Rino Rumiati

Brain correlates of risky decision-making.

Understanding the neurocognitive basis of risk-taking behavior is an important issue, especially in economic decision-making. Classical behavioral studies have shown that risk-attitude changes across different contexts, but little is so far known about the brain correlates of processing of outcomes across such context shifts. In this study, EEG was recorded while subjects performed a gambling task. Participants could choose between a risky and a safer option, within two different contexts: one in which options yielded gains and losses of the same magnitude (Zero Expected Value context) and another in which gains were larger than losses (Positive Expected Value context). Based on their risk-attitude, two groups were compared: subjects who are risk-seekers in the zero Expected Value context (Zero-Oriented group) and subjects who are risk-seekers in the positive Expected Value condition (Positive-Oriented group). The Feedback Related Negativity (FRN) reflects this distinction, with each group being insensitive to magnitude of outcomes in the condition in which they were risk-prone. P300 amplitude mirrored the behavioral results, with larger amplitudes in the condition in which each group showed a higher risk-tendency. Source analyses highlighted the involvement of posterior cingulate cortex in risky decision-making. Taken together, the findings make a contribution to the clarification of the neurocognitive substrates of risky decision-making.

Mentalizing in economic decision-making.

In the Ultimatum Game, participants typically reject monetary offers they consider unfair even if the alternative is to gain no money at all. In the present study, ERPs were recorded while subjects processed different offers of a proposer. In addition to clearly fair and unfair offers, mid-value offers which cannot be easily classified as fair or unfair and therefore involve more elaborate decision making were analyzed. A fast initial distinction between fair and other kinds of offers was reflected by amplitude of the feedback related negativity (FRN). Mid-value offers were associated with longer RTs, and a larger N350 amplitude. In addition, source analyses revealed a specific involvement of the superior temporal gyrus and the inferior parietal lobule during processing of mid-value offers compared to offers categorized clearly as fair or unfair, suggesting a contribution of mentalizing about the intention of the proposer to the decision making process. Taken together, the present findings support the idea that economic decisions are significantly affected by non-rational factors, trying to narrow the gap between formal theory and the real decisional behaviour.

Predicting outcomes of decisions in the brain

When making decisions, the outcomes of different choices play an important role. Feedback is mainly processed in terms of gains and losses. It is as yet unclear whether this distinction holds for predictable as well as unpredictable outcomes. Using ERPs, the present study aimed to determine whether predictable and unpredictable outcomes are coded differently in the brain. Participants had to choose between one of two options: the certain option was always associated with a gain of 10 euro, while the uncertain option entailed a gain of 30 euro or a loss of 10 euro, with a probability of 50% each. Overall, subjects showed a clear preference for the certain option, a tendency which became more pronounced during the course of the experiment. An early ERP component, the P200, reflected the predictability of outcomes, which was critical for the subsequent decisions. The later feedback related negativity (FRN) reflected the known distinction between gains and losses, while the N500 again reflected differential processing of predictable and unpredictable outcomes. Neither FRN nor the N500 were significantly related to behaviour. Predictability appears to play a central role in outcome evaluation.

When people matter more than money: an ERPs study

In the present study, we showed that, in a social gambling task, individuals are influenced more by the type of social interaction than by the pattern of gains and losses. More precisely, the neural responses, as well as the level of pleasantness/unpleasantness following gains and losses, are modulated by social interaction factors. Here we present an Event-Related Potentials (ERPs) study in which three groups of participants were compared. Subjects were engaged in gambling tasks differing with regard to social factors: in a first condition, there was no social context; in a second condition, participants compared their outcomes with those of another individual; in a third condition, participants competed for a limited amount of money with another contender. In all conditions, all participants were revealed the outcome of an unselected alternative (non-obtained outcome) prior to the payoff associated with their selected option (obtained outcome). In addition, affective ratings were measured after the outcomes were presented. In the group without social context, ERPs results replicated previous findings. Interestingly, the P200 was modulated by varying social contexts, suggesting that attentive resources allocated to payoffs in comparison and competitive situations are decreased presumably in favor of social cues. Furthermore, Feedback Related Negativity (FRN) was predictive of the subjective feeling of pleasantness/unpleasantness following monetary outcomes. The present data provide information about neural and cognitive processing underlying economic decision-making when other individuals are involved.

The picture superiority effect in categorization: visual or semantic?

Two experiments are reported whose aim was to replicate and generalize the results presented by Snodgrass and McCullough (1986) on the effect of visual similarity in the categorization process. For pictures, Snodgrass and McCulloughs results were replicated because Ss took longer to discriminate elements from 2 categories when they were visually similar than when they were visually dissimilar. However, unlike Snodgrass and McCullough, an analogous increase was also observed for word stimuli. The pattern of results obtained here can be explained most parsimoniously with reference to the effect of semantic similarity, or semantic and visual relatedness, rather than to visual similarity alone.

Understanding of and attitudes to xenotransplantation: a survey among Italian university students

Abstract:  Xenotransplantation is currently at the experimental stages on animal models and many problems still have to be overcome in the biomedical, immunological and ethical fields. Moreover, peoples attitudes to xenotransplantation vary: surveys among intensive‐care staff have revealed negative opinions, while the general public and students seem to be more positive. Little is known about the influence of schooling and the choice of university faculty on attitudes to xenotransplantation. The aims of this study were: (i) to evaluate university students’ attitudes to xenotransplantation; (ii) to investigate any socio‐demographic, religious and educational determinants behind students’ opinions on xenotransplantation. University undergraduates on five different courses were surveyed at Padua University. A 24‐item questionnaire was distributed to students at the end of lectures and completed anonymously immediately after its distribution. No information was given to students beforehand. Statistical analysis: chi‐squared, Pearsons test; P‐values <0.05 were considered significant. A total of 585 of 602 (97.2%) students completed the questionnaire (132 males, 453 females, mean age 20.4, range 19 to 43 yr). They were on courses in Medicine (33.85%), Agriculture (5.98%), Veterinary Medicine (11.45%), Psychology (18.46%) and Educational Sciences (30.26%). As for their previous schooling, they came from classical or scientific high school (58.3%), technical college (14.7%), language college (6.3%), teacher training college (11.9%) or others (8.8%). Concerning their religious beliefs, 83% were Catholics, and 56.2% defined themselves as practising Catholics. Eighty‐eight percentage of the students knew of the possibility of animal organs being transplanted into humans and 77.9% of them approved of this idea. When grouped according to gender and education, a higher proportion of students approving of xenotransplantation were male (P = 0.017) and had attended classical or scientific high school (P = 0.011). Disapproval for moral, ethical or religious reasons was higher among practising than among non‐practising Catholics; the latter rejected xenotransplantation more for immunological and infectious reasons (P = 0.014). As for the type of university course, a higher proportion of students approving of xenotransplantation attended science courses (Veterinary Medicine, Agriculture and Medicine vs. Educational Sciences and Psychology) (P = 0.013). University students generally approved of xenotransplantation. Male gender and a high‐school education were associated with a greater acceptance of xenotransplantation. Practising vs. non‐practising Catholics reported significantly different reasons for any disapproval of xenotransplantation. The choice of a science rather than an arts faculty at university was more strongly associated with a positive opinion on xenotransplantation.

Constructional apraxia : an information processing analysis

Abstract Constructional apraxia is a disorder resulting from neurological damage which is manifested by the inability to copy and/or construct to command two- and three-dimensional stimuli. Three neurological patients presenting with these clinical symptoms were administered a battery of tests that were developed on the basis of a model describing the processing stages involved in copying and construction to command. The patients investigated differed in the pattern of performance across the tests in the battery. It was suggested that constructional apraxia is a syndrome that may be caused by different processing impairments, although this conclusion was tempered by a difficulty in separating out some of the processing components.

Temporal dynamics of cognitive-emotional interplay in moral decision-making

This study investigated the temporal dynamics of emotional and cognitive processing underlying decision-making in moral judgment. Thirty-seven participants were presented with a set of 60 dilemmas varying in whether killing one individual was an intended means to save others (instrumental dilemmas) or a foreseen but unintended consequence (incidental dilemmas). Participants were required to decide between Options A (letting a specific number of people die) and B (killing one person to save a specific number of people). ERPs were recorded to a slide displaying the letters A and B while subjects were deciding between the options, and movement-related potentials were recorded time-locked to the behavioral response, thus allowing the investigation of both stimulus- and response-related processes during decision-making. Ratings of emotional valence and arousal experienced during decision-making were collected after each decision. Compared with incidental dilemmas, instrumental dilemmas prompted a lower number of B choices and significantly more unpleasant decisions. A larger P260 component was found in the frontopolar and frontal areas when subjects were deciding on instrumental than incidental dilemmas, possibly reflecting an immediate affective reaction during the early stage of assessment and formation of preferences between available options. On the other hand, decisions on incidental dilemmas required greater attentional resources during the fairly controlled later processing, as reflected in the larger slow wave amplitudes. In addition, facilitation of action selection and implementation was found for incidental dilemmas during the second stage of decision-making, as supported by the larger amplitudes of both components of the Bereitschaftspotential.

Mental accounting and acceptance of a price discount

Abstract The paper reports five experiments related to a price reduction choice task. In Experiment 1 and in the control condition of Experiment 4, the finding reported by Tversky and Kahneman (1981) with the calculator problem is replicated. People show a difference in the rate of acceptance of a price reduction across the two versions of this problem. This finding has been explained as due to the use of a topical mental account of the offered price reduction. This paper studies the effect on the previous finding of four experimental manipulations of the calculator problem. In these situations, a relationship between the two purchases is provided in order to make their mental segregation difficult and favour the use of a comprehensive mental account of the price discount. Results show that when the two target purchases are embedded in a shopping list, an expense budget is provided, and subjects are reminded that they can also buy the jacket at the other store, the effect reported in the control condition disappears. These results are interpreted by the notion of the focusing mechanism.

New evidence for the perceptual precedence of global information

Two experiments are reported investigating the order in which global and local information of visual forms is processed. Subjects were presented with compound stimuli and were asked to identify the local level, always consisting of small letters. At the global level, the stimuli could be either large letters, consistent or inconsistent with the local level, or meaningless patterns derived from the large letters by modifying the spatial relations among segments. Results showed that inconsistent stimuli were responded to more slowly than both consistent stimuli and meaningless patterns, which did not differ from each other. This was true both when letters and patterns were presented intermixed, as in experiment 1 or separately, as in experiment 2. The pattern obtained accords well with predictions derived from the perceptual precedence hypothesis which states that global information becomes available at a faster rate than local information. No support for the alternative, post-perceptual, hypothesis was found.