Nonstationary Stochastic Resonance in a Reduced-Order Hodgkin-Huxley Neuron

In this work a physiologically realistic neural system model is shown to be able to detect a weak nonstationary signal through the addition of noise. It is shown that the signal transduction performance is optimised for a nonzero value of noise intenSity in a manner suggestive of stochastic resonance

A Model of the Median Sensory Nerve Compound Action Potential leading to a Method for Nerve Fibre Diameter Distribution

Nerve conduction studies (NCS) are one of the basic tools of the electrodiagnostic clinician and are performed in order to evaluate the integrity of peripheral nerve function . Using such techniques diagnosis of various diseases and disorders of nerve are possible. During NCS a peripheral nerve is stimulated using an electrical pulse of sufficient intensity to recruit as many nerve fibres as possible. This elicits a volley of action potentials (APs) in the individual nerve fibres which is then recorded at a distal point usually using surface electrodes. Usually only two components of the recorded response (called the compound action potential or CAP), the distal amplitude and the distal/peak latency are routinely recorded though the proximal latency is also used to construct an average measure of conduction velocity (CV). In this study a model of the sensory CAP of the median nerve as measured using bipolar electrodes is proposed and using this model an additional measure is extracted from the CAP. This measure represents the distribution of conduction velocities within the nerve trunk and from this a measure of nerve fibre diameter distribution can be ascertaine

A Stochastic Model of the Visual Evoked Response

A stochastic model for visual evoked response generation is proposed based on a compound neurological generator approach. Participation of individual generators is stochastically modelled in a physiologically realistic manner that captures the inherent variability in latencies and amplitudes associated with the component phases of the response. The model is invertible such that decomposition of real responses to reveal individual unit generator participation is possible and suggests that conventional averaging techniques may provide a truer picture of the visual evoked response than previously thought

A Stochastic Model of the Visual Evoked Response

A stochastic model for visual evoked response generation is proposed based on a compound neurological generator approach. Participation of individual generators is stochastically modelled in a physiologically realistic manner that captures the inherent variability in latencies and amplitudes associated with the component phases of the response. The model is invertible such that decomposition of real responses to reveal individual unit generator participation is possible and suggests that conventional averaging techniques may provide a truer picture of the visual evoked response than previously thought

An Oscillatory Neural Network Scheme for Temporal Encoding and Stimulus Recognition

A novel computational neuro-architecture based on the phase resetting properties of physiologically based neural oscillators is proposed. Analog input variables are encOded in the patterns of the firing times with individual recognition units operating as radial basis-functions

Nonstationary Stochastic Resonance in a Reduced-Order Hodgkin-Huxley Neuron

In this work a physiologically realistic neural system model is shown to be able to detect a weak nonstationary signal through the addition of noise. It is shown that the signal transduction performance is optimised for a nonzero value of noise intenSity in a manner suggestive of stochastic resonance

Spatial Filtering Pipeline Evaluation of Cortically Coupled Computer Vision System for Rapid Serial Visual Presentation

Rapid Serial Visual Presentation (RSVP) is a paradigm that supports the application of cortically coupled computer vision to rapid image search. In RSVP, images are presented to participants in a rapid serial sequence which can evoke Event-related Potentials (ERPs) detectable in their Electroencephalogram (EEG). The contemporary approach to this problem involves supervised spatial filtering techniques which are applied for the purposes of enhancing the discriminative information in the EEG data. In this paper we make two primary contributions to that field: 1) We propose a novel spatial filtering method which we call the Multiple Time Window LDA Beamformer (MTWLB) method; 2) we provide a comprehensive comparison of nine spatial filtering pipelines using three spatial filtering schemes namely, MTWLB, xDAWN, Common Spatial Pattern (CSP) and three linear classification methods Linear Discriminant Analysis (LDA), Bayesian Linear Regression (BLR) and Logistic Regression (LR). Three pipelines without spatial filtering are used as baseline comparison. The Area Under Curve (AUC) is used as an evaluation metric in this paper. The results reveal that MTWLB and xDAWN spatial filtering techniques enhance the classification performance of the pipeline but CSP does not. The results also support the conclusion that LR can be effective for RSVP based BCI if discriminative features are available

The Design And Clinical Use Of A Reflective Brachial Photoplethysmograph

This report concerns the design and clinical use of a reflective brachial photoplethysmograph. A plethysmograph is an instrument to obtain tracings showing volume changes of a part of the body. Originally this related to volume variations due to blood circulation within the body part of interest. The instrument is said to have been invented by Mosso of Turin around 1870 [1], known in Italian as a "pletismografo", and first reported in Scientific American in July 1872. A photoplethysmograph is an optical detector that indicates the volume of blood in or passing through an area of tissue. By placing the photoplethysmograph at or near the site of a human artery the pulse waveform can be detected and measured. The photoplethysmograph can be transmissive or reflective. There are a variety of sites around the body that are commonly used for detecting the pulse waveform including the finger, the ear lobe, and the foot. The device developed in this work is a reflective detector that uses the brachial artery as a photoplethysmographic site. There appear to be no prior indications in academic or patent literature of this site being used with this type of detector and consequently the authors believe this device to be novel and worthy of reporting to the research community

Online database for the Assessment and Comparative Evaluation of Rehabilitation Outcomes

The changing face of rehabilitation structures and practices has meant that measurement of outcomes of rehabilitation has become an absolute necessity. Unfortunately the level of agreement over which measures to use is poor as a result of lack of access to measures and lack of knowledge concerning methods of analysis and interpretation of results. In this paper we report on efforts by the authors to address these issues through the establishment of an online database available over a variety of web devices for the comparative evaluation of rehabilitation outcomes. We discuss the background to the problem, the development and use of an initial system and the future directions of the project. Keywords - Outcome measures, Internet, databas