The association between maternal interaction and infant cortisol stress reactivity among preterm and full term infants at 4 months adjusted age

The purpose of this study was to assess the association between maternal interactive behavior and infant cortisol stress reactivity in response to the Still Face paradigm (SF) in a cohort of four-month old infants (adjusted age) born preterm (<32 weeks gestation, N = 22) compared with infants born full term (>37 weeks gestation, N = 28). Infant cortisol reactivity was calculated as area under the curve (AUC) from baseline to the third cortisol sample (30 min post-SF) using the trapezoidal rule, while the percent of time mothers spent using a contingent interaction style was measured (0–100%) during episodes 1 (Play; baseline), 3 (Reunion#1), and 5 (Reunion#2) while mother-infant dyads participated in the SF paradigm. We hypothesized that because infants born preterm are at increased risk for dysregulation, they would show, compared to full-term infants, a blunted stress response, involving under-responsiveness. We found blunted cortisol stress reactivity among the preterm infants. We also found that mothers of preterm infants demonstrated less contingent maternal interaction during Renion#1 of the SF; and that contingent maternal interaction at Reunion#2 of the SF was protective against cortisol stress reactivity in response to the SF. However, we did not find that the influence of maternal interaction on cortisol reactivity was moderated by gestational age group (full term vs preterm): the association between contingent maternal interaction and stress reactivity was similar for both gestational groups across episodes. In order to improve self-regulation and longer term social and cognitive developmental outcomes in medically at-risk infants, future research is warranted to determine how these findings relate to infants’ stress reactions in naturalistic settings, and the directionality and temporal relationship between cortisol stress responses and maternal interactive behavior.     

Affective reactivity to cry sounds predicts young women’s reactivity and behavior in a simulated caregiving task

Different populations of adults (experienced vs. inexperienced caregivers, men vs. women, abusive vs. nonabusive parents, etc.) have been reported to differ in their affective reactions to the sounds of infant crying. These differences are thought to impact caregiving behavior and, in some instances, to affect long-term outcomes for infants. There can be great intra-group variation, however, even when group differences are significant; modeling developmental process will require a finer grained approach. We have undertaken a pair of studies intended to validate the Negative Affect Scale (NA) from the PANAS as a measure of individuals’ affective reactivity to cry sounds. In Study 1, 306 young women who were not yet mothers listened either to infant crying or to birdsong. The results supported the NA as a measure of reactivity to crying. In Study 2, a new sample of 301 young women listened to crying in a screening task; a group of “high reactors” (n = 21) and a group of “low reactors” (n = 22) then participated in a simulated caregiving situation. Individuals’ affective reactivity to the caregiving simulation mirrored their affective reactivity in the screening task, and rates and overall organization of caregiving behavior differed between the groups. Changes in negative affect, then, appear to be both a result of infant crying and a determinant of some aspects of caregiving behavior. Further studies will extend these laboratory results to real infants and their caregivers, and further validate the NA as a measure of individual differences in reactivity to cry sounds.     

The influence of robotic guidance on error detection and correction mechanisms

New technologies have expanded the available methods to help individuals learn or re-learn motor skills. Despite equivocal evidence for the impact of robotic guidance for motor skill acquisition (Marchal-Crespo, McHughen, Cramer, & Reinkensmeyer, 2010), we have recently shown that robotic guidance mixed with unassisted practice can significantly improve the learning of a golf putting task (Bested & Tremblay, 2018). To understand the mechanisms associated with this new mixed approach (i.e., unassisted and robot-guided practice) for the learning of a golf putting task, the current study aimed to determine if such mixed practice extends to one’s ability to detect errors. Participants completed a pre-test, an acquisition phase, as well as immediate, delayed (24-h), and transfer post-tests. During the pre-test, kinematic data from the putter was converted into highly accurate, consistent, and smooth trajectories delivered by a robot arm. During acquisition, 2 groups performed putts towards 3 different targets with robotic guidance on either 0% or 50% of acquisition trials. Only the 50% guidance group significantly reduced ball endpoint distance and variability, as well as ball endpoint error estimations, between the pre-test and the post-tests (i.e., immediate retention, 24-h retention, and 24-h transfer). The current study showed that allowing one to experience both robotic guidance and unassisted (i.e., errorful) performances enhances one’s ability to detect errors, which can explain the beneficial motor learning effects of a mixed practice schedule.     

Differential Effect of Two Mental Stress Tasks on Arterial Stiffness

Acute mental stress is believed to induce transient arterial dysfunction, but relatively few data are available. We therefore examined the effect of mental stress tasks that could induce differential hemodynamic responses on arterial dysfunction. Forty‐eight participants conducted either a mental arithmetic (MA) task or a mirror‐tracing (MT) task. Cardiovascular indices and arterial stiffness were measured before, during, and after these tasks. Analysis revealed that increases in arterial stiffness during the task and during recovery were more pronounced for the MA than for the MT, and that evoked hemodynamic response was more myocardial for MA than for MT. These results clearly show that MA and MT tasks that induce differential hemodynamic responses have a differential effect on arterial stiffness. This finding sheds light on the underlying mechanism that may account for the relationship between cardiovascular reactivity and cardiovascular disease.     

Preliminary evidence of attenuated blood pressure reactivity to acute stress in adults following a recent marital separation

Objective: This study explores cardiovascular reactivity during an acute-stress task in a sample of recently separated adults.

Design: In a cross-sectional design, we examined the association between adults’ subjective separation-related distress and changes in heart rate and blood pressure across the acute-stress laboratory paradigm in a sample of 133 (n = 49 men) recently separated adults.

Main outcome measures: Heart rate (HR) and Blood pressure (BP) were recorded across a resting baseline period, a math stressor task, and a recovery period.

Results: Multilevel analyses revealed that adults who reported greater separation-related distress exhibited higher initial BP and a slower linear increase in BP across the study period. In addition, adults reporting greater separation-related distress evidenced significantly slower declines in diastolic blood pressure (DBP) following the acute-stress task. HR reactivity was not moderated by separation-related distress.

Conclusions: In recently separated adults, preliminary evidence suggests that the context of the stressors may reveal differential patterns of problematic reactivity (exaggerated or blunted responding). Greater emotional intrusion and hyperactivity symptoms may index increased risk for blunted cardiovascular reactivity to general stressors. This pattern of reactivity is consistent with models of allostatic load that emphasise the deleterious effect of hyporesponsivity to environmental demands.     

父母冲突对青少年抑郁的影响:认知反应性的中介作用

采用父母冲突儿童知觉量表(CPIC)、抑郁体验问卷(DEQ)、莱顿抑郁敏感指数量表(LEIDS)测量753名高中生,以便分析认知反应性在父母冲突与抑郁之间的中介作用。结果表明:(1)父母冲突显著正向预测认知反应性; 认知反应性显著正向预测青少年抑郁;(2)认知反应性在父母冲突与青少年抑郁之间具有完全中介作用。因此,认知反应性作为中介变量,父母冲突通过认知反应性对青少年抑郁具有稳定的间接作用。     

A tale of two audiences: Narcissism,failure reactivity,and perceived criticism from the self and others as internalized audiences

We proposed a conceptual model which postulates that anticipating greater destructive (vs. constructive) criticism from the self and others partially explains the differentiation of narcissists’ failure reactivity as a function of narcissism subtype. Participants simulated failure, rated the likelihood of experiencing destructive and constructive criticism from social audiences (self and others [important other, unimportant other, social world]), and indicated failure reactivity (indexed as change in negative affect) following failure. Results generally supported our model. Vulnerable (grandiose) narcissism related to enhanced (reduced) failure reactivity and greater (less) anticipated destructive vs. constructive criticism from audiences, particularly the self. Controlling for perceived criticism from audiences attenuated relations between each narcissism subtype and failure reactivity, supporting the theoretical merit of our model.     

The Fictionalist’s Attitude Problem

According to John Mackie, moral talk is representational (the realists go that bit right) but its metaphysical presuppositions are wildly implausible (the non-cognitivists got that bit right). This is the basis of Mackie’s now famous error theory: that moral judgments are cognitively meaningful but systematically false. Of course, Mackie went on to recommend various substantive moral judgments, and, in the light of his error theory, that has seemed odd to a lot of folk. Richard Joyce has argued that Mackie’s approach can be vindicated by a fictionalist account of moral discourse. And Mark Kalderon has argued that moral fictionalism is attractive quite independently of Mackie’s error-theory. Kalderon argues that the Frege–Geach problem shows that we need moral propositions, but that a fictionalist can and should embrace propositional content together with a non-cognitivist account of acceptance of a moral proposition. Indeed, it is clear that any fictionalist is going to have to postulate more than one kind of acceptance attitude. We argue that this double-approach to acceptance generates a new problem – a descendent of Frege–Geach – which we call the acceptance–transfer problem. Although we develop the problem in the context of Kalderon’s version of non-cognitivist fictionalism, we show that it is not the non-cognitivist aspect of Kalderon’s account that generates the problem. A closely related problem surfaces for the more typical variants of fictionalism according to which accepting a moral proposition is believing some closely related non-moral proposition. Fictionalists of both stripes thus have an attitude problem.

Error analysis of digital filters using HOL theorem proving

When a digital filter is realized with floating-point or fixed-point arithmetics, errors and constraints due to finite word length are unavoidable. In this paper, we show how these errors can be mechanically analysed using the HOL theorem prover. We first model the ideal real filter specification and the corresponding floating-point and fixed-point implementations as predicates in higher-order logic. We use valuation functions to find the real values of the floating-point and fixed-point filter outputs and define the error as the difference between these values and the corresponding output of the ideal real specification. Fundamental analysis lemmas have been established to derive expressions for the accumulation of roundoff error in parametric Lth-order digital filters, for each of the three canonical forms of realization: direct, parallel, and cascade. The HOL formalization and proofs are found to be in a good agreement with existing theoretical paper-and-pencil counterparts.