Synthesizing single-case studies: A Monte Carlo examination of a three-level meta-analytic model

Numerous ways to meta-analyze single-case data have been proposed in the literature; however, consensus has not been reached on the most appropriate method. One method that has been proposed involves multilevel modeling. For this study, we used Monte Carlo methods to examine the appropriateness of Van den Noortgate and Onghena's (2008) raw-data multilevel modeling approach for the meta-analysis of single-case data. Specifically, we examined the fixed effects (e.g., the overall average treatment effect) and the variance components (e.g., the between-person within-study variance in the treatment effect) in a three-level multilevel model (repeated observations nested within individuals, nested within studies). More specifically, bias of the point estimates, confidence interval coverage rates, and interval widths were examined as a function of the number of primary studies per meta-analysis, the modal number of participants per primary study, the modal series length per primary study, the level of autocorrelation, and the variances of the error terms. The degree to which the findings of this study are supportive of using Van den Noortgate and Onghena's (2008) raw-data multilevel modeling approach to meta-analyzing single-case data depends on the particular parameter of interest. Estimates of the average treatment effect tended to be unbiased and produced confidence intervals that tended to overcover, but did come close to the nominal level as Level-3 sample size increased. Conversely, estimates of the variance in the treatment effect tended to be biased, and the confidence intervals for those estimates were inaccurate.     

Box for interaction with objects (BIO): A new device to synchronize the presentation of objects with electrophysiological recordings

Brain event-related potentials are a useful tool for investigating visual processing and action planning. This technique requires extremely accurate synchronization of stimulus delivery with recordings. The precision of the onset time of visual stimulus delivery is a major challenge when attempting to use real, three-dimensional objects as stimuli. Here, we present an innovative device, the “box for interaction with objects” (BIO), that is designed to synchronize the presentation of objects with electroencephalographic (EEG) recordings. To reach the required resolution of stimulus-onset timing, the BIO system features an interface with reflective glass and light-emitting diodes (LEDs). When the LEDs inside the BIO are turned on, the object inside becomes visible, and a synchronizing pulse is sent to the recording systems. The BIO was tested in a motivational study that focused on visual and motor event-related potentials. EEG signals were recorded during the presentation of an emotion-laden object that could be grasped and brought close to the participant’s chest. BIO successfully synchronized the appearance of a three-dimensional object with EEG recordings, which would allow for an analysis of visual and motor event-related potentials in the same experiment. The BIO device, through a high-quality psychophysiological approach, offers a new perspective for the study of the motivational factors that drive actions toward relevant stimuli.     

Aquinas and quantifier mistakes

In his “Third Way” Aquinas appears to argue in a way that relies upon shifting quantifiers in a fallacious way. Some have tried to save this and other parts of the “Third Way” by introducing sophisticated logical and metaphysical machinery. Alternatively, Aquinas’ apparently fallacious quantifier shift can be seen to be part of a valid argument if we supply a simple premise which an Aristotelian natural philosopher would surely hold. In this short paper, I consider candidates for this premise, defend a specific premise, and from that discussion draw a moral about quantifier predicate logic. I conclude that Aristotelian natural philosophy is more than an historical backdrop to Aquinas’ arguments.     

Domain Specificity and the Limits of Creativity Theory

A growing body of research evidence suggests that creativity is very domain‐specific and that domain‐general skills or traits contribute little to creative performance. The term “creativity” is a convenient term for collecting many interesting artifacts, processes, and people into a single category, and the term “creative thinking skills” may be a useful way to connect a diverse set of unrelated cognitive processes that operate on different content and in different domains. These concepts are misleading, however, because although they connect things that may seem similar to observers, they lack any underlying cognitive psychological validity. This has implications for the ways we understand and assess creativity, and also for how we should direct our efforts to develop creative‐thinking skills in diverse domains. Creativity training needs either to target the domains in which creativity enhancement is desired or to use a wide range of activities in diverse domains if the goal is more general improvement in many domains. Creativity assessment needs to focus on domain‐by‐domain assessment and to review findings based on allegedly domain‐general tests of creativity that may have misled researchers to unsupportable interpretations. Creativity theory needs to set more modest goals of domain‐by‐domain theory development and to recognize that theories that may seem domain‐general might better be understood as meta‐theoretical heuristics that do not actually describe domain‐general processes. These meta‐theories might in some cases help guide the search for domain‐based theories.     

Longitudinal stability of friendships in rhesus monkeys (Macaca mulatta): individual- and relationship-level effects

The longevity of children's friendships is influenced by a multitude of individual- and relationship-level attributes, but little is known about the factors that impact friendship maintenance in nonhuman primate juveniles. We investigated whether the following predicted the longitudinal stability of friendships in juvenile rhesus monkeys (Macaca mulatta): (1) individual characteristics including sex, dominance rank, matriline size, and temperament; and (2) relationship characteristics including kinship, reciprocity, complexity, and similarity between friends in sex, rank, and temperament. We recorded affiliative interactions of 29 two-year-old rhesus monkeys, previously observed as yearlings, at the California National Primate Research Center. Friends were defined as peers with whom subjects spent more time affiliating than expected by chance. Temperament had been assessed at 3-4 months of age. Sex was the only individual characteristic predicting friendship stability: males maintained more friendships from age one to two than did females. Relationship characteristics predicting friendship stability included similarity between individuals in temperament, kinship, and sex. In addition, reciprocated friendships, rather than unidirectional friendships, were significantly more likely to persist over time. Our findings suggest that the factors influencing friendship maintenance in rhesus monkeys are similar to those impacting human friendship longevity.