Identifying the information for the visual perception of relative phase

The production and perception of coordinated rhythmic movement are very specifically structured. For production and perception, 0° mean relative phase is stable, 180° is less stable, and no other state is stable without training. It has been hypothesized that perceptual stability characteristics underpin the movement stability characteristics, which has led to the development of a phase-driven oscillator model (e.g., Bingham, 2004a, 2004b). In the present study, a novel perturbation method was used to explore the identity of the perceptual information being used in rhythmic movement tasks. In the three conditions, relative position, relative speed, and frequency (variables motivated by the model) were selectively perturbed. Ten participants performed a judgment task to identify 0° or 180° under these perturbation conditions, and 8 participants who had been trained to visually discriminate 90° performed the task with perturbed 90° displays. Discrimination of 0° and 180° was unperturbed in 7 out of the 10 participants, but discrimination of 90° was completely disrupted by the position perturbation and was made noisy by the frequency perturbation. We concluded that (1) the information used by most observers to perceive relative phase at 0° and 180° was relative direction and (2) becoming an expert perceiver of 90° entails learning a new variable composed of position and speed

A Perception-Action Approach to Rhythmic Movement Coordination

Thesis (PhD) - Indiana University, Psychology, 2005Coordinated rhythmic movement is very specifically structured in humans. 0° mean relative phase (the two oscillating limbs doing the same thing at the same time) is easy and stable; 180° (the two limbs doing the opposite thing at the same time) is less stable; and no other relative phase is stable without training. The present study explored the identity and role of the perceptual information used in rhythmic movement coordination tasks in creating this pattern. 4 participants were trained to improve their perceptual resolution of 90° over a two week period. This training resulted in improved movement stability in a rhythmic movement coordination task, without additional practice of the task itself. Improved ability to detect the information at 90° allowed for improved performance in a movement task at 90°. In a second study, we systematically perturbed three aspects of the coordinated motion of two dots on a computer screen, and tested the effect of these perturbations on the same 4 participants. In line with predictions based on previous modeling results, perturbations that disrupted perceptual information about peak velocity and peak amplitude disrupted participants' ability to perform the task; this information allows rescaling of velocity information and is vital for stable perception of the underlying information (the relative direction of motion). Perturbations that increased the magnitude of the relative speed between the dots added noise to the task, again as predicted. Relative direction proved impossible to perturb, independently of mean relative phase, suggesting it has a vital role in the task. We conclude that the information used in rhythmic movement coordination tasks is both the phase (position within a cycle) and the relative phase, instantiated as the relative direction of motion. Movement stability is a function of perceptual stability, and improving the latter improves the former. The results are explained within a perception-action framework, in which perceptual information is an integral part of the organization of a perception-action dynamical system

Behavioural simulation of biological neuron systems using VHDL and VHDL-AMS

The investigation of neuron structures is an incredibly difficult and complex task that yields relatively low rewards in terms of information from biological forms (either animals or tissue). The structures and connectivity of even the simplest invertebrates are almost impossible to establish with standard laboratory techniques, and even when this is possible it is generally time consuming, complex and expensive. Recent work has shown how a simplified behavioural approach to modelling neurons can allow “virtual” experiments to be carried out that map the behaviour of a simulated structure onto a hypothetical biological one, with correlation of behaviour rather than underlying connectivity. The problems with such approaches are numerous. The first is the difficulty of simulating realistic aggregates efficiently, the second is making sense of the results and finally, it would be helpful to have an implementation that could be synthesised to hardware for acceleration. In this paper we present a VHDL implementation of Neuron models that allow large aggregates to be simulated. The models are demonstrated using a system level VHDL and VHDL-AMS model of the C. Elegans locomotory system

An Intelligent Fuse-box for use with Renewable Energy Sources integrated within a Domestic Environment

This paper outlines a proposal for an intelligent fuse-box that can replace existing fuse-boxes in a domestic context such that a number of renewable energy sources can easily be integrated into the domestic power supply network, without the necessity for complex islanding and network protection. The approach allows intelligent control of both the generation of power and its supply to single or groups of electrical appliances. Energy storage can be implemented in such a scheme to even out the power supplied and simplify the control scheme required, and environmental monitoring and load analysis can help in automatically controlling the supply and demand profiles for optimum electrical and economic efficiency. Simulations of typical scenarios are carried out to illustrate the concept in operation

Gibson’s ecological approach – a model for the benefits of a theory driven psychology

Unlike most other sciences, psychology has no true core theory to guide a coherent research programme. It does have James J Gibson’s ecological approach to visual perception, however, which we suggest should serve as an example of the benefits a good theory brings to psychological research. Here we focus on an example of how the ecological approach has served as a guide to discovery, shaping and constraining a recent hypothesis about how humans perform coordinated rhythmic movements (Bingham 2004a, b). Early experiments on this task were framed in a dynamic pattern approach. This phenomenological, behavioural framework (e.g. Jeka & Kelso 1989) classifies the behaviour of complex action systems in terms of the key order parameters, and describes the dynamical stability of the system as it responds to perturbations. Dynamical systems, however, while a valuable toolkit, is not a theory of behaviour, and this style of research is unable to successfully predict data it is not explicitly designed to fit. More recent work by Bingham & colleagues has used dynamical systems to formalise hypotheses derived from Gibson’s ecological approach to perception and action, with a particular emphasis on perceptual information. The resulting model (Bingham 2001, 2004a, b; Snapp-Childs et al. 2011) has had great success with both the phenomena it was designed to explain as well as a wide range of empirical results from a version of the task it is not specifically designed to explain (specifically, learning a novel coordination). This model and the research programme that produced it stand as an example of the value of theory driven research, and we use it to illustrate the contemporary importance the ecological approach has for psychology

The First World War Centenary in the UK: ‘A Truly National Commemoration’?

Prime Minister David Cameron has called for ‘a truly national commemoration of the First World War’. This article shows this to be problematic, politicised and contested. This is in part due to the elision of English and British histories. Scottish, Welsh and Irish responses are noted, and the role and commemorations of ‘our friends in the Commonwealth’. There are tensions around interpretations of empire and race. There has been a failure to appreciate that the debates about the legacies of the First World War are deeply entangled with those of colonialism