The involvement of model-based but not model-free learning signals during observational reward learning in the absence of choice.

A major open question is whether computational strategies thought to be used during experiential learning, specifically model-based and model-free reinforcement learning, also support observational learning. Furthermore, the question of how observational learning occurs when observers must learn about the value of options from observing outcomes in the absence of choice has not been addressed. In the present study we used a multi-armed bandit task that encouraged human participants to employ both experiential and observational learning while they underwent functional magnetic resonance imaging (fMRI). We found evidence for the presence of model-based learning signals during both observational and experiential learning in the intraparietal sulcus. However, unlike during experiential learning, model-free learning signals in the ventral striatum were not detectable during this form of observational learning. These results provide insight into the flexibility of the model-based learning system, implicating this system in learning during observation as well as from direct experience, and further suggest that the model-free reinforcement learning system may be less flexible with regard to its involvement in observational learning.

How Effective Is Drinking Natural Mineral Water against Heartburn from Functional Dyspepsia, Gastroesophageal Reflux Disease, or Other Causes? A Systematic Review of Clinical Intervention Studies.

BACKGROUND: For centuries, spring and other natural waters have been recommended as external or internal remedies for numerous diseases. For studies that examined the effects of drinking mineral waters against heartburn, gastroesophageal reflux disease (GERD), or functional dyspepsia, a systematic review is lacking. OBJECTIVES: The main aim of this systematic review was to examine the effects of drinking natural mineral waters on heartburn from various causes by identifying all published intervention studies and critically appraising their methods as well as summarizing their results. METHODS: We systematically searched the largest medical literature database MEDLINE, further relevant web sources, and gray literature for randomized and nonrandomized trials, with or without control groups, up to September 2021 and no language restrictions. Further inclusion criteria were adult patients with heartburn, drinking cure with natural mineral water as the intervention, compared to no or other interventions (care-as-usual, waiting list). We defined the reduction of heartburn symptoms and duration of disease episodes as primary and quality of life as secondary outcomes. Two reviewers independently carried out the study quality assessments (risk of bias) using the National Institutes of Health-Study Quality Assessment Tools. RESULTS: Nine trials comprising 393 patients from Italy, Russia, Ukraine, and Germany fulfilled all inclusion criteria. We identified three randomized controlled trials (all with poor methodological quality), plus six before-after (pre/post) intervention studies without a control group. The intervention groups of the three comparative trials seemed to show a stronger reduction of self-reported heartburn symptoms, and duration of heartburn episodes than the respective control groups; however, they all had poor methodological quality. CONCLUSION: Based on the best available evidence of clinical studies, we cannot recommend or advise against drinking natural mineral waters as a treatment for heartburn. The potential benefits of natural mineral waters that were reported in some studies with a lower evidence level (e.g., lacking a control group) should be verified by good quality randomized clinical trials with adequate comparison groups and longer follow-up periods.Seit Jahrhunderten werden Quell- und andere natürliche Wässer als äußerliche oder innerliche Heilmittel für zahlreiche Krankheiten empfohlen. Für Studien, die die Wirkung des Trinkens von Mineralwasser gegen Sodbrennen, gastroösophageale Refluxkrankheit (GERD) oder funktionelle Dyspepsie untersuchten, fehlt eine systematische Übersicht.Das Hauptziel dieser systematischen Übersichtsarbeit war es, die Auswirkungen von Trinkkuren mit natürlichen Mineralwässern auf Sodbrennen verschiedener Ursachen zu untersuchen, indem alle veröffentlichten Interventionsstudien identifiziert und ihre Methoden kritisch bewertet sowie ihre Ergebnisse zusammengefasst wurden.Wir durchsuchten systematisch die größte medizinische Literaturdatenbank MEDLINE, weitere relevante Internetquellen und graue Literatur nach randomisierten und nicht-randomisierten Studien, mit oder ohne Kontrollgruppen, bis September 2021 und ohne sprachliche Einschränkungen. Weitere Einschlusskriterien waren erwachsene Patienten mit Sodbrennen, Trinkkur mit natürlichem Mineralwasser als Intervention, im Vergleich zu keiner oder anderen Interventionen (care-as-usual, Warteliste). Wir definierten die Abnahme der Symptome des Sodbrennens und die Dauer der Krankheitsepisoden als primäre und die Lebensqualität als sekundäre Endpunkte. Zwei Gutachter bewerteten unabhängig voneinander die Qualität der Studien (Verzerrungsrisiko) anhand der National Institutes of Health-Study Quality Assessment Tools.Neun Studien mit 393 Patienten aus Italien, Russland, der Ukraine und Deutschland erfüllten alle Einschlusskriterien. Wir identifizierten drei randomisierte kontrollierte Studien (alle mit schlechter methodischer Qualität) sowie sechs Vorher-Nachher-Studien (Prä-/Post-Studien) ohne Kontrollgruppe. Die Interventionsgruppen der drei randomisierten Vergleichsstudien schienen eine stärkere Verringerung der selbstberichteten Symptome und der Dauer der Episoden des Sodbrennens zu zeigen als die jeweiligen Kontrollgruppen, allerdings waren sie alle von schlechter methodischer Qualität.Auf der Grundlage der besten verfügbaren Belege aus klinischen Studien können wir das Trinken natürlicher Mineralwässer zur Behandlung von Sodbrennen weder empfehlen noch davon abraten. Die potenziellen Vorteile natürlicher Mineralwässer, die in einigen Studien mit geringerer Evidenz (z. B. ohne Kontrollgruppe) berichtet wurden, sollten durch qualitativ hochwertige randomisierte klinische Studien mit angemessenen Vergleichsgruppen und längeren Nachbeobachtungszeiträumen überprüft werden.

Effects of occupational health promotion interventions on health-related outcomes among employees of small businesses and self-employed individuals: A systematic review.

BACKGROUND: Compared to workers of larger companies it is less clear what health promoting interventions might be beneficial for employees of small businesses and self-employed individuals. OBJECTIVE: Our aim was to critically appraise trials investigating health promotion programs among small business workers and self-employed individuals, by means of a systematic review. METHODS: We conducted a search of primary studies using MEDLINE, Web of Science, LIVIVO and the Cochrane library. Our assessment followed the recommendations of the Cochrane Handbook for Systematic Reviews of Interventions and PRISMA. RESULTS: We identified six trials including 5,854 participants from Asia, North America and Australia. Most were of moderate methodological quality, only one was of low quality. Some of the supervised psycho-educational lifestyle programs focusing on individual behavior changes showed benefits in terms of stress reduction and increased physical activity levels among small enterprise employees. CONCLUSIONS: There is a huge knowledge gap on evidence-based health promotion interventions for self-employed and for small business workers, especially in Europe.

How the brain represents the reward value of fat in the mouth.

The palatability and pleasantness of the sensory properties of foods drive food selection and intake and may contribute to overeating and obesity. Oral fat texture can make food palatable and pleasant. To analyze its neural basis, we correlated humans' subjective reports of the pleasantness of the texture and flavor of a high- and low-fat food with a vanilla or strawberry flavor, with neural activations measured with functional magnetic resonance imaging. Activity in the midorbitofrontal and anterior cingulate cortex was correlated with the pleasantness of oral fat texture and in nearby locations with the pleasantness of flavor. The pregenual cingulate cortex showed a supralinear response to the combination of high fat and pleasant, sweet flavor, implicating it in the convergence of fat texture and flavor to produce a representation of highly pleasant stimuli. The subjective reports of oral fattiness were correlated with activations in the midorbitofrontal cortex and ventral striatum. The lateral hypothalamus and amygdala were more strongly activated by high- versus low-fat stimuli. This discovery of which brain regions track the subjective hedonic experience of fat texture will help to unravel possible differences in the neural responses in obese versus lean people to oral fat, a driver of food intake.

A common neural scale for the subjective pleasantness of different primary rewards.

When an economic decision is taken, it is between goals with different values, and the values must be on the same scale. Here, we used functional MRI to search for a brain region that represents the subjective pleasantness of two different rewards on the same neural scale. We found activity in the ventral prefrontal cortex that correlated with the subjective pleasantness of two fundamentally different rewards, taste in the mouth and warmth on the hand. The evidence came from two different investigations, a between-group comparison of two independent fMRI studies, and from a within-subject study. In the latter, we showed that neural activity in the same voxels in the ventral prefrontal cortex correlated with the subjective pleasantness of the different rewards. Moreover, the slope and intercept for the regression lines describing the relationship between activations and subjective pleasantness were highly similar for the different rewards. We also provide evidence that the activations did not simply represent multisensory integration or the salience of the rewards. The findings demonstrate the existence of a specific region in the human brain where neural activity scales with the subjective pleasantness of qualitatively different primary rewards. This suggests a principle of brain processing of importance in reward valuation and decision-making.

Assessment of competence in surgical skills using functional magnetic resonance imaging: a feasibility study.

BACKGROUND: Patient safety is fundamental to modern medical practice; safe surgery saves lives. Ensuring surgical competence is becoming more difficult at a time when surgeons are being trained in fewer hours. Accurate objective assessment of technical skills ability is lacking in standardization. Functional magnetic resonance imaging (fMRI) has a long history in neuroscience, psychiatry, and cognitive studies. Many studies have explored levels of perceived expertise in sports and musical ability. Little has been published on actual rather than perceived motor skills. This study sought to assess the feasibility of utilizing a novel assessment method by measuring blood oxygen level-dependent signal changes (BOLD) in specific brain regions via fMRI during a surgical skills task. METHODS: Images were acquired using fMRI in a pilot study of 9 subjects (3 experts, 3 intermediates, and 3 novices) when performing and imagining performing a basic surgical procedure: hand tying of surgical knots. Level of expertise was based on years of experience and clinical grade. The quality and quantity of knots were assessed objectively by 2 experts who were independent of the study and blinded to the ability of the candidate. The effect of subject head motion caused by the task itself was assessed. The efficacy of fMRI data analyses in removing artifacts caused by this noise source in the data was explored. RESULTS: Shifts of less than 1 voxel (3 × 3 × 3.55 mm(3)) were recorded in all participants and were successfully corrected in all cases in the fMRI preprocessing step. Decreased BOLD activity was observed in experts compared to novices when "knot tying" was compared with the control "finger tap." Increased BOLD activity was observed in experts compared with novices when "imagining a task" in the primary visual cortex, an area important in perceptual learning. Experts and intermediates performed consistently with 100% square knots. Novices had an average of 2 slip knots. Regarding knot quantity, the number of knots ranged from 14 to 26 in novices, 38 to 47 in intermediates, and 54 to 58 in experts. A Kruskal-Wallis rank sum test revealed that the difference between the 3 groups was statistically significant in the quantity of square knots tied (p = 0.147). Specific regions of interest identified concurred with findings of previous studies and included the left supramarginal, left rolandic operculum, and left postcentral regions. CONCLUSION: We found that fMRI is a feasible method of exploring actual and perceived motor skill abilities. Head motion during performance of a motor skill does not preclude the attainment of meaningful data. Larger numbers are needed to further investigate these early findings.

Dysregulation between emotion and theory of mind networks in borderline personality disorder.

Individuals with borderline personality disorder (BPD) commonly display deficits in emotion regulation, but findings in the area of social cognitive (e.g., theory of mind, ToM) capacities have been heterogeneous. The aims of the current study were to investigate differences between patients with BPD and controls in functional connectivity (1) between the emotion and ToM network and (2) in the default mode network (DMN). Functional magnetic resonance imaging was used to investigate 19 healthy controls and 17 patients with BPD at rest and during ToM processing. Functional coupling was analysed. Significantly decreased functional connectivity was found for patients compared with controls between anterior cingulate cortex and three brain areas involved in ToM processes: the left superior temporal lobe, right supramarginal/inferior parietal lobes, and right middle cingulate cortex. Increased functional connectivity was found in patients compared with controls between the precuneus as the DMN seed and the left inferior frontal lobe, left precentral/middle frontal, and left middle occipital/superior parietal lobes during rest. Reduced functional coupling between the emotional and the ToM network during ToM processing is in line with emotion-regulation dysfunctions in BPD. The increased connectivity between precuneus and frontal regions during rest might be related to extensive processing of internal thoughts and self-referential information in BPD.

Magnetic resonance imaging in patients with borderline personality disorder: a study of volumetric abnormalities.

Volumetric abnormalities of the hippocampus and frontal cortex are of major interest in the study of borderline personality disorder (BPD). To our knowledge, no study has examined volumetric abnormalities in the hippocampal subregions (head, body, and tail). Our aims were to investigate hippocampal volumetric abnormalities as well as abnormalities in the gray and white matter of the frontal cortex, basal ganglia, and anterior cingulate cortex in BPD in a sample of BPD patients compared to healthy controls. Using manual volumetry as well as optimized voxel based morphometry (VBM) we assessed the volumetric differences in a sample of females with BPD (n=20), compared to healthy female controls (n=21) (HC). The analyses revealed reductions in the left hippocampal head, body, and tail, and the right hippocampal tail. Hippocampal changes were confirmed also using VBM and additional volumetric reductions were found in the caudate and dorsolateral prefrontal cortex of the BPD group. Our study reaffirms the existence of hippocampal volumetric, prefrontal and caudate abnormalities in BPD and lends support to the stress-related explanation of these reductions, whilst also bringing new data to the topic in terms of the abnormalities found in the subregions.