Probability all the Way Up

Richard Jeffrey’s radical probabilism (‘probability all the way down’) is augmented by the claim that probability cannot be turned into certainty, except by data that logically exclude all alternatives. Once we start being uncertain, no amount of updating will free us from the treadmill of uncertainty. This claim is cast first in objectivist and then in subjectivist terms.     

Self-reported changes in subjective health and anthrax vaccination as reported by over 900 Persian Gulf War era veterans

A 1999 study of United Kingdom servicemembers by Unwin, et al. recently found significant relationships between anthrax and other vaccinations, reactions to those vaccines, and later health problems for male current or former active military Gulf War veterans. Likewise, in 2000 Steele and in 1998 Gilroy found possible adverse effects of vaccinations on Gulf War veterans. However, the role of such vaccinations remains controversial; more recent government reports continue to dispute the existence of any data that might reflect adversely on the role of vaccinations on the health of Gulf War veterans. To address this controversy, the current study assessed similar relationships for over 900 Reserve Component Gulf War Era veterans from Ohio and nearby states. Gulf War veterans were more likely to report poorer health than non-Gulf veterans. Female veterans were more likely to report mild or severe reactions to vaccines than male veterans. Those veterans who received anthrax vaccine reported more reactions to vaccines than those who did not receive anthrax vaccine. Declines in long-term subjective health were associated with receipt of anthrax vaccine by Gulf War veterans but not for those who did not deploy to the Gulf, although few of the latter received anthrax vaccine. Regardless of deployment status, veterans who reported more severe reactions to vaccines were more likely to report declines in subjective health. Female veterans reported poorer health during the Gulf War than did male veterans, but sex was not related to veterans' reports of subjective health at subsequent times. It is recommended that servicemembers who experience severe reactions to anthrax vaccine be medically reevaluated before receiving further anthrax vaccine and that careful follow-ups be conducted of those receiving the vaccine currently, in accordance with Nass's 1999 recommendations. We also recommend that safer alternatives to thimerosal (a mercury sodium salt, 50% mercury) be used to preserve all vaccines.     

The acquisition of vector knowledge and its relation to self-rated direction sense

Self-rated sense of direction is reliably related to people's accuracy when pointing in the direction of unseen landmarks from imagined or actual perspectives. It is proposed that the cognitive substrate of accurate pointing responses is a vector representation, which is defined as an integrated network of displacement vectors. Experiment 1 isolated the body senses and tested displacement vector formation in a path-integration task. Experiment 2 isolated the visual modality and tested displacement vector formation in a virtual-learning task. Both experiments tested whether people reporting a good sense of direction (GSOD) were more likely to compute displacement vectors than people reporting a poor sense of direction (PSOD). The results showed that both GSOD and PSOD people computed displacement vectors in the path-integration task, but not in the virtual-learning task. When interlandmark relations were visually specified, GSOD people made more accurate pointing responses than PSOD people, adding to a growing body of cognitive correlates of self-rated direction sense.     

Family processes as pathways from income to young children's development

A variety of family processes have been hypothesized to mediate associations between income and young children's development. Maternal emotional distress, parental authoritative and authoritarian behavior (videotaped mother-child interactions), and provision of cognitively stimulating activities (Home Observation for Measurement of the Environment [HOME] scales) were examined as possible mediators in a sample of 493 White and African American low-birth-weight premature infants who were followed from birth through age 5. Cognitive ability was assessed by standardized test, and child behavior problems by maternal report, when the children were 3 and 5 years of age. As expected, family income was associated with child outcomes. The provision of stimulating experiences in the home mediated the relation between family income and both children's outcomes; maternal emotional distress and parenting practices mediated the relation between income and children's behavior problems.     

Links Between Motor Control and Classroom Behaviors: Moderation by Low Birth Weight

It is unclear from past research on effortful control whether one of its components, motor control, independently contributes to adaptive classroom behaviors. The goal of this study was to identify associations between early motor control, measured by the walk-a-line task at age 3, and teacher-reported learning-related behaviors (approaches to learning and attention problems) and behavior problems in kindergarten classrooms. Models tested whether children who were vulnerable to poorer learning behaviors and more behavior problems due to having been born low birth weight benefited more, less, or the same as other children from better motor control. Data were drawn from the national Fragile Families and Child-Wellbeing Study (n = 751). Regression models indicated that motor control was significantly associated with better approaches to learning and fewer behavior problems. Children who were low birth weight benefitted more than normal birth weight children from better motor control with respect to their approaches to learning, but equally with respect to behavior problems. Additionally, for low but not normal birth weight children, better motor control predicted fewer attention problems. These findings suggest that motor control follows a compensatory model of development for low birth weight children and classroom behaviors.     

Depression and emotional reactivity: variation among Asian Americans of East Asian descent and European Americans

Studies of Western samples (e.g., European Americans [EAs]) suggest that depressed individuals tend to show diminished emotional reactivity (J. G. Gehricke & A. J. Fridlund, 2002; G. E. Schwartz, P. L. Fair, P. Salt, M. R. Mandel, & G. L. Klerman, 1976a, 1976b). Do these findings generalize to individuals oriented to other cultures (e.g., East Asian cultures)? The authors compared the emotional reactions (i.e., reports of emotional experience, facial behavior, and physiological reactivity) of depressed and nondepressed EAs and Asian Americans of East Asian descent (AAs) to sad and amusing films. Their results were consistent with previous findings: Depressed EAs showed a pattern of diminished reactivity to the sad film (less crying, less intense reports of sadness) compared with nondepressed participants. In contrast, depressed AAs showed a pattern of heightened emotional reactivity (greater crying) compared with nondepressed participants. Across cultural groups, depressed and nondepressed participants did not differ in their reports of amusement or facial behavior during the amusing film. Physiological reactivity to the film clips did not differ between depressed and control participants for either cultural group. Thus, although depression may influence particular aspects of emotional reactivity across cultures (e.g., crying), the specific direction of this influence may depend on prevailing cultural norms regarding emotional expression.     

Conflicting social motives in negotiating groups

Negotiators' social motives (cooperative vs. individualistic) influence their strategic behaviors. In this study, the authors used multilevel modeling and analyses of strategy sequences to test hypotheses regarding how negotiators' social motives and the composition of the group influence group members' negotiation strategies. Four-person groups negotiating a 5-issue mixed-motive decision-making task were videotaped, and the tapes were transcribed and coded. Group composition included 2 homogeneous conditions (all cooperators and all individualists) and 3 heterogeneous conditions (3 cooperators and 1 individualist, 2 cooperators and 2 individualists, 1 cooperator and 3 individualists). Results showed that cooperative negotiators adjusted their use of integrative and distributive strategies in response to the social-motive composition of the group, but individualistic negotiators did not. Results from analyses of strategy sequences showed that cooperators responded more systematically to others' behaviors than did individualists. They also redirected the negotiation depending on group composition.     

Adult brains don't fully overcome biases that lead to incorrect performance during cognitive development: an fMRI study in young adults completing a Piaget‐like task

A current issue in developmental science is that greater continuity in cognition between children and adults may exist than is usually appreciated in Piaget‐like (stages or ‘staircase’) models. This phenomenon has been demonstrated at the behavioural level, but never at the brain level. Here we show with functional magnetic resonance imaging (fMRI), for the first time, that adult brains do not fully overcome the biases of childhood. More specifically, the aim of this fMRI study was to evaluate whether the perceptual bias that leads to incorrect performance during cognitive development in a Piaget‐like task is still a bias in the adult brain and hence requires an executive network to overcome it. Here, we compared two numerical‐judgment tasks, one being a Piaget‐like task with number–length interference (called ‘INT’) and the other being a control task with number–length covariation (‘COV’). We also used a colour‐detection task to control for stimuli numerosity, spatial distribution, and frequency. Our behavioural results confirmed that INT remains a difficult task for young adults. Indeed, response times were significantly higher in INT than in COV. Moreover, we observed that only in INT did response times increase linearly as a function of the number of items. The fMRI results indicate that the brain network common to INT and COV shows a large rightward functional asymmetry, emphasizing the visuospatial nature of these two tasks. When INT was compared with COV, activations were found within a right frontal network, including the pre‐supplementary motor area, the anterior cingulate cortex, and the middle frontal gyrus, which probably reflect detection of the number/length conflict and inhibition of the ‘length‐equals‐number’ response strategy. Finally, activations related to visuospatial and quantitative processing, enhanced or specifically recruited in the Piaget‐like task, were found in bilateral posterior areas.