Measuring, estimating, and understanding the psychometric function: A commentary

The psychometric function, relating the subject’s response to the physical stimulus, is fundamental to psychophysics. This paper examines various psychometric function topics, many inspired by this special symposium issue ofPerception & Psychophysics: What are the relative merits of objective yes/no versus forced choice tasks (including threshold variance)? What are the relative merits of adaptive versus constant stimuli methods? What are the relative merits of likelihood versus up-down staircase adaptive methods? Is 2AFC free of substantial bias? Is there no efficient adaptive method for objective yes/no tasks? Should adaptive methods aim for 90% correct? Can adding more responses to forced choice and objective yes/no tasks reduce the threshold variance? What is the best way to deal with lapses? How is the Weibull function intimately related to thed’ function? What causes bias in the likelihood goodness-of-fit? What causes bias in slope estimates from adaptive methods? How good are nonparametric methods for estimating psychometric function parameters? Of what value is the psychometric function slope? How are various psychometric functions related to each other? The resolution of many of these issues is surprising.     

The Contribution of Attributional Style to Perceived Disability in Rheumatoid Arthritis: A Longitudinal Study

The current study investigated the influence of general causal attributions on self-reported physical disability over the course of 1 year in a sample of 42 patients with rheumatoid arthritis (RA). Participants completed measures of attributional style, pain, and disability; physician assistants completed objective measures of disability on two occasions, approximately 1 year apart. Results indicated that internal attributions for disease-unrelated negative events assessed at Time 1 were associated with lower perceived physical disability, whereas stable attributions for negative events were associated with greater perceived physical disability 1 year later. These findings are discussed in terms of behavioral and characterological self-blame models, respectively. Implications of our findings for clinical management of RA are also discussed.     

Maximum likelihood estimation of latent interaction effects with the LMS method

In the context of structural equation modeling, a general interaction model with multiple latent interaction effects is introduced. A stochastic analysis represents the nonnormal distribution of the joint indicator vector as a finite mixture of normal distributions. The Latent Moderated Structural Equations (LMS) approach is a new method developed for the analysis of the general interaction model that utilizes the mixture distribution and provides a ML estimation of model parameters by adapting the EM algorithm. The finite sample properties and the robustness of LMS are discussed. Finally, the applicability of the new method is illustrated by an empirical example. This research has been supported by a grant from the Deutsche Forschungsgemeinschaft, Germany, No. Mo 474/1 and Mo 474/2. The data for the empirical example have been provided by Andreas Thiele of the University of Frankfurt, Germany. The authors are indebted to an associate editor and to three anonymous reviewers ofPsychometrika whose comments and suggestions have been very helpful.     

REDUCTION WITHOUT REDUCTIONISM: A DEFENCE OF NAGEL ON CONNECTABILITY

Unlike the overall framework of Ernest Nagel's work on reduction, his theory of intertheoretic connection still has life in it. It handles aptly cases where reduction requires complex representation of a target domain. Abandoning his formulation as too liberal was a mistake. Arguments that it is too liberal at best touch only Nagel's deductivist theory of explanation, not his condition of connectability. Taking this condition seriously gives a powerful view of reduction, but one which requires us to index explanatory power to sciences as they are formulated at particular times. While we may thereby reduce more than philosophers have supposed, we must abandon hope (as Nagel did) of saying anything useful about reductionism.     

The exact vs. approximate distinction in numerical cognition may not be exact, but only approximate: How different processes work together in multi-digit addition

Two types of calculation processes have been distinguished in the literature: approximate processes are supposed to rely heavily on the non-verbal quantity system, whereas exact processes are assumed to crucially involve the verbal system. These two calculation processes were commonly distinguished by manipulation of two factors in addition problems: the identity of the target and the distance of the distractor. However, in all previous studies, these two factors were not manipulated independently. In this fMRI study, we could disentangle the two factors by using a different (two-digit) number stimulus set. Both behavioral and neurofunctional data suggest that the cognitive processes involved could be best explained by the (independent) factors target and distractor distance. Based on these data we suggest that the exact/approximate distinction does not seem to be as generally valid as previously assumed. We conclude that this study may be a starting point for a closer examination of the experimental, procedural and strategic conditions of when the exact/approximate distinction is valid and when it is not.     

Brain regions as difference-makers

Contrastive neuroimaging is often taken to provide evidence about the localization of cognitive functions. After canvassing some problems with this approach, I offer an alternative: neuroimaging gives evidence about regions of the brain that bear difference-making relationships to psychological processes of interest. I distinguish between the specificity and what I call the systematicity of a difference-making relationship, and I show how at least some neuroimaging experiments can give evidence for systematic difference-making.     

Improving the quality of parental interaction with very low birth weight children: A longitudinal study using a Mediated Learning Experience model

Cognitive performance of 3-year-old, very low birth weight children (N = 42) was found to be more significantly related to the quality of parent-child interaction than to early measures of cognitive performance or measures of developmental risk such as birth weight and APGAR. The subjects were randomly divided into an intervention and a control group. The intervention group was visited at home, infrequently, by a mediator who identified basic criteria of quality of parent-child interaction and provided the parents with feedback on the quality of interaction with their own children. The intervention procedure continued for 7 months. The extent of a family's participation in the intervention varied depending upon the initial quality of parent-child interaction and the amount of time it took a family to reach criteria. Quality of parent-child interaction and children's cognitive performance were pretested and reassessed 3 years after the intervention. The sample was reduced to 29 due to attrition over time. Parental behavior following the intervention had changed significantly with respect to all criteria. Parents who had received intervention, as compared to the control group parents, provided their children with more behaviors related to focusing attention, exciting and rewarding, expanding children's understanding of the world around them, preplanning and regulating behavior. Three years after the relatively unintensive intervention, parents continued to show significant gains in quality of mediation. Differences were found between parents of Small for Gestational Age (SGA) and Appropriate for Gestational Age (AGA) children in favor of the SGA group. In children's cognitive performance, scores of the intervention group on the Peabody Picture Vocabulary Test (PPVT) were significantly higher than those of the control group. On other cognitive measures, a consistent trend in favor of the intervention group was noted. More children in the control as compared to the experimental group were rated by their parents as having difficulties with language, fine motor, and sociability skills 3 years after the intervention.     

Early childhood cortisol reactivity moderates the effects of parent–child relationship quality on the development of children's temperament in early childhood

Positive parenting has been related both to lower cortisol reactivity and more adaptive temperament traits in children, whereas elevated cortisol reactivity may be related to maladaptive temperament traits, such as higher negative emotionality (NE) and lower positive emotionality (PE). However, no studies have examined whether hypothalamic‐pituitary‐adrenal axis activity, as measured by cortisol reactivity, moderates the effect of the quality of the parent–child relationship on changes in temperament in early childhood. In this study, 126 3‐year‐olds were administered the Laboratory Temperament Assessment Battery (Lab‐TAB; Goldsmith et al., 1995) as a measure of temperamental NE and PE. Salivary cortisol was collected from the child at 4 time points during this task. The primary parent and the child completed the Teaching Tasks battery (Egeland et al., 1995), from which the quality of the relationship was coded. At age 6, children completed the Lab‐TAB again. From age 3 to 6, adjusting for age 3 PE or NE, a better quality relationship with their primary parent predicted decreases in NE for children with elevated cortisol reactivity and predicted increases in PE for children with low cortisol reactivity. Results have implications for our understanding of the interaction of biological stress systems and the parent–child relationship in the development of temperament in childhood.     

Pain,Care, and the Body: A Response to de Vignemont

Frédérique de Vignemont argues on the basis of several empirical counterexamples that Bain and Klein are wrong about the relationship between pain and bodily care. I argue that the force of the putative counterexamples is weak. Properly understood, the association between pain and care is preserved in a way that is consistent with both de Vignemont's own views and the empirical facts.     

Prosocial behavior increases perceptions of meaning in life

Finding meaning in life is a fundamental personal need, and motivating prosocial behavior is a fundamental societal need. The present research tests whether the two are connected – whether helping other people can increase helpers’ perceptions of meaning in life. Evidence from a nationally representative data-set and two experiments support this hypothesis. Participants who engaged in prosocial behaviors – volunteering and spending money to benefit others – reported experiencing greater meaning in their lives (Studies 1–3). Study 3 also identifies increased self-worth as the mechanism – participants who spent money to benefit other people felt higher personal worth and self-esteem, and this mediated the effect of prosocial behavior on meaningfulness. The present results join other findings in suggesting that the incentives for helping others do not necessarily depend on the prospect of others’ reciprocity. Prosocial behavior can be incentivized through the psychological benefits it creates for prosocial actors.