Effect of religious context on the content of visual hallucinations in individuals high in religiosity

This study investigated the interaction between the current environment and personality factors associated with religiosity in determining the content of false perceptions (used as a model for hallucinations). A primed word-detection task was used to investigate the effect of a 'religious' context on false perceptions in individuals scoring highly on religiosity. After a subliminal prime, participants viewed letter strings, and stated any words that they saw. The prime and the actual words could have a religious connotation or not. Participants measuring high on religiosity were more likely to report false perceptions of a religious type than participants low on religiosity. It is suggested that context affects the content of false perceptions through the activation of stored beliefs and values, which vary between individuals, offering a mechanism for the effect of context on idiosyncratic content of hallucinations in schizophrenia. The effect of context and individual differences on false-perception content in the current study provides possibilities for future work regarding the underlying nature of hallucinations and their treatment.

Priming of microglia in a DNA-repair deficient model of accelerated aging

Aging is associated with reduced function, degenerative changes, and increased neuroinflammation of the central nervous system (CNS). Increasing evidence suggests that changes in microglia cells contribute to the age-related deterioration of the CNS. The most prominent age-related change of microglia is enhanced sensitivity to inflammatory stimuli, referred to as priming. It is unclear if priming is due to intrinsic microglia ageing or induced by the ageing neural environment. We have studied this in Ercc1 mutant mice, a DNA repair-deficient mouse model that displays features of accelerated aging in multiple tissues including the CNS. In Ercc1 mutant mice, microglia showed hallmark features of priming such as an exaggerated response to peripheral lipopolysaccharide exposure in terms of cytokine expression and phagocytosis. Specific targeting of the Ercc1 deletion to forebrain neurons resulted in a progressive priming response in microglia exemplified by phenotypic alterations. Summarizing, these data show that neuronal genotoxic stress is sufficient to switch microglia from a resting to a primed state.

The "emotion misattribution" procedure: processing beyond good and bad under masked and unmasked presentation conditions

In general, it is assumed that misattribution in the Affect Misattribution Procedure (AMP) is restricted to crude affect due to its unbound nature, especially under limited presentation conditions. In two experiments, we investigated whether emotion-specific misattributions occur using a four-category misattribution procedure. Experiment 1 yielded emotion-specific misattribution effects under clearly visible presentation conditions demonstrating that the procedure is principally susceptible for emotion-specific effects. In Experiment 2, we employed masked presentation conditions impeding conscious prime perception. A specific pattern of emotion-specific misattributions effects emerged indicating some emotion-specific processing at initial stages of processing. However, not each emotion was misattributed equally. We discuss the implications of these results for the non-conscious processing of emotional information, for the supposed mechanisms of the AMP and its implicit nature.

Penetrating thorax injury leads to mild systemic activation of neutrophils without inflammatory complications

INTRODUCTION

Trauma is one of the major causes of morbidity and mortality. Thoracic injuries are associated with inflammatory complications such as ARDS. The pathogenesis of this complication after pulmonary injury is incompletely understood, but neutrophils are thought to play a pivotal role. The aim of this project was to gain more insight in the role of thoracic injuries in the pathophysiological processes that link systemic neutrophil activation with inflammatory complications after trauma.

METHODS

In this prospective cohort study fifty-five patients with isolated penetrating thoracic injury were included at a level one Trauma Unit. Blood samples were analysed for neutrophil phenotype with the use of flowcytometry within 3 h of trauma and repeated six and 24 h after injury. The presence of inflammatory complications (e.g. ARDS or sepsis/septic shock) was assessed during admission, and this was related to the neutrophil phenotpe.

RESULTS

The clinical follow-up of fifty-three patients was uneventful. Only two patients developed an inflammatory complication. Within 3 h after trauma, neutrophils showed a decreased expression of FcγRII (p=0.007) and FcγRIII (p=0.001) compared to healthy individuals. After 6 h, expression of active FcγRII (p=0.017), C5aR (p=0.004) and CAECAM8 (p=0.043) increased, whereas L-selectin (p=0.002) decreased. After 24 h also CXCR-2 (CD182) expression increased compared to healthy individuals (p=0.001).

CONCLUSIONS

Penetrating thoracic trauma leads to a distinct primed activation status of circulating neutrophils within hours. In addition to activation of cells, both young and reverse migrated neutrophils are released into the circulation. This degree of systemic inflammation does not exceed a threshold of inflammation that is needed for the development of inflammatory complications like ARDS.

Chronic exposure to exogenous glucocorticoids primes microglia to pro-inflammatory stimuli and induces NLRP3 mRNA in the hippocampus

Chronic stress as well as chronic treatment with glucocorticoids (GCs) primes the neuroinflammatory response to a subsequent pro-inflammatory challenge. However, it remains unclear whether chronic GCs sensitize the response of key CNS immune substrates (i.e. microglia) to pro-inflammatory stimuli. In the present set of studies, male Sprague-Dawley rats underwent sham surgery or were adrenalectomized and then treated with varying concentrations of corticosterone (CORT; 0, 25, 50, and 75 μg/ml) administered in their drinking water. After 10 days of CORT exposure, whole hippocampus was collected and expression of glial activation markers measured or hippocampal microglia were isolated and challenged with LPS to probe for CORT-induced sensitization of pro-inflammatory responses. Chronic CORT exposure increased the gene expression of NLRP3, Iba-1, MHCII, and NF-κBIα in a concentration dependent manner. Chronic CORT (75 μg/ml) exposure potentiated the microglial proinflammatory response (TNFα, IL-1β, IL-6 and NLRP3) to LPS compared to the microglial response of sham surgery animals treated with vehicle. The present set of results demonstrate that chronic exposure to GCs primes microglia to pro-inflammatory stimuli and add to a growing body of evidence suggesting that a permissive function of GCs is that of an endogenous danger signal or alarmin.

How lexical is the lexicon? Evidence for integrated auditory memory representations

Previous research has shown that lexical representations must include not only linguistic information (what word was said), but also indexical information (how it was said, and by whom). The present work demonstrates that even this expansion is not sufficient. Seemingly irrelevant information, such as an unattended background sound, is retained in memory and can facilitate subsequent speech perception. We presented participants with spoken words paired with environmental sounds (e.g., a phone ringing), and had them make an "animate/inanimate" decision for each word. Later performance identifying filtered versions of the words was impaired to a similar degree if the voice changed or if the environmental sound changed. Moreover, when quite dissimilar words were used at exposure and test, we observed the same result when we reversed the roles of the words and the environmental sounds. The experiments also demonstrated limits to these effects, with no benefit from repetition. Theoretically, our results support two alternative possibilities: (1) Lexical representations are memory representations, and are not walled off from those for other sounds. Indexical effects reflect simply one type of co-occurrence that is incorporated into such representations. (2) The existing literature on indexical effects does not actually bear on lexical representations - voice changes, like environmental sounds heard with a word, produce implicit memory effects that are not tied to the lexicon. We discuss the evidence and implications of these two theoretical alternatives.

Naive T cells: the crux of cellular immune aging?

When encountering foreign antigens, naïve T cells become activated and differentiate into effector and memory T cells. They represent therefore the primary source to mount an immune response against pathogens or tumors. Recent evidence of both quantitative and qualitative alterations of naïve T cells has accumulated in aged mice, indicating that the successful generation of primary T cell responses from the naïve T cell pool may be compromised with old age. However, the vast majority of the data supporting compromised naïve T cell priming efficacy with old age have been produced in animal models, and the situation is much less clear in humans. In the elderly, the involution of the thymus and the associated decline in thymic output result in a decreased number of naïve T cells, which is partially compensated by homeostatic proliferation. Emerging evidence suggest that alterations of the TCR repertoire diversity and intrinsic defects of old CD4(+) naïve T cells may impact on their responsiveness to antigenic stimulation. Increasing focus on the study of naïve T cells (in particular CD8(+)) in old humans are needed to fill the gaps in our understanding of reduced cellular immunity with aging.

Spatial primes produce dissociated inhibitory effects on saccadic latencies and trajectories

In masked priming, a briefly presented prime can facilitate or inhibit responses to a subsequent target. In most instances, targets with an associated response that is congruent with the prime direction speed up reaction times to the target (a positive compatibility effect; PCE). However, under certain circumstances, slower responses for compatible primes are obtained (a negative compatibility effect; NCE). NCEs can be found when a long pre-target delay is used. During the delay, inhibition is assumed to take place, and therefore an effect on saccade trajectories may also be expected. In a previous study, we found the effects of inhibition on response times and trajectories to be dissociated, but this experiment varied the timing of several aspects of the stimulus sequence and it is therefore unclear what caused the dissociation. In the present study, we varied only one aspect of the timing, but replicated the dissociation. By varying just the pre-target delay, we found a PCE for a short delay, and an NCE for a long delay, but saccade trajectories deviated away from prime directions in both conditions. This suggests dissociated inhibitory effects of primes on response times and saccade trajectories.

Warm-up with a weighted vest improves running performance via leg stiffness and running economy

OBJECTIVES

To determine the effects of "strides" with a weighted-vest during a warm-up on endurance performance and its potential neuromuscular and metabolic mediators. A bout of resistance exercise can enhance subsequent high-intensity performance, but little is known about such priming exercise for endurance performance.

DESIGN

A crossover with 5-7 days between an experimental and control trial was performed by 11 well-trained distance runners.

METHODS

Each trial was preceded by a warm-up consisting of a 10-min self-paced jog, a 5-min submaximal run to determine running economy, and six 10-s strides with or without a weighted-vest (20% of body mass). After a 10-min recovery period, runners performed a series of jumps to determine leg stiffness and other neuromuscular characteristics, another 5-min submaximal run, and an incremental treadmill test to determine peak running speed. Clinical and non-clinical forms of magnitude-based inference were used to assess outcomes. Correlations and linear regression were used to assess relationships between performance and underlying measures.

RESULTS

The weighted-vest condition resulted in a very-large enhancement of peak running speed (2.9%; 90% confidence limits ±0.8%), a moderate increase in leg stiffness (20.4%; ±4.2%) and a large improvement in running economy (6.0%; ±1.6%); there were also small-moderate clear reductions in cardiorespiratory measures. Relationships between change scores showed that changes in leg stiffness could explain all the improvements in performance and economy.

CONCLUSIONS

Strides with a weighted-vest have a priming effect on leg stiffness and running economy. It is postulated the associated major effect on peak treadmill running speed will translate into enhancement of competitive endurance performance.

The use of the reinstatement model to study relapse to palatable food seeking during dieting

Excessive consumption of unhealthy foods is a major public health problem. While many people attempt to control their food intake through dieting, many relapse to unhealthy eating habits within a few months. We have begun to study this clinical condition in rats by adapting the reinstatement model, which has been used extensively to study relapse to drug seeking. In our adaptation of the relapse model, reinstatement of palatable food seeking by exposure to food-pellet priming, food-associated cues, or stress is assessed in food-restricted (to mimic dieting) rats after operant food-pellet self-administration training and subsequent extinction of the food-reinforced responding. In this review, we first outline the clinical problem and discuss a recent study in which we assessed the predictive validity of the reinstatement model for studying relapse to food seeking during dieting by using the anorexigenic drug fenfluramine. Next, we summarize results from our initial studies on the role of several stress- and feeding-related peptides (corticotropin-releasing factor, hypocretin, melanin-concentrating hormone, peptide YY3-36) in reinstatement of palatable food seeking. We then present results from our studies on the role of dopamine and medial prefrontal cortex in stress-induced reinstatement of food seeking. We conclude by discussing potential clinical implications. We offer two main conclusions: (1) the food reinstatement model is a simple, reliable, and valid model to study mechanisms of relapse to palatable food seeking during dieting, and to identify medications to prevent this relapse; (2) mechanisms of relapse to food seeking are often dissociable from mechanisms of ongoing food intake. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'.

Phonological encoding in apraxia of speech and aphasia

BACKGROUND

Apraxia of speech (AOS) is considered a speech motor planning/programming disorder. While it is possible that co-occurring phonological impairments exist, the speech motor planning/programming deficit often makes it difficult to assess the phonological encoding stage directly. Studies using on-line methods have suggested that activation of phonological information may be protracted in AOS (Rogers, Redmond, & Alarcon, 1999).

AIMS

The present study was designed to investigate the integrity of the phonological encoding stage in AOS and aphasia. We tested two specific hypotheses, the Frame Hypothesis and the Segment Hypothesis. According to the Frame Hypothesis, speakers with AOS have an impairment in retrieving metrical frames (e.g., number of syllables); according to the Segment Hypothesis, speakers with AOS have an impairment in retrieving segments (e.g., consonants).

METHODS & PROCEDURES

Four individuals with AOS and varying degrees of aphasia, two speakers with aphasia, and 13 age-matched control speakers completed an on-line priming task in which participants name pictures in sets that do or do not share number of syllables (e.g., balcony-coconut-signature vs. balcony-carrot-sock), the initial consonant (e.g., carpenter-castle-cage vs. carpenter-beaver-sun), or both (e.g., boomerang-butterfly-bicycle vs. boomerang-sausage-cat). Error rates and reaction times were measured.

OUTCOMES & RESULTS

Data for controls replicated previous literature. Reaction time data supported the Segment Hypothesis for speakers with AOS and for one speaker with aphasia without AOS, with no differences in pattern from controls for the other speaker with aphasia without AOS.

CONCLUSIONS

These results suggest that speakers with AOS may also have difficulties at the phonological encoding stage. Theoretical and clinical implications of these findings are discussed.

Out of Mind, Out of Sight: Unexpected Scene Elements Frequently Go Unnoticed Until Primed

The human visual system employs a sophisticated set of strategies for scanning the environment and directing attention to stimuli that can be expected given the context and a person's past experience. Although these strategies enable us to navigate a very complex physical and social environment, they can also cause highly salient, but unexpected stimuli to go completely unnoticed. To examine the generality of this phenomenon, we conducted eight studies that included 15 different experimental conditions and 1,577 participants in all. These studies revealed that a large majority of participants do not report having seen a woman in the center of an urban scene who was photographed in midair as she was committing suicide. Despite seeing the scene repeatedly, 46 % of all participants failed to report seeing a central figure and only 4.8 % reported seeing a falling person. Frequency of noticing the suicidal woman was highest for participants who read a narrative priming story that increased the extent to which she was schematically congruent with the scene. In contrast to this robust effect of inattentional blindness, a majority of participants reported seeing other peripheral objects in the visual scene that were equally difficult to detect, yet more consistent with the scene. Follow-up qualitative analyses revealed that participants reported seeing many elements that were not actually present, but which could have been expected given the overall context of the scene. Together, these findings demonstrate the robustness of inattentional blindness and highlight the specificity with which different visual primes may increase noticing behavior.

ERP evidence for conceptual mappings and comparison processes during the comprehension of conventional and novel metaphors

Cognitive linguists suggest that understanding metaphors requires activation of conceptual mappings between the involved concepts. We tested whether mappings are indeed in use during metaphor comprehension, and what mapping means as a cognitive process with Event-Related Potentials. Participants read literal, conventional metaphorical, novel metaphorical, and anomalous target sentences preceded by primes with related or unrelated mappings. Experiment 1 used sentence-primes to activate related mappings, and Experiment 2 used simile-primes to induce comparison thinking. In the unprimed conditions of both experiments, metaphors elicited N400s more negative than the literals. In Experiment 1, related sentence-primes reduced the metaphor-literal N400 difference in conventional, but not in novel metaphors. In Experiment 2, related simile-primes reduced the metaphor-literal N400 difference in novel, but not clearly in conventional metaphors. We suggest that mapping as a process occurs in metaphors, and the ways in which it can be facilitated by comparison differ between conventional and novel metaphors.

The effect of priming with a love concept on blood donation promise

This field study on blood donor behavior tests the effectiveness of semantic priming on donor intention and commitment. Using face-to-face interactions, participants were primed with the concept of love and solicited to promise blood to the French National Blood Bank. Results showed a significant effect on willingness to donate blood and on donor commitment. The relatively simple and easily implemented technique used in this study could be of interest in improving performance of recruitment and retention campaigns.

Priming of beta-2 agonist and antimuscarinic induced physiological responses induced by 1200mg/day NAC in moderate to severe COPD patients: A pilot study

This study evaluated antioxidant modulations of lung physiological-responses to beta-2-agonist and antimuscarinic bronchodilators with 1200mg/day n-acetyl-cysteine (NAC) in a placebo-controlled, randomised, double-blind, parallel-group study, in moderate-very severe COPD patients.

METHODS

15 COPD patients received NAC treatment, while 9 COPD patients received placebo treatment, for 15 days. Pre-and-post salbutamol and ipratopium-bromide lung-physiology responses were measured using body-plethysmography, impulse-oscillometry (IOS) and spirometry before-and-after study treatments.

RESULTS

Compared to pre-treatment, the NAC-treatment significantly enhanced the potential of ipratopium-bromide to reduce functional-residual-capacity (FRC) by nearly 3-folds (mean% FRC-response: pre-NAC: -5.51%±10.42% versus post-NAC: -17.89%±12.94%, p=0.02; mean-absolute FRC-response: pre-NAC: -300ml±450ml versus post-NAC: -770ml±550ml, p=0.02), which was superior to placebo-treatment. The increase in total-lung-capacity response to ipratopium-bromide, although insignificant, was superior with post-NAC treatment versus post-placebo treatment (p=0.049). The salbutamol-response remained unaltered with either treatment.

CONCLUSION

The treatment with 1200mg/day NAC has potential to enhance the bronchodilator ability of antimuscarinic-agents but not beta-2-agonist. However, its clinical application has to be established in large sample-size studies for longer-duration.

Differential impact of relevant and irrelevant dimension primes on rule-based and information-integration category learning

Research has identified multiple category-learning systems with each being "tuned" for learning categories with different task demands and each governed by different neurobiological systems. Rule-based (RB) classification involves testing verbalizable rules for category membership while information-integration (II) classification requires the implicit learning of stimulus-response mappings. In the first study to directly test rule priming with RB and II category learning, we investigated the influence of the availability of information presented at the beginning of the task. Participants viewed lines that varied in length, orientation, and position on the screen, and were primed to focus on stimulus dimensions that were relevant or irrelevant to the correct classification rule. In Experiment 1, we used an RB category structure, and in Experiment 2, we used an II category structure. Accuracy and model-based analyses suggested that a focus on relevant dimensions improves RB task performance later in learning while a focus on an irrelevant dimension improves II task performance early in learning.

Mobilization of CD34+CD38- hematopoietic stem cells after priming in acute myeloid leukemia

AIM: To evaluate quantitatively and qualitatively the different CD34⁺ cell subsets after priming by chemotherapy granulocyte colony-stimulating factor (± G-CSF) in patients with acute myeloid leukemia.

METHODS: Peripheral blood and bone marrow samples were harvested in 8 acute myeloid leukemia patients during and after induction chemotherapy. The CD34/CD38 cell profile was analyzed by multi-parameter flow cytometry. Adhesion profile was made using CXC chemokine receptor 4 (CXCR4) (CD184), VLA-4 (CD49d/CD29) and CD47.

RESULTS: Chemotherapy ± G-CSF mobilized immature cells (CD34⁺CD38⁻ population), while the more mature cells (CD34⁺CD38^low and CD34⁺CD38⁺ populations) decreased progressively after treatment. Circulating CD34⁺ cells tended to be more sensitive to chemotherapy after priming with G-CSF. CD34⁺ cell mobilization was correlated with a gradual increase in CXCR4 and CD47 expression, suggesting a role in cell protection and the capacity of homing back to the marrow.

CONCLUSION: Chemotherapy ± G-CSF mobilizes into the circulation CD34⁺ bone marrow cells, of which, the immature CD34⁺CD38^– cell population. Further manipulations of these interactions may be a means with which to control the trafficking of leukemia stem cells to improve patients’ outcomes.

Repeating a strongly masked stimulus increases priming and awareness

Previous studies [Marcel, A. J. (1983). Conscious and unconscious perception: Experiments on visual masking and word recognition. Cognitive Psychology, 15(2), 197-237; Wentura, D., & Frings, C. (2005). Repeated masked category primes interfere with related exemplars: New evidence for negative semantic priming. Journal of Experimental Psychology: Learning, Memory, and Cognition, 31(1), 108-120] suggested that repeatedly presenting a masked stimulus improves priming without increasing perceptual awareness. However, neural theories of consciousness predict the opposite: Increasing bottom-up strength in such a paradigm should also result in increasing availability to awareness. Here, we tested this prediction by manipulating the number of repetitions of a strongly masked digit. Our results do not replicate the dissociation observed in previous studies and are instead suggestive that repeating an unconscious and attended masked stimulus enables the progressive emergence of perceptual awareness.

Complement fragment 3a priming of umbilical cord blood progenitors: safety profile

Preclinical data showed that priming CD34(+) hematopoietic progenitor cells with complement fragment 3a (C3a) improved homing and engraftment. Thus, we hypothesized that priming of umbilical cord blood (UCB) hematopoietic progenitors with C3a would facilitate homing and could potentially be used to address the need for improved engraftment after UCB transplantation. We primed 1 of 2 UCB units for double UCB transplantation after nonmyeloablative conditioning. This design provided adequate safety and the potential to observe skewed long-term chimerism in favor of the C3a-primed unit as a surrogate measure of efficacy. C3a priming of 1 UCB unit did not result in infusional toxicity. Increased grades 1 to 3 hypertension were the only infusional adverse events observed in 9 (30%) patients. We observed no activation of inflammatory or coagulation pathways downstream of C3a. As tested, C3a priming did not impair engraftment, but did not skew chimerism toward the treated unit. As compared with historical controls, mortality and survival were not adversely affected. Thus, before any additional clinical studies, C3a priming to promote engraftment will require further preclinical optimization.

Parkinson's disease disrupts both automatic and controlled processing of action verbs

The problem of how word meaning is processed in the brain has been a topic of intense investigation in cognitive neuroscience. While considerable correlational evidence exists for the involvement of sensory-motor systems in conceptual processing, it is still unclear whether they play a causal role. We investigated this issue by comparing the performance of patients with Parkinson's disease (PD) with that of age-matched controls when processing action and abstract verbs. To examine the effects of task demands, we used tasks in which semantic demands were either implicit (lexical decision and priming) or explicit (semantic similarity judgment). In both tasks, PD patients' performance was selectively impaired for action verbs (relative to controls), indicating that the motor system plays a more central role in the processing of action verbs than in the processing of abstract verbs. These results argue for a causal role of sensory-motor systems in semantic processing.

Rapid visuomotor processing of phobic images in spider- and snake-fearful participants

This study investigates enhanced visuomotor processing of phobic compared to fear-relevant and neutral stimuli. We used a response priming design to measure rapid, automatic motor activation by natural images (spiders, snakes, mushrooms, and flowers) in spider-fearful, snake-fearful, and control participants. We found strong priming effects in all tasks and conditions; however, results showed marked differences between groups. Most importantly, in the group of spider-fearful individuals, spider pictures had a strong and specific influence on even the fastest motor responses: Phobic primes entailed the largest priming effects, and phobic targets accelerated responses, both effects indicating speeded response activation by phobic images. In snake-fearful participants, this processing enhancement for phobic material was less pronounced and extended to both snake and spider images. We conclude that spider phobia leads to enhanced processing capacity for phobic images. We argue that this is enabled by long-term perceptual learning processes.

Stress-induced glucocorticoids as a neuroendocrine alarm signal of danger

A considerable number of studies demonstrate that acute and chronic stressors prime CNS innate immune responses to subsequent pro-inflammatory challenges and that glucocorticoids mediate, in part, stress-induced sensitization of pro-inflammatory immune responses. Here, we explore the notion that GCs produce a persisting sensitization of CNS innate immune effectors (e.g. microglia) so that they will generate a potentiated pro-inflammatory response after the GC rise has dissipated, thereby enhancing the sickness response to infection or injury and maximizing the animal's ability to neutralize danger. The stress-induced GC response is conceptualized here as an neuroendocrine warning signal or alarmin to the innate immune system, which prepares or sensitizes the innate immune response to potential danger. Thus, a new understanding of the stress response and its function (priming CNS innate immune responses to infection or injury during a fight/flight emergency) would be suggested.

Masked and unmasked priming in schizophrenia

Dehaene et al. (2003) showed an absence of conscious, but not masked, conflict effects when patients with schizophrenia performed a number-categorisation priming task. We aimed to replicate these influential results using a different word-categorisation priming task. Counter to Dehaene et al.'s findings, 21 patients and 20 healthy controls showed similar congruence effects for both masked and visible primes. Within patients, a reduced congruence effect for visible primes associated with longer duration of illness and more severe behavioural disorganisation. Patients, unlike controls, were no slower to respond to targets that followed visible compared to masked primes. Conscious conflict effects on priming tasks are not universally reduced in schizophrenia but may associate with chronicity and behavioural disorganisation. That patients were no slower when the preceding primes were clearly visible accords with evidence elsewhere that information processing in schizophrenia is driven more by immediate conscious experience and constrained less by prior events.

Impact of environmental olfactory cues on hand hygiene behaviour in a simulated hospital environment: a randomized study

This study investigated the impact of a fresh scent on the rate of hand hygiene compliance (HHC) among novice healthcare providers. In all, 165 participants examined a standardized patient with one sample exposed to fresh scent (N = 79) and the other exposed to the standard environment (N = 86). Hand hygiene behaviours were tracked before patient contact using video surveillance. The standard environment group had an HHC rate of 51% whereas participants in the fresh scent group had a higher HHC rate of 80% (P < 0.001). These data demonstrate that hand hygiene behaviour may be subconsciously influenced by cues in the environment.

Predicting lymph node output efficiency using systems biology

Dendritic cells (DCs) capture pathogens and foreign antigen (Ag) in peripheral tissues and migrate to secondary lymphoid tissues, such as lymph nodes (LNs), where they present processed Ag as MHC-bound peptide (pMHC) to naïve T cells. Interactions between DCs and T cells result, over periods of hours, in activation, clonal expansion and differentiation of antigen-specific T cells, leading to primed cells that can now participate in immune responses. Two-photon microscopy (2PM) has been widely adopted to analyze lymphocyte dynamics and can serve as a powerful in vivo assay for cell trafficking and activation over short length and time scales. Linking biological phenomena between vastly different spatiotemporal scales can be achieved using a systems biology approach. We developed a 3D agent-based cellular model of a LN that allows for the simultaneous in silico simulation of T cell trafficking, activation and production of effector cells under different antigen (Ag) conditions. The model anatomy is based on in situ analysis of LN sections (from primates and mice) and cell dynamics based on quantitative measurements from 2PM imaging of mice. Our simulations make three important predictions. First, T cell encounters by DCs and T cell receptor (TCR) repertoire scanning are more efficient in a 3D model compared with 2D, suggesting that a 3D model is needed to analyze LN function. Second, LNs are able to produce primed CD4+T cells at the same efficiency over broad ranges of cognate frequencies (from 10(-5) to 10(-2)). Third, reducing the time that naïve T cells are required to bind DCs before becoming activated will increase the rate at which effector cells are produced. This 3D model provides a robust platform to study how T cell trafficking and activation dynamics relate to the efficiency of T cell priming and clonal expansion. We envision that this systems biology approach will provide novel insights for guiding vaccine development and understanding immune responses to infection.