Integration of targeted metabolome and transcript profiling of Pseudomonas syringae-triggered changes in defence-related phytochemicals in oat plants.

MAIN CONCLUSION: A gene-to-metabolite approach afforded new insights regarding defence mechanisms in oat plants that can be incorporated into plant breeding programmes for the selection of markers and genes related to disease resistance. Monitoring metabolite levels and changes therein can complement and corroborate transcriptome (mRNA) data on plant-pathogen interactions, thus revealing mechanisms involved in pathogen attack and host defence. A multi-omics approach thus adds new layers of information such as identifying metabolites with antimicrobial properties, elucidating metabolomic profiles of infected and non-infected plants, and reveals pathogenic requirements for infection and colonisation. In this study, two oat cultivars (Dunnart and SWK001) were inoculated with Pseudomonas syringae pathovars, pathogenic and non-pathogenic on oat. Following inoculation, metabolites were extracted with methanol from leaf tissues at 2, 4 and 6 days post-infection and analysed by multiple reaction monitoring (MRM) on a triple quadrupole mass spectrometer system. Relatedly, mRNA was isolated at the same time points, and the cDNA analysed by quantitative PCR (RT-qPCR) for expression levels of selected gene transcripts associated with avenanthramide (Avn) biosynthesis. The targeted amino acids, hydroxycinnamic acids and Avns were successfully quantified. Distinct cultivar-specific differences in the metabolite responses were observed in response to pathogenic and non-pathogenic strains. Trends in aromatic amino acids and hydroxycinnamic acids seem to indicate stronger activation and flux through these pathways in Dunnart as compared to SWK001. A positive correlation between hydroxycinnamoyl-CoA:hydroxyanthranilate N-hydroxycinnamoyl transferase (HHT) gene expression and the abundance of Avn A in both cultivars was documented. However, transcript profiling of selected genes involved in Avn synthesis did not reveal a clear pattern to distinguish between the tolerant and susceptible cultivars.

Avenanthramides, Distinctive Hydroxycinnamoyl Conjugates of Oat, Avena sativa L.: An Update on the Biosynthesis, Chemistry, and Bioactivities.

Avenanthramides are a group of N-cinnamoylanthranilic acids (phenolic alkaloid compounds) that are produced in oat plants as phytoalexins, in response to pathogen attack and elicitation. The enzyme catalysing the cinnamamide-generating reaction is hydroxycinnamoyl-CoA: hydroxyanthranilate N-hydroxycinnamoyltransferase (HHT, a member of the super family of BAHD acyltransferases). HHT from oat appears to have a narrow range of substrate usage, with preferred use of 5-hydroxyanthranilic acid (and to a lesser extent, other hydroxylated and methoxylated derivatives) as acceptor molecules, but is able to use both substituted cinnamoyl-CoA and avenalumoyl-CoA thioesters as donor molecules. Avenanthramides thus combine carbon skeletons from both the stress-inducible shikimic acid and phenylpropanoid pathways. These features contribute to the chemical characteristics of avenanthramides as multifunctional plant defence compounds, as antimicrobial agents and anti-oxidants. Although avenanthramides are naturally and uniquely synthesised in oat plants, these molecules also exhibit medicinal and pharmaceutical uses important for human health, prompting research into utilisation of biotechnology to enhance agriculture and value-added production.

A Genomic Survey of the Natural Product Biosynthetic Potential of Actinomycetes Isolated from New Zealand Lichens.

Actinomycetes are prolific producers of industrially valuable and medically important compounds. Historically, the most efficient method of obtaining compounds has been bioactivity-guided isolation and characterization of drug-like molecules from culturable soil actinomycetes. Unfortunately, this pipeline has been met with an increasing number of rediscoveries, to the point where it is no longer considered an attractive approach for drug discovery. To address this challenge and to continue finding new compounds, researchers have increasingly focused on alternative environmental niches and screening methods. Here, we report the genetic investigation of actinomycetes from an underexplored source, New Zealand lichens. In this work, we obtain draft genome sequences for 322 lichen-associated actinomycetes. We then explore this genetic resource with an emphasis on biosynthetic potential. By enumerating biosynthetic gene clusters (BGCs) in our data sets and comparing these to various reference collections, we demonstrate that actinomycetes sourced from New Zealand lichens have the genetic capacity to produce large numbers of natural products, many of which are expected to be broadly different from those identified in previous efforts predominantly based on soil samples. Our data shed light on the actinomycete assemblage in New Zealand lichens and demonstrate that lichen-sourced actinobacteria could serve as reservoirs for discovering new secondary metabolites. IMPORTANCE Lichens are home to complex and distinctive microbial cohorts that have not been extensively explored for the ability to produce novel secondary metabolites. Here, we isolate and obtain genome sequence data for 322 actinomycetes from New Zealand lichens. In doing so, we delineate at least 85 potentially undescribed species, and show that lichen associated actinomycetes have the potential to yield many new secondary metabolites, and as such, might serve as a productive starting point for drug discovery efforts.

To Pay or Just Play? Examining Individual Differences Between Purchasers and Earners of Loot Boxes in Overwatch.

Video-game loot boxes are a popular form of microtransaction that have been widely criticized for their structural similarities to gambling. Recent research linking loot box expenditure to gambling activity has illuminated potential harms associated with loot box use. However, whether the harms differ between earning loot boxes through gameplay versus acquiring loot boxes through purchasing remains understudied. This pre-registered study explores gambling, gaming and loot box-related harms between loot box purchasers and earners in the scope of the game Overwatch. To our knowledge, this is the first study to assess loot box-related harms in a single game. We found that loot box purchasers experienced greater video-game related expenditure harms, risky loot box use, impulsivity related to planning and reward reactivity in comparison to loot box earners. Surprisingly, Overwatch loot box earners displayed greater gambling-related harms and there were no differences in general problem video-gaming between the two groups. Our results suggest that the relationship between loot box purchasing and gambling is in need of refined examination. Particularly, our results indicate that potential harms stemming from loot box engagement should be assessed on a game-by-game basis in order to better understand the potentially problematic nature of loot box use.

Metabolomic Characterisation of Discriminatory Metabolites Involved in Halo Blight Disease in Oat Cultivars Caused by Pseudomonas syringae pv. coronafaciens.

The metabolome is the underlying biochemical layer of the phenotype and offers a functional readout of the cellular mechanisms involved in a biological system. Since metabolites are considered end-products of regulatory processes at a cellular level, their levels are considered the definitive response of the biological system to genetic or environmental variations. The metabolome thus serves as a metabolic fingerprint of the biochemical events that occur in a biological system under specific conditions. In this study, an untargeted metabolomics approach was applied to elucidate biochemical processes implicated in oat plant responses to Pseudomonas syringae pv. coronafaciens (Ps-c) infection, and to identify signatory markers related to defence responses and disease resistance against halo blight. Metabolic changes in two oat cultivars ("Dunnart" and "SWK001") responding to Ps-c, were examined at the three-leaf growth stage and metabolome changes monitored over a four-day post-inoculation period. Hydromethanolic extracts were analysed using an ultra-high-performance liquid chromatography (UHPLC) system coupled to a high-definition mass spectrometer (MS) analytical platform. The acquired multi-dimensional data were processed using multivariate statistical analysis and chemometric modelling. The validated chemometric models indicated time- and cultivar-related metabolic changes, defining the host response to the bacterial inoculation. Further multivariate analyses of the data were performed to profile differential signatory markers, putatively associated with the type of launched defence response. These included amino acids, phenolics, phenolic amides, fatty acids, flavonoids, alkaloids, terpenoids, lipids, saponins and plant hormones. Based on the results, metabolic alterations involved in oat defence responses to Ps-c were elucidated and key signatory metabolic markers defining the defence metabolome were identified. The study thus contributes toward a more holistic understanding of the oat metabolism under biotic stress.

Contrasting Mind-Wandering, (Dark) Flow, and Affect During Multiline and Single-Line Slot Machine Play.

Slot machines are a very popular form of gambling in which a small proportion of gamblers experience gambling-related problems. These players refer to a trance-like state that researchers have labelled 'dark flow'-a pleasurable, but maladaptive state where players become completely occupied by the game. We assessed 110 gamblers for mindfulness (using the Mindful Attention Awareness Scale), gambling problems (using the Problem Gambling Severity Index), depressive symptoms (using the Depression, Anxiety, and Stress Scale), and boredom proneness (using the Boredom Proneness Scale). Participants played both a multiline and single-line slot machine simulator and were occasionally interrupted with thought probes to assess whether they were thinking about the game or something else. After playing each game, we retrospectively assessed dark flow and affect during play. Our key results were that the number of "on-game" reports during the multiline game were significantly higher than the single-line game, and that we found significantly greater flow during the multiline game than the single-line game. We also found significantly lower negative affect during the multiline game than the single-line game. Using hierarchical multiple regression, we found that dark flow accounted for unique variance when predicting problem gambling severity (over and above depression, mindfulness, and boredom proneness). These assessments help bolster our previous assertions about escape gambling-if some players are prone to having their mind-wander to negative places, the frequent but unpredictable reinforcement of multiline slot machines may help rein in the wandering mind and prevent minds from unintentionally wandering to negative thoughts.

The presence of oxygenated lipids in plant defense in response to biotic stress: a metabolomics appraisal.

Recent lipid-based findings suggest more direct roles for fatty acids and their degradation products in inducing/modulating various aspects of plant defense, e.g. as signaling molecules following stress responses that may regulate plant innate immunity. The synthesis of oxylipins is a highly dynamic process and occurs in both a developmentally regulated mode and in response to abiotic and biotic stresses. This mini-review summarizes the occurrence of free - and oxygenated fatty acid derivatives in plants as part of an orchestrated metabolic defense against pathogen attack. Oxygenated C18 derived polyunsaturated fatty acids were identified by untargeted metabolomics studies of a number of different plant-microbe pathosystems and may serve as potential biomarkers of oxidative stress. Untargeted metabolomics in combination with targeted lipidomics, can uncover previously unrecognized aspects of lipid mobilization during plant defense.

Metabolomics for Biomarker Discovery: Key Signatory Metabolic Profiles for the Identification and Discrimination of Oat Cultivars.

The first step in crop introduction-or breeding programmes-requires cultivar identification and characterisation. Rapid identification methods would therefore greatly improve registration, breeding, seed, trade and inspection processes. Metabolomics has proven to be indispensable in interrogating cellular biochemistry and phenotyping. Furthermore, metabolic fingerprints are chemical maps that can provide detailed insights into the molecular composition of a biological system under consideration. Here, metabolomics was applied to unravel differential metabolic profiles of various oat (Avena sativa) cultivars (Magnifico, Dunnart, Pallinup, Overberg and SWK001) and to identify signatory biomarkers for cultivar identification. The respective cultivars were grown under controlled conditions up to the 3-week maturity stage, and leaves and roots were harvested for each cultivar. Metabolites were extracted using 80% methanol, and extracts were analysed on an ultra-high performance liquid chromatography (UHPLC) system coupled to a quadrupole time-of-flight (qTOF) high-definition mass spectrometer analytical platform. The generated data were processed and analysed using multivariate statistical methods. Principal component analysis (PCA) models were computed for both leaf and root data, with PCA score plots indicating cultivar-related clustering of the samples and pointing to underlying differential metabolic profiles of these cultivars. Further multivariate analyses were performed to profile differential signatory markers, which included carboxylic acids, amino acids, fatty acids, phenolic compounds (hydroxycinnamic and hydroxybenzoic acids, and associated derivatives) and flavonoids, among the respective cultivars. Based on the key signatory metabolic markers, the cultivars were successfully distinguished from one another in profiles derived from both leaves and roots. The study demonstrates that metabolomics can be used as a rapid phenotyping tool for cultivar differentiation.

Rare Loot Box Rewards Trigger Larger Arousal and Reward Responses, and Greater Urge to Open More Loot Boxes.

Loot boxes are a purchasable video-game feature consisting of randomly determined, in-game virtual items. Due to their chance-based nature, there is much debate as to whether they constitute a form of gambling. We sought to address this issue by examining whether players treat virtual loot box rewards in a way that parallels established reward reactivity for monetary rewards in slots play. Across two sets of experiments, we show that loot boxes containing rarer items are more valuable, arousing, rewarding and urge-inducing to players, similar to the way slots gamblers treat rare large wins in slots play. Importantly, we show in Experiment 2 that the duration of Post Reinforcement Pauses, an index of reward reactivity, are longer for boxes with rarer items. Boxes containing rarer rewards also trigger larger Skin Conductance Responses and larger force responses-indices of positive arousal. Findings of Experiment 2 also revealed that there was an increase in anticipatory arousal prior to the reveal of loot box rewards. Collectively, our results elucidate the structural similarities between loot boxes and specific gambling games. The fact that players find rarer game items hedonically rewarding and motivating has implications for potential risky or excessive loot box use for some players.

Do losses disguised as wins create a "sweet spot" for win overestimates in multiline slots play?

Multiline slots are popular electronic gaming machines. Research suggests that particular outcomes on these games, namely losses disguised as a wins or LDWs, may make these games particularly alluring to gamblers. LDWs occur when one wins less than they wager, but the machine celebrates these net losses with flashing lines and winning sounds (e.g., bet a dollar, win back a dime). Players are known to somatically, psychologically, and behaviourlly miscategorize LDWs as wins rather than losses. Furthermore, LDWs lead players to overestimate how many times they thought they won during a playing session - leading to what is known as the LDW-triggered win-overestimation effect. In this paper, we analyzed experienced players' win-overestimates from 13 studies after playing slots with different LDW percentages. The combined data showed an inverted U-shaped function for win-overestimates. There appears to be a "sweet spot" for the LDW-triggered win-overestimation effect; wherein, a moderate number of LDWs maximizes this effect, but a high number of LDWs decreases the effect. In Study 2, we confirmed with 132 experienced gamblers that there appears to be maximal win overestimates at around 19.6% LDWs. We conjecture that a high number of LDWs may lead players to see a disconnection between the running total on the machine going down and the number of "wins", leading to more accurate win estimates. This inverted "U" effect for win-overestimates parallels previous research showing that gamblers continue to play for longer during a losing streak following a playing session with a moderate (versus low or high) number of LDWs. LDW-triggered win-overestimates may contribute to the allure of multiline slots -games that cause significant problems for a subset of gamblers.

The Need for Comprehensive Care for Persons with Chronic Immune Thrombocytopenic Purpura.

Chronic platelet disorders (CPD), including chronic immune thrombocytopenic purpura (cITP), thrombotic thrombocytopenic purpura (TTP) and platelet function disorders are among the most common bleeding disorders and are associated with morbidity and mortality. The clinical phenotype and complexity of cITP is much like that of hemophilia. In cITP and hemophilia, bleeding is problematic for many, complicating employability, insurability and overall quality-of-life (QoL). While myriad drug therapies are available for cITP and hemophilia, each are variable in their effectiveness, very few (except for clotting factor concentrates for hemophilia) alter the natural history of the disorder and sometimes contribute to specific morbidities and mortality. Like in hemophilia, the management of cITP is not solely based on access to effective treatment but also includes accurate diagnosis and comprehensive care by a multidisciplinary team of specialists trained in the management of bleeding disorders. The model of comprehensive care in Hemophilia Treatment Centers (HTCs) has been recognized as highly effective, improving life expectancy for persons with hemophilia. cITP, and other CPDs, are complex disorders requiring specialized care. However, an integrated care model with a systematic and reliable population-based surveillance program does not exist. Extending the Comprehensive Care model with all its related benefits to the community of persons with cITP is sorely needed. This review will focus on cITP as a prototype chronic platelet disorder that could benefit greatly from the Comprehensive Care model.

Using deliberate mind-wandering to escape negative mood states: Implications for gambling to escape.

BACKGROUND AND AIMS: Slot machines are a pervasive form of gambling in North America. Some gamblers describe entering "the slot machine zone"-a complete immersion into slots play to the exclusion of all else. METHODS: We assessed 111 gamblers for mindfulness (using the Mindful Attention Awareness Scale (MAAS)), gambling problems (using the Problem Gambling Severity Index (PGSI)), depressive symptoms (using the Depression, Anxiety, and Stress Scale), and boredom proneness (using the Boredom Proneness Scale). In a counterbalanced order, participants played a slot machine simulator and completed an auditory vigilance task. During each task, participants were interrupted with thought probes to assess whether they were: on-task, spontaneously mind-wandering, or deliberately mind-wandering. After completing each task, we retrospectively assessed flow and affect. Compared to the more exciting slots play, we propose that gamblers may use deliberate mind-wandering as a maladaptive means to regulate affect during a repetitive vigilance task. RESULTS: Our key results were that gamblers reported greater negative affect following the vigilance task (when compared to slots) and greater positive affect following slots play (when compared to the vigilance task). We also found that those who scored higher in problem gambling were more likely to use deliberate mind-wandering as a means to cope with negative affect during the vigilance task. Using hierarchical multiple regression, we found that the number of "deliberately mind-wandering" responses accounted for unique variance when predicting problem gambling severity (over and above depression, mindfulness, and boredom proneness). CONCLUSIONS: These assessments highlight a potential coping mechanism used by problem gamblers in order to deal with negative affect.

The relationship between the skill-challenge balance, game expertise, flow and the urge to keep playing complex mobile games.

BACKGROUND AND AIMS: Interest surrounding the relationship between flow and problematic gameplay has surged. An important antecedent of flow in the context of video-gaming is the skill-challenge balance, but researchers have only manipulated this balance by changing speed of play. The current research seeks to examine the skill-challenge balance and flow in a mobile game in which challenge is increased via the complexity of puzzles. We predicted games like Candy-Crush would more strongly support a model of flow in which the greatest flow would be experienced by more skilled players and that high flow games would induce the most urge to continue play. METHODS: We had 60 Candy-Crush players play games near their level standing (maximal skill-challenge balance), or games that were too easy or too hard. Perceived skill, challenge, flow, and urge to continue gameplay were measured after each game. RESULTS: Players felt the highest degree of skill-challenge balance when playing games around their level standing. Easy games produced the least flow, while both regular and hard games produced comparable flow despite hard games being far more challenging and frustrating. The findings support models of flow positing those with highest perceived skill will experience greater flow. Finally, flow and arousal combine to increase urge to keep playing. DISCUSSION AND CONCLUSIONS: Our findings suggest those with high perceived skill will experience deep, immersive flow which motivates players to keep playing.

Reward reactivity and dark flow in slot-machine gambling: "Light" and "dark" routes to enjoyment.

BACKGROUND AND AIMS: Slot machines are a very popular form of gambling. In this study, we look at two different routes to enjoying slots play. One route involves the degree to which players react to rewards. The other route involves what we call dark flow - a pleasurable, but maladaptive state where players become completely engrossed in slots play, providing an escape from the depressing thoughts that characterize their everyday lives. METHODS: One hundred and twenty-nine high-frequency slots players were tested on slot-machine simulators set up in the lobby of a casino. We measured reward reactivity using post-reinforcement pauses (PRPs) and the force with which players pressed the spin button following different slot-machine outcomes. For each player, we calculated the slopes of PRPs and force as a function of credit gains. We also assessed players' slots game enjoyment and their experience of dark flow, depression, and problem gambling. RESULTS: Both the PRP and the force measures of reward reactivity were significantly correlated with players' enjoyment of the slots session, but neither measure was correlated with either problem gambling or depression. Ratings of dark flow were strongly correlated with slots enjoyment (which accounted for far more positive affect variance than the reward reactivity measures) and were correlated with both problem gambling scores and depression. DISCUSSION AND CONCLUSIONS: Our results suggest that of these two routes to enjoying slot-machine play, the dark flow route is especially problematic. We contend that the dark flow state may be enjoyable because it provides escape from the negative thoughts linked to depression.

Mindfulness problems and depression symptoms in everyday life predict dark flow during slots play: Implications for gambling as a form of escape.

Slot machine players refer to a state of absorption that researchers have labeled dark flow. Players become completely occupied by the game and forget everything else (leading to "dark" consequences such as spending more money than intended). We propose that players who experience dark flow have difficulty staying on task in everyday life, but, the reinforcing sights and sounds of slot machines rein in these otherwise wandering minds and induce these flow-like states. We assessed 129 gamblers for mindfulness problems (using the Mindful Attention Awareness Scale), gambling problems (using the Problem Gambling Severity Index), and depressive symptoms (using the Depression Anxiety and Stress Scale). Participants played a slot machine simulator and were periodically interrupted with thought probes to assess whether they were thinking about the game or about something else. After playing, we retrospectively assessed dark flow and positive affect during play. Our key results were that mindfulness problems outside of the gambling context were positively correlated with depression, problem gambling status, and most importantly, dark flow within the gambling context. Dark flow was positively correlated with positive affect during play and the combination of dark flow and depression predicted gambling problems. The picture that emerges is that individuals with mindfulness problems in everyday life find their attention locked in by slot machines inducing dark flow, which in turn leads to a state of positive affect. For depressed players especially, this state may be enjoyable because it provides an escape from the negative mentation linked to depression that characterizes the everyday lives of these troubled players. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

EphA4 Regulates Hippocampal Neural Precursor Proliferation in the Adult Mouse Brain by d-Serine Modulation of N-Methyl-d-Aspartate Receptor Signaling.

The hippocampal dentate gyrus (DG) is a major region of the adult rodent brain in which neurogenesis occurs throughout life. The EphA4 receptor, which regulates neurogenesis and boundary formation in the developing brain, is also expressed in the adult DG, but whether it regulates adult hippocampal neurogenesis is not known. Here, we show that, in the adult mouse brain, EphA4 inhibits hippocampal precursor cell proliferation but does not affect precursor differentiation or survival. Genetic deletion or pharmacological inhibition of EphA4 significantly increased hippocampal precursor proliferation in vivo and in vitro, by blocking EphA4 forward signaling. EphA4 was expressed by mature hippocampal DG neurons but not neural precursor cells, and an EphA4 antagonist, EphA4-Fc, did not activate clonal cultures of precursors until they were co-cultured with non-precursor cells, indicating an indirect effect of EphA4 on the regulation of precursor activity. Supplementation with d-serine blocked the increased precursor proliferation induced by EphA4 inhibition, whereas blocking the interaction between d-serine and N-methyl-d-aspartate receptors (NMDARs) promoted precursor activity, even at the clonal level. Collectively, these findings demonstrate that EphA4 indirectly regulates adult hippocampal precursor proliferation and thus plays a role in neurogenesis via d-serine-regulated NMDAR signaling.

Dark Flow, Depression and Multiline Slot Machine Play.

Multiline slot machines allow for a unique outcome type referred to as a loss disguised as a win (LDW). An LDW occurs when a player gains credits on a spin, but fewer credits than their original wager (e.g. 15-cent gain on a 20-cent wager). These outcomes alter the gambler's play experience by providing frequent, albeit smaller, credit gains throughout a playing session that are in fact net losses. Despite this negative overall value, research has shown that players physiologically respond to LDWs as if they are wins, not losses. These outcomes also create a "smoother" experience for the player that seems to promote a highly absorbing, flow-like state that we have called "dark flow". Past research has indicated that there may be a relationship between problem gambling status and dark flow, as well as between dark flow, depression, and gambling expectancies. In this study, we sought to further understand these relationships, while examining the influence of LDWs on game preference in the context of single versus multiline slots play. We used a realistic slot machine simulator equipped with a force transducer to measure how hard players pressed the spin button following different outcomes. This measure of arousal showed that LDWs were treated similarly to small wins. Participants overwhelmingly preferred the multiline game and experienced more positive affect while playing it, compared to the single-line game. Problem gambling severity index scores were related to dark flow in both games, but this relationship was stronger for the multiline game. Additionally, depression symptomatology and dark flow were strongly correlated in the multiline game, with significant relationships between depression and gambling expectancy, and gambling expectancy and dark flow ratings also emerging.

Near-Misses and Stop Buttons in Slot Machine Play: An Investigation of How They Affect Players, and May Foster Erroneous Cognitions.

In modern casinos, multiline slot machines are becoming increasingly popular compared to traditional, three-reel slot machines. A paucity of research has examined how the unique presentation of near-misses and the use of a stop button in multiline slot machines impact erroneous cognitions related to the perception of skill and agency during play. Our goal therefore was to determine the prevalence of erroneous cognitions pertaining to near-miss outcomes and the usage of a stop button and then to see whether the stop button affected players' experiences of winning, losing and near-miss outcomes. We recruited 132 gamblers from a casino in Ontario. They played two versions of a slot machine simulator: one with a stop button and one without a stop button. We measured player's arousal [skin conductance responses (SCRs), pressure on the spin-button), and behavioural responses (post-reinforcement pauses (PRPs)] to wins, losses and near-misses during play. We predicted more robust physiological SCRs and longer PRPs to wins in the stop button game. We also predicted that near-misses encountered in the stop button game would trigger greater levels of arousal and frustration in players, as indexed by larger SCRs, and greater force applied to the spin button to initiate the next spin. Erroneous cognitions pertaining to the stop button and near-misses respectively were assessed following play. Results showed that a small but meaningful percentage of players held erroneous cognitions about the stop button (13.6%) and near-misses (16%). Players depressed the spin button harder, and had larger SCRs for all outcomes when using the stop button. Players also paused longer for near-misses in the game involving the stop button. Our findings converge to suggest that the stop button encourages an erroneous perception of skill in some players, and consequentially impacts how such players perceive their outcomes in multiline slot machines.

The Candy Crush Sweet Tooth: How 'Near-misses' in Candy Crush Increase Frustration, and the Urge to Continue Gameplay.

Like many gambling games, the exceedingly popular and lucrative smartphone game "Candy Crush" features near-miss outcomes. In slot machines, a near-miss involves getting two of the needed three high-paying symbols on the pay-line (i.e., just missing the big win). In Candy Crush, the game signals when you just miss getting to the next level by one or two moves. Because near-misses in gambling games have consistently been shown to invigorate play despite being frustrating outcomes, the goal of the present study was to examine whether such near-misses trigger increases in player arousal, frustration and urge to continue play in Candy Crush. Sixty avid Candy Crush players were recruited to play the game for 30 min while having their Heart Rate, Skin Conductance Level, subjective arousal, frustration and urge to play recorded for three types of outcomes: wins (where they level up), losses (where they don't come close to levelling up), and near-misses (where they just miss levelling up). Near-misses were more arousing than losses as indexed by increased heart rate and greater subjective arousal. Near-misses were also subjectively rated as the most frustrating of all outcomes. Most importantly, of any type of outcome, near-misses triggered the most substantial urge to continue play. These findings suggest that near-misses in Candy Crush play a role in player commitment to the game, and may contribute to players playing longer than intended.

Synaptic Organization of the Neuronal Circuits of the Claustrum.

The claustrum, a poorly understood subcortical structure located between the cortex and the striatum, forms widespread connections with almost all cortical areas, but the cellular organization of claustral circuits remains largely unknown. Based primarily on anatomical data, it has been proposed that the claustrum integrates activity across sensory modalities. However, the extent to which the synaptic organization of claustral circuits supports this integration is unclear. Here, we used paired whole-cell recordings and optogenetic approaches in mouse brain slices to determine the cellular organization of the claustrum. We found that unitary synaptic connections among claustrocortical (ClaC) neurons were rare. In contrast, parvalbumin-positive (PV) inhibitory interneurons were highly interconnected with both chemical and electrical synapses. In addition, ClaC neurons and PV interneurons formed frequent synaptic connections. As suggested by anatomical data, we found that corticoclaustral afferents formed monosynaptic connections onto both ClaC neurons and PV interneurons. However, the responses to cortical input were comparatively stronger in PV interneurons. Consistent with this overall circuit organization, activation of corticoclaustral afferents generated monosynaptic excitatory responses as well as disynaptic inhibitory responses in ClaC neurons. These data indicate that recurrent excitatory circuits within the claustrum alone are unlikely to integrate across multiple sensory modalities. Rather, this cellular organization is typical of circuits sensitive to correlated inputs. Although single ClaC neurons may integrate corticoclaustral input from different cortical regions, these results are consistent with more recent proposals implicating the claustrum in detecting sensory novelty or in amplifying correlated cortical inputs to coordinate the activity of functionally related cortical regions. Significance statement: The function of the claustrum, a brain nucleus found in mammals, remains poorly understood. It has been proposed, based primarily on anatomical data, that claustral circuits play an integrative role and contribute to multimodal sensory integration. Here we show that the principal neurons of the claustrum, claustrocortical (ClaC) projection neurons, rarely form synaptic connections with one another and are unlikely to contribute to broad integration within the claustrum. We show that, although single ClaC neurons may integrate corticoclaustral inputs carrying information for different sensory modalities, the synaptic organization of ClaC neurons, local parvalbumin-positive interneurons within the claustrum, and cortical afferents is also consistent with recent proposals that the claustrum plays a role in detecting salient stimuli or amplifying correlated cortical inputs.