Spearman's law of diminishing returns: A statistical artifact?

Spearman's Law of Diminishing Returns (SLODR) is the idea that the structure of human cognitive ability is more differentiated and g a weaker determinant of cognitive performance at higher levels of ability. In this study, we distinguish between ‘traditional’ methods of testing SLODR and ‘contemporary’ methods of testing SLODR. It is the former set of methods from which the vast majority of the evidence base for SLODR derives. We demonstrated that it is easy to mimic SLODR and reverse SLODR effects in these traditional methods of assessing SLODR by using data with skewed observed variable distributions. The skewness magnitudes did not need to be large to produce these effects and they fell well within the range of values that are usually considered unproblematic for parametric statistic analysis. In simulated datasets, positive subtest skewness resulted in SLODR and negative subtest skewness resulted in reverse SLODR. In contemporary methods of testing SLODR, non-linear g-loadings or a skewed g are assumed to reflect evidence for SLODR. When we applied contemporary methods of testing SLODR to these data, there was evidence of heteroscedastic residuals but no evidence of non-linear g-loadings or skewed g distributions. We broadly replicated the effects of subtest skew from these simulated datasets in real data from the Minnesota Study of Twins Reared Apart. Results imply that traditional methods of assessing SLODR cannot distinguish between effects due to subtest characteristics that have nothing to do with differences in ability structure at different levels of g and true SLODR effects. This calls into question the empirical support for SLODR.     

Reduced Reliance on Optimal Facial Information for Identity Recognition in Autism Spectrum Disorder

Previous research into face processing in autism spectrum disorder (ASD) has revealed atypical biases toward particular facial information during identity recognition. Specifically, a focus on features (or high spatial frequencies [HSFs]) has been reported for both face and nonface processing in ASD. The current study investigated the development of spatial frequency biases in face recognition in children and adolescents with and without ASD, using nonverbal mental age to assess changes in biases over developmental time. Using this measure, the control group showed a gradual specialization over time toward middle spatial frequencies (MSFs), which are thought to provide the optimal information for face recognition in adults. By contrast, individuals with ASD did not show a bias to one spatial frequency band at any stage of development. These data suggest that the “midband bias” emerges through increasing face-specific experience and that atypical face recognition performance may be related to reduced specialization toward optimal spatial frequencies in ASD.     

Grasping remaps the distribution of visuospatial attention and enhances competing action activation

We examined how action goals influence the distribution of visuospatial attention near the body (Experiment 1) and how the temporal relationship between distractors and targets modifies shifts in visuospatial attention (Experiment 2). Targets were light emitting diodes (LEDs) in the left and right hemispace of a visual display. Following left or right target illumination, participants reached to point-to or grasp target object in blocked trials. Coincident with target onset, a distractor LED illuminated in the same or opposite hemispace between the initiation point and target, or no distractor appeared. In Experiment 1, during grasping there was a larger temporal interference effect (slower reach initiation) than with pointing. When grasping versus pointing, participants deviated more towards same-side distractors and away from opposite-side distractors. In Experiment 2, distractors onset 200ms prior to (?200-ms), coincident with (0 ms), or 200ms following (+200 ms) the target. For both reach types, ?200-ms distractors had greater onset temporal interference than 0 ms and +200-ms distractors. For grasping, +200 ms distractors had larger temporal interference than 0 ms distractors. For ?200-ms, reach trajectories deviated more towards opposite-side distractors and away from same-side distractors, the reverse of the pattern for 0 ms and +200-ms distractors.     

Symptoms of Psychological Distress Among Mothers and their Adult Offspring: A Longitudinal Examination

We examined the association between maternal psychological distress during offspring’s early development and offspring’s later distress in adulthood, as well as the influence of maternal characteristics at offspring’s birth and offspring’s characteristics in adulthood on distress. Data were obtained from the British Cohort Study, a longitudinal study of children born in a one-week period in 1970. Children were followed up multiple times from birth through to age 30. Results indicate that greater symptoms of maternal psychological distress during offspring’s early childhood are associated with greater symptoms of distress in adult offspring. A large component of this association is indirect, occurring through mother’s distress in later childhood and offspring’s problem behavior during adolescence. Findings that the association between maternal and offspring’s distress is more indirect than direct support arguments that early maternal distress has long-term consequences for offspring.     

Comparing Attention to Socially-Relevant Stimuli in Autism Spectrum Disorder and Developmental Coordination Disorder

Difficulties with social interaction have been reported in both children with an autism spectrum disorder (ASD) and children with developmental coordination disorder (DCD), although these disorders have very different diagnostic characteristics. To date, assessment of social skills in a DCD population has been limited to paper-based assessment or parent report. The present study employed eye tracking methodology to examine how children attend to socially-relevant stimuli, comparing 28 children with DCD, 28 children with ASD and 26 typically-developing (TD) age-matched controls (aged 7–10). Eye movements were recorded while children viewed 30 images, half of which were classed as ‘Individual’ (one person in the scene, direct gaze) and the other half were ‘Social’ (more naturalistic scenes showing an interaction). Children with ASD spent significantly less time looking at the face/eye regions in the images than TD children, but children with DCD performed between the ASD and TD groups in this respect. Children with DCD demonstrated a reduced tendency to follow gaze, in comparison to the ASD group. Our findings confirm that social atypicalities are present in both ASD and to a lesser extent DCD, but follow a different pattern. Future research would benefit from considering the developmental nature of the observed findings and their implications for support.     

Are mothers’ work-to-family conflict,school involvement,and work status related to academic achievement?

This study investigates a moderated mediational model whereby maternal involvement in schooling mediates the association between maternal work-to-family conflict and children’s academic achievement in early adolescence, and socioeconomic contexts interact with maternal work status to moderate this association. Participants reflect a subsample of 725 fifth graders (and their employed mothers and teachers) from the Eunice Kennedy Shriver National Institute of Child Health and Human Development Study of Early Child Care and Youth Development (NICHD SECCYD). Of the children in this subsample, 49.4% were female and 79.7% were White, non-hispanic. On average mothers completed 14.7 years of education (SD?=?2.4), with 75.4% of mothers completing more than a high school education. Multi-group analyses in SEM using Mplus 7.4 tested whether maternal work status would interact with core socioeconomic contexts (e.g., maternal education, child race, marital status, poverty status, work schedule, and number of children in the home) to moderate the relationship between maternal work-to-family conflict, maternal involvement in school, and academic outcomes. Results revealed partial mediation between maternal work-to-family conflict and achievement through maternal involvement in school. Our hypothesis that maternal work status would interact with other core socioeconomic contexts to moderate the relationship between maternal work-to-family conflict, maternal involvement in school, and academic outcomes was supported. We conclude that mothers’ involvement in school may be an important way in which negative outcomes of work-to-family conflict may be minimized. We also highlight the importance of situating maternal employment in a larger familial and socioeconomic context.     

The role of observer strategy in the single-target AB paradigm

Identification of the second of two targets (T1, T2) inserted in a stream of distractors is impaired when presented 200–500 ms after the first (attentional blink, AB). An AB-like effect has been reported by Nieuwenstein, Potter, and Theeuwes, Journal of Experimental Psychology: Human Perception and Performance, 35, 159-169, (2009, Experiment 2), with a distractor stream that contained only one target and a gap just before the target. Nieuwenstein et al. hypothesized that the gap enhanced the salience of the last distractor, causing it to be processed much like T1 in conventional AB studies. This hypothesis can also account for Lag-1 sparing (enhanced target performance when presented directly after the last distractor, without an intervening gap). We propose an alternative account of the Lag-1 sparing in the single-target paradigm based on observer strategy, and test it by presenting the single-target and dual-target conditions to separate groups (Experiment 2) instead of mixed across trials (Experiment 1 and Nieuwenstein et al.'s study). The single-target condition exhibited Lag-1 sparing when it was mixed with the dual-target condition, but Lag-1 deficit when it was done in isolation. This outcome is consistent with an observer-strategy account but not with an enhanced salience account of the Lag-1 sparing effect in the single-target condition.     

Phonological neighborhood density in the picture naming of young children who stutter: preliminary study

The purpose of this study was to assess the effect of phonological neighborhood density on the speech reaction time (SRT) and errors of children who do and do not stutter during a picture-naming task. Participants were nine 3-5-year-old children who stutter (CWS) matched in age and gender to nine children who do not stutter (CWNS). Initial analyses indicated that both CWNS and CWS were significantly faster (i.e., exhibited shorter SRTs) and more accurate on phonologically sparse than phonologically dense words, findings consistent with those found with older children (Newman & German, 2002). Further analyses indicated that talker group differences in receptive language scores weakened these findings. These preliminary findings were taken to suggest that phonological neighborhood density appears to influence the picture-naming speed and accuracy of preschool-aged children. EDUCATIONAL OBJECTIVES: The reader will learn about and be able to: (1) recognize the relevance of examining phonological variables in relation to childhood stuttering; and (2) describe the method of measuring speech reaction times and errors during a picture-naming task as a means of assessing linguistic skills.