Prospective and retrospective values integrated in frontal cortex drive predictive choice.

To make a deliberate action in a volatile environment, the brain must frequently reassess the value of each action (action-value). Choice can be initially made from the experience of trial-and-errors, but once the dynamics of the environment is learned, the choice can be made from the knowledge of the environment. The action-values constructed from the experience (retrospective value) and the ones from the knowledge (prospective value) were identified in various regions of the brain. However, how and which neural circuit integrates these values and executes the chosen action remains unknown. Combining reinforcement learning and two-photon calcium imaging, we found that the preparatory activity of neurons in a part of the frontal cortex, the anterior-lateral motor (ALM) area, initially encodes retrospective value, but after extensive training, they jointly encode the retrospective and prospective value. Optogenetic inhibition of ALM preparatory activity specifically abolished the expert mice's predictive choice behavior and returned them to the novice-like state. Thus, the integrated action-value encoded in the preparatory activity of ALM plays an important role to bias the action toward the knowledge-dependent, predictive choice behavior.

Subtly encouraging more deliberate decisions: using a forcing technique and population stereotype to investigate free will.

Magicians' forcing techniques allow them to covertly influence spectators' choices. We used a type of force (Position Force) to investigate whether explicitly informing people that they are making a decision results in more deliberate decisions. The magician placed four face-down cards on the table in a horizontal row, after which the spectator was asked to select a card by pushing it forward. According to magicians and position effects literature, people should be more likely to choose a card in the third position from their left, because it can be easily reached. We manipulated whether participants were reminded that they were making a decision (explicit choice) or not (implicit choice) when asked to select one of the cards. Two experiments confirmed the efficiency of the Position Force-52% of participants chose the target card. Explicitly informing participants of the decision impairs the success of the force, leading to a more deliberate choice. A range of awareness measures illustrates that participants were unaware of their stereotypical behaviours. Participants who chose the target card significantly underestimated the number of people who would have chosen the same card, and felt as free as the participants who chose another card. Finally, we tested an embodied-cognition idea, but our data suggest that different ways of holding an object do not affect the level of self-control they have over their actions. Results are discussed in terms of theoretical implications regarding free will, Wegner's apparent mental causation, choice blindness and reachability effects.

Anterior Cingulate Cortex and the Control of Dynamic Behavior in Primates.

The brain mechanism for controlling continuous behavior in dynamic contexts must mediate action selection and learning across many timescales, responding differentially to the level of environmental uncertainty and volatility. In this review, we argue that a part of the frontal cortex known as the anterior cingulate cortex (ACC) is particularly well suited for this function. First, the ACC is interconnected with prefrontal, parietal, and subcortical regions involved in valuation and action selection. Second, the ACC integrates diverse, behaviorally relevant information across multiple timescales, producing output signals that temporally encapsulate decision and learning processes and encode high-dimensional information about the value and uncertainty of future outcomes and subsequent behaviors. Third, the ACC signals behaviorally relevant information flexibly, displaying the capacity to represent information about current and future states in a valence-, context-, task- and action-specific manner. Fourth, the ACC dynamically controls instrumental- and non-instrumental information seeking behaviors to resolve uncertainty about future outcomes. We review electrophysiological and circuit disruption studies in primates to develop this point, discuss its relationship to novel therapeutics for neuropsychiatric disorders in humans, and conclude by relating ongoing research in primates to studies of medial frontal cortical regions in rodents.

Antidepressant Effect of Blue Light on Depressive Phenotype in Light-Deprived Male Rats.

Blue light has been previously reported to play a salient role in the treatment of seasonal affective disorder. The present study aimed to investigate whether blue light had antidepressant effect on light-deprivation-induced depression model, and the underlying visual neural mechanism. Blue light mitigated depression-like behaviors induced by light deprivation as measured by elevated sucrose preference and reduced immobility time. Blue light enhanced melanopsin expression and light responses in the retina. We also found the upregulation of serotonin and brain derived neurotrophic factor expression in the c-fos-positive areas of rats treated with blue light compared with those maintained in darkness. The species gap between nocturnal albino (Sprague-Dawley rat) and diurnal pigmented animals (human) might have influenced extrapolating data to humans. Blue light has antidepressant effect on light-deprived Sprague-Dawley rats, which might be related to activating the serotonergic system and neurotrophic activity via the retinoraphe and retinoamygdala pathways. Blue light is the effective component of light therapy for treatment of depression.

Training negative connectivity patterns between the dorsolateral prefrontal cortex and amygdala through fMRI-based neurofeedback to target adolescent socially-avoidant behaviour.

Social anxiety is prevalent in adolescence. Given its role in maintaining fears, reducing social avoidance through cognitive reappraisal may help attenuate social anxiety. We used fMRI-based neurofeedback (NF) to increase 'adaptive' patterns of negative connectivity between the dorsolateral prefrontal cortex (DLPFC) and the amygdala to change reappraisal ability, and alter social avoidance and approach behaviours in adolescents. Twenty-seven female participants aged 13-17 years with varying social anxiety levels completed a fMRI-based NF training task where they practiced cognitive reappraisal strategies, whilst receiving real-time feedback of DLPFC-amygdala connectivity. All participants completed measures of cognitive reappraisal and social approach-avoidance behaviour before and after NF training. Avoidance of happy faces was associated with greater social anxiety pre-training. Participants who were unable to acquire a more negative pattern of connectivity through NF training displayed significantly greater avoidance of happy faces at post-training compared to pre-training. These 'maladaptive' participants also reported significant decreases in re-appraisal ability from pre to post-training. In contrast, those who were able to acquire a more 'adaptive' connectivity pattern did not show these changes in social avoidance and re-appraisal. Future research could consider using strategies to improve the capacity of NF training to boost youth social-approach behaviour.

Auditory information enhances post-sensory visual evidence during rapid multisensory decision-making.

Despite recent progress in understanding multisensory decision-making, a conclusive mechanistic account of how the brain translates the relevant evidence into a decision is lacking. Specifically, it remains unclear whether perceptual improvements during rapid multisensory decisions are best explained by sensory (i.e., 'Early') processing benefits or post-sensory (i.e., 'Late') changes in decision dynamics. Here, we employ a well-established visual object categorisation task in which early sensory and post-sensory decision evidence can be dissociated using multivariate pattern analysis of the electroencephalogram (EEG). We capitalize on these distinct neural components to identify when and how complementary auditory information influences the encoding of decision-relevant visual evidence in a multisensory context. We show that it is primarily the post-sensory, rather than the early sensory, EEG component amplitudes that are being amplified during rapid audiovisual decision-making. Using a neurally informed drift diffusion model we demonstrate that a multisensory behavioral improvement in accuracy arises from an enhanced quality of the relevant decision evidence, as captured by the post-sensory EEG component, consistent with the emergence of multisensory evidence in higher-order brain areas.

Interactions Between Motor Thalamic Field Potentials and Single-Unit Spiking Are Correlated With Behavior in Rats.

Field potential (FP) oscillations are believed to coordinate brain activity over large spatiotemporal scales, with specific features (e.g., phase and power) in discrete frequency bands correlated with motor output. Furthermore, complex correlations between oscillations in distinct frequency bands (phase-amplitude, amplitude-amplitude, and phase-phase coupling) are commonly observed. However, the mechanisms underlying FP-behavior correlations and cross-frequency coupling remain unknown. The thalamus plays a central role in generating many circuit-level neural oscillations, and single-unit activity in motor thalamus (Mthal) is correlated with behavioral output. We, therefore, hypothesized that motor thalamic spiking coordinates motor system FPs and underlies FP-behavior correlations. To investigate this possibility, we recorded wideband motor thalamic (Mthal) electrophysiology as healthy rats performed a two-alternative forced-choice task. Delta (1-4 Hz), beta (13-30 Hz), low gamma (30-70 Hz), and high gamma (70-200 Hz) power were strongly modulated by task performance. As in the cortex, the delta phase was correlated with beta/low gamma power and reaction time. Most interestingly, subpopulations of Mthal neurons defined by their relationship to the behavior exhibited distinct relationships with FP features. Specifically, neurons whose activity was correlated with action selection and movement speed were entrained to delta oscillations. Furthermore, changes in their activity anticipated power fluctuations in beta/low gamma bands. These complex relationships suggest mechanisms for commonly observed FP-FP and spike-FP correlations, as well as subcortical influences on motor output.

Black widows as plastic wallflowers: female choosiness increases with indicators of high mate availability in a natural population.

Female choice is an important driver of sexual selection, but can be costly, particularly when choosy females risk remaining unmated or experience delays to reproduction. Thus, females should reduce choosiness when mate encounter rates are low. We asked whether choosiness is affected by social context, which may provide reliable information about the local availability of mates. This has been demonstrated in the lab, but rarely under natural conditions. We studied western black widow spiders (Latrodectus hesperus) in the field, placing experimental final-instar immature females so they were either 'isolated' or 'clustered' near naturally occurring conspecifics (≥10 m or ≤1 m, respectively, from a microhabitat occupied by at least one other female). Upon maturity, females in both treatments were visited by similar numbers of males, but clustered females were visited by males earlier and in more rapid succession than isolated females, confirming that proximity to conspecifics reduces the risk of remaining unmated. As predicted, isolated females were less choosy in staged mating trials, neither rejecting males nor engaging in pre-copulatory cannibalism, in contrast to clustered females. These results demonstrate that exposure of females to natural variation in demography in the field can alter choosiness of adults. Thus, female behaviour in response to cues of local population density can affect the intensity of sexual selection on males in the wild.

Dissociation between wanting and liking for coffee in heavy drinkers.

BACKGROUND: There is an ongoing discussion about the addictive strength of caffeine. According to the incentive-sensitization theory, the development and the maintenance of drug addiction is the result of a selective sensitization of brain regions that are relevant for wanting without a corresponding increase in liking. Dissociations of wanting and liking have been observed with a wide range of drugs in animals. For human subjects, results are inconclusive, which is possibly due to invalid operationalizations of wanting and liking. AIM: The present study examined dissociations of wanting and liking for coffee in heavy and low/non-consumers with newly developed and validated response time-based assessment procedures for wanting and liking. METHODS: For this study 24 heavy and 32 low/non-consumers of coffee completed two versions of the Implicit-Association Test (IAT), one of which has been developed and validated recently to assess wanting for coffee, whereas the other reflects an indicator of liking for coffee. RESULTS: Results revealed a significant interaction between group (heavy vs. low/non-consumers) and IAT type (wanting vs. liking) indicating that heavy coffee drinkers differed from low/non-consumers by displaying increased wanting but not liking for coffee. INTERPRETATION: These data confirm that heavy coffee consumption is associated with strong wanting despite low liking for coffee, indicating that wanting becomes independent from liking through repeated consumption of caffeine. This dissociation provides a possible explanation for the widespread and stable consumption of caffeine-containing beverages.

Does Listening to Music Regulate Negative Affect in a Stressful Situation? Examining the Effects of Self-Selected and Researcher-Selected Music Using Both Silent and Active Controls.

BACKGROUND: Stress and anxiety are increasingly common among young people. The current research describes two studies comparing the effects of self-selected and researcher-selected music on induced negative affect (state anxiety and physiological arousal), and state mindfulness. METHOD: In Study 1, 70 undergraduates were randomly assigned to one of three conditions: researcher-selected music, self-selected music, or a silent control condition. In Study 2, with 75 undergraduates, effects of music were compared to an active control (listening to a radio show). Negative affect was induced using a speech preparation and arithmetic task, followed by music listening or control. Self-reported anxiety and blood pressure were measured at baseline, post-induction, and post-intervention. Study 2 included state mindfulness as a dependent measure. RESULTS: Study 1 indicated that participants who listened to music (self-selected and researcher-selected) reported significantly greater anxiety reduction than participants in the silent control condition. Music did not reduce anxiety compared to an active control in Study 2. However, music listening significantly increased levels of state mindfulness, which predicted lower anxiety after self-selected music listening. CONCLUSIONS: Music may provide regulation in preparation for stressful events. Yet, the results of Study 2 indicate that other activities have similar benefits, and shows, for the first time, that music listening increases mindfulness following a stressor.

Mice lacking neuronal calcium sensor-1 show social and cognitive deficits.

Neuronal calcium sensor-1 or Frequenin is a calcium sensor widely expressed in the nervous system, with roles in neurotransmission, neurite outgrowth, synaptic plasticity, learning, and motivated behaviours. Neuronal calcium sensor-1 has been implicated in neuropsychiatric disorders including autism spectrum disorder, schizophrenia, and bipolar disorder. However, the role of neuronal calcium sensor-1 in behavioural phenotypes and brain changes relevant to autism spectrum disorder have not been evaluated. We show that neuronal calcium sensor-1 deletion in the mouse leads to a mild deficit in social approach and impaired displaced object recognition without affecting social interactions, behavioural flexibility, spatial reference memory, anxiety-like behaviour, or sensorimotor gating. Morphologically, neuronal calcium sensor-1 deletion leads to increased dendritic arbour complexity in the frontal cortex. At the level of hippocampal synaptic plasticity, neuronal calcium sensor-1 deletion leads to a reduction in long-term potentiation in the dentate gyrus, but not area Cornu Ammonis 1. Metabotropic glutamate receptor-induced long-term depression was unaffected in both dentate and Cornu Ammonis 1. These studies identify roles for neuronal calcium sensor-1 in specific subregions of the brain including a phenotype relevant to neuropsychiatric disorders.

Overstepping the boundaries of free choice: Folk beliefs on free will and determinism in real world contexts.

We know little about the commonality of folk beliefs around applications of psychological research on the unconscious control of behaviours. To address this, in Experiment 1 (N = 399) participants volunteered examples of where research on the unconscious has been applied to influence their behaviours. A subset of these were presented in Experiment 2 (N = 198) and Experiment 3 (N = 100). Participants rated the extent to which the behaviour being influenced in these contexts was: (1) via the unconscious, (2) free, (3) the result of prior conscious intentions, (4) under conscious control. Relative to judgements about the extent to which behaviour was influenced via the unconscious, the remaining judgements regarding conscious control of behaviours were either higher (e.g., political contexts) or lower (e.g., therapy). This study is the first to show, using ecologically valid examples, the folk beliefs people share on psychological constructs concerning free will and determinism.

Thirst regulates motivated behavior through modulation of brainwide neural population dynamics.

Physiological needs produce motivational drives, such as thirst and hunger, that regulate behaviors essential to survival. Hypothalamic neurons sense these needs and must coordinate relevant brainwide neuronal activity to produce the appropriate behavior. We studied dynamics from ~24,000 neurons in 34 brain regions during thirst-motivated choice behavior in 21 mice as they consumed water and became sated. Water-predicting sensory cues elicited activity that rapidly spread throughout the brain of thirsty animals. These dynamics were gated by a brainwide mode of population activity that encoded motivational state. After satiation, focal optogenetic activation of hypothalamic thirst-sensing neurons returned global activity to the pre-satiation state. Thus, motivational states specify initial conditions that determine how a brainwide dynamical system transforms sensory input into behavioral output.

Short-Term Influence of Recent Trial History on Perceptual Choice Changes with Stimulus Strength.

Perceptual decisions, especially for difficult stimuli, can be influenced by choices and outcomes in previous trials. However, it is not well understood how stimulus strength modulates the temporal characteristics as well as the magnitude of trial history influence. We addressed this question using a contrast detection task in freely moving mice. We found that, at lower as compared to higher stimulus contrast, the current choice of the mice was more influenced by choices and outcomes in the past trials and the influence emerged from a longer history. To examine the neural basis of stimulus strength-dependent history influence, we recorded from the secondary motor cortex (M2), a prefrontal region that plays an important role in cue-guided actions and memory-guided behaviors. We found that more M2 neurons conveyed information about choices on the past two trials at lower than at higher contrast. Furthermore, history-trial activity in M2 was important for decoding upcoming choice at low contrast. Thus, trial history influence of perceptual choice is adaptive to the strength of sensory evidence, which may be important for action selection in a dynamic environment.

Increased motor impulsivity in a rat gambling task during chronic ropinirole treatment: potentiation by win-paired audiovisual cues.

RATIONALE: Chronic administration of D2/3 receptor agonists ropinirole or pramipexole can increase the choice of uncertain rewards in rats, theoretically approximating iatrogenic gambling disorder (iGD). OBJECTIVES: We aimed to assess the effect of chronic ropinirole in animal models that attempt to capture critical aspects of commercial gambling, including the risk of losing rather than failing to gain, and the use of win-paired sensory stimuli heavily featured in electronic gambling machines (EGMs). METHODS: Male Long-Evans rats learned the rat gambling task (rGT; n = 24), in which animals sample between four options that differ in the magnitude and probability of rewards and time-out punishments. In the cued rGT (n = 40), reward-concurrent audiovisual cues were added that scaled in complexity with win size. Rats were then implanted with an osmotic pump delivering ropinirole (5 mg/kg/day) or saline for 28 days. RESULTS: Chronic ropinirole did not unequivocally increase preference for more uncertain outcomes in either the cued or uncued rGT. Ropinirole transiently increased premature responses, a measure of motor impulsivity, and this change was larger and more long-lasting in the cued task. CONCLUSIONS: These data suggest that explicitly signaling loss prevents the increase in preference for uncertain rewards caused by D2/3 receptor agonists observed previously. The ability of win-paired cues to amplify ropinirole-induced increases in motor impulsivity may explain why compulsive use of EGMs is particularly common in iGD. These data offer valuable insight into the cognitive-behavioral mechanisms through which chronic dopamine agonist treatments may induce iGD and related impulse control disorders.

Contingent negative variation and P3 modulations following mindful movement training.

In the study of the electrophysiological correlates of attention, a phasic change in alertness has been classically related to a negative frontal-central shift called Contingent Negative Variation (CNV). Studies investigating the effects of meditation on the CNV in participants reporting frequent transcendental experiences (TE) reported reduced CNV in choice reaction time task (CRT), and increased CNV in simple reaction time task (SRT), suggesting that meditation can induce a more balanced attentional state. In the current study, we tested whether a similar effect could be obtained in healthy non-meditators using a single session of a specifically structured sensorimotor training (Quadrato Motor Training-QMT). In addition, in contrast to previous studies, we further examined the P3 component, reflecting cognitive load and novelty detection. We found that similar to previous studies, following a QMT session, CNV amplitude reduced in CRT and increased in SRT. Conversely, the P3 amplitude increased in CRT and decreased in SRT. Taken together, these results support the idea that QMT has attentional benefits in normal healthy participants, similar to those observed in experienced meditators.

Short-term mindful breath awareness training improves inhibitory control and response monitoring.

Mindfulness meditation is thought to lead to positive changes in cognitive and affective functioning. However, the mechanisms underlying these changes are not well understood. One reason for this is that so far only very few studies considered the effects of specific meditation practices. We thus investigated the effects of engaging in one specific form of mindfulness meditation for a brief time period on behavioral and neural indicators of inhibitory control and metacognition. Performance on the Go/No-Go task and concurrent neural activity (EEG) was assessed before and after participants engaged in 3 weeks of mindful breath awareness meditation. Compared to a waitlist control group, meditation training enhanced the N2 event-related potential in No-Go trials and the error-related negativity (ERN) after error responses. As these two components reflect conflict and response monitoring, respectively, our results support the notion that mindfulness meditation improves metacognitive processes. The changes in the ERN were correlated with the accumulated amount of meditation time, highlighting the importance of meditation practice. Furthermore, meditation improved a behavioral marker of impulsive responding, indicating the relevance of mindfulness-based approaches for supporting health-related behaviors that are associated with deficits in impulsive control, such as substance abuse or over-eating. This study demonstrated that investigating one particular meditation practice rather than complex mindfulness-based interventions can contribute to a deeper understanding of mindfulness meditation mechanisms.

Enhanced Population Coding for Rewarded Choices in the Medial Frontal Cortex of the Mouse.

Instrumental behavior is characterized by the selection of actions based on the degree to which they lead to a desired outcome. However, we lack a detailed understanding of how rewarded actions are reinforced and preferentially implemented. In rodents, the medial frontal cortex is hypothesized to play an important role in this process, based in part on its capacity to encode chosen actions and their outcomes. We therefore asked how neural representations of choice and outcome might interact to facilitate instrumental behavior. To investigate this question, we imaged neural ensemble activity in layer 2/3 of the secondary motor region (M2) while mice engaged in a two-choice auditory discrimination task with probabilistic outcomes. Correct choices could result in one of three reward amounts (single, double or omitted reward), which allowed us to measure neural and behavioral effects of reward magnitude, as well as its categorical presence or absence. Single-unit and population decoding analyses revealed a consistent influence of outcome on choice signals in M2. Specifically, rewarded choices were more robustly encoded relative to unrewarded choices, with little dependence on the exact magnitude of reinforcement. Our results provide insight into the integration of past choices and outcomes in the rodent brain during instrumental behavior.

Differential coactivation in a redundant signals task with weak and strong go/no-go stimuli.

When participants respond to stimuli of two sources, response times (RTs) are often faster when both stimuli are presented together relative to the RTs obtained when presented separately (redundant signals effect [RSE]). Race models and coactivation models can explain the RSE. In race models, separate channels process the two stimulus components, and the faster processing time determines the overall RT. In audiovisual experiments, the RSE is often higher than predicted by race models, and coactivation models have been proposed that assume integrated processing of the two stimuli. Where does coactivation occur? We implemented a go/no-go task with randomly intermixed weak and strong auditory, visual, and audiovisual stimuli. In one experimental session, participants had to respond to strong stimuli and withhold their response to weak stimuli. In the other session, these roles were reversed. Interestingly, coactivation was only observed in the experimental session in which participants had to respond to strong stimuli. If weak stimuli served as targets, results were widely consistent with the race model prediction. The pattern of results contradicts the inverse effectiveness law. We present two models that explain the result in terms of absolute and relative thresholds.

Psychoacoustic measurements of ipsilateral cochlear gain reduction as a function of signal frequency.

Forward masking experiments at 4 kHz have demonstrated that preceding sound can elicit changes in masking patterns consistent with a change in cochlear gain. However, the acoustic environment is filled with complex sounds, often dominated by lower frequencies, and ipsilateral cochlear gain reduction at frequencies below 4 kHz is largely unstudied in the forward masking literature. In this experiment, the magnitude of ipsilateral cochlear gain reduction was explored at 1, 2, and 4 kHz using forward masking techniques in an effort to evaluate a range of frequencies in listeners with normal hearing. Gain reduction estimates were not significantly different at 2 and 4 kHz using two forward masking measurements. Although the frequency was a significant factor in the analysis, post hoc testing supported the interpretation that gain reduction estimates measured without a masker were not significantly different at 1, 2, and 4 kHz. A second experiment provided evidence that forward masking in this paradigm at 1 kHz cannot be explained by excitation alone. This study provides evidence of ipsilateral cochlear gain reduction in humans at frequencies below the 4 kHz region.