The effect of bicephalic stimulation of the dorsolateral prefrontal cortex on the attentional bias for threat: A transcranial direct current stimulation study

Previous stimulation studies demonstrated that the dorsolateral prefrontal cortex (DLPFC) is involved in threat processing. According to a model of emotional processing, an unbalance between the two DLPFCs, with a hyperactivation of right frontal areas, is involved in the processing of negative emotions and genesis of anxiety. In the present study, we investigated the role of the right and left DLPFC in threat processing in healthy women who also completed the State-Trait Anxiety Inventory (STAI). We simultaneously modulated the activity of the right and left dorsolateral prefrontal cortex by applying bicephalic transcranial direct current stimulation (tDCS) before participants completed a modified version of the classic Posner task using threatening and nonthreatening stimuli as spatial cues. Anodal stimulation on the right DLPFC with a simultaneous cathodal stimulation over the left side induced a disengagement bias in individuals with low STAI scores and a facilitation bias in individuals with high STAI scores. Anodal stimulation on the left DLPFC with the simultaneous cathodal stimulation over the right side did not affect threat processing. The findings of the present study provided specific support to the hypothesis that unbalanced activation between left and right hemispheres with enhanced activation of the right DLPFC is critical in early top-down threat processing in healthy individuals.     

The Patient Who Was Not There

Many clinicians attest to the challenges of working with the adolescent patient. The phase itself prescribes resistances to forming a transference relationship, not to mention that passions and conflicts can be stirred in the therapist that had long been dormant. Various theoretical positions have dictated different paths, from systems theory to Freud’s treatment of Little Hans. This article describes a case that took an unorthodox route based on an adolescent’s refusal and Lacan’s formulation of the function of a child’s symptom in the intrapsychic world of the parent. The outcome opened pathways for growth for both the adolescent and the parents, suggesting that the uniqueness of the phase of adolescence allows for new pathways for clinical intervention as well.     

At the root of embodied cognition: cognitive science meets neurophysiology

Recent experimental research in the field of neurophysiology has led to the discovery of two classes of visuomotor neurons: canonical neurons and mirror neurons. In light of these studies, we propose here an overview of two classical themes in the cognitive science panorama: James Gibson's theory of affordances and Eleanor Rosch's principles of categorization. We discuss how theoretical perspectives and neuroscientific evidence are converging towards the current paradigm of embodied cognition. From this perspective, we discuss the role of action and simulation in cognitive processes, which lead to the perceptual recognition of objects, and actions and to their conceptual categorization.     

Selective improvement of strain-dependent performances of cognitive tasks by food restriction

Temporary food restriction affects strain differences for behavioral phenotypes in the inbred strains of mice C57BL/6 (C57) and DBA/2 (DBA). Since food restriction is a routine procedure to motivate learning, we evaluated its influence on differences for spatial and non-spatial discrimination between these strains of mice by using two non-associative tasks: the Spatial Novelty Test (SNT) and the Spontaneous Object Recognition Test (SORT). The results confirmed the poor performance of the DBA mice in SNT. Nonetheless, DBA mice were perfectly able to recognize the novel object in SORT. By contrast, C57 mice were good performers in SNT but failed to recognize a novel object in SORT. Finally, food restriction selectively improved C57 performance in SNT and DBA performance in SORT. These results support the view that a food restricting procedure enhances strain differences for discrimination of configurational information.     

A practical guide to time-frequency analysis in the study of human motor behavior: the contribution of wavelet transform

The authors present a practical guide for studying nonstationary data on human motor behavior in a time-frequency representation. They explain the limits of classical methods founded exclusively on the time or frequency basis and then answer those limits with the windowed Fourier transform and the wavelet transform (WT) methods, both of which are founded on time-frequency bases. The authors stress an interest in the WT method because it permits access to the whole complexity of a signal (in terms of time, frequency, amplitude, and phase). They then show that the WT method is well suited for the analysis of the interaction between two signals, particularly in human movement studies. Finally, to demonstrate its practical applications, the authors apply the method to real data.     

Updating and inhibition processes in working memory: a comparison between Alzheimer's type dementia and frontal lobe focal damage

A large debate has recently focused on the componential nature of the working-memory system (), as evidenced by functional-imaging studies and by using more sophisticated experimental paradigms. The present work aims at further disentangling the role and effects of central executive (CE) and of phonological loop (PL). It is suggested that maintaining active verbal information mostly relates to an intact PL, while the inhibition of interfering information preponderantly involves the CE. To distinguish these effects, two groups of brain damaged patients were administered with an updating task. Frontal lobe patients showed major difficulties in inhibiting interfering information, an ability requiring an involvement of the CE component. In contrast, Alzheimer's dementia patients evidenced a relative impairment in maintaining relevant information, requiring the intervention of the PL.     

Evidence for a double dissociation between spatial-simultaneous and spatial-sequential working memory in visuospatial (nonverbal) learning disabled children

The paper describes the performance of three children with specific visuospatial working memory (VSWM) impairments (Study 1) and three children with visuospatial (nonverbal) learning disabilities (Study 2) assessed with a battery of working memory (WM) tests and with a number of school achievement tasks. Overall, performance on WM tests provides evidence of a double dissociation between spatial-simultaneous processes, underpinning the memorization item positioning in a spatial configuration, and spatial-sequential processes, which allow memorization of the presentation order. In both groups of children of the two studies, a selective impairment either on spatial-sequential or on spatial-simultaneous working memory tasks was observed. These data support the existence of -simultaneous and -sequential modality-dependent processes in visuospatial working memory and confirm the importance of distinguishing between different subtypes of visuospatial (nonverbal) learning-disabled children.     

Rethinking the ontogeny of mindreading

We propose a mentalistic and nativist view of human early mental and social life and of the ontogeny of mindreading. We define the mental state of sharedness as the primitive, one-sided capability to take one's own mental states as mutually known to an interactant. We argue that this capability is an innate feature of the human mind, which the child uses to make a subjective sense of the world and of her actions. We argue that the child takes all of her mental states as shared with her caregivers. This allows her to interact with her caregivers in a mentalistic way from the very beginning and provides the grounds on which the later maturation of mindreading will build. As the latter process occurs, the child begins to understand the mental world in terms of differences between the mental states of different agents; subjectively, this also corresponds to the birth of privateness.     

Change in children's understanding of others' intentional actions

The study investigated children's intention understanding using a longitudinal design. Thirty-two Italian children were tested on the 'Demonstration of Intention' in the Re-enactment paradigm devised by Meltzoff (1995a), at two ages. Mean age was 12 months at the first session and 15 months at the second session. Previous research by Meltzoff showed that 18-month-olds are able to re-enact what the adult intended to do, when an adult tried but failed to perform certain target acts. Bellagamba and Tomasello (1999) found that, compared to 18-month-olds, 12-month-olds are less able to imitate unsuccessful goal-directed actions. The current study had two main goals. The first was to replicate earlier findings on intention understanding in 12- and 15-month-olds longitudinally assessed. The second goal was to analyse which actions children perform when not producing the target act. A coding scheme was devised to evaluate these non-target actions. Results confirmed previous findings, i.e. children's tendency to produce the target act was higher at an older age. At a younger age the most frequent response was 'undifferentiated manipulation' of target objects, followed by 'approximation to the target action'. Since children differed in their intention understanding performance at the first session, we decided to check whether these individual differences remained stable at the second session. Individual children with high intention understanding performance at 12 months tended to remain high at 15 months of age.     

The genetic relationship between individual differences in social and nonsocial behaviours characteristic of autism

Two types of behaviours shown in children - those reflecting social impairment and nonsocial obsessive repetitive behaviours - are central to defining and diagnosing autism spectrum disorders (ASDs). Parent and teacher data on social and nonsocial behaviours were obtained from a community sample of >3000 7-year-old twin pairs. Social and nonsocial behaviours were only modestly correlated, and it was found that some individuals had extreme scores on either social or nonsocial scales but not both. Genetic model-fitting showed that social and nonsocial behaviours are both highly heritable, but their genetic overlap is modest, with most of the genetic influence being specific to either social or nonsocial behaviours. Considering these behaviours separately might help clarify gene-brain-behaviour pathways in future research.