Investigating hemispheric lateralization of reflexive attention to gaze and arrow cues

Recent studies have demonstrated that central cues, such as eyes and arrows, reflexively trigger attentional shifts. However, it is not clear whether the attentional mechanisms induced by these two cues are similar or rather differ in some important way. We investigated hemispheric lateralization of the orienting effects induced by the two cue types in a group of 48 healthy participants comparing arrows and eye gaze as central non-predictive cues in a discrimination task, in which a target stimulus was briefly presented in one of two peripheral positions (left or right of fixation). As predicted by neuropsychological data, reflexive orienting to gaze cues was only observed when the target was presented in the left visual field, whereas reflexive orienting to arrow cues occurred for targets presented in both left and right visual fields.     

Early predictors of high school mathematics achievement

Identifying the types of mathematics content knowledge that are most predictive of students' long-term learning is essential for improving both theories of mathematical development and mathematics education. To identify these types of knowledge, we examined long-term predictors of high school students' knowledge of algebra and overall mathematics achievement. Analyses of large, nationally representative, longitudinal data sets from the United States and the United Kingdom revealed that elementary school students' knowledge of fractions and of division uniquely predicts those students' knowledge of algebra and overall mathematics achievement in high school, 5 or 6 years later, even after statistically controlling for other types of mathematical knowledge, general intellectual ability, working memory, and family income and education. Implications of these findings for understanding and improving mathematics learning are discussed.     

Acquired dyslexia in three writing systems: study of a Portuguese-Japanese bilingual aphasic patient

The Japanese language is represented by two different codes: syllabic and logographic while Portuguese employs an alphabetic writing system. Studies on bilingual Portuguese-Japanese individuals with acquired dyslexia therefore allow an investigation of the interaction between reading strategies and characteristics of three different writing codes. The aim of this study was to examine the differential impact of an acquired brain lesion on the reading of the logographic, syllabic and alphabetic writing systems of a bilingual Portuguese-Japanese aphasic patient (PF). Results showed impaired reading in the logographic system and when reading irregularly spelled Portuguese words but no effects on reading regular words and nonwords in syllabic and alphabetic writing systems. These dissociations are interpreted according to a multi-route cognitive model of reading assuming selective damage in the lexical route can result in acquired dyslexia across at least three different writing codes.     

The NK3 receptor agonist senktide ameliorates scopolamine-induced deficits in memory for object, place and temporal order

Senktide, a potent neurokinin-3 receptor (NK₃-R) agonist, increases acetylcholine (ACh) release in the striatum, the prefrontal cortex (Schäble et al., 2011), the amygdala and hippocampus, presumably via postsynaptic mechanisms. A promnestic action of NK₃-R agonists has been described in a variety of learning/memory tasks. The memory-enhancing effects of NK₃-R agonists and their activating influence on ACh suggest a possible role of the NK₃-R in learning and memory via cholinergic modulation. Deterioration of the cholinergic system in the basal forebrain has been associated with learning and memory deficits and cholinergic agents have promnestic effects in a variety of learning paradigms. The anticholinergic drug, scopolamine, a muscarinic ACh receptor antagonist, incurs deficits in a variety of learning tasks and provides a useful tool to investigate the role of the cholinergic systems in mechanisms underlying learning and memory. The aim of this study was to ascertain the effect of the NK₃-R agonist, senktide, in the scopolamine-induced deficit model. We hypothesized that senktide treatment would attenuate scopolamine-induced (subcutaneous – s.c. 0.75 mg/kg) memory impairment in three novelty preference paradigms based on spontaneous object exploration: namely object recognition, object–place recognition and object recognition for temporal order. Administration of senktide reversed the scopolamine-induced memory deficits by re-establishing object recognition (s.c. 0.2 mg/kg), object–place recognition (0.2 and 0.4 mg/kg), as well as object recognition for temporal order (0.4 mg/kg) in adult Wistar rats. These results indicate memory enhancing effects of senktide in animals subjected to scopolamine-induced memory impairments and indicate that the promnestic action of NK₃-R agonists is mediated by muscarinic cholinergic mechanisms.     

Family functioning and socioaffective competencies of children in the beginning of schooling

The aim of this short-term longitudinal study, based on the system theory, was to test the association between different aspects of family functioning of preschoolers and their socioaffective competencies at the end of the first grade. The total sample included 278 children (137 boys and 141 girls) and their families. The analysis of variance results regarding the aspects of family cohesion and harmony showed that preschoolers from more cohesive families display more social skills, while those from more conflicting families display more externalizing behavior problems (aggression and irritability). With respect to the family's ability to resolve problems, it was observed that, especially for middle and upper class families, this aspect is associated with better social skills and fewer internalized behavior problems. Overall, results of the present study suggest that the family functioning at early stage might influence children's abilities to regulate their emotions and to establish/maintain important relationships with peers and teachers in their early school years.     

The role of children’s negative attributions on depressive symptoms: an inherited characteristic or a product of the early environment?

Negative attributional style has been associated with depressive symptoms in children. Yet, it is unclear whether these cognitive biases reflect inherited characteristics of the broader depressive phenotype or are a product of children's environments. While existing data in adolescents show that negative attributions reflect a genetic predisposition, elevating depressive responses to stress, other data suggest that negative attributions in children are more likely to reflect early environmental experiences on symptoms. Here, we assess the degree to which negative attributional style and depressive symptoms arise from common genetic, shared and non-shared environmental influences in childhood. Monozygotic and dizygotic twins reported on attributional style and depressive symptoms at age 8 (n = 300 pairs) and at age 10 (n = 250 pairs). Two multivariate models with varying assumptions on the nature of the relationship between negative attributions and depressive symptoms within and across time were fit to the data. The Common Pathway model provided better fit than the Cholesky decomposition. A common, latent factor influenced both attributional style and depressive symptoms at both time-points in children. The only significant influences on this factor were shared and non-shared aspects of the environment. Placing the present findings with those of adolescents suggests possible developmental differences in the relationship between attributional style and depressive symptoms.     

Cognition, daily living, and health-related quality of life in 85-year-olds in Sweden

This study investigates how cognition influences activities of daily living and health-related quality of life in 85-year-olds in Sweden (n = 373). Data collection included a postal questionnaire comprising demographics and health-related quality of life measured by the EQ-5D. The ability to perform personal activities of daily living (PADL) was assessed during a home visit that included administering the Mini Mental State Examination (MMSE). Cognitive impairment was shown in 108 individuals (29%). The majority were independent with respect to PADL. A larger number of participants with cognitive impairment reported that they needed assistance in instrumental activities of daily living (IADL) compared to the group without cognitive impairment. Impaired cognition was significantly related to problems with IADL. Significant but low correlations were found between cognition and health-related quality of life - higher ratings on perceived quality of life correlated with higher results on the MMSE.     

Emotion words shape emotion percepts

People believe they see emotion written on the faces of other people. In an instant, simple facial actions are transformed into information about another's emotional state. The present research examined whether a perceiver unknowingly contributes to emotion perception with emotion word knowledge. We present 2 studies that together support a role for emotion concepts in the formation of visual percepts of emotion. As predicted, we found that perceptual priming of emotional faces (e.g., a scowling face) was disrupted when the accessibility of a relevant emotion word (e.g., anger) was temporarily reduced, demonstrating that the exact same face was encoded differently when a word was accessible versus when it was not. The implications of these findings for a linguistically relative view of emotion perception are discussed.     

Space coding for sensorimotor transformations can emerge through unsupervised learning

The posterior parietal cortex (PPC) is fundamental for sensorimotor transformations because it combines multiple sensory inputs and posture signals into different spatial reference frames that drive motor programming. Here, we present a computational model mimicking the sensorimotor transformations occurring in the PPC. A recurrent neural network with one layer of hidden neurons (restricted Boltzmann machine) learned a stochastic generative model of the sensory data without supervision. After the unsupervised learning phase, the activity of the hidden neurons was used to compute a motor program (a population code on a bidimensional map) through a simple linear projection and delta rule learning. The average motor error, calculated as the difference between the expected and the computed output, was less than 3°. Importantly, analyses of the hidden neurons revealed gain-modulated visual receptive fields, thereby showing that space coding for sensorimotor transformations similar to that observed in the PPC can emerge through unsupervised learning. These results suggest that gain modulation is an efficient coding strategy to integrate visual and postural information toward the generation of motor commands.