Assessing stimulus–stimulus (semantic) conflict in the Stroop task using saccadic two-to-one color response mapping and preresponse pupillary measures

© 2015, The Psychonomic Society, Inc. Conflict in the Stroop task is thought to come from various stages of processing, including semantics. Two-to-one response mappings, in which two response-set colors share a common response location, have been used to isolate stimulus–stimulus (semantic) from stimulus–response conflict in the Stroop task. However, the use of congruent trials as a baseline means that the measured effects could be exaggerated by facilitation, and recent research using neutral, non-color-word trials as a baseline has supported this notion. In the present study, we sought to provide evidence for stimulus–stimulus conflict using an oculomotor Stroop task and an early, preresponse pupillometric measure of effort. The results provided strong (Bayesian) evidence for no statistical difference between two-to-one response-mapping trials and neutral trials in both saccadic response latencies and preresponse pupillometric measures, supporting the notion that the difference between same-response and congruent trials indexes facilitation in congruent trials, and not stimulus–stimulus conflict, thus providing evidence against the presence of semantic conflict in the Stroop task. We also demonstrated the utility of preresponse pupillometry in measuring Stroop interference, supporting the idea that pupillary effects are not simply a residue of making a response

Early infant HIV-1 diagnosis programs in resource-limited settings: opportunities for improved outcomes and more cost-effective interventions

Early infant diagnosis (EID) of HIV-1 infection confers substantial benefits to HIV-infected and HIV-uninfected infants, to their families, and to programs providing prevention of mother-to-child transmission (PMTCT) services, but has been challenging to implement in resource-limited settings. In order to correctly inform parents/caregivers of infant infection status and link HIV-infected infants to care and treatment, a 'cascade' of events must successfully occur. A frequently cited barrier to expansion of EID programs is the cost of the required laboratory assays. However, substantial implementation barriers, as well as personnel and infrastructure requirements, exist at each step in the cascade. In this update, we review challenges to uptake at each step in the EID cascade, highlighting that even with the highest reported levels of uptake, nearly half of HIV-infected infants may not complete the cascade successfully. We next synthesize the available literature about the costs and cost effectiveness of EID programs; identify areas for future research; and place these findings within the context of the benefits and challenges to EID implementation in resource-limited settings

2 en 1 ou lorsque l'effet de format dépend de l'effet d'ordre: le cas du problème des avocats et des ingénieurs

International audienceThree studies investigated the base-rate sensitivity in the list version of Kahneman and Tversky’s (1973) lawyer-engineer problem (Ginossar & Trope 1987). Study 1 replicated Ginossar and Trope’s results : individuals solving the task within the standard version failed to integrate base rates into their judgment, whereas individuals presented with the list format were rather base rate sensitive. Studies 2 and 3 investigated the extent to which the latter effect was due to the ordinal position of base rates information within the list. Results from these studies suggest that participants attend to base-rate information only when it is presented at the beginning or in the end of the list. The implications of these results for the original explanation (in terms of equalized salience of information) are discussed and an alternative explanation is offered.Nous avons étudié la prise en compte des probabilités a priori dans le cadre du problème des avocats et des ingénieurs (Kahneman & Tversky, 1973), présenté sous format liste (Ginossar & Trope, 1987). Dans la première étude, nous répliquons les résultats obtenus antérieurement par Ginossar et Trope (1987) selon lesquels les individus ignorent les probabilités a priori lorsqu’elles sont présentées dans le problème classique mais qu’ils en tiennent compte lorsque celles-ci sont formulées sous forme de liste. Les deux études suivantes ont pour objectif de savoir si cet effet est dû également à la position des probabilités à l’intérieur de la liste. Les résultats de ces deux études suggèrent que les participants sont sensibles aux probabilités a priori uniquement dans la mesure où ces dernières apparaissent au début ou à la fin de la liste. L’explication classique de Ginossar et Trope (1987), en termes d’« égalisation de la saillance » des informations, est discutée. Une explication alternative, en terme d’« égalisation de la pertinence » est apportée