An automatic micropipette fluid dispenser

An automatic device for repeated dispensation of a precisely controlled amount of fluid is described. The device employs a repeating micropipette powered by an electric motor geared to a rack-and-pinion drive. In our particular application, thirsty rats work for 0.2-ml shots of water delivered to a metal spout connected to a drinkometer circuit. This arrangement permits the recording of both volumetric intake and the number of licks directed at the spout.     

Inclusiveness of identification among farmers in The Netherlands and Galicia (Spain)

In this paper we discuss inclusiveness of identification among farmers in Galicia (Spain) and The Netherlands. Identification with three nested categories—farmers in the local community, farmers in the country, and farmers in Europe was assessed among 167 Dutch and 248 Galician farmers at three points in time: winter of 1993/94, winter 1995 and fall 1995. Our findings suggest that inclusiveness reduces the level of identification. However, the observed patterns of identification were more complex than inclusiveness per se can account for. Borrowing from the common ingroup‐identity model, functional and socialization models of identity formation, and a model of politicized collective identity we formulated hypotheses about patterns of identification that were to be expected. On the whole our findings supported our theoretical reasoning. Galician farmers appear to identify much less with farmers in their country and Europe than Dutch farmers do. Inclusiveness of identification appears to be linked to experience with national and supranational political institutions. More political knowledge and involvement appear to generate more inclusive patterns of identification. Among Galician farmers evaluation of the agricultural policy of the European Union is negatively related to identification with farmers in Europe, among Dutch farmers the two are positively related. Finally, more inclusive identities seem to be more politicized. Copyright © 2004 John Wiley & Sons, Ltd.     

Discounting and the role of the relation between causes

This research investigates how the relation between two causes (i.e. whether they co‐occur or not) affects the likelihood to discount one of them. In two experiments, two causes were either systematically paired together (positive relation), were paired with many other causes (independent relation), or were never paired together (negative relation). The results indicate that discounting of one of the causes (target cause) depends on the relation with the other cause (alternative cause) and the order in which the alternative cause was presented and produced the outcome alone. If information on the independent outcome of the alternative cause came prior to the joint outcome of the alternative and target cause (forward order), then discounting of the target cause occurred regardless of the relation between the two causes. If, however, information on the independent outcome of the alternative cause came after the joint outcome of the alternative and target cause (backward order), then discounting of the target cause occurred mainly when there was a positive or negative relation between the causes, but not when there was an independent relation. The degree of backward discounting given a positive or negative relation was largely identical. These results are consistent with the retrospective revaluation hypothesis of Dickinson and Burke ( 1996 ) and shed new light on the role of the relation between causes on discounting. Copyright © 2004 John Wiley & Sons, Ltd.     

Understanding the Links Between Social Support and Physical Health: A Life-Span Perspective With Emphasis on the Separability of Perceived and Received Support

ABSTRACT— Social support has been reliably related to physical health outcomes. However, the conceptual basis of such links needs greater development. In this article, I argue for a life-span perspective on social support and health that takes into account distinct antecedent processes and mechanisms that are related to measures of support over time. Such a view highlights the need to distinguish measures of perceived and received support and its links to more specific diseases (e.g., chronic, acute) and stages of disease development (e.g., incidence). I discuss both the novel implications of these theoretical arguments for research on social support and physical health, as well as the potential intervention approaches that are apparent from this perspective.     

The predictive value of numerical magnitude comparison for individual differences in mathematics achievement

Although it has been proposed that the ability to compare numerical magnitudes is related to mathematics achievement, it is not clear whether this ability predicts individual differences in later mathematics achievement. The current study addressed this question in typically developing children by means of a longitudinal design that examined the relationship between a number comparison task assessed at the start of formal schooling (mean age = 6 years 4 months) and a general mathematics achievement test administered 1 year later. Our findings provide longitudinal evidence that the size of the individual’s distance effect, calculated on the basis of reaction times, was predictively related to mathematics achievement. Regression analyses showed that this association was independent of age, intellectual ability, and speed of number identification.     

Contextual effects on number-time interaction

Time perception has long been known to be affected by numerical representations. Recent studies further demonstrate that when participants estimate the duration of Arabic numbers, number magnitude, though task-irrelevant, biases duration judgment to produce underestimation for smaller numbers and overestimation for larger numbers. Such effects were found in the present study to be significantly reduced when a weight unit gram was suffixed to the numbers rendering the mental magnitude differences between different numbers less distinctive. The effects were enhanced when a different unit kilogram was suffixed to the numbers enlarging the perceived magnitude differences between different numbers. The results indicate that effects of number magnitude on duration estimation should not be attributed to the mathematical differences between numbers but to how the numbers are perceived to differ from each other in magnitude in specific contexts when they denote concrete items. The results also provide new evidence for the theoretical proposal of a common generalized magnitude system and indicate that the system must be extended to include other action-oriented magnitudes, such as weight.     

The Structure of Grandparental Role Meaning

The present study explored the viability of Kivnick's 5-factor model of grandparental meaning (Kivnick, 1983), wherein this model was tested and subsequently refined on a sample of traditional grandparents (N = 102), and then cross-validated using a sample of custodial grandparents (N = 101). The data suggested that Kivnick's model of grandparental meaning was untenable in both grandparent samples. Instead, a single-factor model was supported in both samples. This suggests that grandparental meaning is best understood without regard to Kivnick's distinctions (Kivnick, 1983). This may reflect a cohort effect in the meaning of grandparenting, as evidenced in the diversity of roles into which grandparents are thrust, increased role confusion, as well as the idiosyncratic manner in which grandparents are often forced to define their roles in today's society.     

Conscious and unconscious proportion effects in masked priming

The global neuronal workspace theory [Dehaene, S., & Naccache, L. (2001). Towards a cognitive neuroscience of consciousness: basic evidence and a workspace framework. Cognition, 79, 1–37.] proposes that it is impossible for an unconscious stimulus to be used strategically to enhance task performance (bottom–up effect), while a fully consciously perceived stimulus can be used to improve task performance (top–down effect). Two experiments were designed to investigate these hypotheses. In a first experiment we investigated whether a manipulation of the proportion of Arabic/number word targets had a top–down effect. Since the subjects were fully aware of the target, we expected that this manipulation could be used to enhance task performance. In a second experiment we determined whether a manipulation of the proportion of Arabic/number word primes had a bottom–up effect. Since the subjects were unaware of the prime, we hypothesized that they would be unable to use the manipulation to enhance task performance and therefore the manipulation would have no effect. Both hypotheses were largely confirmed.