infonet-economy

Several regions in human temporal and frontal cortex are known to integrate visual and auditory object features. The processing of audio-visual (AV) associations in these regions has been found to be modulated by object familiarity. The aim of the present study was to explore training-induced plasticity in human cortical AV integration. We used functional magnetic resonance imaging to analyze the neural correlates of AV integration for unfamiliar artificial object sounds and images in naïve subjects (PRE training) and after a behavioral training session in which subjects acquired associations between some of these sounds and images (POST-training). In the PRE-training session, unfamiliar artificial object sounds and images were mainly integrated in right inferior frontal cortex (IFC). The POST-training results showed extended integration-related IFC activations bilaterally, and a recruitment of additional regions in bilateral superior temporal gyrus/sulcus and intraparietal sulcus. Furthermore, training-induced differential response patterns to mismatching compared with matching (i.e., associated) artificial AV stimuli were most pronounced in left IFC. These effects were accompanied by complementary training-induced congruency effects in right posterior middle temporal gyrus and fusiform gyrus. Together, these findings demonstrate that short-term cross-modal association learning was sufficient to induce plastic changes of both AV integration of object stimuli and mechanisms of AV congruency processing.

Trying to understand others is the most pervasive aspect of successful social interaction. To date there is no evidence on whether human products, which signal the workings of a mind in the absence of an explicit agent, also reliably engage neural structures typically associated with mental state attribution. By means of functional magnetic resonance imaging the present study shows that when subjects believe they are listening to a piece of music that was written by a composer (i.e., human product) as opposed to generated by a computer (i.e., nonhuman product), activations in the cortical network typically reported for mental state attribution (anterior medial frontal cortex [aMFC]), superior temporal sulcus, and temporal poles) were observed. The activation in the aMFC correlated highly with the extent to which subjects had engaged in attributing the expression of intentions to the composed pieces, as indicated in a postimaging questionnaire. We interpret these findings as indicative of automatic mechanisms, which reflect mental state attribution in the face of any stimulus that potentially signals the working of another mind and conclude that even in the absence of a socially salient stimulus, our environment is still populated by the indirect social signals inherent to human artifacts.

BACKGROUND: It has been suggested that some psychotic symptoms reflect ‘aberrant salience’, related to dysfunctional reward learning. To test this hypothesis we investigated whether patients with schizophrenia showed impaired learning of task-relevant stimulusreinforcement
associations in the presence of distracting task-irrelevant cues.

METHODS: We tested 20 medicated patients with schizophrenia and 17 controls on a reaction time
game, the Salience Attribution Test. In this game, participants made a speeded response to earn money in the presence of conditioned stimuli (CSs). Each CS comprised two
visual dimensions, colour and form. Probability of reinforcement varied over one of these dimensions (task-relevant), but not the other (task-irrelevant). Measures of adaptive and aberrant motivational salience were calculated on the basis of latency and subjective reinforcement probability rating differences over the task-relevant and task-irrelevant dimensions respectively.

RESULTS: Participants rated reinforcement significantly more
likely and responded significantly faster on high-probability reinforced relative to lowprobability
reinforced trials, representing adaptive motivational salience. Patients exhibited reduced adaptive salience relative to controls, but the two groups did not differ
in terms of aberrant salience. Patients with delusions exhibited significantly greater aberrant salience than those without delusions, and aberrant salience also correlated with negative symptoms. In the controls, aberrant salience correlated significantly with
‘introvertive anhedonia’ schizotypy.

CONCLUSIONS: These data support the hypothesis that aberrant salience is related to the presence of delusions in medicated patients with schizophrenia, but are also suggestive of a link with negative symptoms. The relationship between aberrant salience and psychotic symptoms warrants further investigation in unmedicated patients.

Confronted with a rich sensory environment, the brain must learn statistical regularities across sensory domains to construct causal models of the world. Here, we used functional magnetic resonance imaging and dynamic causal modelling (DCM) to furnish neurophysiological evidence
that statistical associations are learnt, even when task-irrelevant. Subjects performed an audio-visual target detection task while being exposed to distractor stimuli. Unknown to them, auditory distractors predicted the
presence or absence of subsequent visual distractors. We modelled incidental learning of these associations using a Rescorla-Wagner (RW) model. Activity in primary visual cortex and putamen reflected learningdependent
surprise: these areas responded progressively more to
unpredicted, and progressively less to predicted, visual stimuli. Critically, this prediction-error response was observed even when the absence of a visual stimulus was surprising. We investigated the underlying mechanism by embedding the RW model into a DCM to show that
auditory-to-visual connectivity changed significantly over time as a function of prediction error. Thus, consistent with predictive coding models of perception, associative learning is mediated by prediction-error dependent changes in connectivity. These results posit a dual role for
prediction-error in encoding surprise and driving associative plasticity.

We study the impact of reputational incentives in markets characterized by moral hazard problems. Social preferences have been shown to enhance contract enforcement in these markets, while at the same time generating considerable wage and price rigidity. Reputation powerfully amplifies the positive effects of social preferences on contract enforcement by increasing contract efficiency substantially. This effect is, however, associated with a considerable bilateralisation of market interactions, suggesting that it may aggravate price rigidities. Surprisingly, reputation in fact weakens the wage and price rigidities arising from social preferences. Thus, in markets characterized by moral hazard, reputational incentives unambiguously increase mutually beneficial exchanges, reduce rents, and render markets more responsive to supply and demand shocks.

Damit die Schweiz weiterhin in der Weltspitzengruppe der Nationen mit hoher Innovationsneigung präsent sein wird,
muss sie auch als Wissens- und Denkplatz attraktiv bleiben. Dies bedingt, wie im folgenden Beitrag aufgezeigt wird, einen
offenen Arbeitsmarkt.

This paper reports data from an ultimatum mini-game in which responders first had to choose whether or not to participate. Participation was costly, but the participation cost was smaller than the minimum payoff that a responder could guarantee himself in the ultimatum game. Compared to a standard treatment, we find that the rejection rate of unfavorable offers is significantly reduced when participation is costly. A possible explanation based on cognitive dissonance is offered.

Awards in the form of orders, decorations, prizes, and titles are ubiquitous in monarchies and republics, private organizations, not-for-profit, and profit-oriented firms. This paper argues that awards present a unique combination of different stimuli and that they are distinct and unlike other monetary and non-monetary rewards. Despite their relevance in all areas of life awards have not received much scientific attention. We propose to study awards and present results on a vignette experiment that quantifies andnisolates the effects of different award characteristics such as the publicity associated with winning an award. Further, employing a unique data set, we demonstrate that there are substantial differences in the intensity of usage of awards across countries.