Stress, Cortisol, and Externalizing Behavior in Adolescent Males: An Examination in the Context of Multisystemic Therapy

Stress and hypothalamic-pituitary-adrenal (HPA) axis dysregulation have been associated with externalizing behavior in adolescence, but few studies have examined these factors in a treatment context. This study investigated the relationship between stress, cortisol, and externalizing behavior among 120 adolescent males (mean age?=?15) receiving Multisystemic Therapy (MST). To examine the differential relationship of cortisol with various types of stressors, self-report measures assessed lifetime stress, current episodic stress, and daily hassles. Morning and afternoon cortisol samples were collected to examine whether the relationship between stress and treatment outcome depended on the youth's biological stress levels. Regression analyses indicated that awakening cortisol levels moderated the relationship between daily hassles and externalizing behaviors at post-treatment. More specifically, higher levels of daily hassles predicted worse outcomes only among adolescents with high levels of morning cortisol. In addition, lifetime stressors and afternoon measures of cortisol interacted to predict changes in caretaker reports of externalizing problems and youth arrests following treatment; lifetime stressors were positively associated with externalizing behavior when adolescents had low levels of afternoon cortisol. Implications for theory and future directions for evidence-based treatment are discussed.     

Brain activation during spatial updating and attentive tracking of moving targets

Keeping aware of the locations of objects while one is moving requires the updating of spatial representations. As long as the objects are visible, attentional tracking is sufficient, but knowing where objects out of view went in relation to one's own body involves an updating of spatial working memory. Here, multiple object tracking was employed to study spatial updating and its neural correlates. In a dynamic 3D-scene, targets moved among visually indistinguishable distractors. The targets and distractors either stayed visible during continuous viewpoint changes or they turned invisible. The parametric variation of tracking load revealed load-dependent activations of the intraparietal sulcus, the superior parietal lobule, and the lateral occipital cortex in response to the attentive tracking task. Viewpoint changes with invisible objects that demanded retention and updating produced load-dependent activation only in the precuneus in line with its presumed involvement in updating spatial working memory.     

Offline improvement occurs for temporal stability but not accuracy following practice of integer and non-integer rhythms

Procedural learning benefits from memory processes occurring outside practice resulting in offline learning. Offline gains have been demonstrated almost exclusively for the ordinal structure of sequential motor tasks. Many skills also demand that the correct serial order of events be appropriately timed. Evidence indicates that the temporal aspect of a procedural skill can be encoded independent of serial order knowledge and governed by at least two distinct neural circuits. The present experiment determined if (a) offline gains emerge for temporal learning, and (b) if such gains occur for timing supervised by distinct timing systems. Participants experienced 216 practice trials of a 7-key press sequence that involved integer- or non-integer timing rhythms. Twenty-four hours after training 30 test trials were administered. Results revealed robust offline enhancement for timing performance of the non-integer based temporal sequences. This improvement was localized to stabilization of the required relative but not absolute time profiles. The neural circuitry central to supporting the performance of non-integer timing sequences is also a principal constituent of what is described as the "cognitive" timing system. Timing governed by this system appears most susceptible to offline gains via consolidation.     

Using the movement-related cortical potential to study motor skill learning

The movement-related cortical potential (MRCP) is a low-frequency negative shift in the electroencephalographic recording that occurs about 2 s before voluntary movement production. The MRCP is thought to reflect the cortical processes involved in movement planning and movement preparation. In recent years, researchers have used this potential to investigate the processes involved in motor skill learning. Their findings indicate differences in the amplitude and onset times of the MRCP between experienced and novice performers, which have been attributed to long-term training in the experts. The authors discuss these findings critically and consider their implications for both future research and practice.     

Postural asymmetries in response to holding evenly and unevenly distributed loads during self-selected stance

The authors examined postural asymmetries during quiet stance and while holding evenly or unevenly distributed loads. Right-hand dominant subjects preferentially loaded their right lower limb when holding no load or a load evenly distributed in both hands, but no differences in center of pressure (CoP) were observed between the left and right limbs. However, longer CoP displacement was observed under the preferentially loaded limb, which may reflect a functional asymmetry that allows quick movement of one limb in response to a potential perturbation. When a load was held only in the nondominant hand, sample entropy decreased in the left (loaded) limb but increased in the right (unloaded) limb, suggesting the unloaded foot compensated for a loss of control flexibility in the loaded foot.     

Threat and selective exposure: the moderating role of threat and decision context on confirmatory information search after decisions

Previous studies on the impact of perceived threat on confirmatory information search (selective exposure) in the context of decision making have yielded mixed results. Some studies have suggested that confirmatory information search is reduced, yet others have found contradictory effects. The present series of 5 studies consistently found that the crucial moderator for these inconsistent findings was whether the induced threat was contextually related to the subsequent decision and information search tasks. Contextual incongruence (e.g., an induction of terrorist threat followed by an economic decision case) results in reduced levels of confirmatory information search, whereas a congruent threat (e.g., an induction of terrorist threat followed by a decision case on terrorism) results in increased levels of confirmatory information search. Analyses of the underlying psychological processes revealed that decision-unrelated threat inductions increase decision makers' experienced decision uncertainty, thus reducing confirmatory information search.     

Evaluating the Evidence for the General Factor of Personality across Multiple Inventories

A general factor of personality (GFP) has been proposed as the apex of a personality trait hierarchy that explains covariance among the lower-order factors measured by various personality inventories. In this study we evaluated the GFP hypothesis across several personality inventories, unlike most previous research in which the GFP has been derived from individual instruments in isolation. Exploratory analyses did not produce substantial evidence for the existence of a single cross-instrument higher-order factor of factors and efforts to specify a range of GFP-inspired models in a confirmatory framework led to significant estimation difficulties and poor fit to the data. Overall these results fail to support a common GFP that is positioned at the top of a personality trait hierarchy.     

On the role of goal relevance in emotional attention: disgust evokes early attention to cleanliness

Prior evidence has shown that aversive emotional states are characterised by an attentional bias towards aversive events. The present study investigated whether aversive emotions also bias attention towards stimuli that represent means by which the emotion can be alleviated. We induced disgust by having participants touch fake disgusting objects. Participants in the control condition touched non-disgusting objects. The results of a subsequent dot-probe task revealed that attention was oriented to disgusting pictures irrespective of condition. However, participants in the disgust condition also oriented towards pictures representing cleanliness. These findings suggest that the deployment of attention in aversive emotional states is not purely stimulus driven but is also guided by the goal to alleviate this emotional state.