperski, 1998. Philosophy of Science, 40, 194–212). These challenges are incomplete in two respects: (a) they do not show that chaotic regimes are unpredictable in principle (i.e., with unbounded resources) and, as a result, that there is something conceptually wrong with idealized expectations of correct predictions from acceptable theories, and (b) they do not explore whether chaos-induced predictive failures of deterministic models can be remedied by stochastic modeling. In this paper we appeal to an asymptotic analysis of state space trajectories and their numerical approximations to show that chaotic regimes are deterministically unpredictable even with unbounded resources. Additionally, we explain why stochastic models of chaotic systems, while predictively successful in some cases, are in general predictively as limited as deterministic ones. We conclude by suggesting that the way in which scientists deal with such principled obstructions to predictability calls for a more comprehensive approach to theory validation, on which experimental testing is augmented by a multifaceted mathematical analysis of theoretical models, capable of identifying chaos-related predictive failures as due to principled limitations which the world itself imposes on any less-than-omniscient epistemic access to some natural systems. We give special thanks to two anonymous reviewers for their helpful comments that have substantially contributed to the final version of this paper     

Social neuroscience of child and adolescent depression

The social neuroscience of child and adolescent depression is inherently multidisciplinary. Depressive disorders beginning early in life can have serious developmental and functional consequences. Psychopathology research has described depression's defining clinical and contextual features, and intervention research has characterized its response to treatment and prevention programs. Neuroendocrine, electrophysiological, and neuroimaging studies have identified core neurobiological aspects of early-onset mood disorders. These areas are reviewed using a developmental social neuroscience perspective for integrating disparate observations. The paper introduces a dynamic adaptive systems framework, and it discusses hedonic capacity, stress sensitivity, ruminative self-focus, and attentional impairments as fundamental components of mood disorders.     

TEACHING CHOICE MAKING DURING SOCIAL INTERACTIONS TO STUDENTS WITH PROFOUND MULTIPLE DISABILITIES

We taught 4 students with profound multiple disabilities to use a microswitch communication system to request a change in recreational stimuli during social interactions with nondisabled peers. In Study 1, we conducted a preference assessment across a range of stimuli for each student. The most and least preferred stimuli were incorporated into microswitch communication system training in Study 2. During the second study, 3 of the 4 students (a) learned to use the microswitch communication system to control stimulus presentation, (b) more clearly differentiated their time among stimuli, and (c) increased their level of general alertness. Study 3 extended the use of the microswitch communication system to social interactions with nondisabled peers. Two students were more engaged in interactions when they chose when to change stimuli; 1 student was more alert when a peer chose when to change activities; a 4th student showed an undifferentiated pattern. The outcomes of the investigation are discussed in terms of the effects of controlling stimulus presentation on the behavior of students with profound multiple disabilities and the stability of preference hierarchies over time.