In the mood for adaptation: how affect regulates conflict-driven control

Cognitive conflict plays an important role in tuning cognitive control to the situation at hand. On the basis of earlier findings demonstrating emotional modulations of conflict processing, we predicted that affective states may adaptively regulate goal-directed behavior that is driven by conflict. We tested this hypothesis by measuring conflict-driven control adaptations following experimental induction of four different mood states that could be differentiated along the dimensions of arousal and pleasure. After mood states were induced, 91 subjects performed a flanker task, which provided a measure of conflict adaptation. As predicted, pleasure level affected conflict adaptation: Less pleasure was associated with more conflict-driven control. Arousal level did not influence conflict adaptation. This study suggests that affect adaptively regulates cognitive control. Implications for future research and psychopathology are discussed.     

SLV330, a cannabinoid CB1 receptor antagonist,ameliorates deficits in the T-maze,object recognition and Social Recognition Tasks in rodents

Cannabinoid CB₁ receptor (CB₁R) signaling has been suggested to play an important role in the regulation of memory and cognition. In the present study, our aim was to investigate whether the CB₁R antagonist SLV330 (doses ranging from 0.3 to 10 mg/kg, given orally, p.o.) could ameliorate impairments in distinct aspects of cognition using different disruption models in both mice and rats. Effects of SLV330 were tested on working memory deficits in the T-maze Continuous Alternation Task (T-CAT) in mice; episodic memory deficits in the Object Recognition Task (ORT) and Social Recognition Task (SRT) in rats. The acetylcholinesterase inhibitor (AChEI) donepezil (Aricept®, approved for symptomatic treatment of Alzheimer’s disease) and nicotine were used as reference compounds.SLV330 markedly improved aging and scopolamine-induced memory deficits in the T-CAT in mice with a lowest effective dose (LED) of 1 mg/kg p.o., while reversing the cognitive dysfunction induced by the N-methyl-d-aspartate (NMDA) antagonist dizocilpine (MK-801) only at the middle dose of 3 mg/kg. In the ORT, we have found that combined administration of subthreshold doses of SLV330 (1 mg/kg, p.o.) and the AChEI donepezil (0.1 mg/kg, p.o.), that had no discernable effects on performance when given alone, enhanced memory performance in Wistar rats with deficits induced by the muscarinic antagonist scopolamine, suggestive of additive synergistic effects of SLV330 and donepezil on cognitive impairment. Finally, SLV330 was found to have cognition enhancing properties in a time delay paradigm in the SRT at a LED dose of 3 mg/kg (p.o.).In conclusion, the CB₁R antagonist SLV330 was found to clearly improve memory in several preclinical models for cognitive impairment.     

Nonlinear epigenetic variance: review and simulations

We present a review of empirical evidence that suggests that a substantial portion of phenotypic variance is due to nonlinear (epigenetic) processes during ontogenesis. The role of such processes as a source of phenotypic variance in human behaviour genetic studies is not fully appreciated. In addition to our review, we present simulation studies of nonlinear epigenetic variance using a computational model of neuronal network development. In each simulation study, time series for monozygotic and dizygotic twins were generated and analysed using conventional behaviour genetic modelling. In the results of these analyses, the nonlinear epigenetic variance was subsumed under the non-shared environmental component. As is commonly found in behaviour genetic studies, observed heritabilities and unique environmentabilities increased with time, whereas common environmentabilities decreased. The fact that the phenotypic effects of nonlinear epigenetic processes appear as unsystematic variance in conventional twin analyses complicates the identification and quantification of the ultimate genetic and environmental causes of individual differences. We believe that nonlinear dynamical system theories provide a challenging perspective on the development of individual differences, which may enrich behaviour genetic studies.     

When observing gaze shifts of others enhances object desirability

The present research explored when observing gaze shifts of another person, involving both the observer and a specific object, enhances desirability of the gazed-at object. Specifically, we offer an initial attempt to test the idea that a three-step sequence consisting of direct gaze at the observer, followed by object-directed gaze and then by direct gaze at the observer, cues the desirability of an object to the observer and hence increases the perceived desirability of the gazed-at object. We examined this hypothesis in three experiments by manipulating eye-gaze shifts and including a no-gaze control condition. In line with our prediction, results showed that the dynamic sequence of gaze shifts indeed increases perceived object desirability. These findings provide new evidence that a sequence of gaze behavior involving the observer and an object plays an important role in influencing affective evaluation of objects.     

Angry facial expressions hamper subsequent target identification

There is considerable evidence indicating that people are primed to monitor social signals of disapproval. Thus far, studies on selective attention have concentrated predominantly on the spatial domain, whereas the temporal consequences of identifying socially threatening information have received only scant attention. Therefore, this study focused on temporal attention costs and examined how the presentation of emotional expressions affects subsequent identification of task-relevant information. High (n = 30) and low (n = 31) socially anxious women were exposed to a dual-target rapid serial visual presentation (RSVP) paradigm. Emotional faces (neutral, happy, angry) were presented as the first target (T1) and neutral letter stimuli (p, q, d, b) as the second target (T2). Irrespective of social anxiety, the attentional blink was relatively large when angry faces were presented as T1. This apparent prioritized processing of angry faces is consistent with evolutionary models, stressing the importance of being especially attentive to potential signals of social threat.     

Sunscreens with Titanium Dioxide (TiO<Subscript>2</Subscript>) Nano-Particles: A Societal Experiment

The risks of novel technologies, such as nano(bio)technology cannot be fully assessed due to the existing uncertainties surrounding their introduction into society. Consequently, the introduction of innovative technologies can be conceptualised as a societal experiment, which is a helpful approach to evaluate moral acceptability. This approach is illustrated with the marketing of sunscreens containing nano-sized titanium dioxide (TiO₂) particles. We argue that the marketing of this TiO₂ nanomaterial in UV protective cosmetics is ethically undesirable, since it violates four reasonable moral conditions for societal experimentation (absence of alternatives, controllability, limited informed consent, and continuing evaluation). To remedy the current way nano-sized TiO₂ containing sunscreens are utilised, we suggest five complementing actions (closing the gap, setup monitoring tools, continuing review, designing for safety, and regulative improvements) so that its marketing can become more acceptable.     

Experimental study of the differential effects of playing versus watching violent video games on children's aggressive behavior

There is great concern about the effects of playing violent video games on aggressive behavior. The present experimental study was aimed at investigating the differential effects of actively playing vs. passively watching the same violent video game on subsequent aggressive behavior. Fifty-seven children aged 10-13 either played a violent video game (active violent condition), watched the same violent video game (passive violent condition), or played a non-violent video game (active non-violent condition). Aggression was measured through peer nominations of real-life aggressive incidents during a free play session at school. After the active participation of actually playing the violent video game, boys behaved more aggressively than did the boys in the passive game condition. For girls, game condition was not related to aggression. These findings indicate that, specifically for boys, playing a violent video game should lead to more aggression than watching television violence.     

Physical growth delays and stress dysregulation in stunted and non-stunted Ukrainian institution-reared children

To study the effect of institutional rearing on physical growth and stress regulation we examined 16 institution-reared children (3–6 years old) in Ukraine and compared them with 18 native family-reared children pair-matched on age and gender. Physical growth trajectories were examined on the basis of archival medical records and current measurements of height, weight, and head circumference. Stress regulation was studied on the basis of diurnal salivary cortisol sampled six times during 1 day. 31% of institution-reared children were stunted at 48 months whereas none of the family-reared children were. Substantial delays in physical growth were observed in institution-reared children especially during the first year of life. From 24 months onwards a tendency for improvement in physical growth was evident among the temporarily stunted institution-reared children, with complete catch-up in weight and partial catch-up in height by the time of assessment. Chronically stunted institution-reared children demonstrated persistent severe growth delays. Institution-reared and family-reared children showed similar patterns of diurnal cortisol production with decreases over the day. However, temporarily stunted institution-reared children had a significantly higher total daily cortisol production than both chronically stunted institution-reared children and family-reared children. These data confirm previous findings regarding physical growth delays and stress dysregulation associated with institutional care, but also point to differences in cortisol production between stunted and non-stunted institution-reared children.     

Psychophysics of perceiving eye-gaze and head direction with peripheral vision: implications for the dynamics of eye-gaze behavior

Two psychophysical experiments are reported, one dealing with the visual perception of the head orientation of another person (the 'looker') and the other dealing with the perception of the looker's direction of eye gaze. The participant viewed the looker with different retinal eccentricities, ranging from foveal to far-peripheral viewing. On average, judgments of head orientation were reliable even out to the extremes of peripheral vision (90 degrees eccentricity), with better performance at the extremes when the participant was able to view the looker changing head orientation from one trial to the next. In sharp contrast, judgments of eye-gaze direction were reliable only out to 4 degrees eccentricity, signifying that the eye-gaze social signal is available to people only when they fixate near the looker's eyes. While not unexpected, this vast difference in availability of information about head direction and eye direction, both of which can serve as indicators of the looker's focus of attention, is important for understanding the dynamics of eye-gaze behavior.     

At first glance, transparency enhances assimilation

We investigated the role of transparency, perceptual grouping, and presentation time on perceived lightness. Both transparency and perceptual grouping have been found to result in assimilation effects, but only for ambiguous stimulus displays and with specific attentional instructions. By varying the presentation times of displays with two partly overlapping transparent E-shaped objects, we measured assimilation in unambiguous stimulus displays and without specific attentional instructions. The task was to judge which of two simultaneously presented E-shaped objects was darker. With unrestrained presentation times, if a transparency interpretation was possible, assimilation was not found. Inhibiting a transparency interpretation by occluding the local junctions between the two E-shaped objects, did lead to assimilation. With short presentation times, if a transparency interpretation was possible, assimilation was now also found. Thus, we conclude that, although transparency appears to enhance assimilation, with unambiguous stimulus displays and without specific attentional instructions, perceptual grouping is more important for assimilation to occur.