Cognitive functioning and cortisol profiles in first episode major depression

Major Depressive Disorder (MDD) is often associated with high levels of stress and disturbances in the Hypothalamic Pituitary Adrenal (HPA) system, yielding high levels of cortisol, in addition to cognitive dysfunction. Previous studies have shown a relationship between cortisol profile and cognitive functioning in recurrent MDD in general. More specifically, the association between hypercortisolism and cognitive functioning, such as memory and Executive Functioning (EF), and also more recently cortisol suppression has been explored. However, no studies have investigated these relationships in patients diagnosed with first episode MDD. The aim of the present study was to examine the relationship between cortisol levels before and after the Dexamethasone suppression test (DST) and cognitive function in first episode MDD patients. Twenty‐one patients meeting the DSM‐IV criteria for a first episode of MDD diagnosis were included in the study. The control group was matched for age, gender and education level. Cortisol was measured in saliva collected with Salivette sampling devices. Saliva samples were collected 4 times during a 24 hours period over two consecutive days: at awakening, after 45 minutes, after 7 hours and at 11 pm. Dexamethasone (1.0 mg) was given orally on Day 1 at 11 pm. The neuropsychological test battery consisted of standardized tests measuring executive functioning (EF) and memory functioning. Cortisol levels did not differ significantly between patients and controls on Day 1, except for the last sample before Dexamethasone administration, where the control group showed higher levels. Both groups showed suppression after Dexamethasone. On Day 2 there was a significant difference between groups at the third sample, showing a significantly lower level in the control group, suggesting that the controls have a more effective suppression profile than the patients. There were no significant correlations between cortisol levels before or after Dexamethasone and cognitive measures. The results indicate impairment on HPA‐axis functioning in first episode MDD patients, with less suppression functioning compared to healthy controls, but no relationship between cortisol profile and cognitive functioning in EF or Memory.     

Physiological Correlates of Choice‐Induced Dissonance: An Exploration of HPA‐Axis Responses

Choice can produce a negatively arousing cognitive conflict (called dissonance), which is thought to motivate the chooser to spread their preferences for the relevant options (called Spreading of Alternatives, or SA). The current work aimed to determine the relationship between HPA‐axis activity and both choice‐induced dissonance and its reduction (i.e. SA) among individuals with varying cultural backgrounds. European–Americans and Asians made a choice between two equally attractive CDs either in the presence of a cue indicative of social eyes (i.e. public‐choice condition) or in the absence thereof (i.e. private‐choice condition). As predicted, European–Americans and Asians showed a reliable SA primarily in the private and public choice conditions, respectively. Importantly, a sharp decline of salivary cortisol was observed over the span of 30 min, and, moreover, this decline was reliably predicted by the magnitude of SA regardless of either culture or the choice being private vs. public. These results suggest that although choice‐induced dissonance is too weak to elicit an HPA‐axis stress response, SA is associated with variability in the decline of salivary cortisol during the laboratory task. Copyright © 2015 John Wiley & Sons, Ltd.     

Externalized memory in slime mould and the extended (non-neuronal) mind

The hypothesis of extended cognition (HEC) claims that the cognitive processes that materially realise thinking are sometimes partially constituted by entities that are located external to an agent’s body in its local environment. We show how proponents of HEC need not claim that an agent must have a central nervous system, or physically instantiate processes organised in such a way as to play a causal role equivalent to that of the brain if that agent is to be capable of cognition. Focusing on the case of spatial memory, we make our argument by taking a close look at the striking example of Physarum Polycephalum plasmodium (i.e., slime mould) which uses self-produced non-living extracellular slime trails to navigate its environment. We will argue that the use of externalized spatial memory by basal organisms like Physarum is an example of extended cognition. Moreover, it is a possible evolutionary precursor to the use of internal spatial memory and recall in animals thus demonstrating how extended cognition may have emerged early in evolutionary history.     

Why won’t you do what I want? The informative failures of children and models

Computational models are powerful tools – too powerful, according to some. We argue that the idea that models can “do anything” is wrong, and we describe how their failures have been informative. We present new work showing surprising diversity in the effects of feedback on children's task-switching, such that some children perseverate despite this feedback, other children switch as instructed, and yet others play an “opposites” game without truly switching to the newly instructed task. We present simulations that demonstrate the failure of an otherwise-successful neural network model to capture this failure. Simulating this pattern motivates the inclusion of updating mechanisms that make contact with a growing literature on frontostriatal function, despite their absence in theories of the development of cognitive flexibility. We argue from this and other examples that computational models are more constrained than is typically acknowledged and that their resulting failures can be theoretically illuminating.     

Poverty and Single Parenting: Relations with Preschoolers' Cortisol and Effortful Control

Poverty and single parent status, which often co‐occur, have been shown to relate to lower effortful control, and this may be in part due to disruptions in hypothalamic–pituitary–adrenal (HPA) axis activity. Both poverty and single parent status may compromise parenting, which in turn may disrupt HPA axis activity and the development of effortful control. We examined whether parenting and HPA axis activity accounted for the effects of poverty and single parent status on the development of effortful control in preschool children (N = 78). Effortful control was measured at two time points, 6 months apart. Individually, poverty and single parent status were related to blunted HPA axis activity, characterized by low AM and PM cortisol. However, when examined together, the effects were present only for preschoolers whose parents were in poverty. Parental warmth and negativity accounted for the relations between poverty and blunted cortisol. Blunted cortisol was related to lower effortful control at Time 2. These results suggest a pathway through which poverty may impact children's developing effortful control through parenting, which in turn may shape HPA axis activity. Copyright © 2012 John Wiley & Sons, Ltd.     

Objective Evaluation of Performance Stress in Musicians With Focal Hand Dystonia: A Case Series

Five musicians suffering from focal dystonia participated in a pilot study that examined the feasibility of an experimental protocol designed to assess musicians' motor performance under stress. Electrocardiography, free cortisol levels, and subjective assessments were used to monitor alterations of the hypothalamic-pituitary-adrenal axis. As measures of motor outcome, temporal variability of finger movements and muscular cocontraction of the wrist flexor and extensor were assessed. Findings suggest that the specific experimental design could be successfully applied. Several methodological issues such as carryover effects, the use of free cortisol, the inclusion of a double baseline, and the classification of dystonic patients into stress responders and nonresponders are analyzed and discussed.     

Unemployment as a chronic stressor: A systematic review of cortisol studies

Objective: Unemployment is a type of chronic stressor that impacts human health. The reasons for how the stress of unemployment affect health is still a matter of discussion. One of the pathways from chronic stress to ill health is mediated by cortisol, and so we set out to compile extant data on how its secretion is affected by unemployment.

Design: A systematic literature search was conducted to establish the cortisol dysregulatory effects of this stressor.

Main outcome measures: Only studies that specifically examined the effects of unemployment on cortisol excretion, and were written in English were included.

Results: Ten reports were obtained and synthesised to determine the severity and complexity of the effect of unemployment on cortisol secretion. The resulting combined evidence is mixed in terms of degree or dynamic of relationship.

Conclusions: The differences between the cumulate findings of the studies can be understood in the context of the lack of both standardised methodology and an absence of consensus on unemployment definition. We propose existing methodologies may be strengthened by acknowledging and accounting for the individual characteristics that may be relevant to the stress experience of unemployment.     

Analysis of five cases with neurogenic stuttering following brain injury in the basal ganglia

This study examined stuttering patterns in five patients with basal ganglia injury. None of the patients had a history of developmental stuttering. Four patients were right-handed; one patient was ambidextrous. Stuttering tests administered to patients assessed sentence repetition, reading aloud, explanations of a comic strip, and conversation. Accessory behaviors such as facial grimaces, associated movements of the limbs, and avoidance behaviors were observed. The results of this study differ from those of previous studies of neurogenic stuttering in several respects: (1) blocks were frequently observed. (2) Adaptation was observed. (3) Almost all stuttering occurred at the initiation of words. (4) Across patients, stuttering frequency did not vary in a consistent manner with speaking task. New speech characteristics for neurogenic stuttering without aphasia following injury to the basal ganglia are described.Educational objectives: After reading this text, the reader will be able to: (1) provide characteristics of neurogenic stuttering after the basal ganglia in patients without aphasia; (2) discuss the difference of the features and characteristics of stuttering between previously reported patients and present patients.     

Relation of intimate partner violence to salivary cortisol among couples expecting a first child

Despite advances in understanding the role that several physiological systems play in the occurrence of general violence, little progress has been made toward understanding biological correlates of intimate partner violence (IPV). We explored involvement of one physiological system, the hypothalamic-pituitary-adrenal (HPA) axis. Among 137 heterosexual couples expecting a first child, baseline level of HPA activity-assessed via salivary cortisol collected before a couple conflict discussion-was linked to both men's and women's violence perpetration. HPA reactivity to the conflict bout did not show an independent association with IPV. However, persisting elevation in men's, and down-regulation in women's, HPA activity during a further recovery period was linked to men's violence perpetration.     

The cortisol awakening response: Associations with trait anxiety and stress reactivity

This study investigated the extent to which trait anxiety and state anxiety in response to stress are associated with the cortisol awakening response (CAR).Fifty-one healthy participants were recruited. State anxiety measures were taken in anticipation of and during a laboratory stressor. Salivary cortisol levels were measured immediately upon awakening (at 0, 15, 30, and 45 min) on two consecutive mornings. Cortisol awakening response was assessed by the area under the curve with respect to zero (AUC_G).The magnitude of the CAR was found to be negatively associated with both trait anxiety and anticipatory anxiety. Moreover, regression analysis showed that the effects of trait anxiety on the AUC_G were mediated by anticipatory anxiety.These results suggest that the CAR is influenced by trait anxiety. Moreover, the effect of trait anxiety on the CAR seems to operate by impacting on psychological stress reactivity (i.e., anticipatory anxiety).