Music Alters Visual Perception

Background: Visual perception is not a passive process: in order to efficiently process visual input, the brain actively uses previous knowledge (e.g., memory) and expectations about what the world should look like. However, perception is not only influenced by previous knowledge. Especially the perception of emotional stimuli is influenced by the emotional state of the observer. In other words, how we perceive the world does not only depend on what we know of the world, but also by how we feel. In this study, we further investigated the relation between mood and perception. Methods and Findings: We let observers do a difficult stimulus detection task, in which they had to detect schematic happy and sad faces embedded in noise. Mood was manipulated by means of music. We found that observers were more accurate in detecting faces congruent with their mood, corroborating earlier research. However, in trials in which no actual face was presented, observers made a significant number of false alarms. The content of these false alarms, or illusory percepts, was strongly influenced by the observers ’ mood. Conclusions: As illusory percepts are believed to reflect the content of internal representations that are employed by the brain during top-down processing of visual input, we conclude that top-down modulation of visual processing is not purely predictive in nature: mood, in this case manipulated by music, may also directly alter the way we perceive the world

Effects of aversive odour presentation on inhibitory control in the Stroop colour-word interference task

<p>Abstract</p> <p>Background</p> <p>Due to the unique neural projections of the olfactory system, odours have the ability to directly influence affective processes. Furthermore, it has been shown that emotional states can influence various non-emotional cognitive tasks, such as memory and planning. However, the link between emotional and cognitive processes is still not fully understood. The present study used the olfactory pathway to induce a negative emotional state in humans to investigate its effect on inhibitory control performance in a standard, single-trial manual Stroop colour-word interference task. An unpleasant (H₂S) and an emotionally neutral (Eugenol) odorant were presented in two separate experimental runs, both in blocks alternating with ambient air, to 25 healthy volunteers, while they performed the cognitive task.</p> <p>Results</p> <p>Presentation of the unpleasant odorant reduced Stroop interference by reducing the reaction times for incongruent stimuli, while the presentation of the neutral odorant had no effect on task performance.</p> <p>Conclusions</p> <p>The odour-induced negative emotional state appears to facilitate cognitive processing in the task used in the present study, possibly by increasing the amount of cognitive control that is being exerted. This stands in contrast to other findings that showed impaired cognitive performance under odour-induced negative emotional states, but is consistent with models of mood-congruent processing.</p

Dissociable Effects of Valence and Arousal in Adaptive Executive Control

Background: Based on introspectionist, semantic, and psychophysiological experimental frameworks, it has long been assumed that all affective states derive from two independent basic dimensions, valence and arousal. However, until now, no study has investigated whether valence and arousal are also dissociable at the level of affect-related changes in cognitive processing.Methodology/Principal Findings: We examined how changes in both valence (negative vs. positive) and arousal (low vs. high) influence performance in tasks requiring executive control because recent research indicates that two dissociable cognitive components are involved in the regulation of task performance: amount of current control (i.e., strength of filtering goal-irrelevant signals) and control adaptation (i.e., strength of maintaining current goals over time). Using a visual pop-out distractor task, we found that control is exclusively modulated by arousal because interference by goal-irrelevant signals was largest in high arousal states, independently of valence. By contrast, control adaptation is exclusively modulated by valence because the increase in control after trials in which goal-irrelevant signals were present was largest in negative states, independent of arousal. A Monte Carlo simulation revealed that differential effects of two experimental factors on control and control adaptation can be dissociated if there is no correlation between empirical interference and conflict-driven modulation of interference, which was the case in the present data. Consequently, the observed effects of valence and arousal on adaptive executive control are indeed dissociable. Conclusions/Significance: These findings indicate that affective influences on cognitive processes can be driven by independent effects of variations in valence and arousal, which may resolve several heterogeneous findings observed in previous studies on affect-cognition interactions

TRY plant trait database - enhanced coverage and open access

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Gene duplication and fragmentation in the zebra finch major histocompatibility complex

BACKGROUND: Due to its high polymorphism and importance for disease resistance, the major histocompatibility complex (MHC) has been an important focus of many vertebrate genome projects. Avian MHC organization is of particular interest because the chicken Gallus gallus, the avian species with the best characterized MHC, possesses a highly streamlined minimal essential MHC, which is linked to resistance against specific pathogens. It remains unclear the extent to which this organization describes the situation in other birds and whether it represents a derived or ancestral condition. The sequencing of the zebra finch Taeniopygia guttata genome, in combination with targeted bacterial artificial chromosome (BAC) sequencing, has allowed us to characterize an MHC from a highly divergent and diverse avian lineage, the passerines. RESULTS: The zebra finch MHC exhibits a complex structure and history involving gene duplication and fragmentation. The zebra finch MHC includes multiple Class I and Class II genes, some of which appear to be pseudogenes, and spans a much more extensive genomic region than the chicken MHC, as evidenced by the presence of MHC genes on each of seven BACs spanning 739 kb. Cytogenetic (FISH) evidence and the genome assembly itself place core MHC genes on as many as four chromosomes with TAP and Class I genes mapping to different chromosomes. MHC Class II regions are further characterized by high endogenous retroviral content. Lastly, we find strong evidence of selection acting on sites within passerine MHC Class I and Class II genes. CONCLUSION: The zebra finch MHC differs markedly from that of the chicken, the only other bird species with a complete genome sequence. The apparent lack of synteny between TAP and the expressed MHC Class I locus is in fact reminiscent of a pattern seen in some mammalian lineages and may represent convergent evolution. Our analyses of the zebra finch MHC suggest a complex history involving chromosomal fission, gene duplication and translocation in the history of the MHC in birds, and highlight striking differences in MHC structure and organization among avian lineages

Is inhibition of kinase activity the only therapeutic strategy for LRRK2-associated Parkinson's disease?

Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are a common cause of familial Parkinson's disease (PD). Variation around the LRRK2 locus also contributes to the risk of sporadic PD. The LRRK2 protein contains a central catalytic region, and pathogenic mutations cluster in the Ras of complex protein C terminus of Ras of complex protein (mutations N1437H, R1441G/C and Y1699C) and kinase (G2019S and I2020T) domains. Much attention has been focused on the kinase domain, because kinase-dead versions of mutant LRRK2 are less toxic than kinase-active versions of the same proteins. Furthermore, kinase inhibitors may be able to mimic this effect in mouse models, although the currently tested inhibitors are not completely specific. In this review, we discuss the recent progress in the development of specific LRRK2 kinase inhibitors. We also discuss non-kinase-based therapeutic strategies for LRRK2-associated PD as it is possible that different approaches may be needed for different mutations