Speech and non-speech stimuli in the prediction of early reading skills:the influence of processing demands and response-type

Purpose: Both phonological (speech) and auditory (non-speech) stimuli have been shown to predict early reading skills. However, previous studies have failed to control for the level of processing required by tasks administered across the two levels of stimuli. For example, phonological tasks typically tap explicit awareness e.g., phoneme deletion, while auditory tasks usually measure implicit awareness e.g., frequency discrimination. Therefore, the stronger predictive power of speech tasks may be due to their higher processing demands, rather than the nature of the stimuli. Method: The present study uses novel tasks that control for level of processing (isolation, repetition and deletion) across speech (phonemes and nonwords) and non-speech (tones) stimuli. 800 beginning readers at the onset of literacy tuition (mean age 4 years and 7 months) were assessed on the above tasks as well as word reading and letter-knowledge in the first part of a three time-point longitudinal study. Results: Time 1 results reveal a significantly higher association between letter-sound knowledge and all of the speech compared to non-speech tasks. Performance was better for phoneme than tone stimuli, and worse for deletion than isolation and repetition across all stimuli. Conclusions: Results are consistent with phonological accounts of reading and suggest that level of processing required by the task is less important than stimuli type in predicting the earliest stage of reading.

A magnetoencephalographic study of low-level auditory processing in developmental dyslexia

The possibility that developmental dyslexia results from low-level sensory processing deficits has received renewed interest in recent years. Opponents of such sensory-based explanations argue that dyslexia arises primarily from phonological impairments. However, many behavioural correlates of dyslexia cannot be explained sufficiently by cognitive-level accounts and there is anatomical, psychometric and physiological evidence of sensory deficits in the dyslexic population. This thesis aims to determine whether the low-level (pre-attentive) processing of simple auditory stimuli is disrupted in compensated adult dyslexics. Using psychometric and neurophysiological measures, the nature of auditory processing abnormalities is investigated. Group comparisons are supported by analysis of individual data in order to address the issue of heterogeneity in dyslexia. The participant pool consisted of seven compensated dyslexic adults and seven age and IQ matched controls. The dyslexic group were impaired, relative to the control group, on measures of literacy, phonological awareness, working memory and processing speed. Magnetoencephalographic recordings were conducted during processing of simple, non-speech, auditory stimuli. Results confirm that low-level auditory processing deficits are present in compensated dyslexic adults. The amplitude of N1m responses to tone pair stimuli were reduced in the dyslexic group. However, there was no evidence that manipulating either the silent interval or the frequency separation between the tones had a greater detrimental effect on dyslexic participants specifically. Abnormal MMNm responses were recorded in response to frequency deviant stimuli in the dyslexic group. In addition, complete stimulus omissions, which evoked MMNm responses in all control participants, failed to elicit significant MMNm responses in all but one of the dyslexic individuals. The data indicate both a deficit of frequency resolution at a local level of auditory processing and a higher-level deficit relating to the grouping of auditory stimuli, relevant for auditory scene analysis. Implications and directions for future research are outlined.

Handling high level of censoring for endovascular aortic repair risk prediction

Feature selection is important in medical field for many reasons. However, selecting important variables is a difficult task with the presence of censoring that is a unique feature in survival data analysis. This paper proposed an approach to deal with the censoring problem in endovascular aortic repair survival data through Bayesian networks. It was merged and embedded with a hybrid feature selection process that combines cox's univariate analysis with machine learning approaches such as ensemble artificial neural networks to select the most relevant predictive variables. The proposed algorithm was compared with common survival variable selection approaches such as; least absolute shrinkage and selection operator LASSO, and Akaike information criterion AIC methods. The results showed that it was capable of dealing with high censoring in the datasets. Moreover, ensemble classifiers increased the area under the roc curves of the two datasets collected from two centers located in United Kingdom separately. Furthermore, ensembles constructed with center 1 enhanced the concordance index of center 2 prediction compared to the model built with a single network. Although the size of the final reduced model using the neural networks and its ensembles is greater than other methods, the model outperformed the others in both concordance index and sensitivity for center 2 prediction. This indicates the reduced model is more powerful for cross center prediction.

Attentional shifts towards an expected visual target alter the level of alpha-band oscillatory activity in the human calcarine cortex

Neuronal operations associated with the top-down control process of shifting attention from one locus to another involve a network of cortical regions, and their influence is deemed fundamental to visual perception. However, the extent and nature of these operations within primary visual areas are unknown. In this paper, we used magnetoencephalography (MEG) in combination with magnetic resonance imaging (MRI) to determine whether, prior to the onset of a visual stimulus, neuronal activity within early visual cortex is affected by covert attentional shifts. Time/frequency analyses were used to identify the nature of this activity. Our results show that shifting attention towards an expected visual target results in a late-onset (600 ms postcue onset) depression of alpha activity which persists until the appearance of the target. Independent component analysis (ICA) and dipolar source modeling confirmed that the neuronal changes we observed originated from within the calcarine cortex. Our results further show that the amplitude changes in alpha activity were induced not evoked (i.e., not phase-locked to the cued attentional task). We argue that the decrease in alpha prior to the onset of the target may serve to prime the early visual cortex for incoming sensory information. We conclude that attentional shifts affect activity within the human calcarine cortex by altering the amplitude of spontaneous alpha rhythms and that subsequent modulation of visual input with attentional engagement follows as a consequence of these localized changes in oscillatory activity. © 2005 Elsevier B.V. All rights reserved.

Anger and perceived legitimacy of aggression in male Hong Kong Chinese athletes: Effects of type of sport and level of competition

Problem: The vast majority of research examining the interplay between aggressive emotions, beliefs, behaviors, cognitions, and situational contingencies in competitive athletes has focused on Western populations and only select sports (e.g., ice hockey). Research involving Eastern, particularly Chinese, athletes is surprisingly sparse given the sheer size of these populations. Thus, this study examines the aggressive emotions, beliefs, behaviors, and cognitions, of competitive Chinese athletes. Method: Several measures related to aggression were distributed to a large sample (N ¼ 471) of male athletes, representing four sports (basketball, rugby union, association football/soccer, and squash). Results: Higher levels of anger and aggression tended to be associated with higher levels of play for rugby and low levels of play for contact (e.g., football, basketball) and individual sports (e.g., squash). Conclusions: The results suggest that the experience of angry emotions and aggressive behaviors of Chinese athletes are similar to Western populations, but that sport psychology practitioners should be aware of some potentially important differences, such as the general tendency of Chinese athletes to disapprove of aggressive behavior.

Contextual effects in speed perception may occur at an early stage of processing

How does nearby motion affect the perceived speed of a target region? When a central drifting Gabor patch is surrounded by translating noise, its speed can be misperceived over a fourfold range. Typically, when a surround moves in the same direction, perceived centre speed is reduced; for opposite-direction surrounds it increases. Measuring this illusion for a variety of surround properties reveals that the motion context effects are a saturating function of surround speed (Experiment I) and contrast (Experiment II). Our analyses indicate that the effects are consistent with a subtractive process, rather than with speed being averaged over area. In Experiment III we exploit known properties of the motion system to ask where these surround effects impact. Using 2D plaid stimuli, we find that surround-induced shifts in perceived speed of one plaid component produce substantial shifts in perceived plaid direction. This indicates that surrounds exert their influence early in processing, before pattern motion direction is computed. These findings relate to ongoing investigations of surround suppression for direction discrimination, and are consistent with single-cell findings of direction-tuned suppressive and facilitatory interactions in primary visual cortex (V1).

Signal processing in a loudspeaking telephone

One of the major problems associated with communication via a loudspeaking telephone (LST) is that, using analogue processing, duplex transmission is limited to low-loss lines and produces a low acoustic output. An architectural for an instrument has been developed and tested, which uses digital signal processing to provide duplex transmission between a LST and a telopnone handset over most of the B.T. network. Digital adaptive-filters are used in the duplex LST to cancel coupling between the loudspeaker and microphone, and across the transmit to receive paths of the 2-to-4-wire converter. Normal movement of a person in the acoustic path causes a loss of stability by increasing the level of coupling from the loudspeaker to the microphone, since there is a lag associated the adaptive filters learning about a non-stationary path, Control of the loop stability and the level of sidetone heard by the hadset user is by a microprocessoe, which continually monitors the system and regulates the gain. The result is a system which offers the best compromise available based on a set of measured parameters.A theory has been developed which gives the loop stability requirements based on the error between the parameters of the filter and those of the unknown path. The programme to develope a low-cost adaptive filter in LST produced a low-cost adaptive filter in LST produced a unique architecture which has a number of features not available in any similar system. These include automatic compensation for the rate of adaptation over a 36 dB range of output level, , 4 rates of adaptation (with a maximum of 465 dB/s), plus the ability to cascade up to 4 filters without loss o performance. A complex story has been developed to determine the adptation which can be achieved using finite-precision arithmatic. This enabled the development of an architecture which distributed the normalisation required to achieve optimum rate of adaptation over the useful input range. Comparison of theory and measurement for the adaptive filter show very close agreement. A single experimental LST was built and tested on connections to hanset telephones over the BT network. The LST demonstrated that duplex transmission was feasible using signal processing and produced a more comfortable means of communication beween people than methods emplying deep voice-switching to regulate the local-loop gain. Although, with the current level of processing power, it is not a panacea and attention must be directed toward the physical acoustic isolation between loudspeaker and microphone.

Effect of processing on sulphur antioxidants in polyolefins

The effect of processing on the antioxidant activity of sulphur-containing compounds, with particular reference to nickel dialkyldithiophosphates and their corresponding di sulphides, were studied in polyolefins under melt, thermal and photo-oxidative conditions. These compounds were evaluated both at low (normal) and high (concentrates) concentrations. In general, the dithiophosphates were found to be very efficient melt stabilisers at normal concentrtion levels, and compare quite favourably with the best commercially available systems. The nickel dithiophosphates were also found to be very efficient thermal stabilisers for polyolefins, but their activity is highly dependent on the alkyl substituent in the molecule. The corresponding disulphides on the other hand showed very little activity under thermal oxidative conditions, and this was attributed to their inefficiency in scavenging alkyl peroxyl radicals since both compounds possess similar peroxidolytic activity. Furthermore, the nickel dithiophosphates were found to be excellent photo stabilisers for mildly-processed polyolefins while the corresponding disulphides only offer slight protection to the polymer. Oxidative processing of the disulphide, however, results in a dramatic improvement in their photo antioxidant activity. Thionophospho-ric acid, a major oxidation product of dithiophosphates, was also shown to have photo antioxidant activity similar to that of the disulphides. A combination of a U.V. absorber with the nickel complex and/or the disulphide resulted in a synergistic stabiliser system which was further augmented by oxidative processing. Moreover, the dilute analogues of such multicomponent stabiliser concentrates also showed excellent melt, thermal and photo-stabilising activity. The mechanistic studies carried out on the nickel complex and the corresponding disulphide clearly identified the thionophosphoric acid a a major transformation product although various triesters were formed as reaction intermediates. The mechanisms of the antioxidant action of the dithiophosphates, which is believed to involve a cyclical process similar to that shown for simple alkyl sulphides and nitroxyls, are discussed.

Effect of processing variables and bulk composition on the surface composition of spray dried powders of a model food system

The surface composition of food powders created from spray drying solutions containing various ratios of sodium caseinate, maltodextrin and soya oil have been analysed by Electron Spectroscopy for Chemical Analysis. The results show significant enrichment of oil at the surface of particles compared to the bulk phase, and (when the non-oil components only are considered), a significant surface enrichment of sodium caseinate also. The study found evidence of high levels (80%) of surface fat even on particles of food industry grade (92.5%) sodium caseinate containing only 1% fat.

Institutions, finance and the level of development:the impact on entrepreneurship in transition

We investigate the impact of institutions on entrepreneurial entry, based on a large cross-country sample, combining working age population data generated by the GEM project with macro level indicators. Our four key findings indicate that: (a) institutional obstacles to entrepreneurship have different impact in rich countries compared to poor countries; (b) institutional obstacles have a stronger impact on 'opportunity entrepreneurship' than on 'necessity entrepreneurship'; (c) two institutional indicators - property right protection and access to finance - appear to have a dominant impact on entrepreneurship; (d) institutions have a long term impact. More than ten years after the Soviet system imploded in Central and Eastern Europe, these countries still experience significantly lower levels of entrepreneurship than economies coming from different legal traditions.

The impact of stressors and regulatory focus on creativity:a dual level of analysis

Presentation

An investigation into the effects of processing instruction on the acquisition of English relative clauses by Syrian learners

The purpose of this research was to investigate the effects of Processing Instruction (VanPatten, 1996, 2007), as an input-based model for teaching second language grammar, on Syrian learners’ processing abilities. The present research investigated the effects of Processing Instruction on the acquisition of English relative clauses by Syrian learners in the form of a quasi-experimental design. Three separate groups were involved in the research (Processing Instruction, Traditional Instruction and a Control Group). For assessment, a pre-test, a direct post-test and a delayed post-test were used as main tools for eliciting data. A questionnaire was also distributed to participants in the Processing Instruction group to give them the opportunity to give feedback in relation to the treatment they received in comparison with the Traditional Instruction they are used to. Four hypotheses were formulated on the possible effectivity of Processing Instruction on Syrian learners’ linguistic system. It was hypothesised that Processing Instruction would improve learners’ processing abilities leading to an improvement in learners’ linguistic system. This was expected to lead to a better performance when it comes to the comprehension and production of English relative clauses. The main source of data was analysed statistically using the ANOVA test. Cohen’s d calculations were also used to support the ANOVA test. Cohen’s d showed the magnitude of effects of the three treatments. Results of the analysis showed that both Processing Instruction and Traditional Instruction groups had improved after treatment. However, the Processing Instruction Group significantly outperformed the other two groups in the comprehension of relative clauses. The analysis concluded that Processing Instruction is a useful tool for instructing relative clauses to Syrian learners. This was enhanced by participants’ responses to the questionnaire as they were in favour of Processing Instruction, rather than Traditional Instruction. This research has theoretical and pedagogical implications. Theoretically, the study showed support for the Input hypothesis. That is, it was shown that Processing Instruction had a positive effect on input processing as it affected learners’ linguistic system. This was reflected in learners’ performance where learners were able to produce a structure which they had not been asked to produce. Pedagogically, the present research showed that Processing Instruction is a useful tool for teaching English grammar in the context where the experiment was carried out, as it had a large effect on learners’ performance.