Auditory-visual speech integration by prelinguistic infants: Perception of an emergent consonant in the McGurk effect

The McGurk effect, in which auditory [ba] dubbed onto [go] lip movements is perceived as da or tha, was employed in a real-time task to investigate auditory-visual speech perception in prelingual infants. Experiments 1A and 1B established the validity of real-time dubbing for producing the effect. In Experiment 2, 4(1)/(2)-month-olds were tested in a habituation-test paradigm, in which 2 an auditory-visual stimulus was presented contingent upon visual fixation of a live face. The experimental group was habituated to a McGurk stimulus (auditory [ba] visual [ga]), and the control group to matching auditory-visual [ba]. Each group was then presented with three auditory-only test trials, [ba], [da], and [deltaa] (as in then). Visual-fixation durations in test trials showed that the experimental group treated the emergent percept in the McGurk effect, [da] or [deltaa], as familiar (even though they had not heard these sounds previously) and [ba] as novel. For control group infants [da] and [deltaa] were no more familiar than [ba]. These results are consistent with infants'perception of the McGurk effect, and support the conclusion that prelinguistic infants integrate auditory and visual speech information. (C) 2004 Wiley Periodicals, Inc.

Searching oligo sets of human chromosome 12 using evolutionary strategies

DNA Microarray is a powerful tool to measure the level of a mixed population of nucleic acids at one time, which has great impact in many aspects of life sciences research. In order to distinguish nucleic acids with very similar composition by hybridization, it is necessary to design microarray probes with high specificities and sensitivities. Highly specific probes correspond to probes having unique DNA sequences; whereas highly sensitive probes correspond to those with melting temperature within a desired range and having no secondary structure. The selection of these probes from a set of functional DNA sequences (exons) constitutes a computationally expensive discrete non-linear search problem. We delegate the search task to a simple yet effective Evolution Strategy algorithm. The computational efficiency is also greatly improved by making use of an available bioinformatics tool.

Corporate governance options for the local subsidiaries of multinational enterprises

While the corporate governance literature generally focuses on the parent legal entity, many organisations are now multinational enterprises (MNEs) with subsidiaries that are most often legal entities in their host countries. Despite the strengthening of corporate governance regimes internationally, the boards of these subsidiaries are in many instances perfunctory. This paper examines the question of whether developments in corporate governance theory and practice can add value for the local subsidiaries of MNEs. This paper provides a theoretical basis for evaluating governance models in MNEs. The paper commences with a review of the key concepts from the MNE and conglomerates literature with respect to core MNE strategies. The paper then discusses what the "governance roles" are that must be performed in MNE subsidiaries. We propose four governance frameworks for subsidiary corporations. These frameworks are: (1) Direct Control; (2) Dual Reporting; (3) Advisory Board; (4) Local Board. We consider the strengths and weaknesses of each model in relation to international strategy theory. We conclude with recommendations for the conditions under which the various models may be appropriate and practical guidelines for the utilisation of corporate governance theory to improve MNE performance.

The temporal and spatial limits of compensation for fixational eye movements

High-fidelity eye tracking is combined with a perceptual grouping task to provide insight into the likely mechanisms underlying the compensation of retinal image motion caused by movement of the eyes. The experiments describe the covert detection of minute temporal and spatial offsets incorporated into a test stimulus. Analysis of eye motion on individual trials indicates that the temporal offset sensitivity is actually due to motion of the eye inducing artificial spatial offsets in the briefly presented stimuli. The results have strong implications for two popular models of compensation for fixational eye movements, namely efference copy and image-based models. If an efference copy model is assumed, the results place constraints on the spatial accuracy and source of compensation. If an image-based model is assumed then limitations are placed on the integration time window over which motion estimates are calculated. (c) 2006 Elsevier Ltd. All rights reserved.

Tracking the states of a nonlinear system in the weight-space of a feed-forward neural network

Nonlinear, non-stationary signals are commonly found in a variety of disciplines such as biology, medicine, geology and financial modeling. The complexity (e.g. nonlinearity and non-stationarity) of such signals and their low signal to noise ratios often make it a challenging task to use them in critical applications. In this paper we propose a new neural network based technique to address those problems. We show that a feed forward, multi-layered neural network can conveniently capture the states of a nonlinear system in its connection weight-space, after a process of supervised training. The performance of the proposed method is investigated via computer simulations.

Linking contracts, processes and services: An event-driven approach

This paper addresses the problem of mapping business contract conditions onto the messages and rules that represent service interactions in a collaborative business process. We describe why this mapping is not straightforward by means of an example. We then consider a message-driven process language as a target for the mapping and use this mapping solution to discuss broad range of problems related to the mapping problem.

Innovation in teams : a qualitative and quantitative study of team behaviours

This thesis explores the processes of team innovation. It utilises two studies, an organisationally based pilot and an experimental study, to examine and identify aspects of teams' behaviours that are important for successful innovative outcome. The pilot study, based in two automotive manufacturers, involved the collection of team members' experiences through semi-structured interviews, and identified a number of factors that affected teams' innovative performance. These included: the application of ideative & dissemination processes; the importance of good team relationships, especially those of a more informal nature, in facilitating information and ideative processes; the role of external linkages in enhancing quality and radicality of innovations; and the potential attenuation of innovative ideas by time deadlines. This study revealed a number key team behaviours that may be important in successful innovation outcomes. These included; goal setting, idea generation and development, external contact, task and personal information exchange, leadership, positive feedback and resource deployment. These behaviours formed the basis of a coding system used in the second part of the research. Building on the results from the field based research, an experimental study was undertaken to examine the behavioural differences between three groups of sixteen teams undertaking innovative an task to produce an anti-drugs poster. They were randomly assigned to one of three innovation category conditions suggested by King and Anderson (1990), emergent, imported and imposed. These conditions determined the teams level of access to additional information on previously successful campaigns and the degree of freedom they had with regarding to the design of the poster. In addition, a further experimental condition was imposed on half of the teams per category which involved a formal time deadline for task completion. The teams were video taped for the duration of their innovation and their behaviours analysed and coded in five main aspects including; ideation, external focus, goal setting, interpersonal, directive and resource related activities. A panel of experts, utilising five scales developed from West and Anderson's (1996) innovation outcome measures, assessed the teams' outputs. ANOVAs and repeated measure ANOVAs were deployed to identify whether there were significant differences between the different conditions. The results indicated that there were some behavioural differences between the categories and that over the duration of the task behavioural changes were identified. The results, however, revealed a complex picture and suggested limited support for three distinctive innovation categories. There were many differences in behaviours, but rarely between more than two of the categories. A main finding was the impact that different levels of constraint had in changing teams' focus of attention. For example, emergent teams were found to use both their own team and external resources, whilst those who could import information about other successful campaigns were likely to concentrate outside the team and pay limited attention to the internal resources available within the team. In contrast, those operating under task constraints with aspects of the task imposed onto them were more likely to attend to internal team resources and pay limited attention to the external world. As indicated by the earlier field study, time deadlines did significantly change teams' behaviour, reducing ideative and information exchange behaviours. The model shows an important behavioural progression related to innovate teams. This progression involved the teams' openness initially to external sources, and then to the intra-team environment. Premature closure on the final idea before their mid-point was found to have a detrimental impact on team's innovation. Ideative behaviour per se was not significant for innovation outcome, instead the development of intra-team support and trust emerged as crucial. Analysis of variance revealed some limited differentiation between the behaviours of teams operating under the aforementioned three innovation categories. There were also distinct detrimental differences in the behaviour of those operating under a time deadline. Overall, the study identified the complex interrelationships of team behaviours and outcomes, and between teams and their context.

Aspects of tonic accommodation and tonic vergence

Under conditions of reduced visual stimulation, the systems of accommodation and vergence tend towards physiological resting states that are intermediate within their functional range. The terms tonic accommodation (TA) and tonic vergence (TV) are used in the study to describe these stimulus-free, intermediate adjustments and to represent the systems as being in a state of innervational tonicity. The literature relating to TA and TV and the various experiments of this thesis are reviewed. Methodology has been developed enabling the determination of TA and TV under conditions of total darknessl laser optometry for TA and ~ernier-alignment for TV. The thesis describes a series of experiments designed to investigate various aspects of TA and TV, and their role in ametropia, binocular vision and their adaptation to sustained visual tasks. Measurements of TA were also utilised to investigate the effect of various autonomic effector drugs on the ciliary muscle. The effects of ethanol on binocular function are shown to be directly proportional to the .initial level of TVJ which is itself unaffected. These results support the concept of TV as the reference point for normal vergence responses. The results of the pharmacological investigations indicate the presence of a small but significant, beta-receptor mediated inhibitory sympathetic input to the ciliary muscle, and that the wide distribution in TA is a consequence of inter-observer variations in parasympathetic, rather than sympathetic tone. Following interaction with visual tasks of t5mins duration, the levels of TA and TV are found to be biased in the direction of, and proportional to, the task position: except during near-task viewing where the task-to-TA stimulus-distance exceeds 1.5D (for TA) and 3.5deg (for TV). Under these conditions the expected level of bias is attenuated, Adaptive models are discussed, proposing TA and TV as the reference points of the accommodative and vergence system.

The effect of beta-adrenergic receptor antagonists on the temporal accommodative response

In this thesis a modified Canon IR optometer was used to record static and continuous responses of accommodation during sustained visual tasks. The instrument was assessed with regard to the ocular exit pupil used, its frequency response and noise levels. Experimental work concerned essentially the temporal characteristics and neurological basis of the accommodative mechanism. In the absence of visual stimuli, the accommodative system assumes a resting or tonic accommodative (TA) position, which may be modified by periods of sustained fixation. The rate of regression from a near task to TA in darkness has exhibited differences between regression rates for enunetropes (EMMs) compared with late-onset myopes (WMs). The rate of accommodative regression from a task set at 3D above TA was examined for a group of 10 EMMs and 10 LOMs for 3 conditions: saline, timolol and betaxolol. Timolol retarded the regression to TA for a sub-group of EMMs. The patterns of regression for the remaining emmetropes mirrored that for the LOMs, the drugs showing no difference in rate of regression compared with the saline condition. This provides support for the conjecture that LOMs and certain EMMs appear to be deficient in a sympathetic inhibitory component to the ciliary muscle which may attenuate adaptational changes in tonus and which leave them susceptible to the development of LOM. It is well established that the steady-state accommodative response is characterised by temporal changes in lens power having 2 dominant frequency components: a low frequency component (LFC: < 0.6Hz) and a high frequency component (HFC: 1.0-2.2Hz). This thesis investigates various aspects of these microfluctuations of accommodation.The HFC of accommodative fluctuations was shown to be present in central and peripheral lens zones, although the magnitude of the rms of accommodative microfluctuations was found to be reduced in the lens periphery. These findings concur with the proposal that the lens capsule acts as a force distributor, transmitting the tension from the zonules evenly over the whole of the lens surface.An investigation into the correlation between arterial pulse and the HFC of accommodative fluctuations showed that the peak frequency of the HFC was governed by the arterial pulse frequency. It was proposed that the microflucutations comprised a combination of neurological control (LFC) and physiological variations (HFC).The effect of timolol maleate on the steady-state accommodative response for a group of 10 emmetropes showed that timolol reduced significantly the rms of accommodative microfluctuations in treated but not untreated eyes. Consequently, the effect was considered to be locally, rather than systemically induced.The influence of the sympathetic system on within-task measurements of accommodation was examined by recording the accommodative response of 3 subjects to a sinusoidally moving target at 6 temporal frequencies from 0.05Hz to 0.5Hz for 3 drug conditions: saline, timolol and betaxolol. Timolol caused a reduced gain for frequencies below 0.3 whereas betaxolol reduced accommodative gain for all frequencies. It was proposed that the results for timolol were consistent with temporal response characteristics of sympathetic innervation of the ciliary muscle whereas the betaxolol results were thought to be a manifestation of fatigue resulting from the CNS depressant effect of the drug.

Having a word with yourself:neural correlates of self-criticism and self-reassurance

Self-criticism is strongly correlated with a range of psychopathologies, such as depression, eating disorders and anxiety. In contrast, self-reassurance is inversely associated with such psychopathologies. Despite the importance of self-judgements and evaluations, little is known about the neurophysiology of these internal processes. The current study therefore used a novel fMRI task to investigate the neuronal correlates of self-criticism and self-reassurance. Participants were presented statements describing two types of scenario, with the instruction to either imagine being self-critical or self-reassuring in that situation. One scenario type focused on a personal setback, mistake or failure, which would elicit negative emotions, whilst the second was of a matched neutral event. Self-criticism was associated with activity in lateral prefrontal cortex (PFC) regions and dorsal anterior cingulate (dAC), therefore linking self-critical thinking to error processing and resolution, and also behavioural inhibition. Self-reassurance was associated with left temporal pole and insula activation, suggesting that efforts to be self-reassuring engage similar regions to expressing compassion and empathy towards others. Additionally, we found a dorsal/ventral PFC divide between an individual's tendency to be self-critical or self-reassuring. Using multiple regression analyses, dorsolateral PFC activity was positively correlated with high levels of self-criticism (assessed via self-report measure), suggesting greater error processing and behavioural inhibition in such individuals. Ventrolateral PFC activity was positively correlated with high self-reassurance. Our findings may have implications for the neural basis of a range of mood disorders that are characterised by a preoccupation with personal mistakes and failures, and a self-critical response to such events.

Perception while watching movies:effects of physical screen size and scene type

Over the last decade, television screens and display monitors have increased in size considerably, but has this improved our televisual experience? Our working hypothesis was that the audiences adopt a general strategy that “bigger is better.” However, as our visual perceptions do not tap directly into basic retinal image properties such as retinal image size (C. A. Burbeck, 1987), we wondered whether object size itself might be an important factor. To test this, we needed a task that would tap into the subjective experiences of participants watching a movie on different-sized displays with the same retinal subtense. Our participants used a line bisection task to self-report their level of “presence” (i.e., their involvement with the movie) at several target locations that were probed in a 45-min section of the movie “The Good, The Bad, and The Ugly.” Measures of pupil dilation and reaction time to the probes were also obtained. In Experiment 1, we found that subjective ratings of presence increased with physical screen size, supporting our hypothesis. Face scenes also produced higher presence scores than landscape scenes for both screen sizes. In Experiment 2, reaction time and pupil dilation results showed the same trends as the presence ratings and pupil dilation correlated with presence ratings, providing some validation of the method. Overall, the results suggest that real-time measures of subjective presence might be a valuable tool for measuring audience experience for different types of (i) display and (ii) audiovisual material.

Ultrafast all-optical Nth-order differentiator and simultaneous repetition-rate multiplier of periodic pulse train

The letter presents a technique for Nth-order differentiation of periodic pulse train, which can simultaneously multiply the input repetition rate. This approach uses a single linearly chirped apodized fiber Bragg grating, which grating profile is designed to map the spectral response of the Nth-order differentiator, and the chirp introduces a dispersion that, besides space-to-frequency mapping, it also causes a temporal Talbot effect.

Quantitative analysis of multi-spectral fundus images

We have developed a new technique for extracting histological parameters from multi-spectral images of the ocular fundus. The new method uses a Monte Carlo simulation of the reflectance of the fundus to model how the spectral reflectance of the tissue varies with differing tissue histology. The model is parameterised by the concentrations of the five main absorbers found in the fundus: retinal haemoglobins, choroidal haemoglobins, choroidal melanin, RPE melanin and macular pigment. These parameters are shown to give rise to distinct variations in the tissue colouration. We use the results of the Monte Carlo simulations to construct an inverse model which maps tissue colouration onto the model parameters. This allows the concentration and distribution of the five main absorbers to be determined from suitable multi-spectral images. We propose the use of "image quotients" to allow this information to be extracted from uncalibrated image data. The filters used to acquire the images are selected to ensure a one-to-one mapping between model parameters and image quotients. To recover five model parameters uniquely, images must be acquired in six distinct spectral bands. Theoretical investigations suggest that retinal haemoglobins and macular pigment can be recovered with RMS errors of less than 10%. We present parametric maps showing the variation of these parameters across the posterior pole of the fundus. The results are in agreement with known tissue histology for normal healthy subjects. We also present an early result which suggests that, with further development, the technique could be used to successfully detect retinal haemorrhages.

Using Elements of Semantic Parsing in e-Learning Environments

Possibilities for using semantic parsing to estimate the correspondence of text materials to teaching aims, correspondence of test task to theoretical materials and other problems arising during the distance course designing and educational process itself in e-learning environments.

Priming moral self-ambivalence heightens deliberative behaviour in self-ambivalent individuals

Background: Recent work on cognitive-behavioural models of obsessive-compulsive disorder has focused on the roles played by various aspects of self-perception. In particular, moral self-ambivalence has been found to be associated with obsessive-compulsive phenomena. Aims: In this study we used an experimental task to investigate whether artificially priming moral self-ambivalence would increase participants' deliberation on ethical problems, an index that might be analogous to obsessive-compulsive behaviour. Method: Non-clinical participants completed two online tasks designed to prime either moral self-ambivalence, general uncertainty, or neither. All participants then completed a task requiring them to consider solutions to moral dilemmas. We recorded the time participants took to respond to the dilemmas and the length of their responses; we then combined these variables to create a measure of deliberation. Results: Priming moral self-ambivalence led to increases in deliberation, but this was only significant among those participants who scored highly on a baseline measure of moral self-ambivalence. Priming general uncertainty had no significant effect upon deliberation. Conclusions: The results suggest that moral self-ambivalence may play a role in the maintenance of obsessive-compulsive behaviour. We propose that individuals who are morally self-ambivalent might respond to situations in which this ambivalence is made salient by exhibiting behaviour with obsessive-compulsive characteristics. These findings have implications for the incorporation of ideas about self-concept into theories of obsessive-compulsive disorder.