Adolescent sleep and the foundations of prefrontal cortical development and dysfunction

Modern life poses many threats to good-quality sleep, challenging brain health across the lifespan. Curtailed or fragmented sleep may be particularly damaging during adolescence, when sleep disruption by delayed chro-notypes and societal pressures coincides with our brains preparing for adult life via intense refinement of neural connectivity. These vulnerabilities converge on the prefrontal cortex, one of the last brain regions to mature and a central hub of the limbic-cortical circuits underpinning decision-making, reward processing, social interactions and emotion. Even subtle disruption of prefrontal cortical development during adolescence may therefore have enduring impact. In this review, we integrate synaptic and circuit mechanisms, glial biology, sleep neurophys-iology and epidemiology, to frame a hypothesis highlighting the implications of adolescent sleep disruption for the neural circuitry of the prefrontal cortex. Convergent evidence underscores the importance of acknowledging, quantifying and optimizing adolescent sleep's contributions to normative brain development and to lifelong mental health

Selective processing of eating-, shape-, and weight-related words in persons with bulimia nervosa.

The Stroop color-naming task was used to investigate selective information processing in people with bulimia nervosa. Three cards were used: a target card consisting of words related to eating, weight, and shape; a control word card; and the standard conflicting-color card. Thirty-six patients with bulimia nervosa were compared with a group of age-matched female controls. It was found that the amount of disruption caused to color naming by the target card was significantly greater in the bulimia nervosa group than in the female control group, whereas that caused by the color card was similar in the two groups. The Stroop color-naming task may be a useful objective measure of one aspect of the cognitive disturbance of patients with bulimia nervosa

SELECTIVE INFORMATION-PROCESSING IN BULIMIA-NERVOSA

The Stroop color-naming paradigm was used to investigate information processing in bulimia nervosa. Patients with bulimia nervosa were compared with age-matched female controls as well as with a sample of men. It was found that the patients were slower than female controls were in color-naming words related to eating, shape, and weight, whereas there were no differences between the male and female controls. The findings suggest that bulimia nervosa is associated with the selective processing of information related to eating, shape, and weight and that this phenomenon may be restricted to those with an eating disorder of clinical severity

Prognostic factors in bulimia nervosa.

Factors predictive of outcome were sought from the data from a controlled study of the treatment of bulimia nervosa. Four different indices of outcome were used, and outcome was assessed at four points during a 12-month, treatment-free follow-up period. It was found that the pre-treatment level of self-esteem was a consistent predictor of outcome with those patients having low self-esteem responding least well to treatment. There were no other consistent predictors of outcome

A comparison of cognitive therapy, applied relaxation and imipramine in the treatment of panic disorder.

Recent studies have shown that cognitive therapy is an effective treatment for panic disorder. However, little is known about how cognitive therapy compares with other psychological and pharmacological treatments. To investigate this question 64 panic disorder patients were initially assigned to cognitive therapy, applied relaxation, imipramine (mean 233 mg/day), or a 3-month wait followed by allocation to treatment. During treatment patients had up to 12 sessions in the first 3 months and up to three booster sessions in the next 3 months. Imipramine was gradually withdrawn after 6 months. Each treatment included self-exposure homework assignments. Cognitive therapy and applied relaxation sessions lasted one hour. Imipramine sessions lasted 25 minutes. Assessments were before treatment/wait and at 3, 6, and 15 months. Comparisons with waiting-list showed all three treatments were effective. Comparisons between treatments showed that at 3 months cognitive therapy was superior to both applied relaxation and imipramine on most measures. At 6 months cognitive therapy did not differ from imipramine and both were superior to applied relaxation on several measures. Between 6 and 15 months a number of imipramine patients relapsed. At 15 months cognitive therapy was again superior to both applied relaxation and imipramine but on fewer measures than at 3 months. Cognitive measures taken at the end of treatment were significant predictors of outcome at follow-up

Remote collaborative multi-user informal learning experiences: design and evaluation

This paper presents a customizable system used to develop a collaborative multi-user problem solving game. It addresses the increasing demand for appealing informal learning experiences in museum-like settings. The system facilitates remote collaboration by allowing groups of learners to/ncommunicate through a videoconferencing system and by allowing them to simultaneously interact through a shared multi-touch interactive surface. A user study with 20 user groups indicates that the game facilitates collaboration between local and remote groups of learners. The videoconference and multitouch surface acted as communication channels, attracted students’ interest, facilitated engagement, and promoted inter- and intra-group collaboration—/nfavoring intra-group collaboration. Our findings suggest that augmenting/nvideoconferencing systems with a shared multitouch space offers new/npossibilities and scenarios for remote collaborative environments and collaborative learning

Psychophysiological responses in panic and stress

This paper examines the use of ambulatory monitoring in investigating individual differences in physiological functioning during everyday life and the relationship between psychophysiological responses in the laboratory and in the field. Techniques for dealing with confounding variables and analysing the ambulatory data are described. Findings from a study of young volunteers indicated that average cardiovascular responses to specific laboratory tasks did not relate consistently to measures of heart rate responsiveness in the field. However, measures derived from peak cardiovascular responses to a battery of active coping challenges did reliably predict cardiac responsiveness in real life, particularly when non-psychological factors influencing cardiac reactivity were taken into account. These measures may reflect reliable and generalizable differences in the extent of sympathetic activation in response to stress. These findings were largely replicated in a study of panic patients. The peak heart rate response to a battery of psychological stressors was the strongest predictor of heart rate variability in the field. This study also found that panic patients exhibited greater cardiac variability during everyday life than normal controls, suggesting that panic patients may be experiencing more frequent and intense fluctuations in bodily function. Such a propensity may contribute to the increase in perceived body sensations reported by panic patients

GABAergic interneurons form transient layer-specific circuits in early postnatal neocortex

GABAergic interneurons play key roles in cortical circuits, yet little is known about their early connectivity. Here we use glutamate uncaging and a novel optogenetic strategy to track changes in the afferent and efferent synaptic connections of developing neocortical interneuron subtypes. We find that Nkx2-1-derived interneurons possess functional synaptic connections prior to emerging pyramidal cell networks. Subsequent interneuron circuit maturation is both subtype and layer dependent. Glutamatergic input onto fast spiking (FS), but not somatostatin-positive, non-FS interneurons increases over development. Interneurons of both subtype located in layers (L)4 and L5b engage in transient circuits that disappear after the somatosensory critical period. These include a pathway mediated by L5b somatostatin-positive interneurons that specifically targets L4 during the first postnatal week. The innervation patterns of immature cortical interneuron circuits are thus neither static nor progressively strengthened but follow a layer-specific choreography of transient connections that differ from those of the adult brain