Neural computations underlying strategic social decision-making in groups

When making decisions in groups, the outcome of one's decision often depends on the decisions of others, and there is a tradeoff between short-term incentives for an individual and long-term incentives for the groups. Yet, little is known about the neurocomputational mechanisms at play when weighing different utilities during repeated social interactions. Here, using model-based fMRI and Public-good-games, we find that the ventromedial prefrontal cortex encodes immediate expected rewards as individual utility while the lateral frontopolar cortex encodes group utility (i.e., pending rewards of alternative strategies beneficial for the group). When it is required to change one's strategy, these brain regions exhibited changes in functional interactions with brain regions engaged in switching strategies. Moreover, the anterior cingulate cortex and the temporoparietal junction updated beliefs about the decision of others during interactions. Together, our findings provide a neurocomputational account of how the brain dynamically computes effective strategies to make adaptive collective decisions.

Modeling other minds: Bayesian inference explains human choices in group decision-making

To make decisions in a social context, humans have to predict the behavior of others, an ability that is thought to rely on having a model of other minds known as "theory of mind." Such a model becomes especially complex when the number of people one simultaneously interacts with is large and actions are anonymous. Here, we present results from a group decision-making task known as the volunteer's dilemma and demonstrate that a Bayesian model based on partially observable Markov decision processes outperforms existing models in quantitatively predicting human behavior and outcomes of group interactions. Our results suggest that in decision-making tasks involving large groups with anonymous members, humans use Bayesian inference to model the "mind of the group," making predictions of others' decisions while also simulating the effects of their own actions on the group's dynamics in the future.

Shared multisensory experience affects Others' boundary: The enfacement illusion in schizophrenia

Schizophrenia has been described as a psychiatric condition characterized by deficits in one's own and others' face recognition, as well as by a disturbed sense of body-ownership. To date, no study has integrated these two lines of research with the aim of investigating Enfacement Illusion (EI) proneness in schizophrenia. To accomplish this goal, the classic EI protocol was adapted to test the potential plasticity of both Self-Other and Other-Other boundaries. Results showed that EI induced the expected malleability of Self-Other boundary among both controls and patients. Interestingly, for the first time, the present study demonstrates that also the Other-Other boundary was influenced by EI. Furthermore, comparing the two groups, the malleability of the Other-Other boundary showed an opposite modulation. These results suggest that, instead of greater Self-Other boundary plasticity, a qualitative difference can be detected between schizophrenia patients and controls in the malleability of the Other-Other boundary. The present study points out a totally new aspect about body-illusions and schizophrenia disorder, demonstrating that EI is not only confined to self-sphere but it also affects the way we discriminate others, representing a potential crucial aspect in the social domain.

Investigating Neural Sensorimotor Mechanisms Underlying Flight Expertise in Pilots: Preliminary Data From an EEG Study

Over the last decade, the efforts toward unraveling the complex interplay between the brain, body, and environment have set a promising line of research that utilizes neuroscience to study human performance in natural work contexts such as aviation. Thus, a relatively new discipline called neuroergonomics is holding the promise of studying the neural mechanisms underlying human performance in pursuit of both theoretical and practical insights. In this work, we utilized a neuroergonomic approach by combining insights from ecological psychology and embodied cognition to study flight expertise. Specifically, we focused on the Mirror Neuron system as a key correlate for understanding the interaction between an individual and the environment, suggesting that it can be used to index changes in the coupling of perception-action associated with skill development. In this study, we measured the EEG mu suppression as a proxy of the Mirror Neuron system in experts (pilots) and novices while performing a distance estimation task in a landing scenario. To survey the specificity of this measure, we considered central, parietal and occipital electrode pools and analyzed alpha (8–13 Hz) and beta (18–25 Hz) rhythm bands. We hypothesized that in experts vs. novices, specific neural sensorimotor brain activity would underpin the connection between perception and action in an in-flight context. Preliminary results indicate that alpha and beta rhythm suppression was area-specific irrespective of groups, present in the central electrodes placed over the motor areas. Group analysis revealed that specifically alpha mu rhythm, but not beta, was significantly more suppressed in pilots vs. novices. Complementing these findings we found a trend in which the strength of mu suppression increased with the sense of presence experienced by the pilots. Such sensorimotor activation is in line with the idea that for a pilot, a distance judgment is intimately associated with the function of landing. This reflects the ability to use optical invariants to see the world in terms of the capabilities of the aircraft (e.g., reachability and glide angle). These preliminary findings support the role of embodied simulation mechanisms in visual perception and add important insights into a practical understanding of flight expertise, suggesting sensorimotor mechanisms as potential neuro-markers.

Sensing the Worst: Neurophenomenological Perspectives on Neutral Stimuli Misperception in Schizophrenia Spectrum

While investigating social cognitive impairments in schizophrenia, prominent evidence has been found that patients with schizophrenia show a tendency to misclassify neutral stimuli as negatively valenced. Within this population, patients presenting delusions are more prone to this phenomenon. In a previous study, Schizophrenia spectrum (SzSp) patients rated positive, negative and neutral stimuli that were multimodally presented, while assessed with a checklist exploring anomalous subjective experiences and evaluated for positive and negative symptomatology. In the present work, we aimed to further explore the relationship between neutral stimuli misperception, anomalous experiences and positive/negative symptoms in SzSp patients. To this end, we adopted a dimensional approach by reconstructing from available data: (1) four a priori scales representing essential dimensions of SzSp experiential pathology following Parnas et al. (2005); and (2) five clinically meaningful factors to describe illness severity derived by Toomey et al. (1997). Results showed that although overall patients correctly recognized the target emotions, those who misinterpreted neutral auditory cues as negatively valenced also presented higher scores in Perplexity (PY), Bizarre Delusions (BD) and Disorganization (Di) dimensions. Moreover, a positive association between BD and both PY and Self-Disorder (SD) dimensions emerged, suggesting that psychotic symptoms may be directly linked to patients' subjectivity. In an attempt to comprehensively capture the multilayered neutral stimuli misperception phenomenon in SzSp, we aimed at bridging phenomenology and neurobiology by connecting the levels of molecular neurochemistry (i.e., altered dopaminergic neurotransmission), system neuroscience (aberrant salience of perceptual details) and psychopathology (the chain involving hyper-reflexivity, self-disorders and the emergence of delusions).

Anomalous echo: Exploring abnormal experience correlates of emotional motor resonance in Schizophrenia Spectrum

Anomalous experiences such as Basic Symptoms (BS) are considered the first subjective manifestation of the neurobiological substrate of schizophrenia. The purpose of this study was to explore whether a low or high emotional motor resonance occurring in Schizophrenia Spectrum (SzSp) patients was related to patients׳ clinical features and to their anomalous subjective experiences as indexed by the Bonn Scale for the Assessment of Basic Symptoms (BSABS). To this aim, we employed a validated paradigm sensitive in evoking a congruent facial mimicry (measured by means of facial electromyographic activity, EMG) through multimodal positive and negative emotional stimuli presentation. Results showed that SzSp patients more resonating with negative emotional stimuli (i.e. Externalizers) had significantly higher scores in BSABS Cluster 3 (Vulnerability) and more psychotic episodes than Internalizers patients. On the other hand, SzSp patients more resonating with positive emotional stimuli (i.e. Externalizers) scored higher in BSABS Cluster 5 (Interpersonal irritation) than Internalizers. Drawing upon a phenomenological-based perspective, we attempted to shed new light on the abnormal experiences characterizing schizophrenia, explaining them in terms of a disruption of the normal self-perception conveyed by the basic, low-level emotional motor mechanisms.

Mirroring the self: testing neurophysiological correlates of disturbed self-experience in schizophrenia spectrum

BACKGROUND

Self-disorders (SDs) have been described as a core schizophrenia spectrum vulnerability phenotype, both in classic and contemporary psychopathological literature. However, such a core phenotype has not yet been investigated adopting a trans-domain approach that combines the phenomenological and the neurophysiological levels of analysis. The aim of this study is to investigate the relation between SDs and subtle, schizophrenia-specific impairments of emotional resonance that are supposed to reflect abnormalities in the mirror neurons mechanism. Specifically, we tested whether electromyographic response to emotional stimuli (i.e. a proxy for subtle changes in facial mimicry and related motor resonance mechanisms) would predict the occurrence of anomalous subjective experiences (i.e. SDs).

SAMPLING AND METHODS

Eighteen schizophrenia spectrum (SzSp) patients underwent a comprehensive psychopathological examination and were contextually tested with a multimodal paradigm, recording facial electromyographic activity of muscles in response to positive and negative emotional stimuli. Experiential anomalies were explored with the Bonn Scale for the Assessment of Basic Symptoms (BSABS) and then condensed into rational subscales mapping SzSp anomalous self-experiences.

RESULTS

SzSp patients showed an imbalance in emotional motor resonance with a selective bias toward negative stimuli, as well as a multisensory integration impairment. Multiple regression analysis showed that electromyographic facial reactions in response to negative stimuli presented in auditory modality specifically and strongly correlated with SD subscore.

CONCLUSIONS

The study confirms the potential of SDs as target phenotype for neurobiological research and encourages research into disturbed motor/emotional resonance as possible body-level correlate of disturbed subjective experiences in SzSp.

When age matters: differences in facial mimicry and autonomic responses to peers' emotions in teenagers and adults

Age-group membership effects on explicit emotional facial expressions recognition have been widely demonstrated. In this study we investigated whether Age-group membership could also affect implicit physiological responses, as facial mimicry and autonomic regulation, to observation of emotional facial expressions. To this aim, facial Electromyography (EMG) and Respiratory Sinus Arrhythmia (RSA) were recorded from teenager and adult participants during the observation of facial expressions performed by teenager and adult models. Results highlighted that teenagers exhibited greater facial EMG responses to peers' facial expressions, whereas adults showed higher RSA-responses to adult facial expressions. The different physiological modalities through which young and adults respond to peers' emotional expressions are likely to reflect two different ways to engage in social interactions with coetaneous. Findings confirmed that age is an important and powerful social feature that modulates interpersonal interactions by influencing low-level physiological responses.

Facial reactions in response to dynamic emotional stimuli in different modalities in patients suffering from schizophrenia: a behavioral and EMG study

Emotional facial expression is an important low-level mechanism contributing to the experience of empathy, thereby lying at the core of social interaction. Schizophrenia is associated with pervasive social cognitive impairments, including emotional processing of facial expressions. In this study we test a novel paradigm in order to investigate the evaluation of the emotional content of perceived emotions presented through dynamic expressive stimuli, facial mimicry evoked by the same stimuli, and their functional relation. Fifteen healthy controls and 15 patients diagnosed with schizophrenia were presented with stimuli portraying positive (laugh), negative (cry) and neutral (control) emotional stimuli in visual, auditory modalities in isolation, and congruently or incongruently associated. Participants where requested to recognize and quantitatively rate the emotional value of the perceived stimuli, while electromyographic activity of Corrugator and Zygomaticus muscles was recorded. All participants correctly judged the perceived emotional stimuli and prioritized the visual over the auditory modality in identifying the emotion when they were incongruently associated (Audio-Visual Incongruent condition). The neutral emotional stimuli did not evoke any muscle responses and were judged by all participants as emotionally neutral. Control group responded with rapid and congruent mimicry to emotional stimuli, and in Incongruent condition muscle responses were driven by what participants saw rather than by what they heard. Patient group showed a similar pattern only with respect to negative stimuli, whereas showed a lack of or a non-specific Zygomaticus response when positive stimuli were presented. Finally, we found that only patients with reduced facial mimicry (Internalizers) judged both positive and negative emotions as significantly more neutral than controls. The relevance of these findings for studying emotional deficits in schizophrenia is discussed.

When early experiences build a wall to others' emotions: an electrophysiological and autonomic study

Facial expression of emotions is a powerful vehicle for communicating information about others’ emotional states and it normally induces facial mimicry in the observers. The aim of this study was to investigate if early aversive experiences could interfere with emotion recognition, facial mimicry, and with the autonomic regulation of social behaviors. We conducted a facial emotion recognition task in a group of “street-boys” and in an age-matched control group. We recorded facial electromyography (EMG), a marker of facial mimicry, and respiratory sinus arrhythmia (RSA), an index of the recruitment of autonomic system promoting social behaviors and predisposition, in response to the observation of facial expressions of emotions. Results showed an over-attribution of anger, and reduced EMG responses during the observation of both positive and negative expressions only among street-boys. Street-boys also showed lower RSA after observation of facial expressions and ineffective RSA suppression during presentation of non-threatening expressions. Our findings suggest that early aversive experiences alter not only emotion recognition but also facial mimicry of emotions. These deficits affect the autonomic regulation of social behaviors inducing lower social predisposition after the visualization of facial expressions and an ineffective recruitment of defensive behavior in response to non-threatening expressions.

Abstract art and cortical motor activation: an EEG study

The role of the motor system in the perception of visual art remains to be better understood. Earlier studies on the visual perception of abstract art (from Gestalt theory, as in Arnheim, 1954 and 1988, to balance preference studies as in Locher and Stappers, 2002, and more recent work by Locher et al., 2007; Redies, 2007, and Taylor et al., 2011), neglected the question, while the field of neuroesthetics (Ramachandran and Hirstein, 1999; Zeki, 1999) mostly concentrated on figurative works. Much recent work has demonstrated the multimodality of vision, encompassing the activation of motor, somatosensory, and viscero-motor brain regions. The present study investigated whether the observation of high-resolution digitized static images of abstract paintings by Lucio Fontana is associated with specific cortical motor activation in the beholder's brain. Mu rhythm suppression was evoked by the observation of original art works but not by control stimuli (as in the case of graphically modified versions of these works). Most interestingly, previous visual exposure to the stimuli did not affect the mu rhythm suppression induced by their observation. The present results clearly show the involvement of the cortical motor system in the viewing of static abstract art works.

Regression of left ventricular hypertrophy and improvement of renal hemodynamics in hypertensive patients treated with quinapril

Of 17 patients with mild to moderate essential hypertension, 8 showed echocardiographic evidence of left ventricular hypertrophy. Cardiac and renal function evaluated by glomerular filtration rate (GFR) were studied in all patients before and after 20 weeks of quinapril treatment. Systolic pressure decreased from 174.7 +/- 16.7 to 131.7 +/- 7.7 mmHg (p < .0001) and diastolic pressure decreased from 101.8 +/- 9.8 to 80 +/- 4.3 mmHg (p < .0001). Left ventricular mass index decreased in the eight patients with left ventricular hypertrophy (p < .01). Basal values of GFR were lower than normal in 41% of all patients; GFR increased significantly after 20 weeks of treatment (from 96.5 +/- 32.3 to 108.6 +/- 31.12 ml/min, p < .01); it decreased in only one patient. Patients reported few adverse effects to quinapril, and no important clinical laboratory abnormality was observed. Quinapril not only lowered arterial pressure, but it had a distinct effect on regression of left ventricular hypertrophy and favorable effects on renal function.

[Comparison of nisoldipine and diltiazem in the treatment of effort angina pectoris]

BACKGROUND

In order to evaluate the benefits of a calcium-antagonist medium-term treatment, 20 patients with effort stable angina pectoris were treated with nisoldipine in comparison to diltiazem.

METHODS

Twenty patients with stable effort angina completed a double-blind, placebo controlled trial, comparing 10 twice daily nisoldipine per os and diltiazem 120 three times daily per os for 28 days. After wash-out, placebo and drug period, ergometer stress tests were performed. Exercise tolerance, angina frequency, nitrate consumption and side effects were evaluated.

RESULTS

Our results showed that both drugs significantly increased exercise tolerance. Exercise duration was 330 +/- 107 sec after placebo, 397 +/- 106 sec after nisoldipine (p < 0.05) and 378 +/- 99 sec after diltiazem (p < 0.05). Effort angina episodes decreased from 20 after placebo to 8 after nisoldipine and diltiazem. Both drugs reduced rate-pressure product at submaximal exercise in comparison to placebo. There were no differences at peak exercise between placebo or drug periods. Both drugs similarly reduced nitrate consumption and weekly effort angina attacks. No patients referred serious side-effects.

CONCLUSIONS

nisoldipine, like diltiazem, is an effective drug in the treatment of stable effort angina. Moreover, the therapeutic effects of nisoldipine during medium-term treatment are probably related to decrease in oxygen consumption.

[Acute effects of propranolol and its association with nifedipine in aged patients with effort stable angina. Randomized double-blind crossover study, under placebo control]

Calcium-antagonist and B-blockers are effective in improving exercise tolerance in patients with effort angina. We studied the short effects of oral administration of nifedipine (10 mg) and propranolol (80 mg) alone and in combination in 15 elderly patients with chronic exertional angina pectoris in a double-blind, randomized, cross-over study. The 15 patients (13 men and 2 women, mean age 69 years) performed symptoms-limits bicycle exercise stress test 3 h after placebo or active substance administration. Maximal work load, exercise duration, real time to 1 mm ST segment depression were significantly increased and ST depression at peak exercise was significantly decreased by drug alone and in combination. Propranolol and nifedipine improved exercise duration in combination; however, a different response to the three pharmacologic interventions was found in patients treated with single drug. The improvement in exercises tolerance was associated with rate-pressure product values at peak exercise tolerance was associated with rate-pressure product values at peak exercise, unchanged after placebo and significantly reduced after both propranolol alone and in combination. After placebo all patients had exercise-induced angina, in 50% and in 40% after propranolol and the combination of the two drugs, respectively. In aging patients nifedipine and propranolol are effective in the treatment of effort angina and they are superior in patients who show poor response to mono therapy, although this combination will be conditioned by different patient sensibility to the three pharmacologic interventions and then therapeutic choice would be evaluated and verified individually.

Strain differentiation of pathogenic yeasts by the killer system

High sensitivity rates to the activity of killer toxins produced by 25 species of yeasts belonging to the genera Candida, Hansenula, Pichia, Rhodotorula, Saccharomyces and Trichosporon have been observed among 112 yeast isolates (25 Cryptococcus neoformans, 29 C. glabrata 16 C. parapsilosis, 20 C. pseudotropicalis and 22 C. tropicalis). The highest sensitivity has been observed among the C. parapsilosis isolates, the lowest in C. glabrata strains. Genera Pichia and Hansenula proved to have the greatest killer activity. A killer system, formerly used for differentiating C. albicans isolates within the species, proved to be valid as epidemiological marker when applied to 112 strains of pathogenic yeasts.

Killer system: a simple method for differentiating Candida albicans strains

The killer effect of 37 species of Candida, Cryptococcus, Hansenula, Pichia, Rhodotorula, Saccharomyces, and Trichosporon on 100 Candida albicans isolates of human and animal origin was studied. All of the C. albicans cultures were sensitive to one or more killer yeasts. The factors affecting the killer phenomenon on C. albicans were investigated for realizing a simple system for the differentiation of the 100 C. albicans isolates. By using this system, it was possible to differentiate up to 512 isolates of C. albicans according to their susceptibility to the killer effect of nine selected killer yeasts. The use of this method as an epidemiological marker in the case of presumptive nosocomial infections due to C. albicans is also reported.