RESUMEN
It has long been assumed in economic theory that multi-attribute decisions involving several attributes or dimensions - such as probabilities and amounts of money to be earned during risky choices - are resolved by first combining the attributes of each option to form an overall expected value and then comparing the expected values of the alternative options, using a unique evidence accumulation process. A plausible alternative would be performing independent comparisons between the individual attributes and then integrating the results of the comparisons afterwards. Here, we devise a novel method to disambiguate between these types of models, by orthogonally manipulating the expected value of choice options and the relative salience of their attributes. Our results, based on behavioral measures and drift-diffusion models, provide evidence in favor of the framework where information about individual attributes independently impacts deliberation. This suggests that risky decisions are resolved by running in parallel multiple comparisons between the separate attributes - possibly alongside an additional comparison of expected value. This result stands in contrast with the assumption of standard economic theory that choices require a unique comparison of expected values and suggests that at the cognitive level, decision processes might be more distributed than commonly assumed. Beyond our planned analyses, we also discovered that attribute salience affects people of different risk preference type in different ways: risk-averse participants seem to focus more on probability, except when monetary amount is particularly high; risk-neutral/seeking participants, in contrast, seem to focus more on monetary amount, except when probability is particularly low.
Asunto(s)
Conducta de Elección , Toma de Decisiones , Humanos , ProbabilidadRESUMEN
Perceptual discriminations can be strongly biased by the expected reward for a correct decision but the neural mechanisms underlying this influence are still partially unclear. Using functional magnetic resonance imaging (fMRI) during a task requiring to arbitrarily associate a visual stimulus with a specific action, we have recently shown that perceptual decisions are encoded within the same sensory-motor regions responsible for planning and executing specific motor actions. Here we examined whether these regions additionally encode the amount of expected reward for a perceptual decision. Using a task requiring to associate a gradually unmasked female vs. male picture with a spatially-directed hand pointing or saccadic eye movement, we examined whether the fMRI time course of effector-selective regions was modulated by the amount of expected reward. In both the pointing-selective parietal reach region (PRR) and the saccade-selective posterior intraparietal region (pIPS), reward-related modulations were only observed after the onset of the stimulus, during decision formation. However, while in the PRR these modulations were specific for the preferred pointing response, the pIPS showed greater activity when either a saccadic or a pointing movement was associated with a greater reward relative to neutral conditions. Interestingly, the fusiform face area showed a similar reward-related but response-independent modulation, consistent with a general motivational signal rather than with a mechanism for biasing specific sensory or motor representations. Together, our results support an account of perception as a process of probabilistic inference in which top-down and bottom-up information are integrated at every level of the cortical hierarchy.
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Lóbulo Parietal/fisiología , Recompensa , Adulto , Mapeo Encefálico/métodos , Toma de Decisiones/fisiología , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Movimiento , Estimulación Luminosa/métodos , Desempeño Psicomotor/fisiología , Tiempo de Reacción/fisiología , Factores de Tiempo , Adulto JovenRESUMEN
During intertemporal decisions, the preference for smaller, sooner reward over larger-delayed rewards (temporal discounting, TD) exhibits substantial inter-subject variability; however, it is currently unclear what are the mechanisms underlying this apparently idiosyncratic behavior. To answer this question, here we recorded and analyzed mouse movement kinematics during intertemporal choices in a large sample of participants (N = 86). Results revealed a specific pattern of decision dynamics associated with the selection of "immediate" versus "delayed" response alternatives, which well discriminated between a "discounter" versus a "farsighted" behavior-thus representing a reliable behavioral marker of TD preferences. By fitting the Drift Diffusion Model to the data, we showed that differences between discounter and farsighted subjects could be explained in terms of different model parameterizations, corresponding to the use of different choice mechanisms in the two groups. While farsighted subjects were biased toward the "delayed" option, discounter subjects were not correspondingly biased toward the "immediate" option. Rather, as shown by the dynamics of evidence accumulation over time, their behavior was characterized by high choice uncertainty.
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Conducta de Elección/fisiología , Descuento por Demora/fisiología , Individualidad , Modelos Psicológicos , Desempeño Psicomotor/fisiología , Adulto , Fenómenos Biomecánicos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
During simple perceptual decisions, sensorimotor neurons in monkey fronto-parietal cortex represent a decision variable that guides the transformation of sensory evidence into a motor response, supporting the view that mechanisms for decision-making are closely embedded within sensorimotor structures. Within these structures, however, decision signals can be dissociated from motor signals, thus indicating that sensorimotor neurons can play multiple and independent roles in decision-making and action selection/planning. Here we used functional magnetic resonance imaging to examine whether response-selective human brain areas encode signals for decision-making or action planning during a task requiring an arbitrary association between face pictures (male vs. female) and specific actions (saccadic eye vs. hand pointing movements). The stimuli were gradually unmasked to stretch the time necessary for decision, thus maximising the temporal separation between decision and action planning. Decision-related signals were measured in parietal and motor/premotor regions showing a preference for the planning/execution of saccadic or pointing movements. In a parietal reach region, decision-related signals were specific for the stimulus category associated with its preferred pointing response. By contrast, a saccade-selective posterior intraparietal sulcus region carried decision-related signals even when the task required a pointing response. Consistent signals were observed in the motor/premotor cortex. Whole-brain analyses indicated that, in our task, the most reliable decision signals were found in the same neural regions involved in response selection. However, decision- and action-related signals within these regions can be dissociated. Differences between the parietal reach region and posterior intraparietal sulcus plausibly depend on their functional specificity rather than on the task structure.
Asunto(s)
Toma de Decisiones , Lóbulo Parietal/fisiología , Enmascaramiento Perceptual , Tiempo de Reacción , Adulto , Mapeo Encefálico , Femenino , Humanos , MasculinoRESUMEN
Temporal and probability discounting are considered two fundamental constructs in economic science, as they are associated with phenomena with major societal impact and a variety of sub-optimal behaviors and clinical conditions. Although it is well known that positive and negative affective states bear important cognitive/behavioral consequences, the effect of emotional experiences on decision-making remains unclear due to the existence of many conflicting results. Inspired by the need to understand if and to what extent the current COVID-19 pandemic has determined changes in our decision-making processes by means of the unusual, prolonged experience of negative feelings, in this study we investigate the effect of anger, fear, sadness, physical and moral disgust on intertemporal and risky choices. Results show that all emotions significantly increase subjects' preferences for immediate rewards over delayed ones, and for risky rewards over certain ones, in comparison to a "neutral emotion" condition, although the magnitude of the effect differs across emotions. In particular, we observed a more pronounced effect in the case of sadness and moral disgust. These findings contribute to the literature on emotions and decision-making by offering an alternative explanation to the traditional motivational appraisal theories. Specifically, we propose that the increased preference for immediate gratification and risky outcomes serves as a mechanism of self-reward aimed at down-regulating negative feelings and restore the individual's "emotional balance".
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Anti-contagion measures restricting individual freedom, such as social distancing and wearing a mask, are crucial to contain the COVID-19 pandemic. Decision-making patterns and attitudes about uncertainty can highly influence the adherence to these restrictive measures. Here we investigated the relationship between risky behavior and individual preferences for immediate vs. delayed reward, as indexed by temporal discounting (TD), as well as the association between these measures and confidence in the future, perceived risk and confidence in the containment measures. These measures were collected through an online survey administered on 353 participants at the end of the more restrictive phase of the first Italian lockdown. The results showed an unexpected inverse relationship between the individual pattern of choice preferences and risky behavior, with an overall greater adherence to containment measures in more discounter participants. These findings were interpreted in terms of a reframing process in which behaviors aimed at protecting oneself from contagion turn into immediate gains rather than losses. Interestingly, an excessive confidence in a better future was correlated with a higher tendency to assume risky behavior, thereby highlighting the downside of an overly and blindly optimistic view.
RESUMEN
Gambling Disorder (GD) is a behavioral addiction characterized by the persistence of recurrent gambling behaviors despite serious adverse consequences. One of the key features of GD is a marked inability to delay gratification and an overall impairment of decision-making mechanisms. Indeed, in intertemporal choice (ITC) tasks, GD patients usually display a marked tendency to prefer smaller-sooner over larger-later rewards (temporal discounting, TD). However, ITC represents a highly verbal/explicit measure, and as such it might not be sensitive to implicit decision biases. Here we sought to uncover the implicit mechanisms underlying the ITC impairment in GD by employing the process-tracing method of mouse kinematics. To this aim, we collected and analyzed ITCs and kinematics measures from 24 GD patients and 23 matched healthy control participants (HC). In line with the relevant literature, the results showed that GD patients discounted future rewards more steeply compared to HCs. Additionally, the results of kinematics analyses showed that patients were characterized by a strong bias toward the immediate option, which was associated with straight-line trajectories. Conversely, the delayed option was selected with edge-curved trajectories, indicating a bias toward the immediate option which was revised in later stages of processing. Interestingly, kinematics indices were also found to be predictive of individual discounting preferences (i.e., discount rates) across the two groups. Taken together, these results suggest that kinematics indices, by revealing hidden and implicit patterns of attraction toward the unselected choice option, may represent reliable behavioral markers of TD in gambling disorder.
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Conducta Adictiva , Descuento por Demora , Juego de Azar , Animales , Conducta de Elección , Cognición , Humanos , Ratones , RecompensaRESUMEN
During intertemporal decisions, the value of future rewards decreases as a function of the delay of its receipt (temporal discounting, TD). Since high discount rates have been associated with a series of problematic behaviours and clinical conditions, current research has focused on possible modulators of TD. Specifically, a reduction of individual discount rates has been shown during episodic future thinking (EFT), wherein time intervals are anchored to personal future events. However, it is not entirely clear whether this effect is mediated by a change in the representation of future events (i.e., from abstract to concrete) or by a positive-emotion modulation. Here, we investigated this issue by manipulating the valence of the EFT (i.e., using negative, neutral and positive episodic tags), and by collecting explicit and implicit measures of behaviour. The results showed a significant reduction of TD in all the three emotional conditions compared to the baseline, with differences among them, thus suggesting the existence of a cumulative effect of the concreteness and affective components of the EFT. The analyses of implicit measures additionally revealed that this effect was mediated by a simultaneous increase/decrease of attraction toward the delayed/immediate alternative. Finally, these effects appeared to be modulated by participants' baseline discounting preferences. These findings provide important insights on clinical applications in reward-related disorders.
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Conducta de Elección , Toma de Decisiones , Descuento por Demora/fisiología , Emociones/fisiología , Pensamiento/fisiología , Adulto , Femenino , Humanos , Masculino , Recompensa , Percepción del Tiempo , Adulto JovenRESUMEN
On a daily basis, we see how different people can be in keeping or breaking a given promise. However, we know very little about the cognitive conflict dynamics that underlie the decision to keep or break a promise and whether this is shaped by inter-individual variability. In order to fill this gap, we applied an ecologically valid promise decision task with real monetary consequences for all involved interaction partners and used mouse tracking to identify the dynamic, on-line cognitive processes that underlie the decision to keep or break a promise. Our findings revealed that on average, the process of breaking a promise is associated with largely curved mouse trajectories, while the process of keeping a promise was not, indicating that breaking a promise is associated with a larger conflict. Interestingly, however, this conflict pattern was strongly shaped by individual differences. Individuals who always kept their promises did not show any signs of conflict (i.e., straight mouse trajectories), indicating that they were not tempted by the monetary benefits associated with breaking the promise. In contrast, individuals who did not always keep their promise exhibited a large conflict (i.e., curved mouse trajectories), irrespective of whether they broke or kept their promise. A possible interpretation of these findings is that these individuals were always tempted by the unchosen decision option - the desire to act in a fair manner when breaking the promise and the monetary benefits when keeping the promise. This study provides the first piece of evidence that there are substantial inter-individual differences in cognitive conflict dynamics that underlie the decision to keep or break promises and that mouse tracking is able to illuminate important insights into individual differences in complex human's decision processes.
RESUMEN
Direct eye gaze is a powerful stimulus in social interactions, yet people vary considerably in the range of gaze lines that they accept as being direct (cone of direct gaze, CoDG). Here, we searched for a possible neural trait marker of these individual differences. We measured the width of the CoDG in 137 healthy participants and related their individual CoDG to their neural baseline activation as measured with resting electroencephalogram. Using a source-localization technique, we found that resting theta current density in the left temporo-parietal junction (TPJ) and adjacent posterior superior temporal sulcus (pSTS) was associated with the width of CoDG. Our findings suggest that the higher the baseline cortical activation in the left TPJ/pSTS, the wider the CoDG and thus the more liberal the individuals' judgments were in deciding whether a looker stimulus was making eye contact or not. This is a first demonstration of the neural signatures underlying individual differences in the feeling of being looked at.
Asunto(s)
Electroencefalografía , Articulación Temporomandibular/fisiología , Ritmo Teta , Visión Ocular/fisiología , Adulto , Emociones , Femenino , Voluntarios Sanos , Humanos , Individualidad , Masculino , Persona de Mediana Edad , Red Nerviosa/fisiología , Estimulación Luminosa , Corteza Prefrontal/fisiología , Lóbulo Temporal/fisiología , Adulto JovenRESUMEN
The present study presents a novel social observation paradigm to examine whether temporal discounting (TD) can be modulated in a specific direction. In particular, after estimating a baseline discount rate, we exposed subjects to a pattern of choice that was opposite to their baseline preferences, i.e., subjects preferring immediate over delayed rewards were exposed to a farsighted pattern of behavior and vice-versa. The results showed a significant decrease of the discount rate in the discounter group and an increase in the farsighted group. The effect was mainly guided by a modification of the subjective values at short time delays and was stronger in subjects with extreme, compared to mild, baseline preferences. Importantly, the magnitude and direction of the effect predicted the baseline preferences. These findings have potentially very relevant implications for the prevention and treatment of clinical conditions, such as addition-related disorders, characterized by severe impairments of decision-making mechanisms.
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Conducta de Elección/ética , Descuento por Demora/ética , Medio Social , Toma de Decisiones , Femenino , Voluntarios Sanos/psicología , Humanos , Masculino , Pruebas Neuropsicológicas , Recompensa , Adulto JovenRESUMEN
During intertemporal choice (IT) future outcomes are usually devaluated as a function of the delay, a phenomenon known as temporal discounting (TD). Based on task-evoked activity, previous neuroimaging studies have described several networks associated with TD. However, given its relevance for several disorders, a critical challenge is to define a specific neural marker able to predict TD independently of task execution. To this aim, we used resting-state functional connectivity MRI (fcMRI) and measured TD during economic choices several months apart in 25 human subjects. We further explored the relationship between TD, impulsivity and decision uncertainty by collecting standard questionnaires on individual trait/state differences. Our findings indicate that fcMRI within and between critical nodes of task-evoked neural networks associated with TD correlates with discounting behavior measured a long time afterwards, independently of impulsivity. Importantly, the nodes form an intrinsic circuit that might support all the mechanisms underlying TD, from the representation of subjective value to choice selection through modulatory effects of cognitive control and episodic prospection.