The role of interference control in working memory: a study with children at risk of ADHD

The study aimed to test whether the impairment in a working memory task observed in children at risk of ADHD was due to a lack of control of interfering information being processed whilst carrying out the memory task. Two groups of children at risk of ADHD with or without a learning disability (reading impairment) were compared to a control group in a working memory task. Activation of irrelevant items was tested with a lexical decision task presented immediately after the final recall in about half of the trials. Results showed a poor working memory performance in children at risk of ADHD and reading disability associated with a larger activation of irrelevant information than that of control children. Results indicated that the to-be-excluded and interfering items are still highly accessible to working memory in children that fail the working memory task. The examination of working memory and interference control of children at risk of ADHD with a learning disability revealed a counterintuitive picture of children with poor working memory showing better recall/activation of processed information. This picture is consistent with a view of working memory related to an efficient inhibitory control that influences cognitive functioning.     

Do updating tasks involve updating? Evidence from comparisons with immediate serial recall

Updating tasks require participants to process a sequence of items, varying in length, and afterwards to remember only a fixed number of the elements of the sequence; the assumption being that participants actively update the to-be-recalled list as presentation progresses. However recent evidence has cast doubt on this assumption, and the present study examined the strategies that participants employ in such tasks by comparing the serial position curves found in verbal and visuo-spatial updating tasks with those seen in standard serial recall tasks. These comparisons showed that even when the same number of items are presented or recalled, participants perform less well in an updating than a serial recall context. In addition, while standard serial position effects were observed for serial recall, marked recency and reduced or absent primacy effects were seen in updating conditions. These findings suggest that participants do not typically adopt a strategy of actively updating the memory list in updating tasks, but instead tend to wait passively until the list ends before trying to recall the most recently presented items.     

Families with Distinct Levels of Marital Conflict and Child Adjustment: Which Role for Maternal and Paternal Stress?

This study addresses the links between distinct levels of marital conflict and mothers’ and fathers’ parenting stress and their associations with children’s adjustment. Using a sample of 358 Italian father–mother dyads with school–aged children, we computed a cluster analysis to identify distinct groups of families with different levels of interparental conflict. In each of the three groups identified (low, moderate, and high marital conflict), we conducted correlational and mediational analyses to explore the relationship between interparental conflict and children’s adjustment, the relationship between interparental conflict and maternal and paternal stress, and the potential mediating role of these components of maternal and paternal stress in the association between interparental conflict and children’s adjustment. We administered the R-CTS, PSI-SF, and CBCL to parents in order to assess marital conflict, maternal and paternal stress, and children’s behavioral problems; children completed the CPIC in order to evaluate their perceptions of interparental conflict. Results show that, in the high marital conflict group, levels of interparental conflict negatively affect children’s adjustment; moreover, the parent–child dysfunctional interaction component of maternal stress partially mediates the relationship between interparental discord and children’s internalizing behaviors, while the difficult child component of paternal stress fully mediates the effects of marital conflict on externalizing behaviors. In the moderate marital conflict group, levels of interparental conflict are correlated with the difficult child component of both maternal and paternal stress, while in the low marital conflict group, interparental conflict does not correlate with both maternal and paternal stress and children’s adjustment.     

The role of in-group identification in infra-humanization

People tend to infra-humanize by attributing more human essence to their in-group than to out-groups. In the present article, we focus on the attribution of primary and secondary emotions to operationalize the human essence. We propose that, in order to infra-humanize, people need to be categorized in meaningful groups. In addition, we argue that what differentiates meaningful from nonmeaningful groups is that the people essentialize, perceiving members of the group as sharing an underlying, common essence. Also, we hypothesize that participants will identify more with their in-group in the case of meaningful groups. Three types of groups were created to manipulate the meaningfulness of the categorization. Participants were either randomly assigned to a group or they chose their group as a function of their preferences for a colour or the type of career they wished to pursue. As expected, infra-humanization occurred only where the categorization's criterion was meaningful. In addition, in-group identification, but not essentialism, mediated the impact of the categorization criteria on the tendency to infra-humanize. Data also showed that infra-humanization is different from classic in-group favouritism. This is because in-group favouritism, but not infra-humanization, was observed in the situation where group membership was based on random assignment. In other words, for infra-humanization to occur mere categorization is not enough; meaningfulness is also needed. For in-group favouritism to arise, the knowledge of being part of a group is a sufficient prerequisite. The discussion focuses on conditions for reducing infra-humanization and on the relationship between in-group favouritism and out-group derogation.     

Generating animal and tool names: an fMRI study of effective connectivity

The present fMRI study of semantic fluency for animal and tool names provides further evidence for category-specific brain activations, and reports task-related changes in effective connectivity among defined cerebral regions. Two partially segregated systems of functional integration were highlighted: the tool condition was associated with an enhancement of connectivity within left hemispheric regions, including the inferior prefrontal and premotor cortex, the inferior parietal lobule and the temporo-occipital junction; the animal condition was associated with greater coupling among left visual associative regions. These category-specific functional differences extend the evidence for anatomical specialization to lexical search tasks, and provide for the first time evidence of category-specific patterns of functional integration in word-retrieval.     

The control of responsiveness in ADHD by catecholamines: evidence for dopaminergic, noradrenergic and interactive roles

We explore the neurobiological bases of attention deficit hyperactivity disorder (ADHD) from the viewpoint of the neurochemistry and psychopharmacology of the catecholamine-based behavioural systems. The contributions of dopamine (DA) and noradrenaline (NA) neurotransmission to the motor and cognitive symptoms of ADHD (e.g. hyperactivity, variable and impulsive responses) are studied in rodent and primate models. These models represent elements of the behavioural units observed in subjects with ADHD clinically, or in laboratory settings (e.g. locomotion, changed sensitivity/responsivity to novelty/reinforcement and measures of executive processing). In particular, the models selected emphasize traits that are strongly influenced by mesocorticolimbic DA in the spontaneously hypertensive (SHR) and the Naples high excitability (NHE) rat lines. In this context, the mode of action of methylphenidate treatment is discussed. We also describe current views on the altered control by mesolimbic catecholamines of appropriate and inappropriate goal-directed behaviour, and the tolerance or intolerance of delayed reinforcement in ADHD children and animal models. Recent insights into the previously underestimated role of the NA system in the control of mesocortical DA function, and the frontal role in processing information are elaborated.     

The place of white in a world of grays: a double-anchoring theory of lightness perception

The specific gray shades in a visual scene can be derived from relative luminance values only when an anchoring rule is followed. The double-anchoring theory I propose in this article, as a development of the anchoring theory of Gilchrist et al. (1999), assumes that any given region (a) belongs to one or more frameworks, created by Gestalt grouping principles, and (b) is independently anchored, within each framework, to both the highest luminance and the surround luminance. The region's final lightness is a weighted average of the values computed, relative to both anchors, in all frameworks. The new model accounts not only for all lightness illusions that are qualitatively explained by the anchoring theory but also for a number of additional effects, and it does so quantitatively, with the support of mathematical simulations.     

Talis pater,talis filius: perceived resemblance and the belief in genetic relatedness

People hardly ever realize that their belief in their high rate of success in detecting family resemblances is affected by their knowledge of the actual genetic link between individuals. In the three studies reported here, 100 men and 100 women were requested to estimate the facial resemblance of photographically portrayed child-adult pairs, while being given either truthful or deceitful information, or no information, about their relatedness. Believing that the members of a pair were parent and offspring was the main predictor of the perceived similarity between them. Men and women agreed in judging children as more similar to female than to male adults, except when the pair members were believed to be related; in this case, men judged the child as resembling the alleged parents equally. Common remarks on family resemblance thus appear to ensue less from a conscious desire to please or reassure the parents than from general hypothesis-testing biases in human reasoning, made perhaps more specific in men by a concern with the problem of uncertain paternity.