Contiguity and covariation in human causal inference

Nearly every theory of causal induction assumes that the existence and strength of causal relations needs to be inferred from observational data in the form of covariations. The last few decades have seen much controversy over exactly how covariations license causal conjectures. One consequence of this debate is that causal induction research has taken for granted that covariation information is readily available to reasoners. This perspective is reflected in typical experimental designs, which either employ covariation information in summary format or present participants with clearly marked discrete learning trials. I argue that such experimental designs oversimplify the problem of causal induction. Real-world contexts rarely are structured so neatly; rather, the decision about whether a cause and effect co-occurred on a given occasion constitutes a key element of the inductive process. This article will review how the event-parsing aspect of causal induction has been and could be addressed in associative learning and causal power theories.     

The relationship of social support to physically abused children's adjustment

OBJECTIVE: This study had three main objectives: First, to assess physically abused children's perceptions of teacher, peer, and family support; second, to determine whether the levels of perceived support differ according to the person's social role; and third to assess which sources of social support show stronger associations with adjustment in a physically abused sample. METHOD: Perceived social support from teachers, families and peers was assessed in a sample of 37 physically abused children using a shortened version of the Survey of Children's Social Support (Dubow & Ullman, 1989). Child adjustment was indexed by child and parent reports of child depression, anxiety, and anger. RESULTS: Analyses indicated that the children rated their families, peers, and teachers highly as sources of social support, with families being rated as the most important source. Hierarchical multiple regression analyses indicated that perceived peer support was significantly negatively related to children's and parent's reports of children's depression and anxiety. Furthermore, perceived family support was significantly negatively associated with child reported depression. No significant relationships were found between perceived teacher support and symptomatology. CONCLUSIONS: Overall, the results suggest that peer and family support are particularly important for physically abused children's psychological functioning, particularly for internalizing problems.     

The importance of shared environment in mother-infant attachment security: a behavioral genetic study

In a sample of 157 monozygotic and dizygotic twins, genetic and environmental influences on infant attachment and temperament were quantified. Only unique environmental or error components could explain the variance in disorganized versus organized attachment as assessed in the Ainsworth Strange Situation Procedure. For secure versus nonsecure attachment, 52% of the variance in attachment security was explained by shared environment, and 48% of the variance was explained by unique environmental factors and measurement error. The role of genetic factors in attachment disorganization and attachment security was negligible. Genetic factors explained 77% of the variance in temperamental reactivity, and unique environmental factors and measurement error explained 23%. Differences in temperamental reactivity were not associated with attachment concordance.     

The perception of static subjective contours in infancy

Only a few empirical investigations have focused on infants' ability to perceive static subjective contours. Furthermore, these experiments have provided contradictory findings regarding the age at which this capability emerges. The present study examined the development of infants' sensitivity to an elliptical version of the subjective circle described by Ehrenstein. A habituation-dishabituation procedure was used to test the ability of 4-, 5-, and 7-month-old infants (N = 128) to differentiate between a subjective ellipse and a nonsubjective pattern that was constructed by displacing the inducing elements of the illusory figure. Results indicated that even the 4-month-olds were capable of discriminating between the subjective ellipse and the nonillusory display. A control experiment secured that this behavior was not generated by certain local differences between the test patterns. Furthermore, the results suggest that the perceived strength of the subjective contour was size dependent. This observation is discussed within the context of more recent neurophysiological models.     

Acute phase reaction and acute phase proteins

INTRODUCTION The first reaction of the body to immunological stress is the innate, non-specific response preceding specific immune reactions. The acute phase response (APR) is a prominent systemic reaction of the or- ganism to local or systemic disturbances in its ho- meostasis caused by infection, tissue injury, trauma or surgery, neoplastic growth or immunological disor- ders (Gordon and Koy, 1985; Gruys et al., 1999). At the site of invasion by a micro-organism and the place of tissu…     

Rhesus monkeys (<Emphasis Type="Italic">Macaca mulatta</Emphasis>) select Arabic numerals or visual quantities corresponding to a number of sequentially completed maze trials

Four number-trained rhesus monkeys were trained to enumerate their sequential responses. After completing a series of computerized maze trials, the monkeys were given a same/different discrimination involving a numerical stimulus (an Arabic numeral or a visual quantity) and the letterD. The goal was to choose the numerical stimulus if it matched the number of just-completed maze trials, and to choose the letterD if it did not. There were large individual differences in performance, but one animal performed above 70% when receiving randomly intermixed series of 1, 3, 5, and 9 maze trials. This indicates that the monkey was keeping track of the approximate number of maze trials completed in each series and using that numerical cue to respond during the same/different discrimination.     

Emotional neglect and family structure: impact on student functioning

OBJECTIVE: The goal of this study was to demonstrate the relationship between retrospective reports of child neglect, family of origin functioning, and current psychological distress. It was hypothesized that experience of childhood emotional neglect would be associated with lower levels of cohesion and adaptability in participants' family of origin and greater levels of current psychological distress. Gender effects were explored. METHOD: Retrospective reports of emotional neglect in childhood were quantified by use of a parental bonding measure, specifically by assessing level of perceived parental care. Participants were assigned to one of three groups based on level of care scores: neglect by a primary male caregiver, neglect by a primary female caregiver, and no neglect. These groups were compared on three variables: current psychological functioning, retrospective report of family of origin adaptability, and retrospective report of family of origin cohesiveness. Amount of time left in the care of others was used as a covariate based on attachment theory literature. RESULTS: Data were analyzed for 69 female and 22 male undergraduate students. Participants who reported a childhood experience of emotional neglect by a primary female caregiver described greater current psychological distress than those reporting no neglect or neglect by a primary male caregiver. Participants who experienced emotional neglect by a primary female caregiver, as compared to those reporting emotional neglect by a primary male caregiver and those reporting no neglect, described lower cohesion and adaptability in their family of origin. There were no differences between male and female participants in terms of impact of emotional neglect. CONCLUSIONS: This study suggests potential caregiver gender effects, regardless of respondent gender. Perceived neglect by female, but not male caregivers, led to psychological distress in adulthood and was associated with lower cohesion and adaptability in one's family of origin. Future research should attempt to account for the participants' expectations regarding male and female caregiver roles.     

Disseminate your findings

While research training often takes place during every day practice, for the majority of library and information professionals, essential training will have been received as part of the dissertation element of their degree. However, there is a danger that important dissertation study findings are not disseminated if, for example, the student has moved onto a new job. The Health Information and Libraries Journal seek to address this research/practice gap with the introduction of a new feature 'Dissertations into Practice' specifically tasked with providing a safe and structured environment for students to disseminate their dissertation project findings.     

Counting cells with a low-cost integrated microfluidics-waveguide sensor

The capability to count cells from biofluids at low cost has important diagnostic implications in resource-poor settings. Many approaches have been developed to address this important need, and while most envision a low per-test cost, the detector instrument can be quite expensive. In this report, we present a novel device that enables low-cost and rapid counting of cells from a drop of blood. We demonstrate a shallow, buried, planar waveguide fabricated by ion exchange in glass that underlies a microfluidic structure for capturing cells. Laser light transmitted through the waveguide was attenuated by the number of metal nanoparticles tagged to the cells because of the interaction of the metal particles with the evanescent field of the waveguide. Calibration of the sensor using bead-tagged lymphocytes captured from human blood showed that the sensor could semi-quantitatively count as few as 100 cells/μL of blood. This technology enables the enumeration of specifically captured cells, allowing for a point-of-care, hand-held device for fast and affordable cell counting in screening, remote, or resource-poor settings.     

Implications of intra-limb variability on asymmetry analyses

The aim of this study was to investigate the effect of intra-limb variability on the calculation of asymmetry with the purpose of informing future analyses. Asymmetry has previously been quantified for discrete kinematic and kinetic variables; however, intra-limb variability has not been routinely included in these analyses. Synchronized lower-limb kinematic and kinetic data were collected from eight trained athletes (age 22 ± 5 years, mass 74.0 ± 8.7 kg, stature 1.79 ± 0.07 m) during maximal velocity sprint running. Asymmetry was quantified using a modified version of the symmetry angle for selected kinematic and kinetic variables. Significant differences (P < 0.05) between left and right values for each variable were calculated to indicate intra-limb variability relative to between-limb differences. Significant asymmetry was present in only 39% of kinematic variables and 23% of kinetic variables analysed. Large kinetic asymmetry values (>90%) were calculated for some athletes that were not significant, due to large intra-limb variability. Variables that displayed significant asymmetry were athlete-specific. Findings highlight the potential for misleading results if intra-limb variability is not included in asymmetry analyses. The exclusion of asymmetry scores for variables not displaying significant asymmetry will be useful when calculating overall asymmetry for different participants and could be applied to future running gait analyses.