Applying a longitudinal tracer methodology to evaluate complex interventions in complex settings

Long-running multi-faceted intervention studies are particularly problematic in large complex organizations where traditional methods prove too resource intensive and can yield inaccurate and incomplete findings. This paper describes the first use of, longitudinal tracer methodology (LTM), a realist approach to evaluation, to examine the links between multiple complex intervention activities (processes) and their outcomes on a construction megaproject. LTM is especially useful when the researcher has little control over intervention delivery but has evidence drawn from multiple sources to evaluate the intervention activities effects over time. This methodology has rarely been deployed in complex organizational settings and not on a construction megaproject. This paper presents a case study of its use over a period of three years, on 24 construction sites forming London’s Thames Tideway Tunnel (Tideway) megaproject. The study examines the “transformational” power of occupational safety and health (OSH) interventions across the multiple organizations and supply chains in the megaproject. The study shows how the method can be adapted in-flight to accommodate shifting lines of inquiry as the intervention activities progress and change. This feature along with its resource-efficient operation, make it an attractive option where interventions are likely to have differential effects across multiple sites of enactment.     

The nature of the language faculty and its implications for evolution of language (Reply to Fitch, Hauser, and Chomsky)

In a continuation of the conversation with Fitch, Chomsky, and Hauser on the evolution of language, we examine their defense of the claim that the uniquely human, language-specific part of the language faculty (the “narrow language faculty”) consists only of recursion, and that this part cannot be considered an adaptation to communication. We argue that their characterization of the narrow language faculty is problematic for many reasons, including its dichotomization of cognitive capacities into those that are utterly unique and those that are identical to nonlinguistic or nonhuman capacities, omitting capacities that may have been substantially modified during human evolution. We also question their dichotomy of the current utility versus original function of a trait, which omits traits that are adaptations for current use, and their dichotomy of humans and animals, which conflates similarity due to common function and similarity due to inheritance from a recent common ancestor. We show that recursion, though absent from other animals' communications systems, is found in visual cognition, hence cannot be the sole evolutionary development that granted language to humans. Finally, we note that despite Fitch et al.'s denial, their view of language evolution is tied to Chomsky's conception of language itself, which identifies combinatorial productivity with a core of “narrow syntax.” An alternative conception, in which combinatoriality is spread across words and constructions, has both empirical advantages and greater evolutionary plausibility.     

Career aspirations of youth: Untangling race/ethnicity, SES, and gender

This study examined the influence of gender, socioeconomic status, and race/ethnicity on the career aspirations of over 22,000 8th and 10th grade youth. The top five occupations identified by youth as aspirations included artist, lawyer, musician, FBI agent, and actor/actress. Top occupations were also reported for each gender × socioeconomic status × race/ethnicity group. Aspirations were coded by social prestige level, minimum education requirements, and median salary. Results revealed significant main effects for socioeconomic status and race/ethnicity as well as significant interaction effects. Further, significant gender main effects and a significant gender × ethnicity interaction were found for occupational prestige and educational requirements.     

Goal attribution to schematic animals: do 6‐month‐olds perceive biological motion as animate?

Infants are sensitive to biological motion, but do they recognize it as animate? As a first step towards answering this question, two experiments investigated whether 6‐month‐olds selectively attribute goals to shapes moving like animals. We habituated infants to a square moving towards one of two targets. When target locations were switched, infants reacted more to movement towards a new goal than a new location – but only if the square moved non‐rigidly and rhythmically, in a schematic version of bio‐mechanical movement older observers describe as animal‐like ( Michotte, 1963 ). Goal attribution was specific to schematic animal motion: It did not occur if the square moved rigidly with the same rhythm as the animate stimulus, or if the square had the same amount of non‐rigid deformation, but in an inanimate configuration. The data would seem to show that perception of schematic animal motion is linked to a system for psychological reasoning from infancy. This in turn suggests that 6‐month‐olds may already interpret biological motion as animate.     

Is the use of sentient animals in basic research justifiable?

Animals can be used in many ways in science and scientific research. Given that society values sentient animals and that basic research is not goal oriented, the question is raised: "Is the use of sentient animals in basic research justifiable?" We explore this in the context of funding issues, outcomes from basic research, and the position of society as a whole on using sentient animals in research that is not goal oriented. We conclude that the use of sentient animals in basic research cannot be justified in light of society's priorities.     

Two routes for activation in the priming of categorical coordinates

The authors operationalized category priming as participants' recognition facilitation of nonstudied, low semantically similar exemplars by studied exemplars in a category. The existing literature either does not examine the effect of studied exemplars on nonstudied exemplars in a category or fails to show an appreciable amount of category priming. In 2 experiments, the authors demonstrated a unique process to account for the category priming effect and distinguish it from the semantic priming effect, facilitation of semantically similar exemplars, in the context of a category. In Experiment 1A, the authors used a multidimensional scaling technique to examine participants' internal structure of different categories. In Experiment 1B, the authors used a lexical decision task that used these internal structures to show that semantic encoding of category exemplars causes activation of existing category knowledge in memory. Consequently, participants easily recognized nonstudied, low semantically similar exemplars in a category. However, recognition facilitation between high semantically similar exemplars did not require category knowledge activation.     

All in the mind's eye? Anger rumination and reappraisal

Research on rumination has demonstrated that compared with distraction, rumination intensifies and prolongs negative emotion. However, rumination and distraction differ both in what one thinks about and how one thinks about it. Do the negative outcomes of rumination result from how people think about negative events or simply that they think about them at all? To address this question, participants in 2 studies recalled a recent anger-provoking event and then thought about it in 1 of 2 ways: by ruminating or by reappraising. The authors examined the impact of these strategies on subsequent ratings of anger experience (Study 1) as well as on perseverative thinking and physiological responding over time (Study 2). Relative to reappraisal, rumination led to greater anger experience, more cognitive perseveration, and greater sympathetic nervous system activation. These findings provide compelling new evidence that how one thinks about an emotional event can shape the emotional response one has.     

Ceftriaxone rescues hippocampal neurons from excitotoxicity and enhances memory retrieval in chronic hypobaric hypoxia

Exposure to high altitude is known to cause impairment in cognitive functions in sojourners. The molecular events leading to this behavioral manifestation, however, still remain an enigma. The present study aims at exploring the nature of memory impairment occurring on chronic exposure to hypobaric hypoxia and the possible role of glutamate in mediating it. Increased ionotropic receptor stimulation by glutamate under hypobaric hypoxic conditions could lead to calcium mediated excitotoxic cell death resulting in impaired cognitive functions. Since glutamate is cleared from the synapse by the Glial Glutamate Transporter, upregulation of the transporter can be a good strategy in preventing excitotoxic cell death. Considering previous reports on upregulation of the expression of Glial Glutamate Transporter on ceftriaxone administration, the therapeutic potential of ceftriaxone in ameliorating hypobaric hypoxia induced memory impairment was investigated in male Sprague Dawley rats. Exposure to hypobaric hypoxia equivalent to an altitude of 7600 m for 14 days lead to oxidative stress, chromatin condensation and neuronal degeneration in the hippocampus. This was accompanied by delayed memory retrieval as evident from increased latency and pathlength in Morris Water Maze. Administration of ceftriaxone at a dose of 200 mg/kg for 7 days and 14 days during the exposure on the other hand improved the performance of rats in the water maze along with decreased oxidative stress and enhanced neuronal survival when compared to hypoxic group without drug administration. An increased expression of Glial Glutamate Transporter was also observed following drug administration indicating faster clearance of glutamate from the synapse. The present study not only brings to light the effect of longer duration of exposure to hypobaric hypoxia on the memory functions, but also indicates the pivotal role played by glutamate in mediating excitotoxic neuronal degeneration at high altitude. The therapeutic potential of ceftriaxone in providing neuroprotection in excitotoxic conditions by increasing Glial Glutamate Transporter expression and thereby enhancing glutamate uptake from the synapse has also been explored.