A primer on the understanding of meta-analysis

ObjectivesThe purpose of the present paper is to provide a primer on the understanding of meta-analysis.Design and methodAfter presenting the rationale behind meta-analysis, the present paper defines statistical artifacts of sampling error and measurement.FindingsExamples show that statistical artifacts influence the correlation coefficient. The paper also explains the notions of confidence intervals and credibility intervals and how correlations corrected for sampling error and measurement error are calculated.ConclusionsThe paper concludes by explaining the notion of second-order sampling error and moderator meta-analysis.     

Reduction and emergence in the physical sciences: Reply to Rueger

I analyse Rueger’s application of Kim’s model of functional reduction to the relation between the thermal conductivities of metal bars at macroscopic and atomic scales. 1) I show that it is a misunderstanding to accuse the functional reduction model of not accounting for the fact that there are causal powers at the micro-level which have no equivalent at the macro-level. The model not only allows but requires that the causal powers by virtue of which a functional predicate is defined, are only a subset of the causal powers of the properties filling the functional specification. 2) The fact that the micro-equation does not converge to the macro-equation in general but only under the constraint of a “solvability condition” does not show that reduction is impossible, as Rueger claims, but only that reduction requires inter-level constraints. 3) Rueger tries to analyse inter-level reduction with the conceptual means of intra-level reduction. This threatens the coherence of his analysis, given that it makes no sense to ascribe macroproperties such as thermal conductivity to entities at the atomic level. Ignoring the distinction between theses two senses of “reduction” is especially confusing because they have opposite directions: in intra-level reduction, the more detailed account reduces to the less detailed one, whereas in inter-level reduction, the less detailed theory is reduced to the more detailed one. 4) Finally I criticize Rueger’s way of using Wimsatt’s criteria for emergence in terms of non-aggregativity, to construct a concept of synchronic emergence. It is wrong to require, over and above non-aggregativity, irreducibility as a criterion for emergence.     

Modeling adaptive cooperative and competitive metaphors as mental models for joint decision making

In this paper, joint decision making processes are studied and the role of cognitive metaphors as mental models in them. A second-order self-modeling network model is introduced based on mechanisms known from cognitive and social neuroscience and cognitive metaphor and mental model literature. The cognitive metaphors were modeled as specific forms of mental models providing a form of modulation within the joint decision making process. The model addresses not only the use of these mental models in the decision making, but also their hebbian learning and the control over the learning. The obtained self-modeling network model was applied to two types of metaphors that affect joint decision making in different manners: a cooperative metaphor and a competitive metaphor. By a number of scenarios it was shown how the obtained self-modeling network model can be used to simulate and analyze joint decision processes and how they are influenced by such cognitive metaphors.     

A second-order adaptive network model for emotion regulation in addictive social media behaviour

Social media addiction has spread rapidly among young people in recent years. Individuals with social media addiction are more likely to avoid and suppress negative emotions instead of reappraising these emotions, which can cause psychological and even physical harm. This study presents a second-order adaptive mental network model to simulate the process of emotion regulation in social media addicts and the impacts of stress and therapy in this process. This network model can use three types of emotion regulation strategies: suppression, avoidance (by escaping to social media), and reappraisal. Using this model, two scenarios for a person with social media addiction are compared: with and without therapy. It is found that if therapy successfully improves the regulation by reappraisal, the use of suppression and avoidance can be reduced. Characteristics of this model were tuned by simulated annealing, using data points estimated from psychological literature, indicating that the model matches well with empirical information. The presented mental network model may also be used for other types of addictions which involve avoidance of emotions, such as alcohol abuse and game addiction.     

Pentylenetetrazole as an unconditioned stimulus for olfactory and contextual fear conditioning in rats

The association of five footshocks with a neutral odor is able to establish an olfactory fear conditioning in rats. The present study sought to investigate whether the systemic administration of pentylenetetrazole (PTZ; 3.75–15 mg/kg) would turn the coffee odor in a conditioned stimulus in the fear conditioning paradigm. The results showed that rats started to display risk assessment and avoidance after PTZ (15 mg/kg)–coffee odor pairing. When three mild footshocks (0.4 mA for 2 s) were delivered during this pairing, the conditioned response exhibited was greater than before. In both cases, however, pretreatment with the benzodiazepine midazolam (MDZ. 0.5 mg/kg i.p.) fully counteracted the expression of these defensive behaviors. Moreover, after being paired with 15 mg/kg of PTZ alone or combined with footshocks, the coffee odor was able to promote a new fear conditioning related to the context where it was re-exposed. The present findings point out the usefulness of PTZ as an unconditioned stimulus to promote fear conditioning to olfactory and contextual cues in rats.     

Short report: The impact of measurement conditions on the validity of self-assessment in a selection setting

Two experimental studies investigated the impact of format and instructions on the validity of SAs, using participants applying for junior management positions in a public sector organization. In Study 1 (607 participants) self-assessments (SAs) were valid when applicants rated overall competencies or the same competencies broken down into discrete elements, but not when providing behavioural evidence prior to rating competencies. The effect of social comparison instructions was also explored but found to have no impact on validity. Study 2 used a subset of 193 candidates from the previous study who attended the next stage of the selection process. Consistent with predictions it was found that unbalanced, positively toned scales were more valid than conventional scales, and highest validities were achieved when used with instructions requesting a realistic SA of strengths and weaknesses. Interestingly, gender differences were found in both studies. These findings are discussed in terms of their implications for both research and practice.     

Evaluative conditioning without directly experienced pairings of the conditioned and the unconditioned stimuli

Evaluative conditioning (EC) is the valence change of a stimulus (conditioned stimulus, CS) that is due to the previous pairing with another stimulus (unconditioned stimulus, US). We investigated whether EC can occur also when the CS–US pairings are not experienced directly by the participant but are implied by other events that the participant encounters. In two experiments, positive USs were presented in some trials and negative USs in other trials. Afterwards, participants were given information from which it was possible to conclude that CSs were covertly present during these trials. Finally, the valence of these CSs was registered using both implicit (Implicit Association Test, affective priming) and explicit measures (valence ratings). In line with the assumption that EC effects can be based on CS–US pairings that are not directly experienced, the valence of the CSs changed in the direction of the US with which they were covertly paired. This effect was observed both on explicit and on implicit measures. We argue that several aspects of our results are in line with propositional models of EC and fit less well with association formation models.     

Perceptual specialization and configural face processing in infancy

Adults’ face processing expertise includes sensitivity to second-order configural information (spatial relations among features such as distance between eyes). Prior research indicates that infants process this information in female faces. In the current experiments, 9-month-olds discriminated spacing changes in upright human male and monkey faces but not in inverted faces. However, they failed to process matching changes in upright house stimuli. A similar pattern of performance was exhibited by 5-month-olds. Thus, 5- and 9-month-olds exhibited specialization by processing configural information in upright primate faces but not in houses or inverted faces. This finding suggests that, even early in life, infants treat faces in a special manner by responding to changes in configural information more readily in faces than in non-face stimuli. However, previously reported differences in infants’ processing of human versus monkey faces at 9 months of age (but not at younger ages), which have been associated with perceptual narrowing, were not evident in the current study. Thus, perceptual narrowing is not absolute in the sense of loss of the ability to process information from other species’ faces at older ages.     

Sensitivity to spacing changes in faces and nonface objects in preschool-aged children and adults

Sensitivity to variations in the spacing of features in faces and a class of nonface objects (i.e., frontal images of cars) was tested in 3- and 4-year-old children and adults using a delayed or simultaneous two-alternative forced choice matching-to-sample task. In the adults, detection of spacing information was robust against exemplar differences for faces but varied across exemplars for cars (Experiment 1A). The 4-year-olds performed above chance in both face and car discrimination even when differences in spacing were very small (within ±1.6 standard deviations [SDs]) and the task involved memory components (Experiment 1B), and the same was true for the 3-year-olds when tested with larger spacing changes (within ±2.5 SDs) in a task that posed no memory demands (Experiment 2). An advantage in the discrimination of faces over cars was found at 4 years of age, but only when spacing cues were made more readily available (within ±2.5 SDs). Results demonstrate that the ability to discriminate objects based on feature spacing (i.e., sensitivity to second-order information) is present at 3 years of age and becomes more pronounced for faces than cars by 4 years of age.     

Multilevel analysis of individual differences in regularities of grapheme–color associations in synesthesia

Grapheme–color synesthesia is a neurological phenomenon where visual perception of letters and numbers stimulates perception of a specific color. Grapheme–color correspondences have been shown to be systematically associated with grapheme properties, including visual shape difference, ordinality, and frequency. However, the contributions of grapheme factors differ across individuals. In this study, we applied multilevel analysis to test whether individual differences in regularities of grapheme–color associations could be explained by individual styles of processing grapheme properties. These processing styles are reflected by the type of synesthetic experience. Specifically, we hypothesized that processing focusing on shape differences would be associated with projector synesthetes, while processing focusing on ordinality or familiarity would be associated with associator synesthetes. The analysis revealed that ordinality and familiarity factors were expressed more strongly among associators than among projectors. This finding suggests that grapheme–color associations are partly determined by the type of synesthetic experience.