Impact of online poker gambling on behavioural and neurophysiological responses to a virtual gambling task.

Online poker gambling (OPG) involves various executive control processes and emotion regulation. In this context, we hypothesized that online poker players, accustomed to handling virtual cards, would show high performance on computerized decision-making tasks such as the Iowa Gambling Task (IGT). Using press advertisements, we recruited a non-gambler group (NG; n = 20) and an OPG group (n = 22). All participants performed the IGT while their cerebral activity was recorded by electroencephalography. Compared with the OPG group, the NG group showed significantly better progression in the IGT in the last trials. Recording of brain activity revealed the appearance of a temporal map between 150 and 175 ms specific to the gain condition in both groups. A second map was observed at 215-295 ms specifically in the NG group, and the generators were identified in the occipital regions. This activity is indicative of a high level of visual awareness; thus, it reflects additional processing of visual information, which can be assumed to be induced by the lower exposure of the NGs to online card games. We hypothesize that the absence of this activity in the OPG group might be due to their online habituation to virtual environments.

Don't forget the lyrics! Spatiotemporal dynamics of neural mechanisms spontaneously evoked by gaps of silence in familiar and newly learned songs.

The vast majority of people experience musical imagery, the sensation of reliving a song in absence of any external stimulation. Internal perception of a song can be deliberate and effortful, but also may occur involuntarily and spontaneously. Moreover, musical imagery is also involuntarily used for automatically completing missing parts of music or lyrics from a familiar song. The aim of our study was to explore the onset of musical imagery dynamics that leads to the automatic completion of missing lyrics. High-density electroencephalography was used to record the cerebral activity of twenty healthy volunteers while they were passively listening to unfamiliar songs, very familiar songs, and songs previously listened to for two weeks. Silent gaps inserted into these songs elicited a series of neural activations encompassing perceptual, attentional and cognitive mechanisms (range 100-500ms). Familiarity and learning effects emerged as early as 100ms and lasted 400ms after silence occurred. Although participants reported more easily mentally imagining lyrics in familiar rather than passively learnt songs, the onset of neural mechanisms and the power spectrum underlying musical imagery were similar for both types of songs. This study offers new insights into the musical imagery dynamics evoked by gaps of silence and on the role of familiarity and learning processes in the generation of these dynamics. The automatic and effortless method presented here is a potentially useful tool to understand failure in the familiarity and learning processes of pathological populations.

Left Prefrontal Repetitive Transcranial Magnetic Stimulation in a Logopenic Variant of Primary Progressive Aphasia: A Case Report.

BACKGROUND/AIMS: High frequency repetitive transcranial magnetic stimulation (hf-rTMS) improves language skills in Alzheimer's disease (AD). We report the use of hf-rTMS in a patient with logopenic primary progressive aphasia (LPPA) due to AD. METHOD: hf-rTMS was applied to the left dorsolateral prefrontal cortex of a LPPA patient. Cerebral perfusion, neuropsychological and linguistic performances were evaluated before and 1 month after hf-rTMS. RESULTS: The tolerance was good. Improvements on linguistic (fluency, naming, lesser paraphasia) and cognitive skills (Mini Mental State Examination, verbal memory free recall, speed processing) and cerebral perfusion were observed. CONCLUSION: hf-rTMS can be used in LPPA patients. A procognitive effect persisting several weeks after stimulation in LPPA patients was suggested and should therefore be evaluated in a clinical trial as an adjunctive therapeutic tool.

Visual scanning behavior during processing of emotional faces in older adults with major depression.

OBJECTIVES: Although several reported studies have suggested that younger adults with depression display depression-related biases during the processing of emotional faces, there remains a lack of data concerning these biases in older adults. The aim of our study was to assess scanning behavior during the processing of emotional faces in depressed older adults. METHOD: Older adults with and without depression viewed happy, neutral or sad portraits during an eye movement recording. RESULTS: Depressed older adults spent less time with fewer fixations on emotional features than healthy older adults, but only for sad and neutral portraits, with no significant difference for happy portraits. CONCLUSION: These results suggest disengagement from sad and neutral faces in depressed older adults, which is not consistent with standard theoretical proposals on congruence biases in depression. Also, aging and associated emotional regulation change may explain the expression of depression-related biases. Our preliminary results suggest that information processing in depression consists of a more complex phenomenon than merely a general searching for mood-congruent stimuli or general disengagement from all kinds of stimuli. These findings underline that care must be used when evaluating potential variables, such as aging, which interact with depression and selectively influence the choice of relevant stimulus dimensions.

Acute effect of transcranial direct current stimulation (tDCS) on postural control of trained athletes: A randomized controlled trial.

Transcranial direct current stimulation (tDCS) is used to modulate brain function, and can modulate motor and postural control. While the acute effect of tDCS is well documented on patients, little is still known whether tDCS can alter the motor control of healthy trained participants. This study aimed to assess the acute effect of tDCS on postural control of parkour practitioners, known for their good balance abilities and their neuromuscular specificities that make them good candidates for tDCS intervention. Eighteen parkour practitioners were tested on three occasions in the laboratory for each stimulation condition (2 mA; 20 minutes)-primary motor cortex (M1), dorsolateral prefrontal cortex (dlPFC) and sham (placebo). Postural control was evaluated PRE and POST each stimulation by measuring Center of Pressure (CoP) displacements on a force platform during static conditions (bipedal and unipedal stance). Following M1 stimulation, significant decreases were observed in CoP area in unipedal (from 607.1 ± 297.9 mm2 to 451.1 ± 173.9 mm2, P = 0.003) and bipedal (from 157.5 ± 74.1 mm2 to 117.6 ± 59.8 mm2 P<0.001) stances. As well, the CoP total length was significantly reduced in bipedal (from 3416.8 ± 295.4 mm to 3280.6 ± 306.2 mm, P = 0.005) as well as in unipedal stance (from 4259.6 ± 398.4 mm to 3846.5 ± 468.9 mm, P<0.001), only after M1 stimulation. Relative pre-post changes observed after M1 stimulation were negatively correlated to experience in parkour only after unipedal stance (r = 0.715, P<0.001), meaning that the more participants were trained the less tDCS was effective. No significant changes were noticed after sham and dlPFC stimulation. These results suggested that the modulation of gait performance in athletes following an acute intervention of tDCS is specific to the targeted brain region, and that postures with reduced base of support (such as unipedal stance) were more sensitive to tDCS.

Efficacy of the my health too online cognitive behavioral therapy program for healthcare workers during the COVID-19 pandemic: A randomized controlled trial.

Background: Healthcare workers' mental health has been impacted by the COVID-19 pandemic, emphasizing the need for mental health interventions in this population. Online cognitive behavioral therapy (CBT) is efficient to reduce stress and may reach numerous professionals. We developed "MyHealthToo", an online CBT program to help reduce stress among healthcare workers during the COVID-19 pandemic. Objective: The aim of our study is to investigate the efficacy of an online CBT program on stress and mental health conditions among healthcare workers during a health crisis. Methods: We performed a multicentric randomized controlled trial among 155 participants allocated either to the experimental or active control group (bibliotherapy). The primary outcome was the decrease of perceived stress scores (PSS-10) post-treatment. Secondary outcomes included depression, insomnia and PTSD symptoms along with self-reported resilience and ruminations. Assessments were scheduled pretreatment, mid-treatment (4 weeks), post-treatment (8 weeks), and at 1-month and 4-months follow-up. Results: For both interventions, mean changes on the PSS-10 were significant post-therapy (W8), as at 1-month (W12) and 4-months (W24) follow-ups. The between-group comparison showed no difference at any time point (ps > 0.88). Work-related ruminations significantly decreased in the experimental group with a significant between-group difference at W8 (Δ = -1.83 [-3.57; -0.09], p = 0.04). Posttraumatic stress symptoms significantly decreased in the experimental group with a significant between-group difference at W12 (Δ = -1.41 [-2.68; -0.14], p = 0.03). The decrease in work-related ruminations at W8 mediated the decrease in posttraumatic stress symptoms at W12 (p = 0.048). Conclusion: The "MyHealthToo" online CBT intervention may help reduce ruminations about work and posttraumatic stress symptoms among healthcare workers during a major health crisis. Work-related ruminations may represent a relevant target of online interventions to improve mental health among healthcare workers.

Resting motor threshold changes and clinical response to prefrontal repetitive transcranial magnetic stimulation in depressed patients.

AIMS: Several variables are able to influence the antidepressant effects of repetitive transcranial magnetic stimulation (rTMS), particularly the intensity of stimulation, which is generally expressed according to the resting motor threshold (RMT). The aim of our study was to investigate whether or not RMT changes during the treatment of resistant depression by rTMS and whether these fluctuations could alter treatment outcome. METHODS: Seventy-five inpatients suffering from unipolar or bipolar treatment-resistant depression and who had been antidepressant-free or taking a stable antidepressant drug and a daily dose of benzodiazepine for at least a month received a left prefrontal rTMS session once a day for 10 days at 10 Hz and 95% RMT. RESULTS: For the whole group, no significant fluctuation of RMT was observed between the first and the second week of rTMS treatment. However, RMT increased, decreased or remained constant throughout treatment depending on the patient. These RMT changes influenced the outcome of the 10 sessions concerning the severity of depressive and anxiety symptoms, measured by the Beck Depression Inventory and State Trait Anxiety, respectively. CONCLUSIONS: Our results justify calculating RMT regularly, and suggest that its variations play a role in treatment outcome.

Predictors of Gaming Disorder or Protective from It, in a French Sample: A Symptomatic Approach to Self-Regulation and Pursued Rewards, Providing Insights for Clinical Practice.

Gaming disorder (GD) is a new health condition still requiring a lot of evidence established around its underlying and related psychological mechanisms. In our study we focused on Massively Multiplayer Online Role Playing Games (MMORPGs), a specific very popular and engaging game genre, to determine that benefit, motivation and control aspects could be predictive of a dysfunctional engagement in gaming. In total, 313 participants were recruited from private forums of gamers between May 2009 and March 2010. They filled out a questionnaire on their socio-demographic data and their weekly gaming time. They also completed different psychometric assessments such as the DSM IV-TR criteria for substance dependence adapted to gaming such as the Dependence Adapted Scale (DAS), the external rewards they expected from gaming (External Motives), the expected internal reward they expected from gaming (Internal Motives), the Zuckerman Sensation Seeking Scale (ZSSS), and the Barratt impulsiveness Scale (BIS-10). Results showed that some psychological factors related to online gaming represented risk factors for GD in participants (i.e., competition and advancement motives, reduced anxiety, solace, greater personal satisfaction, and sense of power), whereas some others were found to be protective factors from GD (i.e., recreation, enjoyment and experience seeking) in participants. Additionally, the study found that disinhibition, boredom susceptibility, thrill and adventure seeking, and high impulsivity were correlated to GD in participants. In conclusion, not only motives for gaming and impulsivity could be predictors for GD, but maladaptive coping strategies based on experienced relief in-game from negative feelings (anxiety and boredom) or experienced improvement in-game of self-perception (personal satisfaction, sense of power) could play as well a role of negative reinforcers for GD. Some benefits from gaming, typically entertainment and enjoyment, are shown to be protective factors from GD, playing the role of positive reinforcing factors. They are worthy of being identified and promoted as functional gaming habits. These findings can feed the clinical and health promotion fields, with a more in-depth understanding of diverse psychological factors in gamers, identifying those at risk for GD and those protective from it. The current work can foster a more balanced approach towards gaming activities, taking their opportunities for mankind and controlling for their adverse effects in some individuals.

Do Individuals with Internet Gaming Disorder Share Personality Traits with Substance-Dependent Individuals?

(1) Background: Internet gaming disorder (IGD) shares many similarities with substance use disorder (SUD), contributing to its recognition as an addictive disorder. Nevertheless, no study has compared IGD to other addictive disorders in terms of personality traits established as highly co-occurring with SUDs. (2) Methods: We recruited a sample of gamers (massively multiplayer online role-playing games) (MMORPGs) via online in-game forums. We compared 83 individuals with IGD (MMORPG-IGD group) to 47 former heroin addicts under methadone maintenance treatment (MMT; MMT group) with regard to alexithymia, impulsivity, sensation seeking and aggressiveness assessed through self-administered scales, being TAS-20, BIS-10, Z-SSS and BDHI, respectively. (3) Results: Our results draw a relatively similar personality profile between groups but indicate that the subject traits are generally more pronounced in the MMT cohort. The overall lesser intensity of these traits in the MMORPG-IGD group might reflect the greater variability in the severity of the IGD. (4) Conclusions: IGD shares personality traits with MMT, and intensity may be influenced by the severity of the addiction or by certain direct environmental factors, and might also influence the propensity towards one behavior rather than another.

Massively multiplayer online role-playing games: comparing characteristics of addict vs non-addict online recruited gamers in a French adult population.

BACKGROUND: Massively Multiplayer Online Role-Playing Games (MMORPGs) are a very popular and enjoyable leisure activity, and there is a lack of international validated instruments to assess excessive gaming. With the growing number of gamers worldwide, adverse effects (isolation, hospitalizations, excessive use, etc.) are observed in a minority of gamers, which is a concern for society and for the scientific community. In the present study, we focused on screening gamers at potential risk of MMORPG addiction. METHODS: In this exploratory study, we focused on characteristics, online habits and problematic overuse in adult MMORPG gamers. In addition to socio-demographical data and gamer behavioral patterns, 3 different instruments for screening addiction were used in French MMORPG gamers recruited online over 10 consecutive months: the substance dependence criteria for the Diagnostic and Statistical Manual of Mental Disorder, fourth revised edition (DSM-IV-TR) that has been adapted for MMORPG (DAS), the qualitative Goldberg Internet Addiction Disorder scale (GIAD) and the quantitative Orman Internet Stress Scale (ISS). For all scales, a score above a specific threshold defined positivity. RESULTS: The 448 participating adult gamers were mainly young adult university graduates living alone in urban areas. Participants showed high rates of both Internet addiction (44.2% for GIAD, 32.6% for ISS) and DAS positivity (27.5%). Compared to the DAS negative group, DAS positive gamers reported significantly higher rates of tolerance phenomenon (increased amount of time in online gaming to obtain the desired effect) and declared significantly more social, financial (OR: 4.85), marital (OR: 4.61), family (OR: 4.69) and/or professional difficulties (OR: 4.42) since they started online gaming. Furthermore, these gamers self-reported significantly higher rates (3 times more) of irritability, daytime sleepiness, sleep deprivation due to play, low mood and emotional changes since online gaming onset. CONCLUSIONS: The DAS appeared to be a good first-line instrument to screen MMORPG addiction in online gamers. This study found high MMORPG addiction rates, and self-reported adverse symptoms in important aspects of life, including mood and sleep. This confirms the need to set up relevant prevention programs against online game overuse.

Towards a Functional Neuromarker of Impulsivity: Feedback-Related Brain Potential during Risky Decision-Making Associated with Self-Reported Impulsivity in a Non-Clinical Sample.

Risk-taking is part of the multidimensional nature of impulsivity, consisting of an active engagement in behaviors or choices with potentially undesirable results, with probability as the cost for an expected reward. In order to understand the neurophysiological activity during risky behavior and its relationship with other dimensions of impulsivity, we have acquired event-related-potential (ERP) data and self-reported impulsivity scores from 17 non-clinical volunteers. They underwent high-resolution electroencephalography (HR-EEG) combined with an adapted version of the Balloon Analogue Risk Task (BART), and completed the Barratt Impulsiveness Scale (BIS-10) and the Urgency, Premeditation, Perseverance, Sensation Seeking, Impulsive Behavior Scale (UPPS). The ERP components were sensitive to valence (FRN, P300) and risk/reward magnitude (SPN, RewP). Our main finding evidenced a positive correlation between the amplitude of the P300 component following positive feedback and both the global UPPS score and the (lack of) perseverance UPPS subscale, significant for several adjacent electrodes. This finding might suggest an adaptive form of impulsive behavior, which could be associated to the reduction on the difference of the P300 amplitude following negative and positive feedback. However, further investigation with both larger clinical and non-clinical samples is required.

Effect of transcranial direct current stimulation on the psychomotor, cognitive, and motor performances of power athletes.

In sports science, transcranial direct current stimulation (tDCS) has many unknown effects on neuromuscular, psychomotor and cognitive aspects. Particularly, its impact on power performances remains poorly investigated. Eighteen healthy young males, all trained in a jumping sport (parkour) performed three experimental sessions: anodal tDCS applied either on the left dorsolateral prefrontal cortex (dlPFC, cathode in supraorbital area) or on the primary motor cortex (M1, cathode on contralateral shoulder), and a placebo condition (SHAM), each applied for 20 min at 2 mA. Pre and post, maximal vertical and horizontal jumps were performed, associated to leg neuromuscular assessment through electromyography and peripheral nerve stimulations. Actual and imagined pointing tasks were also performed to evaluate fine motor skills, and a full battery of cognitive and psychomotor tests was administered. M1 tDCS improved jump performance accompanied by an increase in supraspinal and spinal excitabilities. dlPFC stimulation only impacted the pointing tasks. No effect on cognitive tests was found for any of the tDCS conditions. To conclude, the type of performance (maximal versus accurate) affected depended upon the tDCS montage. Finally, athletes responded well to tDCS for motor performance while results to cognitive tests seemed unaffected, at least when implemented with the present rationale.

Repetitive Transcranial Magnetic Stimulation as an Add-On Treatment for Cognitive Impairment in Alzheimer's Disease and Its Impact on Self-Rated Quality of Life and Caregiver's Burden.

Alzheimer's disease (AD) is associated with progressive memory loss and decline in executive functions, as well as neuropsychiatric symptoms. Patients usually consider quality of life (QoL) and mood as more important for their health status than disease-specific physical and mental symptoms. In this open-label uncontrolled trial, 12 subjects diagnosed with AD underwent 10 sessions of repetitive transcranial magnetic stimulation (rTMS) over the left dorsolateral prefrontal cortex (10 Hz, 20 min, 2000 pulses/day, 110% MT). Outcomes were measured before and 30 days after treatment. Our primary objective was to test the efficacy of rTMS as an add-on treatment for AD on the global cognitive function, assessed through the Mini-Mental State Examination (MMSE) and the Mattis Dementia Rating Scale (MDRS). As secondary objectives, the detailed effect on cognitive functions, depression and anxiety symptoms, QoL, and functionality in daily life activities were evaluated, as well as correlations between QoL and cognition, depression and anxiety scores. The treatment significantly enhanced semantic memory and reduced anxiety. Improvement of these features in AD could become an important target for treatment strategies. Although limited by its design, this trial may contribute with another perspective on the analysis and the impact of rTMS on AD.

Spatiotemporal activation of caspase-dependent and -independent pathways in staurosporine-induced apoptosis of p53wt and p53mt human cervical carcinoma cells.

BACKGROUND INFORMATION: Caspase-dependent and -independent death mechanisms are involved in apoptosis in a variety of human carcinoma cells treated with antineoplastic compounds. Our laboratory has reported that p53 is a key contributor of mitochondrial apoptosis in cervical carcinoma cells after staurosporine exposure. However, higher mitochondrial membrane potential dissipation and greater DNA fragmentation were observed in p53wt (wild-type p53) HeLa cells compared with p53mt (mutated p53) C-33A cells. Here, we have studied events linked to the mitochondrial apoptotic pathway. RESULTS: Staurosporine can induce death of HeLa cells via a cytochrome c/caspase-9/caspase-3 mitochondrial-dependent apoptotic pathway and via a delayed caspase-independent pathway. In contrast with p53wt cells, p53mt C-33A cells exhibit firstly caspase-8 activation leading to caspase-3 activation and Bid cleavage followed by cytochrome c release. Attenuation of PARP-1 [poly(ADP-ribose) polymerase-1] cleavage as well as oligonucleosomal DNA fragmentation in the presence of z-VAD-fmk points toward a major involvement of a caspase-dependent pathway in staurosporine-induced apoptosis in p53wt HeLa cells, which is not the case in p53mt C-33A cells. Meanwhile, the use of 3-aminobenzamide, a PARP-1 inhibitor known to prevent AIF (apoptosis-inducing factor) release, significantly decreases staurosporine-induced death in these p53mt carcinoma cells, suggesting a preferential implication of caspase-independent apoptosis. On the other hand, we show that p53, whose activity is modulated by pifithrin-alpha, isolated as a suppressor of p53-mediated transactivation, or by PRIMA-1 (p53 reactivation and induction of massive apoptosis), that reactivates mutant p53, causes cytochrome c release as well as mitochondrio-nuclear AIF translocation in staurosporine-induced apoptosis of cervical carcinoma cells. CONCLUSIONS: The present paper highlights that staurosporine engages the intrinsic mitochondrial apoptotic pathway via caspase-8 or caspase-9 signalling cascades and via caspase-independent cell death, as well as through p53 activity.

Effect of transcranial direct current stimulation on sports performance for two profiles of athletes (power and endurance) (COMPETE): a protocol for a randomised, crossover, double blind, controlled exploratory trial.

BACKGROUND: Transcranial direct current stimulation (tDCS) is promising for improving motor and cognitive performance. Nevertheless, its mechanisms of action are unclear and need to be better characterised according to the stimulated brain area and the type of exercise performed. METHODS/DESIGN: This is a double-blind crossover study, organised into two parts: the first is to assess the effects of tDCS on explosive performance (jump task) and the second is to assess the effects on endurance performance (cycling time trial task). Participants, who are recreationally active or athletes (parkour practitioners, cyclists), will receive two active tDCS sessions (over the left dorsolateral prefrontal cortex and right motor cortex) and one sham tDCS session (part A), or two sequences (one active and one sham) of two daily tDCS sessions over 5 days (part B). Motor and cognitive performance will be compared before and after tDCS sessions (part A), and before and after the first session, after the last session and at day 12 and day 30 of each tDCS sequence (part B). DISCUSSION: This study investigates the acute and repeated effects of tDCS on the motor and cognitive performance of healthy subjects. It will try to evaluate if tDCS could be considered as a neuroenhancement technology according to the physical task investigated (endurance versus explosive). TRIAL REGISTRATION: ClinicalTrials.gov, NCT03937115. Registered on 3 May 2019; retrospectively registered.

Can transcranial direct current stimulation (tDCS) improve impulsivity in healthy and psychiatric adult populations? A systematic review.

Impulsivity is a multidimensional phenomenon that remains hard to define. It compounds the core pathological construct of many neuropsychiatric illnesses, and despite its close relation to suicide risk, it currently has no specific treatment. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique whose application results in cognitive function improvement, both in healthy and psychiatric populations. Following PRISMA recommendations, a systematic review of the literature concerning tDCS's effects on impulsive behaviour was performed using the PubMed database. The research was based on the combination of the keyword 'tDCS' with 'impulsivity', 'response inhibition', 'risk-taking', 'planning', 'delay discounting' or 'craving'. The initial search yielded 309 articles, 92 of which were included. Seventy-four papers demonstrated improvement in task performance related to impulsivity in both healthy and clinical adult populations. However, results were often inconsistent. The conditions associated with improvement, such as tDCS parameters and other aspects that may influence tDCS's outcomes, are discussed. The overall effects of tDCS on impulsivity are promising. Yet further research is required to develop a more comprehensive understanding of impulsivity, allowing for a more accurate assessment of its behavioural outcomes as well as a definition of tDCS therapeutic protocols for impulsive disorders.

Event-Related Potentials (ERP) Indices of Motivation during the Effort Expenditure for Reward Task.

Dynamic and temporal facets of the various constructs that comprise motivation remain to be explored. Here, we adapted the Effort Expenditure for Reward Task, a well-known laboratory task used to evaluate motivation, to study the event-related potentials associated with reward processing. The Stimulus Preceding Negativity (SPN) and the P300 were utilized as motivation indicators with high density electroencephalography. The SPN was found to be more negative for difficult choices compared to easy choices, suggesting a greater level of motivation, at a neurophysiological level. The insula, a structure previously associated with both effort discounting and prediction error, was concomitantly activated during the generation of the SPN. Processing a gain significantly altered the amplitude of the P300 compared to an absence of gain, particularly on centroparietal electrodes. One of the generators of the P300 was located on the vmPFC, a cerebral structure involved in the choice between two positive results and their predictions, during loss processing. Both the SPN and the P300 appear to be reliable neural markers of motivation. We postulate that the SPN represents the strength of the motivational level, while the P300 represents the impact of motivation on updating memories of the feedback.

Behavioral and Neural Arguments of Motivational Influence on Decision Making During Uncertainty.

The scientific world is increasingly interested in motivation, primarily due to the suspected impact on decision-making abilities, particularly in uncertain conditions. To explore this plausible relationship, 28 healthy participants were included in the study and performed decision-making and motivational tasks while their neural activity was recorded. All participants performed the Iowa Gambling Task (IGT) and were split into two groups based on their score, one favorable group with 14 participants who performed advantageously and one undecided group with 14 participants who failed to develop the correct strategy on the IGT. In addition, all participants performed the Effort Expenditure for Reward Task (EEfRT), which defines the motivational level of each participant by the effort that participants agree to do in function of reward magnitudes and probabilities to receive these reward (10, 50, and 90%). The completion of both tasks allowed for the exploration of the relationship between the motivational level and decision-making abilities. The EEfRT was adapted to electroencephalography (EEG) recordings to explore how motivation could influence reward experience. Behavioral results showed no difference in EEfRT performances on the whole task between the two groups' performances on the IGT. However, there was a negative correlation between the difficulty to develop an optimal strategy on the IGT and the percentage of difficult choices at the 90% condition on the EEfRT. Each probability condition has been previously associated to different motivational and emotional states, with the 90% condition associated to the reward sensitivity. This behavioral result leads to the hypothesis that reward sensitivity may induce an inability to develop an optimal strategy on the IGT. Group analysis demonstrated that only the undecided group showed a P300 during the processing of the outcome, whereas the favorable group showed a blunted P300. Similarly, there was a negative correlation between the P300 amplitude and the ability to develop an optimal strategy on the IGT. In conclusion, behavioral and neuronal data provides evidence that the propensity to focus only on the immediate outcomes is related to the development of an inefficient strategy on the IGT, without influence of motivation.

Modelling decision-making under uncertainty: A direct comparison study between human and mouse gambling data.

Decision-making is a conserved evolutionary process enabling us to choose one option among several alternatives, and relies on reward and cognitive control systems. The Iowa Gambling Task allows the assessment of human decision-making under uncertainty by presenting four card decks with various cost-benefit probabilities. Participants seek to maximise their monetary gain by developing long-term optimal-choice strategies. Animal versions have been adapted with nutritional rewards, but interspecies data comparisons are scarce. Our study directly compares the non-pathological decision-making performance between humans and wild-type C57BL/6 mice. Human participants completed an electronic Iowa Gambling Task version, while mice a maze-based adaptation with four arms baited in a probabilistic way. Our data shows closely matching performance between both species with similar patterns of choice behaviours. However, mice showed a faster learning rate than humans. Moreover, both populations were clustered into good, intermediate and poor decision-making categories with similar proportions. Remarkably, mice characterised as good decision-makers behaved the same as humans of the same category, but slight differences among species are evident for the other two subpopulations. Overall, our direct comparative study confirms the good face validity of the rodent gambling task. Extended behavioural characterisation and pathological animal models should help strengthen its construct validity and disentangle the determinants in animals and humans decision-making.

Effects of High Frequency Repetitive Transcranial Magnetic Stimulation (HF-rTMS) on Delay Discounting in Major Depressive Disorder: An Open-Label Uncontrolled Pilot Study.

BACKGROUND: Delay discounting (DD) refers to the decrease of a present subjective value of a future reward as the delay of its delivery increases. Major depressive disorder (MDD), besides core emotional and physical symptoms, involves difficulties in reward processing. Depressed patients often display greater temporal discounting rates than healthy subjects. Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique applied in several countries to adult patients with treatment resistant depression. Studies suggest that this technique can be used to modulate DD, but no trial has assessed its effects on depressed patients. METHODS: In this open-label uncontrolled trial, 20 patients diagnosed with MDD and at least stage II treatment resistance criteria underwent 20 HF-rTMS sessions over the dorsolateral prefrontal cortex (dlPFC; 10 Hz, 110% MT, 20 min). Pre-post treatment DD rates were compared. Effects on impulsivity, personality factors, and depressive symptoms were also evaluated. RESULTS: No significant effect of HF-rTMS over the left dlPFC on DD of depressed individuals was observed, although rates seemed to increase after sessions. However, treatment resulted in significant improvement on cognitive impulsivity and depressive symptoms, and was well-tolerated. CONCLUSION: Despite the limitations involved, this pilot study allows preliminary evaluation of HF-rTMS effects on DD in MDD, providing substrate for further research.