Age-Related Changes in Smoothness of Gait of Healthy Children and Early Adolescents

Abstract

In this study, we acquired and processed trunk accelerations during level walking in 85 children aged 8-13?years to calculate spatio-temporal parameters and Harmonic Ratio (HR), which is a metrics representative of gait smoothness and step-to-step symmetry. The results show that while spatio-temporal parameters remain unchanged once normalized considering individuals’ anthropometry, significantly higher values of HR for both the antero-posterior and vertical directions were found in participants aged 12–13 with respect to those of 8–9. This indicates an improvement of gait symmetry, which suggests that the gait maturation process is still ongoing for the age ranges tested here.     

Effect of anosmia on the behavior of standard non-aggressive male mice opponents during agonistic encounters

This study assessed whether the differences observed in a previous experiment [Martinez M, Salvador A, Simon VM (1994): Aggressive Behavior 20:441–451] in the behavior of isolated male mice over several agonistic encounters in which they confronted either an “anosmic” or an “intact” non-aggressive “standard opponent” were due to the differences in the behavior of the opponents themselves. Ethologically-inspired analysis was used to assess the behavior of the opponents during the first agonistic encounter. Anosmic opponents spent less time in social investigation and defense and more time in immobility than intact ones. These results suggest that the differences in the behavior of the opponents could be one of the causes of the differences observed in the behavior of the aggressive males confronting them. However, more research is needed to study if other variables, such as the production of odors, are also affected by the state (deprived or intact) of the olfactory sense. These findings provide additional support for the view that the type of opponent used in studies on intermale aggression is of paramount importance.Aggr. Behav. 23:179–181, 1997.© 1997 Wiley-Liss, Inc.     

Three‐year‐old children intervene in third‐party moral transgressions

We investigated children's moral behaviour in situations in which a third party was harmed (the test case for possession of agent‐neutral moral norms). A 3‐year‐old and two puppets each created a picture or clay sculpture, after which one puppet left the room. In the Harm condition, the remaining (actor) puppet then destroyed the absent (recipient) puppet's picture or sculpture. In a Control condition, the actor acted similarly but in a way that did not harm the recipient. Children protested during the actor's actions, and, upon the recipient's return, tattled on the actor and behaved prosocially towards the recipient more in the Harm than in the Control condition. This is the first study to show that children as young as 3 years of age actively intervene in third‐party moral transgressions.     

Development and Psychometric Properties of the Self-Representation Questionnaire for Adolescents (SRQA)

Given the lack of validated measures of adolescents’ self-representation, in this paper we present the development process and psychometric properties of a new self-representation questionnaire for adolescents (SRQA), aged 12–16 year old. We examined SRQA factor structure through two studies. In the first study, 32 attributes (16 positive and 16 negative), previously validated in three studies, were administered to 239 adolescents (M = 13.8; SD = 1.28). An exploratory factor analysis showed that 21 attributes (13 positive and 8 negative) were organized in five factors: instrumental, social, emotional, intelligence, and physical appearance. In the second study, these 21 attributes were administered to 232 adolescents (M = 13.8; SD = 1.23). A confirmatory factor analysis supported the SRQA five factor model (Model fit: χ ²/df ratio = 2.392; CFI = .90; RMSEA = .08). Internal consistency was acceptable, ranging between .60 and .85. Girls displayed higher scores in the instrumental and social factors, whereas boys presented higher scores on the physical appearance factor. In line with previous research, results regarding age differences were inconsistent: while in Study 1 results suggested that as, age increases, adolescents’ intelligence self-representation becomes more negative, in Study 2 no age differences were found. Concurrent validity of the SRQA was explored through correlations with the Teacher Report Form, filled out by the adolescents’ homeroom teachers. Results revealed significant negative correlations between two dimensions of self-representation (i.e., instrumental and intelligence) and several dimensions of adolescents’ internalizing and externalizing problems, providing evidence of concurrent validity for the SRQA.     

Developmental trajectory of number acuity reveals a severe impairment in developmental dyscalculia

Developmental dyscalculia is a learning disability that affects the acquisition of knowledge about numbers and arithmetic. It is widely assumed that numeracy is rooted on the “number sense”, a core ability to grasp numerical quantities that humans share with other animals and deploy spontaneously at birth. To probe the links between number sense and dyscalculia, we used a psychophysical test to measure the Weber fraction for the numerosity of sets of dots, hereafter called number acuity. We show that number acuity improves with age in typically developing children. In dyscalculics, numerical acuity is severely impaired, with 10-year-old dyscalculics scoring at the level of 5-year-old normally developing children. Moreover, the severity of the number acuity impairment predicts the defective performance on tasks involving the manipulation of symbolic numbers. These results establish for the first time a clear association between dyscalculia and impaired “number sense”, and they may open up new horizons for the early diagnosis and rehabilitation of mathematical learning deficits.     

Auditory, visual, tactile, olfactory, and bodily hallucinations in patients with obsessive-compulsive disorder

Although much attention has been paid to patients who lack insight into their obsessional beliefs, less importance has been given to individuals with obsessive-compulsive disorder (OCD) who display perceptual disturbances typically found in psychotic disorders, including schizophrenia, schizoaffective disorders, or mood disorders with psychotic features. We would like to call the attention to a phenomenon that has been neglected in the psychiatric literature: the occurrence of hallucinations and related phenomena in patients with OCD. In this case report, we describe five clinical vignettes of patients with OCD with hallucinations in several different sensory modalities, including the auditory, the visual, the tactile, the olfactory, and the cenesthetic ones. Further psychopathological research should clarify the clinical significance of hallucinations among patients with OCD.