Medidas operantes de limiar auditivo em crianças com surdez pré-lingual, usuárias de implante coclear

Limiares auditivos de crianças surdas pré-linguais usuárias de implante coclear foram avaliados com estimulação elétrica em um dos eletrodos mediais. A avaliação empregou um procedimento operante do tipo go/no go para ensinar uma discriminação simples, evidenciada por uma resposta motora, entre presença e ausência do estímulo auditivo. Estabelecida a linha de base, a manipulação na intensidade do estímulo foi implementada de acordo com o método psicofísico de escada modificado, começando por uma seqüência descendente. Os sete participantes do estudo mostraram perda da precisão no responder sob controle do estímulo quando a intensidade diminuía além de um certo valor e a precisão era recuperada quando a intensidade era novamente aumentada, o que permitiu a identificação de limiares individuais. Os resultados sugerem que o método psicofísico combinado com o procedimento operante pode ser uma alternativa viável para avaliar limiar auditivo de pessoas sem linguagem em situação clínica de regulagem do implante coclear.

Operant measurement of auditory threshold in prelingually deaf users of cochlear implants: II

Two experiments evaluated an operant procedure for establishing stimulus control using auditory and electrical stimuli as a baseline for measuring the electrical current threshold of electrodes implanted in the cochlea. Twenty-one prelingually deaf children, users of cochlear implants, learned a Go/No Go auditory discrimination task (i.e., pressing a button in the presence of the stimulus but not in its absence). When the simple discrimination baseline became stable, the electrical current was manipulated in descending and ascending series according to an adapted staircase method. Thresholds were determined for three electrodes, one in each location in the cochlea (basal, medial, and apical). Stimulus control was maintained within a certain range of decreasing electrical current but was eventually disrupted. Increasing the current recovered stimulus control, thus allowing the determination of a range of electrical currents that could be defined as the threshold. The present study demonstrated the feasibility of the operant procedure combined with a psychophysical method for threshold assessment, thus contributing to the routine fitting and maintenance of cochlear implants within the limitations of a hospital setting.

The failure of Australian legislation on indirect discrimination to detect the systemic racism which prevents Aboriginal people from fully participating in the workforce

Government figures put the current indigenous unemployment rate at around 23%, 3 times the unemployment rate for other Australians. This thesis aims to assess whether Australian indirect discrimination legislation can provide a remedy for one of the causes of indigenous unemployment - the systemic discrimination which can result from the mere operation of established procedures of recruitment and hiring. The impact of those practices on indigenous people is examined in the context of an analysis of anti-discrimination legislation and cases from all Australian jurisdictions from the time of the passing of the Racial Discrimination Act by the Commonwealth in 1975 to the present. The thesis finds a number of reasons why the legislation fails to provide equality of opportunity for indigenous people seeking to enter the workforce. In nearly all jurisdictions it is obscurely drafted, used mainly by educated middle class white women, and provides remedies which tend to be compensatory damages rather than change to recruitment policy. White dominance of the legal process has produced legislative and judicial definitions of "race" and "Aboriginality" which focus on biology rather than cultural difference. In the commissions and tribunals complaints of racial discrimination are often rejected on the grounds of being "vexatious" or "frivolous", not reaching the required standard of proof, or not showing a causal connection between race and the conduct complained of. In all jurisdictions the cornerstone of liability is whether a particular employment term, condition or practice is reasonable. The thesis evaluates the approaches taken by appellate courts, including the High Court, and concludes that there is a trend towards an interpretation of reasonableness which favours employer arguments such as economic rationalism, the maintenance of good industrial relations, managerial prerogative to hire and fire, and the protection of majority rights. The thesis recommends that separate, clearly drafted legislation should be passed to address indigenous disadvantage and that indigenous people should be involved in all stages of the process.

Magnocellular and parvocellular pathway mediated luminance contrast discrimination in amblyopia

To evaluate whether luminance contrast discrimination losses in amblyopia on putative magnocellular (MC) and parvocellular (PC) pathway tasks reflect deficits at retinogeniculate or cortical sites. Fifteen amblyopes including six anisometropes, seven strabismics, two mixed and 12 age-matched controls were investigated. Contrast discrimination was measured using established psychophysical procedures that differentiate MC and PC processing. Data were described with a model of the contrast response of primate retinal ganglion cells. All amblyopes and controls displayed the same contrast signatures on the MC and PC tasks, with three strabismics having reduced sensitivity. Amblyopic PC contrast gain was similar to electrophysiological estimates from visually normal, non-human primates. Sensitivity losses evident in a subset of the amblyopes reflect cortical summation deficits, with no change in retinogeniculate contrast responses. The data do not support the proposal that amblyopic contrast sensitivity losses on MC and PC tasks reflect retinogeniculate deficits, but rather are due to anomalous post-retinogeniculate cortical processing of retinal signals.

12 fingers or one, it’s how you play? Genetic discrimination in the Australian workforce

For quite some time, debate has raged about what the human race can and should do with its knowledge of genetics. We are now nearly 60 years removed from the work of Watson and Crick who determined the structure of deoxyribonucleic acid (DNA), yet our opinions as how best to employ scientific knowledge of the human genome, remain as diverse and polarised as ever. Human judgment is often shaped and coloured by popular media and culture, so it should come as no surprise that box office movies such as Gattaca (1997) continue to play a role in informing public opinion on genetics. In order to perform well at the box office, movies such as Gattaca take great liberty in sensationalising (and even distorting) the implications that may result from genetic screening and testing. If the public’s opinion on human genetics is strongly derived from the box office and popular media, then it is no wonder that the discourse on human genetics is couched in the polar parlances of future utopias or future dystopias. When legislating in an area like genetic discrimination in the workforce, we must be mindful of not overplaying the causal link between genetic predisposition towards a disability and an employee’s ability to perform the inherent requirements of their job. Genetic information is ultimately about people, it is not about genes. Genetic discrimination is ultimately about actions, it is not about the intrinsic value of genetic information.

Discrimination or Differential Involvement? A Review of the Research Exploring the Impact of Indigenous Status on Sentencing

Existing court data suggest that adult Indigenous offenders are more likely than non-Indigenous defendants to be sentenced to prison but once imprisoned generally receive shorter terms. Using findings from international and Australian multivariate statistical analyses, this paper reviews the three key hypotheses advanced as plausible explanations for these differences: 1) differential involvement, 2) negative discrimination, 3) positive discrimination. Overall, prior research shows strong support for the differential involvement thesis, some support for positive discrimination and little foundation for negative discrimination in the sentencing of Indigenous defendants. Where discrimination is found, we argue that this may be explained by the lack of a more complete set of control variables in researchers’ multivariate models.