The psychology of psychiatric genetics: evidence that positive emotions in females moderate genetic sensitivity to social stress associated with the BDNF Val-sup-6-sup-6Met polymorphism

Previous work indicated protective effects of positive emotions on genetically influenced stress sensitivity. Given the fact that expression of brain-derived-neurotrophic-factor (BDNF) is associated with stress-induced behavioral changes, it was hypothesized that the BDNF Val-sup-6-sup-6Met genotype may mediate genetic effects on stress sensitivity, conditional on the level of concurrent positive emotions. Subjects (n=446) participated in a momentary assessment study, collecting appraisals of stress and affect in the flow of daily life. Multilevel regression analyses examined moderation of daily life stress-induced negative affect (NA) by BDNF genotype, and to what degree this was conditional on concurrent positive emotions. Results showed that heterozygous BDNF "Met" carriers exhibited an increased NA response to social stress compared with "Val/Val" subjects. Positive emotions at the time of the stressor decreased BDNF genetic moderation of the NA response to social stress in a dose-response fashion. This effect was most pronounced in BDNF Met carriers. Thus, the impact of BDNF genotype on stress sensitivity is conditional on the experience of positive emotions. Interdisciplinary research in psychology and psychiatric genetics may lead to the improvement of treatment choices in stress-related disorders.     

Evidence for attenuated affective processing in obesity

Attenuated affective processing is hypothesized to play a role in the development and maintenance of obesity. Using an affective priming task measuring automatic affective processing of verbal stimuli, a group of 30 obese participants in a weight-loss program at the Psychosomatic University Clinic Bonn (M age = 48.3, SD = 10.7) was compared with a group of 25 participants of normal weight (M age = 43.6, SD = 12.5). A smaller affective priming effect was observed for participants with obesity, indicating less pronounced reactions to valenced adjectives. The generally reduced affective processing in obese participants was discussed as a possible factor in the etiology of obesity. Individuals who generally show less pronounced affective reactions to a given stimulus may also react with less negative affect when confronted with weight gain or less positive affect when weight is lost. Consequently, they could be expected to be less motivated to stop overeating or to engage in dieting and will have a higher risk of becoming or staying obese.     

Caregiver Involvement in the Intensive Mental Health Program: Influence on Changes in Child Functioning

We examined behavioral markers of caregiver involvement and the ways in which family participation was related to treatment outcomes in 47 elementary school children with SED enrolled in a school-based intensive mental health program. Measures of caregiver involvement included therapeutic home visits, attendance at therapeutic meetings, completion of ratings on the daily point sheet, and extra communications with the therapeutic team on the point sheet. Greater initial impairment was associated with greater caregiver involvement. Greater caregiver involvement was linked to improvement in child thought processes, increased ability to provide emotional and social supports for the child, and greater overall child functioning at discharge. Our findings also reflected increased therapists’ attempts to provide additional in-home services in cases where caregivers demonstrated a decline in their ability to provide for their children’s physical and material needs, or in which therapists discovered that the family functioning was more impaired than what was initially assessed. We provide a case study that exemplifies many of these findings.     

Item performance in visual word recognition

Standard factorial designs in psycholinguistics have been complemented recently by large-scale databases providing empirical constraints at the level of item performance. At the same time, the development of precise computational architectures has led modelers to compare item-level performance with item-level predictions. It has been suggested, however, that item performance includes a large amount of undesirable error variance that should be quantified to determine the amount of reproducible variance that models should account for. In the present study, we provide a simple and tractable statistical analysis of this issue. We also report practical solutions for estimating the amount of reproducible variance for any database that conforms to the additive decomposition of the variance. A new empirical database consisting of the word identification times of 140 participants on 120 words is then used to test these practical solutions. Finally, we show that increases in the amount of reproducible variance are accompanied by the detection of new sources of variance.     

Varying cautionary instructions, monetary incentives, and comorbid diagnostic training in malingered psychopathology research

In this article, we combine two analogue experiments in which we empirically examined three malingering methodological issues in individuals trained and instructed to simulate posttraumatic stress disorder (PTSD) on the Trauma Symptom Inventory (TSI; Briere, 1995). In Experiment 1, we examined TSI scale effects of the following manipulations using a 2 x 2 design with 330 college students: (a) inclusion or exclusion of cautionary instructions regarding believability of participants' simulation and (b) different financial incentive levels. In Experiment 2, we examined comorbid psychiatric diagnostic training with 180 college students who were either trained to simulate PTSD and comorbid major depressive disorder or trained to simulate only PTSD. Caution main effects were significant for all but two TSI Clinical Scales, incentive main effects and interactions were only significant for one Clinical scale each, and the comorbidity manipulation did not yield any scale differences. We discuss malingering research design implications regarding the use of cautionary instructions, financial incentive levels, and comorbid training.     

Stress administered prior to encoding impairs neutral but enhances emotional long-term episodic memories

Stressful events frequently comprise both neutral and emotionally arousing information, yet the impact of stress on emotional and neutral events is still not fully understood. The hippocampus and frontal cortex have dense concentrations of receptors for stress hormones, such as cortisol, which at high levels can impair performance on hippocampally dependent memory tasks. Yet, the same stress hormones can facilitate memory for emotional information, which involves interactions between the hippocampus and amygdala. Here, we induced psychosocial stress prior to encoding and examined its long-term effects on memory for emotional and neutral episodes. The stress manipulation disrupted long-term memory for a neutral episode, but facilitated long-term memory for an equivalent emotional episode compared with a control condition. The stress manipulation also increased salivary cortisol, catecholamines as indicated by the presence of alpha-amylase, heart rate, and subjectively reported stress. Stressed subjects reported more false memories than nonstressed control subjects, and these false memories correlated positively with cortisol levels, providing evidence for a relationship between stress and false memory formation. Our results demonstrate that stress, when administered prior to encoding, produces different patterns of long-term remembering for neutral and emotional episodes. These differences likely emerge from differential actions of stress hormones on memory-relevant regions of the brain.     

Pseudohomophone effects in lexical decision: still a challenge for current word recognition models.

Computational models that implement a serial mechanism of phonological assembly predict interactions between the size of the pseudohomophone (PsH) effect and stimulus length. Models with frequency-sensitive word representations predict baseword frequency effects. These predictions were tested in a lexical-decision task. The results showed constant PsH effects across different word lengths (in favor of parallel phonological activation) and baseword frequency effects (in favor of frequency-sensitive representations). However, the baseword frequency effect was opposite of what the models predicted. This result is most easily accommodated by models that assume an orthographic verification mechanism. The plausibility of such a mechanism was further supported by the results of 2 additional experiments investigating the effects of response speed and spelling probability (feedback consistency) on the size of the PsH effect.     

Increased cognitive problem reporting after information about chemotherapy-induced cognitive decline: The moderating role of stigma consciousness

Objective: Information about treatment side effects can increase their occurrence; breast cancer (BC) patients showed increased cognitive problem reporting (CPR) and decreased memory performance after information about cognitive side effects. The current study extends previous research on adverse information effects (AIE) by investigating (a) risk factors, (b) underlying mechanisms and (c) an intervention to reduce AIE.

Design: In an online experiment, 175 female BC patients were randomly assigned to one of three conditions. In the two experimental groups, patients were informed about the possible occurrence of cognitive problems after chemotherapy with (intervention group) or without (experimental group) reassuring information that ‘there are still patients who score well on memory tests’. In the control group, no reference to chemotherapy-related cognitive problems was made.

Main outcome measures: Main dependent measure was CPR. Four moderating and five mediating processes were examined.

Results: CPR increased with higher levels of stigma consciousness in the two experimental groups, but not in the no-information control group.

Conclusion: Merely informing patients about cognitive side effects may increase their occurrence, especially among individuals vulnerable to patient stereotypes. Adding reassuring information is not sufficient to reduce AIE.     

Neural correlates of rumination in adolescents with remitted major depressive disorder and healthy controls

The aim of the present study was to use fMRI to examine the neural correlates of engaging in rumination among a sample of remitted depressed adolescents, a population at high risk for future depressive relapse. A rumination induction task was used to assess differences in the patterns of neural activation during rumination versus a distraction condition among 26 adolescents in remission from major depressive disorder (rMDD) and in 15 healthy control adolescents. Self-report depression and rumination, as well as clinician-rated depression, were also assessed among all participants. All of the participants recruited regions in the default mode network (DMN), including the posterior cingulate cortex, medial prefrontal cortex, inferior parietal lobe, and medial temporal gyrus, during rumination. Increased activation in these regions during rumination was correlated with increased self-report rumination and symptoms of depression across all participants. Adolescents with rMDD also exhibited greater activation in regions involved in visual, somatosensory, and emotion processing than did healthy peers. The present findings suggest that during ruminative thought, adolescents with rMDD are characterized by increased recruitment of regions within the DMN and in areas involved in visual, somatosensory, and emotion processing.     

Experience, context, and the visual perception of human movement

Why are human observers particularly sensitive to human movement? Seven experiments examined the roles of visual experience and motor processes in human movement perception by comparing visual sensitivities to point-light displays of familiar, unusual, and impossible gaits across gait-speed and identity discrimination tasks. In both tasks, visual sensitivity to physically possible gaits was superior to visual sensitivity to physically impossible gaits, supporting perception-action coupling theories of human movement perception. Visual experience influenced walker-identity perception but not gait-speed discrimination. Thus, both motor experience and visual experience define visual sensitivity to human movement. An ecological perspective can be used to define the conditions necessary for experience-dependent sensitivity to human movement.