Attention and relative novelty in human perceptual learning

Four experiments examined the role of attention in human perceptual learning. In Experiment 1, participants were preexposed to a pair of visual (checkerboard) stimuli AX and BX, with common elements X and unique features A and B. A same-different task was then used to assess discrimination of AX and BX and a pair of control stimuli, CY and DY. In addition, participants' eye movements were recorded to assess the role of attentional processes. The results showed that preexposure enhanced discrimination between AX and BX. Furthermore, participants showed greater attention to the preexposed unique features A and B than to the novel unique features C and D, as measured by the eye gaze monitor. Experiments 2 and 3 examined the prediction that perceptual learning is due to the relative familiarity of the common and unique stimulus features. Experiment 4 replicated the intermixed-blocked effect and showed that the way in which AX and BX are presented is also important for perceptual learning. The results generally support the idea that intermixed preexposure to AX and BX increases attention to the unique stimulus features A and B. Some aspects of the results are consistent with a relative novelty account, whereas others implicate a high-level attentional process that is not driven by stimulus novelty.     

Young adult female fragile X premutation carriers show age- and genetically-modulated cognitive impairments

The high frequency of the fragile X premutation in the general population and its emerging neurocognitive implications highlight the need to investigate the effects of the premutation on lifespan cognitive development. Until recently, cognitive function in fragile X premutation carriers (fXPCs) was presumed to be unaffected by the mutation. Here we show that young adult female fXPCs show subtle, yet significant, age- and FMR1 gene mutation-modulated cognitive impairments as tested by a quantitative magnitude comparison task. Our results begin to define the neurocognitive endophenotype associated with the premutation in adults, who are at risk for developing a neurodegenerative disorder associated with the fragile X premutation. Results from the present study may potentially be applied toward the design of early interventions wherein we might be able to target premutation carriers most at risk for degeneration for preventive treatment.     

Perceived psychosocial benefits associated with perceived restorative potential of wilderness river-rafting trips

Analysis of the restorative experiences and psychosocial benefits of wilderness river rafting trips of varying difficulty with 186 Canadian participants of different ages supported the restorative potential of natural settings for all age groups as measured by the Perceived Restorativeness Scale. The two-factor structure (General Restorativeness and Coherence) was confirmed. Significant associations were found between scores on the General Restorative subscale and perceived psychosocial benefits (relaxation, nature appreciation or kinship, and physical fitness or achievement) and positive affect. However, the findings associated with the Coherence subscale were not conclusive.     

Compulsive Internet Use Among Adolescents: Bidirectional Parent–Child Relationships

Although parents experience growing concerns about their children’s excessive internet use, little is known about the role parents can play to prevent their children from developing Compulsive Internet Use (CIU). The present study addresses associations between internet-specific parenting practices and CIU among adolescents, as well as the bidirectionality of these associations. Two studies were conducted: a cross-sectional study using a representative sample of 4,483 Dutch students and a longitudinal study using a self-selected sample of 510 Dutch adolescents. Results suggest that qualitatively good communication regarding internet use is a promising tool for parents to prevent their teenage children from developing CIU. Besides, parental reactions to excessive internet use and parental rules regarding the content of internet use may help prevent CIU. Strict rules about time of internet use, however, may promote compulsive tendencies. Finally, one opposite link was found whereby CIU predicted a decrease in frequency of parental communication regarding internet use.     

Frontal cortex functioning in the infant broader autism phenotype

Atypical attention has been proposed as a marker of the broader autism phenotype. In the present study we investigated this and the related process of inhibitory control at the youngest possible age through the study of infant siblings of children with an autism spectrum disorder (Sibs-ASD). Both attention and inhibition have been related to the frontal cortex of the brain. Nine- to ten-month-old Sibs-ASD and low-risk control infants completed the Freeze-Frame task, in which infants are encouraged to inhibit looks to peripherally presented distractors whilst looking at a central animation. The attractiveness of the central stimulus is varied in order to investigate the selectivity of infants’ responses. In line with previous studies, it was found that a subset of Sibs-ASD infants had difficulty disengaging attention from a central stimulus in order to orient to a peripheral stimulus. The Sibs-ASD group also showed less Selective Inhibition than controls. However, Sibs-ASD infants did demonstrate Selective Inhibitory Learning. These results provide preliminary evidence for atypical frontal cortex functioning in the infant broader autism phenotype.     

An extended motor network generates beta and gamma oscillatory perturbations during development

This study examines the time course and neural generators of oscillatory beta and gamma motor responses in typically-developing children. Participants completed a unilateral flexion–extension task using each index finger as whole-head magnetoencephalography (MEG) data were acquired. These MEG data were imaged in the frequency-domain using spatial filtering and the resulting event-related synchronizations and desynchronizations (ERS/ERD) were subjected to voxel-wise statistical analyses to illuminate time–frequency specific activation patterns. Consistent with adult data, these children exhibited a pre-movement ERD that was strongest over the contralateral post-central gyrus, and a post-movement ERS response with the most prominent peak being in the contralateral precentral gyrus near premotor cortices. We also observed a high-frequency (∼80 Hz) ERS response that coincided with movement onset and was centered on the contralateral precentral gyrus, slightly superior and posterior to the beta ERS. In addition to pre- and post-central gyri activations, these children exhibited beta and gamma activity in supplementary motor areas (SMA) before and during movement, and beta activation in cerebellar cortices before and after movement. We believe the gamma synchronization may be an excellent candidate signal of basic cortical motor control, as the spatiotemporal dynamics indicate the primary motor cortex generates this response (and not the beta oscillations) which is closely yoked to the initial muscle activation. Lastly, these data suggest several additional neural regions including the SMA and cerebellum are involved in basic movements during development.     

Effects of COMT genotype on behavioral symptomatology in the 22q11.2 Deletion Syndrome.

The 22q11.2 Deletion Syndrome (DiGeorge/velocardiofacial syndrome) is associated with elevated rates of psychosis, and is also characterized by severe attentional difficulties and executive dysfunction. Behavioral manifestations of this syndrome could result from haploinsufficiency of the catechol-O-methyltransferase (COMT) gene, located within the 22q11 region. The goal of the present study was to examine COMT genotype in relation to behavioral symptomatology in this syndrome. Val158/108Met was genotyped in 38 patients (16 Met/-, 22 Val/-) with confirmed 22q11.2 deletions who had received the Child Behavior Checklist (CBCL) as part of a comprehensive evaluation. Results indicated that the Val genotype was associated with significantly greater internalizing and externalizing behavioral symptomatology in children with 22q11.2 deletions. Val allele status was associated with a greater-than-four-fold increase in risk for clinically significant behavior problems in children with this syndrome. These data are consistent with previous findings of increased psychopathology associated with the Val genotype in normal individuals and suggest that a functional genetic polymorphism in the 22q11 region may influence behavior in individuals with COMT haploinsufficiency.     

Shaftesbury's “SUBLIME and BEAUTIFUL” Naturalism

The 3rd Earl of Shaftesbury drew on the naturalism of Locke to open up a naturalistic reading of experience conceived as a matter of reality revealing pattern perception that was lost to view in the impact of subsequent idealist readings of Locke's epistemology offered by Bishop Berkeley (1685–1753) and David Hume (1711–1776). This essay recovers and explicates Shaftesbury's alternative to idealist conceptions of pattern making.     

Autism Spectrum Symptomatology in Children: The Impact of Family and Peer Relationships

This study examines the potential impact of family conflict and cohesion, and peer support/bullying on children with autism spectrum disorder (ASD). While such impacts have been established for a range of non-ASD childhood disorders, these findings may not generalize to children with ASD because of unique problems in perspective-taking, understanding others’ emotion, cognitive rigidity, and social reasoning. A structural model-building approach was used to test the extent to which family and peer variables directly or indirectly affected ASD via child anxiety/depression. The sample (N = 322) consisted of parents of children with ASD referred to two specialist clinics. The sample contained parents of children with Autistic Disorder (n = 76), Asperger Disorder (n = 188), Pervasive Disorder Not Otherwise Specified (n = 21), and children with a non-ASD or no diagnosis (n = 37). Parents completed questionnaires on-line via a secure website. The key findings were that anxiety/depression and ASD symptomatology were significantly related, and family conflict was more predictive of ASD symptomatology than positive family/peer influences. The results point to the utility of expanding interventions to include conflict management for couples, even when conflict and family distress is low. Further research is needed on the potentially different meanings of family cohesion and conflict for children with ASD relative to children without ASD.     

Factor structure of the Child Behavior Checklist/6-18 in a sample of girls adopted from China

Confirmatory factor analysis with robust weighted least squares estimation of the 103 dichotomously scored items of the Child Behavior Checklist/6-18 (T. M. Achenbach & L. A. Rescorla, 2001) in a sample of 516 girls adopted from China (ages 6.0-15.7 years; M = 8.2, SD = 1.9) indicated that the fit of the 8-factor model was good (root-mean-square error of approximation = .047) and was slightly better than what T. M. Achenbach and L. A. Rescorla (2001) reported for the same model (.06). Support for the 2nd-order factor structure of Internalizing and Externalizing Problems also was provided. Comparisons of the mean scores for the syndromes and Internalizing, Externalizing, and Total Problems revealed mostly small differences between the sample of adopted Chinese girls and T. M. Achenbach and L. A. Rescorla's normative samples.