Eric Loken

Human face recognition ability is specific and highly heritable

Compared with notable successes in the genetics of basic sensory transduction, progress on the genetics of higher level perception and cognition has been limited. We propose that investigating specific cognitive abilities with well-defined neural substrates, such as face recognition, may yield additional insights. In a twin study of face recognition, we found that the correlation of scores between monozygotic twins (0.70) was more than double the dizygotic twin correlation (0.29), evidence for a high genetic contribution to face recognition ability. Low correlations between face recognition scores and visual and verbal recognition scores indicate that both face recognition ability itself and its genetic basis are largely attributable to face-specific mechanisms. The present results therefore identify an unusual phenomenon: a highly specific cognitive ability that is highly heritable. Our results establish a clear genetic basis for face recognition, opening this intensively studied and socially advantageous cognitive trait to genetic investigation.

Understanding reporting bias in the dietary recall data of 11-year-old girls

Objective: This study describes patterns of bias in self‐reported dietary recall data of girls by examining differences among girls classified as under‐reporters, plausible reporters, and over‐reporters on weight, dietary patterns, and psychosocial characteristics.

Practices Associated with Weight Loss Versus Weight-Loss Maintenance Results of a National Survey

BACKGROUND Few studies have examined the weight-control practices that promote weight loss and weight-loss maintenance in the same sample. PURPOSE To examine whether the weight control practices associated with weight loss differ from those associated with weight-loss maintenance. METHODS Cross-sectional survey of a random sample of 1165 U.S. adults. The adjusted associations of the use of 36 weight-control practices in the past week with success in weight loss (≥10% lost in the past year) and success in weight-loss maintenance (≥10% lost and maintained for ≥1 year) were examined. RESULTS Of the 36 practices, only 8 (22%) were associated with both weight loss and weight-loss maintenance. Overall, there was poor agreement (kappa=0.22) between the practices associated with weight loss and/or weight-loss maintenance. For example, those who reported more often following a consistent exercise routine or eating plenty of low-fat sources of protein were 1.97 (95% CI=1.33, 2.94) and 1.76 (95% CI=1.25, 2.50) times more likely, respectively, to report weight-loss maintenance but not weight loss. Alternatively, those who reported more often doing different kinds of exercises or planning meals ahead of time were 2.56 (95% CI=1.44, 4.55) and 1.68 (95% CI=1.03, 2.74) times more likely, respectively, to report weight loss but not weight-loss maintenance. CONCLUSIONS Successful weight loss and weight-loss maintenance may require two different sets of practices. Designing interventions with this premise may inform the design of more effective weight-loss maintenance interventions.

Measurement error and the replication crisis

The assumption that measurement error always reduces effect sizes is false Measurement error adds noise to predictions, increases uncertainty in parameter estimates, and makes it more difficult to discover new phenomena or to distinguish among competing theories. A common view is that any study finding an effect under noisy conditions provides evidence that the underlying effect is particularly strong and robust. Yet, statistical significance conveys very little information when measurements are noisy. In noisy research settings, poor measurement can contribute to exaggerated estimates of effect size. This problem and related misunderstandings are key components in a feedback loop that perpetuates the replication crisis in science.

Effects of restriction on children’s intake differ by child temperament, food reinforcement, and parent’s chronic use of restriction ☆

Parents’ use of restrictive feeding practices is counterproductive, increasing children’s intake of restricted foods and risk for excessive weight gain. The aims of this research were to replicate Fisher and Birch’s (1999b) original findings that short-term restriction increases preschool children’s (3–5 y) selection, intake, and behavioral response to restricted foods, and to identify characteristics of children who were more susceptible to the negative effects of restriction. The experiment used a within-subjects design; 37 children completed the food reinforcement task and heights/weights were measured. Parents reported on their use of restrictive feeding practices and their child’s inhibitory control and approach. Overall, the findings replicated those of and revealed that the effects of restriction differed by children’s regulatory and appetitive tendencies. Greater increases in intake in response to restriction were observed among children lower in inhibitory control, higher in approach, who found the restricted food highly reinforcing, and who had previous experience with parental use of restriction. Results confirm that the use of restriction does not reduce children’s consumption of these foods, particularly among children with lower regulatory or higher appetitive tendencies.

A day-centered approach to modeling cortisol: Diurnal cortisol profiles and their associations among U.S. adults

Diurnal cortisol is a marker of HPA-axis activity that may be one of the biological mechanisms linking stressors to age-related health declines. The current study identified day-centered profiles of diurnal cortisol among 1101 adults living in the United States. Participants took part in up to four consecutive days of salivary cortisol collection, assessed at waking, 30min post-waking, before lunch, and before bedtime. Growth mixture modeling with latent time basis was used to estimate common within-day trajectories of diurnal cortisol among 2894 cortisol days. The 3-class solution provided the best model fit, showing that the majority of study days (73%) were characterized by a Normative cortisol pattern, with a robust cortisol awakening response (CAR), a steep negative diurnal slope, coupled with low awakening and bedtime levels. Relative to this profile, diurnal cortisol on the remainder of days appeared either elevated throughout the day (20% of days) or flattened (7% of days). Relative to the normative trajectory, the elevated trajectory was distinguished by a higher morning cortisol level, whereas the flattened trajectory was characterized by a high bedtime level, with weaker CAR and diurnal slope parameters. Relative to the normative profile, elevated profile membership was associated with older age and cigarette smoking. Greater likelihood of the flattened cortisol pattern was observed among participants who were older, male, smoked cigarettes, used medications that are known to affect cortisol output, and reported poorer health. The current study demonstrates the value of a day-centered growth mixture modeling approach to the study of diurnal cortisol, showing that deviations from the classic robust rhythm of diurnal cortisol are associated with older age, male sex, use of medications previously shown to affect cortisol levels, poorer health behaviors, and poorer self-reported health.

Using Latent Class Analysis to Model Temperament Types

Mixture models are appropriate for data that arise from a set of qualitatively different subpopulations. In this study, latent class analysis was applied to observational data from a laboratory assessment of infant temperament at four months of age. The EM algorithm was used to fit the models, and the Bayesian method of posterior predictive checks was used for model selection. Results show at least three types of infant temperament, with patterns consistent with those identified by previous researchers who classified the infants using a theoretically based system. Multiple imputation of group memberships is proposed as an alternative to assigning subjects to the latent class with maximum posterior probability in order to reflect variance due to uncertainty in the parameter estimation. Latent class membership at four months of age predicted longitudinal outcomes at four years of age. The example illustrates issues relevant to all mixture models, including estimation, multi-modality, model selection, and comparisons based on the latent group indicators.

Mapping cardiac physiology and parenting processes in maltreating mother-child dyads.

Child maltreatment (CM) lies on an extreme end of the continuum of parenting-at-risk, and while CM has been linked with a variety of behavioral indicators of dysregulation in children, less is known about how physiological markers of regulatory capacity contribute to this association. The present study examined patterns of mother and child physiological regulation and their relations with observed differences in parenting processes during a structured interaction. Abusing, neglecting, and non-CM mothers and their 3- to 5-year-old children completed a resting baseline and moderately challenging joint task. The structural analysis of social behavior was used to code mother-child interactions while simultaneous measures of respiratory sinus arrhythmia were obtained. Results indicated that physically abusive mothers were more likely to react to childrens positive bids for autonomy with strict and hostile control, than either neglecting or non-CM mothers. CM exposure and quality of maternal responding to childrens autonomous bids were uniquely associated with lower parasympathetic tone in children. Results provide evidence of neurodevelopmental associations between early CM exposure, the immediate interactive context of parenting, and childrens autonomic physiology.

Measurement of food reinforcement in preschool children. Associations with food intake, BMI, and reward sensitivity.

Progressive ratio (PR) schedules of reinforcement have been used to measure the relative reinforcing value (RRV) of food in humans as young as 8 years old; however, developmentally appropriate measures are needed to measure RRV of food earlier in life. Study objectives were to demonstrate the validity of the RRV of food task adapted for use among for preschool children (3-5 y), and examine individual differences in performance. Thirty-three children completed the RRV of food task in which they worked to access graham crackers. They also completed a snack task where they had free access these foods, liking and hunger assessments, and their heights and weights were measured. Parents reported on their childs reward sensitivity. Overall, children were willing work for palatable snack foods. Boys and older children made more responses in the task, while children with higher BMI z-scores and reward sensitivity responded at a faster rate. Children who worked harder in terms of total responses and response rates consumed more calories in the snack session. This study demonstrates that with slight modifications, the RRV of food task is a valid and developmentally appropriate measure for assessing individual differences in food reinforcement among very young children.

I’ve Fallen and I Can’t Get Up: Can High Ability Students Recover From Early Mistakes in CAT?

A difficult result to interpret in Computerized Adaptive Tests (CATs) occurs when an ability estimate initially drops and then ascends continuously until the test ends, suggesting that the true ability may be higher than implied by the final estimate. This study explains why this asymmetry occurs and shows that early mistakes by high-ability students can lead to considerable underestimation, even in tests with 45 items. The opposite response pattern, where low-ability students start with lucky guesses, leads to much less bias. The authors show that using Barton and Lords four-parameter model (4PM) and a less informative prior can lower bias and root mean square error (RMSE) for high-ability students with a poor start, as the CAT algorithm ascends more quickly after initial underperformance. Results also show that the 4PM slightly outperforms a CAT in which less discriminating items are initially used. The practical implications and relevance for psychological measurement more generally are discussed.