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Animals and humans in natural environments balance their time between vigilance for threats and foraging for rewards. We designed a decision-making task to investigate how mood states and psychiatrically-relevant transdiagnostic dimensions affected this in a large online sample (discovery: N=374, replication: N=702). Mood was related to task environmental factors and stress showed homeostatic relationships with task behaviours such as foraging. Anxiety was associated with decreased vigilance due to threat-related worry, while compulsive checking was linked with increased but sub-optimal vigilance. Apathy was related to reduced vigilance and more frequent foraging, potentially reflecting reluctance to switch behaviours. Anhedonia was linked with a reduction in self-reported task engagement. Women reported higher stress and favoured vigilance over foraging. In sum, behavioural traits associated with psychological illness corresponded not simply to responsivity to threat but to specific, replicable patterns of balancing behaviour between foraging and vigilance for predatory threat.

IntroductionMood instability in bipolar disorder (BD) is poorly understood. Here we examined cognitive and neural mechanisms related to these fluctuations and how they are changed with the mood stabilizer lithium.MethodsWe recruited volunteers with low (n=37) or high (n=40) risk of BD (using the Mood Disorder Questionnaire, MDQ). We also recruited patients with BD who were assigned (randomized, double-blind) to six weeks of lithium (n=19) or placebo (n=16) after a two-week baseline period. Participants completed mood ratings daily over 50 (healthy) or 42 (BD) days, as well as a risky decision-making task and one functional magnetic resonance imaging session. The task measured adaptation of risk taking to past outcomes (increased risk aversion after a previous win, ‘outcome history’).ResultsWhile the low MDQ group was risk averse after a win, this was less evident in the high MDQ group and least so in the patients with BD. Neurally, ‘outcome history’ was linked to medial frontal pole activation at the time of the decision. Corresponding to the behavioural effect, this activation was reduced in the high MDQ vs. the low MDQ group. While lithium did not reverse the pattern of BD in the task, it changed reward processing in the dorsolateral prefrontal cortex.DiscussionHealthy participants’ modulation of risk-taking in response to reward outcomes was reduced by risk of BD and BD. These results provide a model for how reward may prime escalation of risk-related behaviours in bipolar disorder and how mood stabilising treatments may work.

Much work has investigated beneficial effects of mindfulness-based meditation methods, but less work has investigated potential risks and differences across meditation methods. We addressed this in a large pre-registered online survey including 613 mediators where we correlated participants’ experience with fifty meditation techniques to psychotic-like experiences - PLEs (e.g. hallucinations) as detrimental outcomes, and mystical experiences as beneficial outcomes. We found a positive correlation for both PLEs and mystical experiences with techniques aiming at reducing phenomenological content (‘null-directed’, NDM) or classified as non-dual or less embodied. In contrast, methods aiming at achieving an enhanced cognitive state also described as ‘attentional’ or strongly embodied, showed negative correlations with PLEs. Interestingly, participants’ subjectively perceived that all types of meditation techniques were preventative of PLEs but less so for NDM. This study provides important information for meditators about the relationship of different techniques with PLEs and the moderating influences of individual traits.

BACKGROUND: Depression is a leading cause of disability worldwide and its prevalence is on the rise. One of the most debilitating aspects of depression is the dominance and persistence of depressive rumination, a state of mind that is linked to onset and recurrence of depression. Mindfulness meditation trains adaptive attention regulation and present-moment embodied awareness, skills that may be particularly useful during depressive mind states characterized by negative ruminative thoughts.METHODS: In a randomized controlled functional magnetic resonance imaging study (N = 80), we looked at the neurocognitive mechanisms behind mindfulness-based cognitive therapy (n = 50) for recurrent depression compared with treatment as usual (n = 30) across experimentally induced states of rest, mindfulness practice and rumination, and the relationship with dispositional psychological processes.RESULTS: Mindfulness-based cognitive therapy compared with treatment as usual led to decreased salience network connectivity to the lingual gyrus during a ruminative state, and this change in salience network connectivity mediated improvements in the ability to sustain and control attention to body sensations.CONCLUSIONS: These findings showed that a clinically effective mindfulness intervention modulates neurocognitive functioning during depressive rumination and the ability to sustain attention to the body.

International audience; Decisions made by mammals and birds are often temporally extended. They require planning and sampling of decision-relevant information. Our understanding of such decision-making remains in its infancy compared with simpler, forced-choice paradigms. However, recent advances in algorithms supporting planning and information search provide a lens through which we can explain neural and behavioral data in these tasks. We review these advances to obtain a clearer understanding for why planning and curiosity originated in certain species but not others; how activity in the medial temporal lobe, prefrontal and cingulate cortices may support these behaviors; and how planning and information search may complement each other as means to improve future action selection.

Environments furnish multiple information sources for making predictions about future events. Here we use behavioural modelling and functional magnetic resonance imaging to describe how humans select predictors that might be most relevant. First, during early encounters with potential predictors, participants’ selections were explorative and directed towards subjectively uncertain predictors (positive uncertainty effect). This was particularly the case when many future opportunities remained to exploit knowledge gained. Then, preferences for accurate predictors increased over time, while uncertain predictors were avoided (negative uncertainty effect). The behavioural transition from positive to negative uncertainty-driven selections was accompanied by changes in the representations of belief uncertainty in ventromedial prefrontal cortex (vmPFC). The polarity of uncertainty representations (positive or negative encoding of uncertainty) changed between exploration and exploitation periods. Moreover, the two periods were separated by a third transitional period in which beliefs about predictors’ accuracy predominated. The vmPFC signals a multiplicity of decision variables, the strength and polarity of which vary with behavioural context. Trudel et al. find that the ventromedial prefrontal cortex carries multiple decision variables, the strength and polarity of which vary according to their relevance to the context of exploration, exploitation and the transition between these states.

Introduction Mood instability is a prominent feature of bipolar disorder (BD) and other affective disorders [1]. Recent research has begun to highlight a strong association between mood instability and cognitive processing, particularly within the decision-making and reward-processing domain, suggesting the ability for mood to bias perception of reward and loss, and to induce risk-taking behaviour [2,3]. However, whilst this has provided an interesting first-line understanding of the phenotypic nature of BD, research to date has failed to explore the complexities of this relationship over a longitudinal basis. Modern technologies, such as remote online platforms, can address this issue by using high frequency and prospective monitoring. This is particularly important given the dynamic nature of mood instability [4] and the expanding need to understand its underlying neural mechanisms in order to develop new and better-suited targets for treatment [1]. Aims Given the emergence of new technologies and the ubiquity of internet access, we aimed to assess whether remote monitoring can capture dynamic mood instability in individuals showing dimensions of BD as measured by the Mood Disorder Questionnaire (MDQ) screening tool, and whether such instability is reflected in risk-taking behaviour in a longitudinal decision-making and reward-processing task. Methods Remote mood and cognitive monitoring over 10 weeks, as part of the Cognition and Mood Evolution across Time (COMET) study. We analysed data from 37 participants scoring >7 on the MDQ (high MDQ group) and 35 matched controls (MDQ Results The high MDQ group showed greater variability in their PANAS positive affect, F (1)=10.56, p F (1)=15.01, p F (1)=14.46, p Whilst the high MDQ participants did not show a significant bias towards riskier decisions in the gambling task in these preliminary analyses, all participants appeared to make less risky choices, F (5.00)=7.42, p F (4.81)=2.50, p Conclusions Longitudinal daily remote mood monitoring captures mood instability in individuals showing dimensions of BD. Concurrent monitoring of cognition, particularly within the reward processing domain, suggests a pattern of dynamic decision-making and warrants further sophisticated analyses to better elucidate the cognitive underpinnings of such mood instability. Nevertheless, findings add to the increasing evidence for mood instability as a marker for BD, and suggest the efficacy of remote monitoring as a modern phenotyping technology in prospectively assessing mood instability and associated cognition. This will aid in the search for biomarkers that can be used in determining the effectiveness of current treatments and in the development of novel therapeutic targets.

Although neuroimaging techniques have provided vital insights into the anatomical regions involved in motor learning, the underlying changes in temporal dynamics are not well understood. Using magnetoencephalography and Hidden Markov Modelling to model the dynamics of neural oscillations on data-adaptive time-scales, we detected specific changes in movement-related sensorimotor β-activity during practice of a self-paced sequential visuo-motor task. The behaviourally-relevant neural signature generalised to another motor task, emphasising the centrality of β-activity in motor plasticity.

Despite its physiological and clinical relevance, the influence of hydrocortisone on specific kinds of learning remains relatively unexplored. We measured the effect of hydrocortisone on motor sequence and reward learning under non-stress conditions. For the study, 54 healthy young volunteers were randomly assigned to a dose of 20 mg hydrocortisone versus placebo. Participants performed two well-defined learning tasks. Hydrocortisone did not affect motor sequence or reward learning.

A striking observation in obsessive-compulsive disorder is that patients know that their obsessions and compulsions are excessive, but their symptoms nevertheless persist. Drawing on computational models from basic neuroscience, Vaghi and colleagues (2017) suggest a quantitative account of this clinical finding.

Dorsal anterior cingulate cortex (dACC) mediates updating and maintenance of cognitive models of the world used to drive adaptive reward-guided behavior. We investigated the neurochemical underpinnings of this process. We used magnetic resonance spectroscopy in humans, to measure levels of glutamate and GABA in dACC. We examined their relationship to neural signals in dACC, measured with fMRI, and cognitive task performance. Both inhibitory and excitatory neurotransmitters in dACC were predictive of the strength of neural signals in dACC and behavioral adaptation. Glutamate levels were correlated, first, with stronger neural activity representing information to be learnt about the tasks’ costs and benefits and, second, greater use of this information in the guidance of behavior. GABA levels were negatively correlated with the same neural signals and the same indices of behavioral influence. Our results suggest that glutamate and GABA in dACC affect the encoding and use of past experiences to guide behavior. DOI: http://dx.doi.org/10.7554/eLife.20365.001

Natural environments are complex, and a single choice can lead to multiple outcomes. Agents should learn which outcomes are due to their choices and therefore relevant for future decisions and which are stochastic in ways common to all choices and therefore irrelevant for future decisions between options. We designed an experiment in which human participants learned the varying reward and effort magnitudes of two options and repeatedly chose between them. The reward associated with a choice was randomly real or hypothetical (i.e., participants only sometimes received the reward magnitude associated with the chosen option). The real/hypothetical nature of the reward on any one trial was, however, irrelevant for learning the longer-term values of the choices, and participants ought to have only focused on the informational content of the outcome and disregarded whether it was a real or hypothetical reward. However, we found that participants showed an irrational choice bias, preferring choices that had previously led, by chance, to a real reward in the last trial. Amygdala and ventromedial prefrontal activity was related to the way in which participants' choices were biased by real reward receipt. By contrast, activity in dorsal anterior cingulate cortex, frontal operculum/anterior insula, and especially lateral anterior prefrontal cortex was related to the degree to which participants resisted this bias and chose effectively in a manner guided by aspects of outcomes that had real and more sustained relationships with particular choices, suppressing irrelevant reward information for more optimal learning and decision making.In complex natural environments, a single choice can lead to multiple outcomes. Human agents should only learn from outcomes that are due to their choices, not from outcomes without such a relationship. We designed an experiment to measure learning about reward and effort magnitudes in an environment in which other features of the outcome were random and had no relationship with choice. We found that, although people could learn about reward magnitudes, they nevertheless were irrationally biased toward repeating certain choices as a function of the presence or absence of random reward features. Activity in different brain regions in the prefrontal cortex either reflected the bias or reflected resistance to the bias.

N-methyl-D-aspartate (NMDA) receptors are known to fulfill crucial functions in many forms of learning and plasticity. More recently, biophysical models, however, have suggested an additional role of NMDA receptors in evidence integration for decision-making, going beyond their role in learning. We designed a task to study the role of NMDA receptors in human reward-guided learning and decision-making. Human participants were assigned to receive either 250 mg of the partial NMDA agonist d-cycloserine (n=20) or matching placebo capsules (n=27). Reward-guided learning and decision-making were assessed using a task in which participants had to integrate learnt and explicitly shown value information to maximize their monetary wins and minimize their losses. To tease apart the effects of NMDA on learning and decision-making we used simple learning models. D-cycloserine shifted decision-making towards a more optimal integration of the learnt and the explicitly shown information, in the absence of a direct learning effect. In conclusion, our results reveal a distinct role for NMDA receptors in reward-guided decision-making. We discuss these findings in the context of NMDA's roles in neuronal super-additivity and as crucial for evidence integration for decisions.

International audience; Categorical choices are preceded by the accumulation of sensory evidence in favor of one action or another. Current models describe evidence accumulation as a continuous process occurring at a constant rate, but this view is inconsistent with accounts of a psychological refractory period during sequential information processing. During multisample perceptual categorization, we found that the neural encoding of momentary evidence in human electrical brain signals and its subsequent impact on choice fluctuated rhythmically according to the phase of ongoing parietal delta oscillations (1-3 Hz). By contrast, lateralized beta-band power (10-30 Hz) overlying human motor cortex encoded the integrated evidence as a response preparation signal. These findings draw a clear distinction between central and motor stages of perceptual decision making, with successive samples of sensory evidence competing to pass through a serial processing bottleneck before being mapped onto action.