Handedness, emotional problems, and schizotypy

The purpose of this study was to analyse the relationship between emotional or behavioural problems and schizotypy. An assessment of handedness and schizotypal personality traits were also performed by means of the Thinking and Perceptual Style Questionnaire, the Multidimensional Schizotypal Traits Questionnaire, the Edinburgh Handedness Inventory, and the Youth Self-Report. The sample comprised 296 participants with a mean age of 13.8 and a standard deviation of 1.34. Data indicate that adolescents with high scores on psychometric factors of schizotypy displayed higher patterns of problem behaviours as well as a significant difference in all the core factors of the Youth Self-Report, compared to those who scored low on these measures. Discriminant analysis showed that the core factors of the Youth Self-Report correctly classified 84% of the adolescents with high or low scores on psychometric schizotypy. Lastly, no significant association between the factors of schizotypy and left-handedness, right-handedness, or mixed-handedness was found.     

Transthyretin influences spatial reference memory

Transthyretin (TTR) is a plasma and cerebrospinal fluid carrier for thyroxine and retinol, described also to sequester the amyloid beta peptide. TTR levels have been described as decreased in the cerebrospinal fluid of patients with Alzheimer's disease. In order to investigate the role of TTR in learning and memory, we studied young adult and old TTR-null 129/Sv mice for cognitive performance. In the absence of TTR, 5-month-old mice display spatial reference memory impairment when compared to age-matched wild-type mice. Interestingly, while aging in wild-type mice is associated with a worsening reference memory performance, TTR-null mice show no further impairment with increasing age. As a result, no significant differences were found in this spatial reference task in old mice. Our data show that the absence of TTR seems to accelerate the poorer cognitive performance normally associated with aging.     

Cognitive Plasticity and Cortical Modules

ABSTRACT— Some organisms learn to calculate, accumulate knowledge, and communicate in ways that others do not. What factors determine which intellectual abilities a particular species or individual can easily acquire? I propose that cognitive-skill learning capacity reflects (a) the availability of specialized cortical circuits, (b) the flexibility with which cortical activity is coordinated, and (c) the customizability of cortical networks. This framework can potentially account for differences in learning capacity across species, individuals, and developmental stages. Understanding the mechanisms that constrain cognitive plasticity is fundamental to developing new technologies and educational practices that maximize intellectual advancements.     

Possible Worlds Semantics for Partial Meet Multiple Contraction

In the logic of theory change, the standard model is AGM, proposed by Alchourrón et al. (J Symb Log 50:510–530, 1985). This paper focuses on the extension of AGM that accounts for contractions of a theory by a set of sentences instead of only by a single sentence. Hansson (Theoria 55:114–132, 1989), Fuhrmann and Hansson (J Logic Lang Inf 3:39–74, 1994) generalized Partial Meet Contraction to the case of contractions by (possibly non-singleton) sets of sentences. In this paper we present the possible worlds semantics for partial meet multiple contractions.     

Reliability and sources of validity evidence of the Oviedo Schizotypy Assessment Questionnaire-Abbreviated (ESQUIZO-Q-A)

The main goal of this research was to examine the reliability and different sources of validity evidence of the Oviedo Schizotypy Assessment Questionnaire-Abbreviated (ESQUIZO-Q-A) in nonclinical adolescents. The final sample was made up of 1,455 participants, 705 males (48.5%), with a mean age of 15.92 years (SD = 1.18). The internal consistency of the subscales ranged from .62 to .75. The analysis of its internal structure yielded a three-dimensional solution based on the dimensions: Reality Distortion, Anhedonia, and Interpersonal Disorganization. Likewise, the goodness-of-fit indices derived from the Confirmatory Factor Analysis for the hypothesized three-factor model were adequate. The three dimensions of the ESQUIZO-Q-A were significantly correlated with the subscales of the Strengths and Difficulties Questionnaire. The ESQUIZO-Q is a brief and simple self-report with adequate psychometric properties for the assessment of schizotypal traits in nonclinical adolescent populations. Future research should continue to explore the metric quality of the ESQUIZO-Q-A (e.g., sensitivity and specificity) and incorporate the new advances in psychological and educational assessment such as Computerized Adaptive Testing.     

Development and validation of the Childhood Perfectionism Inventory (I.P.I.)

There are a few studies linking children's perfectionism with diverse internalized or externalized disorders. Likewise, in Spanish, there is no scale that measures the diverse aspects that comprise it. This paper presents the Children's Perfectionism Inventory (IPI). The sample comprised 2,260 participants (51.2% males and 48.8% females). The age range is between 8 and 13 years (mean= 9.94 and SD= 1.27). Sampling was stratified and random. Of the sample, 78.1% are from public education and 21.9% from private education. 16.2% reside in rural areas and 83.8% in urban areas. To study the validity of the questionnaire, cross-validation was performed. Initially three factors were obtained through exploratory factor analysis: Self-assessment, Self-imposed and External Pressures, with adequate reliability indices (Cronbach's alpha= .89, .87 and .88, respectively). Subsequently, using a confirmatory method, it was found that the three initial factors were explained by a single second-order factor called Perfectionism.     

Phenotypic expression of schizotypal traits in an adolescent population

The main goal of the present study was to examine the influence of gender and age in the phenotypic expression of schizotypal traits in a community sample of adolescents. The sample was composed of a total of 1,618 participants, 776 (48%) males, with a mean age of 15.9 years (SD = 1.2). The ESQUIZO-Q: Oviedo Schizotypy Assessment Questionnaire was used for the assessment of schizotypal traits, a measure specifically developed for its use in adolescents. The results showed that gender and age were two sociodemographical variables that influenced the expression of schizotypal features. The males in the study obtained higher mean scores than the females in the Negative dimension (Physical and Social Anhedonia); however, the females obtained higher mean scores in Magical Thinking, Lack of Close Friends, and Social Disorganization. With regard to age, the younger adolescents had lower scores in Odd Thinking and Language, Lack of Close Friends, Excessive Social Anxiety, and Social Disorganization compared to the older adolescents. This differential pattern is similar to the one found in patients with schizophrenia and in nonclinical young adults, and these findings improve our understanding about the phenotypic expression of schizotypy during adolescence.     

The role of a lifetime history of oppositional defiant and conduct disorders in adults with ADHD: implications for clinical practice

IntroductionAttention-deficit/hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), and conduct disorder (CD) are frequently co-occurring disorders in children and adolescents. However, their clinical status among adults is still under discussion. This study analyzes how the current clinical presentation of adult ADHD might be influenced by a lifetime history of CD and ODD. METHODS: We compared three groups of patients: ADHD without history of CD/ODD (n = 178), ADHD + history of ODD (n = 184), and ADHD + history of CD (n = 96). RESULTS: A history of CD (and to a lower extent ODD) is associated with a more severe and externalizing profile.ConclusionPast CD and ODD entail a significant negative mental health impact on persistent ADHD, reinforcing the importance of actively assessing the developmental history of adult ADHD patients.