Aging is associated with increased Weber ratios for caffeine, but not for sucrose

To investigate whether age-associated changes in the human taste system are quality-specific, we compared young and elderly subjects' suprathreshold discrimination abilities for caffeine and sucrose. The method of constant stimuli was used to obtain just noticeable differences and Weber ratios. The elderly generated larger Weber ratios than did the young for both the medium and high concentrations of caffeine, but not for the low concentration. For example, a 74% increase in .005 M caffeine was required to obtain a perceptible difference for the elderly, whereas a 34% increase produced a perceptible difference for the young. The Weber ratios for sucrose did not differ for the two age groups. The results of this study indicate that age-associated changes in the taste system are quality-specific.     

Increased forefoot loading is associated with an increased plantar flexion moment

The aim of this study was to identify the cascade of effects leading from alterations in force generation around the ankle joint to increased plantar pressures under the forefoot. Gait analysis including plantar pressure measurement was performed at an individually preferred and a standardized, imposed gait velocity in diabetic subjects with polyneuropathy (n = 94), without polyneuropathy (n = 39) and healthy elderly (n = 19). The plantar flexion moment at 40% of the stance phase was negatively correlated with the displacement rate of center of pressure (r = ?.749, p < .001 at the imposed, and r = ?.693, p < .001 at the preferred gait velocity). Displacement rate of center of pressure was strongly correlated with forefoot loading (r = ?.837, p < .001 at the imposed, and r = ?.731, p < .001 at the preferred gait velocity). People with a relatively high plantar flexion moment at 40% of the stance phase, have a faster forward transfer of center of pressure and consequently higher loading of the forefoot. This indicates that interventions aimed at increasing the control of the roll-off of the foot may contribute to a better plantar pressure distribution.     

Uncertainty is associated with increased selective attention and sustained stimulus processing

Uncertainty about future threat has been found to be associated with an overestimation of threat probability and is hypothesized to elicit additional allocation of attention. We used event-related potentials to examine uncertainty-related dynamics in attentional allocation, exploiting brain potentials’ high temporal resolution and sensitivity to attention. Thirty participants performed a picture-viewing task in which cues indicated the subsequent picture valence. A certain-neutral and a certain-aversive cue accurately predicted subsequent picture valence, whereas an uncertain cue did not. Participants overestimated the effective frequency of aversive pictures following the uncertain cue, both during and after the task, signifying expectancy and covariation biases, and they tended to express lower subjective valences for aversive pictures presented after the uncertain cue. Pictures elicited increased P2 and LPP amplitudes when their valence could not be predicted from the cue. For the LPP, this effect was more pronounced in response to neutral pictures. Uncertainty appears to enhance the engagement of early phasic and sustained attention for uncertainly cued targets. Thus, defensive motivation related to uncertainty about future threat elicits specific attentional dynamics implicating prioritization at various processing stages, especially for nonthreatening stimuli that tend to violate expectations.     

Decreased latent inhibition is associated with increased creative achievement in high-functioning individuals

Reductions in latent inhibition (LI), the capacity to screen from conscious awareness stimuli previously experienced as irrelevant, have been generally associated with the tendency towards psychosis. However, "failure" to screen out previously irrelevant stimuli might also hypothetically contribute to original thinking, particularly in combination with high IQ. Meta-analysis of two studies, conducted on youthful high-IQ samples. demonstrated that high lifetime creative achievers had significantly lower LI scores than low creative achievers (r(effect size) = .31, p = .0003, one-tailed). Eminent creative achievers (participants under 21 years who reported unusually high scores in a single domain of creative achievement) were 7 times more likely to have low rather than high LI scores, chi2 (1, N = 25) = 10.69, phi = .47. p = .003.     

Trauma exposure is associated with increased context-dependent adjustments of cognitive control in patients with posttraumatic stress disorder and healthy controls

Recent evidence has suggested that posttraumatic stress disorder (PTSD) is associated with alterations in prefrontal-cortex-dependent cognitive processes (e.g., working memory, cognitive control). However, it remains unclear whether these cognitive dysfunctions are related to PTSD symptomatology or trauma exposure. Furthermore, regarding cognitive control, research has only focused on the integrity of selected control functions, but not their dynamic regulation in response to changing environmental demands. Therefore, the present study investigated dynamic variations in interference control, in addition to overall interference susceptibility and working memory (WM) performance in matched groups of 24 PTSD patients and 26 traumatized and 30 nontraumatized healthy controls. The Simon task was used to measure overall interference susceptibility and the flexible adjustment of cognitive control, on the basis of the occurrence of response conflicts (conflict adaptation effect). WM performance was assessed with the forward and backward digit span tasks. Since we have previously shown that trauma exposure per se is associated with reduced hair cortisol concentrations (HCC), we further explored whether PTSD/trauma-related cognitive alterations are related to HCC in proximal 3-cm hair segments. The results revealed that PTSD patients and traumatized controls showed significantly more pronounced conflict adaptation effects than nontraumatized controls. Moreover, the conflict adaptation effect was positively related to the number of lifetime traumatic events and the frequency of traumatization. The groups did not differ in overall interference susceptibility or WM performance. Exploratory analyses revealed no association between HCC and the observed cognitive differences. These results suggest that context-driven control adjustments constitute a sensitive correlate of trauma exposure, irrespective of PTSD.     

Shortening of the QT interval of the EKG is associated primarily with increased ventricular contractility rather than heart rate

The objective of this study was to gather direct evidence on whether the duration of the QT interval relates primarily to heart rate or to ventricular contractility. The electrocardiographic and cardiodynamic consequences of electrical stimulation (15 V, 5 ms, 10Hz) of various intrathoracic sympathetic efferent neuronal structures were studied in 10 anesthetized mongrel dogs. Stimulation of efferent sympathetic axons in the right intraganglionic nerve, which innervates the sinoatrial node, induced tachycardia (110±5 - 133±6 bpm; p<0.01) without significantly altering right or left ventricular intramyocardial ventricular chamber pressures. The QT interval, as determined by leads I, II and III of the EKG and a transthoracic lead, was not affected by this intervention (310±8 - 302±ms). Increasing heart rate to a similar degree (111±3 - 131±3 bpm) by right atrial pacing did not induce changes in the QT interval. When right (23±3 - 49±8 mm Hg; p<0.01) and left (81±10 - 127±19 mm Hg; p<0.01) ventricular forces were augmented without concomitant increases in heart rate by stimulating efferent sympathetic axons in the left caudal pole cardiopulmonary nerve the QT interval shortened (322±11 - 290±12 ms; p<0.01). Only when an efferent sympathetic nerve, that contains fibers destined for both the sinoatrial node and the ventricles was stimulated did both heart rate and ventricular contractility augment and QT shorten (318±10 - 290±11 ms; p<0.01). These results indicate that QT interval shortening induced by efferent sympathetic neurons is primarily associated with augmentation of ventricular contractility rather than heart rate.     

Digit ratios,but not facial width-to-height ratios,are associated with the priority placed on attending to faces versus bodies

Testosterone has been linked to a sexual preference for bodies rather than faces. Low digit ratio (2D:4D) and high facial width-to-height ratio (WHR) are associated with high prenatal testosterone. We tested whether low 2D:4D and high facial WHR were correlated with a preference for bodies over faces. Our sample consisted of 109 college students (64 males). A two-way analysis of variance demonstrated a significant main effect of digit ratio on the priority placed on paying attention to faces or bodies such that low 2D:4D was linked to a preference for bodies, but the effect of sex was not significant. There were no significant interaction effects. Another two-way analysis of variance revealed no significant effects for facial WHR and attentional priority but significant associations between sex and attentional priority. There were no significant interaction effects. Our findings indicate that individuals with low digit ratios tended to pay more attention to bodies than to faces compared with individuals with higher digit ratios, independently of sex. We also found that males tended to pay more attention to bodies than to faces compared with females, independently of facial WHR.     

Implicit need for affiliation is associated with increased corrugator activity in a non-positive, but not in a positive social interaction

Affective changes in response to motive-relevant stimuli are a defining feature of implicit motives. We therefore expected to find an effect of individual differences in the implicit need for affiliation (nAff) on corrugator supercilii activity, an indicator of affect, when participants were confronted with nonverbal indicators of a conversational partner’s withdrawal. Participants’ nAff was assessed with a Picture Story Exercise (PSE). They were then involved in an interaction with a smiling or a neutral experimenter while their corrugator activity was measured with electromyography (EMG). As expected, we found higher corrugator activity for people high in nAff compared to people low in nAff when the experimenter kept a neutral facial expression throughout the interaction but not when he/she was smiling.     

Referential competence is associated with motivational congruence

[Schultheiss, 2001] and [Schultheiss, 2008] hypothesized that referential competence (RC) - stable individual differences in the ability to quickly name nonverbally represented information - should predict congruence between implicit and explicit motives. We tested this hypothesis using a color-naming task to assess RC, picture-story measures of implicit motives, and self-report measures of participants’ motivational values and goals. Study 1 showed that the RC measure captures a stable individual difference by test-retest and internal consistency criteria. Studies 2 and 3 provided correlational evidence for the hypothesized association between RC and measures of between- and within-individual motivational congruence. Study 4 showed that in the absence of situationally induced referential processing, RC predicts preferences for motive-congruent goals.     

PTSD arousal and depression symptoms associated with increased right-sided parietal EEG asymmetry

Researchers have proposed that depression and particular types of anxiety are associated with unique patterns of regional brain activation. The authors examined the relationship among posttraumatic stress disorder (PTSD), anxiety, and depressive symptoms and frontal, temporal, and parietal EEG alpha asymmetry in female Vietnam War nurse veterans. The results indicate that PTSD arousal symptoms are associated with increased right-sided parietal activation. However, the combination of arousal, depression, and their interaction explain more than twice the variance in parietal asymmetry compared with arousal alone. The results support the contention that the association between anxiety and right-sided posterior activation is specific to the anxious arousal subtype. These findings underscore the importance of isolating, both theoretically and statistically, emotional subcomponents in studies of regional brain activation.     

Childhood maltreatment is associated with increased neural response to ambiguous threatening facial expressions in adulthood: Evidence from the late positive potential

Childhood maltreatment increases lifetime vulnerability for psychopathology. One proposed mechanism for this association is that early maltreatment increases vigilance for and attention to subtle threat cues, persisting outside of the environment in which maltreatment occurs. To test this possibility, the present study examined neural responses to ambiguous and nonambiguous threatening facial expressions in a sample of 25 adults reporting a history of low-to-moderate levels of abuse in childhood and 46 reporting no or low levels of childhood maltreatment. The measure of neural response used was the late positive potential (LPP), a neural marker of sustained attention to motivationally salient information that is sensitive to subtle variation in emotional content. Participants passively viewed angry–neutral and fearful–neutral face blends and rated emotional intensity for each face. In the maltreated group, as fearful faces increased in emotional intensity, the LPP similarly increased, suggesting increased sensitivity to subtle variation in threatening content. Moreover, the LPP at each level of emotional intensity was not related to current symptoms of anxiety and depression. However, contrary to our hypotheses, adults with a history of abuse did not rate angry or fearful faces as more threatening, nor did they exhibit a larger LPP to angry faces, compared to controls. These findings suggest that childhood maltreatment may be associated with increased sensitivity to ambiguous threatening information in adulthood.     

Childhood conduct problems are associated with increased partnership and parenting difficulties in adulthood

This paper uses data from a sample of 337 parents studied at age 30 to examine the linkages between childhood conduct problems assessed at ages 7–9 and later partnership and parenting outcomes. The key findings of this study were: 1) increasing levels of childhood conduct problems were associated with increased risk of partnership difficulties, including relationship ambiguity, inter-partner conflict/violence and lower levels of relationship satisfaction; 2) increasing levels of childhood conduct problems were associated with increased risk of parenting difficulties, including over-reactivity, lax and inconsistent discipline, child physical punishment and lower levels of parental warmth and sensitivity. These findings were consistent across both parent reports and interviewer ratings, and in nearly all cases remained after extensive adjustment for confounding and selection bias. Study findings add to the growing body of evidence documenting the adverse consequences of early conduct problems for later adult interpersonal relationships and parenting behaviors.     

12-month-old infants allocate increased neural resources to stimuli associated with negative adult emotion

Young infants use caregivers' emotional expressions to guide their behavior in novel, ambiguous situations. This skill, known as social referencing, likely involves at least 3 separate abilities: (a) looking at an adult in an unfamiliar situation, (b) associating that adult's emotion with the novel situation, and (c) regulating their own emotions in response to the adult's emotional display. The authors measured each of these elements individually as well as how they related to each other. The results revealed that 12-month-olds allocated more attention, as indicated by event-related potential measures, to stimuli associated with negative adult emotion than to those associated with positive or neutral emotion. Infants' interaction with their caregiver was affected by adult emotional displays. In addition, how quickly infants referenced an adult predicted both their brain activity in response to pictures of stimuli associated with negative emotion as well as some aspects of their behavior regulation. The results are discussed with respect to their significance for understanding why infants reference and regulate their behavior in response to adult emotion. Suggestions for further research are provided.     

Consolidation of vocabulary is associated with sleep in children

Although the acquisition of a novel word is apparently rapid, adult research suggests that integration of novel and existing knowledge (measured by engagement in lexical competition) requires sleep‐associated consolidation. We present the first investigation of whether a similar time‐course dissociation characterizes word learning across development. Consistent with previous research but counter to adults, 7–12‐year‐olds showed sleep‐associated consolidation effects in declarative but not procedural memory. Nevertheless, the relationship between sleep and word learning in children was remarkably similar to the pattern for adults. Following exposure to nonword competitors (e.g. biscal) in the a.m. or p.m., children’s ability to recognize and recall the nonwords improved only after sleep (after approximately 12‐hrs for the p.m. group and 24‐hrs for the a.m. group), with performance stable 1 week later. Novel nonwords only induced lexical competition effects after sleep. These findings suggest that children utilize a dual memory system when acquiring and integrating new vocabulary and highlight sleep as integral to this process. A video abstract of this article can be viewed at http://www.youtube.com/watch?v=8mm8SDUXw_0&feature=plcp .     

Synaesthesia is associated with enhanced, self-rated visual imagery

Although the condition known as synaesthesia is currently undergoing a scientific resurgence, to date the literature has largely focused on the heterogeneous nature of synaesthesia across individuals. In order to provide a better understanding of synaesthesia, however, general characteristics need to be investigated. Synaesthetic experiences are often described as occurring 'internally' or in the 'mind's eye', which is remarkably similar to how we would describe our experience of visual mental imagery. We assessed the role of visual imagery in synaesthesia by sampling a large group of synaesthetes and found that they report experiencing more vivid mental images than controls. These findings have important implications for our general understanding of synaesthesia and, in particular, emphasize the need to control for visual imagery in behavioural and neuroimaging paradigms.     

Positive mood is associated with the implicit use of distraction

Previous research demonstrates that individuals in a positive mood are differentially distracted by irrelevant information during an ongoing task (Rowe et al. in Proc Natl Acad Sci 104:383–388, 2007). The present study investigated whether susceptibility to distraction shown by individuals in a positive mood results in greater implicit memory for that distraction. Participants performed a similarity-judgment task on pictures that were superimposed with distracting words. When these previously distracting words could be used as solutions on a delayed implicit task administered several minutes later, performance was positively correlated with pleasantness of mood. Individuals in a positive mood are more likely than others to use previously irrelevant information to facilitate performance on a subsequent implicit task, a finding with implications for the relationship between positive mood and creativity.     

Trait compassion is associated with the neural substrate of empathy

Individual differences in the personality trait Agreeableness underlie humans’ ability to interpret social cues and coordinate effectively with others. However, previous investigations of the neural basis of Agreeableness have yielded largely inconsistent results. Recent evidence has demonstrated that Agreeableness can be divided into two, correlated subdimensions. Compassion reflects tendencies toward empathy, sympathy, and concern for others, while Politeness reflects tendencies toward compliance and refraining from aggression and exploitation. The present study seeks to clarify the neural substrates of Agreeableness by examining whether structural differences in the brain show distinct associations with Compassion and Politeness. Results of a meta-analysis of fMRI studies examining empathy were used to generate hypotheses about the brain regions and networks that underlie trait Compassion. Results of a large-scale structural neuroimaging investigation (N = 275) were largely consistent with the meta-analysis: Compassion was positively correlated with gray matter volume in the bilateral anterior cingulate cortex (ACC) and anterior insula (AI). Further, these differences appear to be associated with Compassion specifically, as opposed to Politeness, suggesting that these two traits have at least partially distinct neuroanatomical substrates.     

Evidence that secretory IgA antibody is associated with daily mood

In this study, we examined the secretory immune system, the body's first line of defense against invading organisms, and its relation to daily fluctuations of mood. Specifically, secretory immunoglobulin A (sIgA) was studied. Unlike other psychoimmunity studies that examined all sIgA protein regardless of specificity to invading organisms, ours examined an antigen-specific sIgA response to the oral administration of a harmless protein (rabbit albumin) and monitored the antibody produced in response to the protein. Dental students recorded their daily mood thrice weekly for 8 1/3 weeks, and parotid saliva was obtained from subjects during these contacts. Using a within-subjects analyses strategy, we found that antibody response was lower on days with high negative mood relative to days with lower negative mood, and conversely, sIgA antibody response was higher on days with high positive mood relative to days with lower positive mood. Results from total sIgA protein were in the opposite direction, although not significantly so. These results extend our knowledge of immunological changes and mood, and they suggest that minor life events' role in health may be mediated by the secretory immune system.     

Need for closure is associated with urgency in perceptual decision-making

Constant decision-making underpins much of daily life, from simple perceptual decisions about navigation through to more complex decisions about important life events. At many scales, a fundamental task of the decision-maker is to balance competing needs for caution and urgency: fast decisions can be more efficient, but also more often wrong. We show how a single mathematical framework for decision-making explains the urgency/caution balance across decision-making at two very different scales. This explanation has been applied at the level of neuronal circuits (on a time scale of hundreds of milliseconds) through to the level of stable personality traits (time scale of years).     

Trait reappraisal is associated with resilience to acute psychological stress

Life is full of stressful events. However, while some individuals are negatively affected by stress, others are more resilient to its effects. The factors that contribute to variability in stress resilience are not fully understood. Here, we tested the hypothesis that trait reappraisal would be associated with greater stress resilience to a first-time tandem skydive. Specifically, we expected measures of “anxiety” to be lower and measures of “euphoria” to be higher in high trait reappraising individuals. Our findings that trait reappraisal is negatively correlated with stress reactivity as measured by cortisol, heart rate, and self-report state anxiety, but positively correlated with self-report state euphoria suggest that individuals high in trait reappraisal are more stress resilient.