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A dislike of waiting for pain, aptly termed ‘dread’, is so great that people will increase pain to avoid delaying it. However, despite many accounts of altruistic responses to pain in others, no previous studies have tested whether people take delay into account when attempting to ameliorate others' pain. We examined the impact of delay in 2 experiments where participants (total N = 130) specified the intensity and delay of pain either for themselves or another person. Participants were willing to increase the experimental pain of another participant to avoid delaying it, indicative of dread, though did so to a lesser extent than was the case for their own pain. We observed a similar attenuation in dread when participants chose the timing of a hypothetical painful medical treatment for a close friend or relative, but no such attenuation when participants chose for a more distant acquaintance. A model in which altruism is biased to privilege pain intensity over the dread of pain parsimoniously accounts for these findings. We refer to this underestimation of others' dread as a ‘Dread Empathy Gap’.

SummaryThe dystopian scenario of an ‘artificial intelligence takeover’ imagines artificial intelligence (AI) becoming the dominant form of intelligence on Earth, rendering humans redundant. As a society we have become increasingly familiar with AI and robots replacing humans in many tasks, certain jobs and even some areas of medicine, but surely this is not the fate of psychiatry?Here a computational neuroscientist (Janaina Mourão-Miranda) and psychiatrist (Justin Taylor Baker) suggest that psychiatry as a profession is relatively safe, whereas psychiatrists Christian Brown and Giles William Story predict that robots will be taking over the asylum.

People often form polarized beliefs about others. In a clinical setting this is referred to as a dichotomous or ‘split’ representation of others, whereby others are not imbued with possessing mixtures of opposing properties. Here, we formalise these accounts as an oversimplified categorical model of others’ internal, intentional, states. We show how a resulting idealization and devaluation of others can be stabilized by attributing unexpected behaviour to fictive external factors. For example, under idealization, less-than-perfect behaviour is attributed to unfavourable external conditions, thereby maintaining belief in the other’s goodness. This feature of the model accounts for how extreme beliefs are buffered against counter-evidence, while at the same time being prone to precipitous changes of polarity. Equivalent inference applied to the self creates an oscillation between self-aggrandizement and self-deprecation, capturing oscillatory relational and affective dynamics. Notably, such oscillatory dynamics arise out of the Bayesian nature of the model, wherein a subject arrives at the most plausible explanation for their observations, given their current expectations. Thus, the model we present accounts for aspects of splitting that appear ‘defensive’, without the need to postulate a specific defensive intention. By contrast, we associate psychological health with a fine-grained representation of internal states, constrained by an integrated prior, corresponding to notions of ‘character’. Finally, the model predicts that extreme appraisals of self or other are associated with causal attribution errors.

Early theories of schizophrenia considered the illness as a fragmentation of mental content in response to psychological trauma. Here we present a case of very late onset schizophrenia in a previously high-functioning man in his mid-60s, precipitated by having lost his family in a terrorist attack, while he was living in Africa. He presented with symptoms consistent with post-traumatic stress disorder, however also exhibited visual and auditory hallucinations and marked deterioration in daily functioning. He showed mild impairment on cognitive testing, however brain imaging and screening for reversible causes of cognitive impairment were normal. The case highlights the need for a formulation-based approach to understanding and managing responses to severe trauma, from resolution through to psychotic disintegration.

Impatience can be formalized as a delay discount rate, describing how the subjective value of reward decreases as it is delayed. By analogy, selfishness can be formalized as a social discount rate, representing how the subjective value of rewarding another person decreases with increasing social distance. Delay and social discount rates for reward are correlated across individuals. However no previous work has examined whether this relationship also holds for aversive outcomes. Neither has previous work described a functional form for social discounting of pain in humans. This is a pertinent question, since preferences over aversive outcomes formally diverge from those for reward. We addressed this issue in an experiment in which healthy adult participants (N = 67) chose the timing and intensity of hypothetical pain for themselves and others. In keeping with previous studies, participants showed a strong preference for immediate over delayed pain. Participants showed greater concern for pain in close others than for their own pain, though this hyperaltruism was steeply discounted with increasing social distance. Impatience for pain and social discounting of pain were weakly correlated across individuals. Our results extend a link between impatience and selfishness to the aversive domain.

Selectively attributing beliefs to specific agents is core to reasoning about other people and imagining oneself in different states. Evidence suggests humans might achieve this by simulating each other’s computations in agent-specific neural circuits, but it is not known how circuits become agent-specific. Here we investigate whether agent-specificity adapts to social context. We train subjects on social learning tasks, manipulating the frequency with which self and other see the same information. Training alters the agent-specificity of prediction error (PE) circuits for at least 24 h, modulating the extent to which another agent’s PE is experienced as one’s own and influencing perspective-taking in an independent task. Ventromedial prefrontal myelin density, indexed by magnetisation transfer, correlates with the strength of this adaptation. We describe a frontotemporal learning network, which exploits relationships between different agents’ computations. Our findings suggest that Self-Other boundaries are learnable variables, shaped by the statistical structure of social experience., The human brain can simulate other people’s mental processes with Self-specific and Other-specific neural circuits, but it is not known how these circuits emerge. Here, the authors show that these circuits adapt to social experience, to determine whether a computation is attributed to Self or Other.

Background Second-generation antipsychotics (SGAs) are often prescribed in the treatment of Behavioral and Psychological Symptoms of Dementia (BPSD), however, their use has been discouraged in light of clinical trials suggesting that they cause an increased risk of cerebrovascular accidents (CVAs). Objective Aim of the study was to assess relative risk of CVA in dementia patients prescribed SGA rather than first-generation antipsychotics (FGAs), through meta-analysis of population-based studies. Methods A literature search was conducted using several relevant databases. Five studies were included in the review and data were pooled to conduct meta-analysis using the inverse variance method. Results A total of 79,910 patients were treated with SGAs and 1287 cases of CVA were reported. Of 48,135 patients treated with FGAs, a total of 511 cases of CVA were reported. The relative risk of CVA was 1.02 (95% CI 0.56–1.84) for the SGA group. There was no significant difference in the risk of stroke (p = 0.96) between groups, but significant heterogeneity was found among the results of included studies (p

When people anticipate uncertain future outcomes, they often prefer to know their fate in advance. Inspired by an idea in behavioral economics that the anticipation of rewards is itself attractive, we hypothesized that this preference of advance information arises because reward prediction errors carried by such information can boost the level of anticipation. We designed new empirical behavioral studies to test this proposal, and confirmed that subjects preferred advance reward information more strongly when they had to wait for rewards for a longer time. We formulated our proposal in a reinforcement-learning model, and we showed that our model could account for a wide range of existing neuronal and behavioral data, without appealing to ambiguous notions such as an explicit value for information. We suggest that such boosted anticipation significantly drives risk-seeking behaviors, most pertinently in gambling. DOI: http://dx.doi.org/10.7554/eLife.13747.001, eLife digest People, pigeons and monkeys often want to know in advance whether they will receive a reward in the future. This behaviour is irrational when individuals pay for costly information that makes no difference to an eventual outcome. One explanation is that individuals seek information because anticipating reward has hedonic value (it produces a feeling of pleasure). Consistent with this, pigeons are more likely to seek information when they have to wait longer for the potential reward. However, existing models cannot account for why this anticipation of rewards leads to irrational information-seeking. In many situations, animals are uncertain about what is going to happen. Providing new information can produce a “prediction error” that indexes a discrepancy between what is expected and what actually happens. Iigaya et al. have now developed a mathematical model of information-seeking in which anticipation is boosted by this prediction error. The model accounts for a wide range of previously unexplained data from monkeys and pigeons. It also successfully explains the behaviour of a group of human volunteers from whom Iigaya et al. elicited informational and actual decisions concerning uncertain and delayed rewards. The longer that the participants had to wait for possible rewards, the more avidly they wanted to find out about them. Further research is now needed to investigate the neural underpinnings of anticipation and its boosting by prediction errors. DOI: http://dx.doi.org/10.7554/eLife.13747.002

Saccadic latencies have long been known to depend on the relative timing of the appearance of the new target, and offset of the original fixation target. Previous studies have tended to conclude that two separate effects are at work, one equivalent to competitive inhibition from the fixation target, and the other due to its offset providing a warning that shortens latency. In this study, we propose a simpler explanation, based on a well-established model of reaction time, LATER (linear approach to threshold with ergodic rate), that in addition to predicting mean latencies also--more challengingly--predicts latency distributions. We show that observed distributions, using gap, step and appearance tasks under three conditions of prior probability, can be accurately predicted by using a pair of LATER units, one corresponding to fixation target offset and the other to peripheral target onset. Because fixation offset is probabilistically associated with target appearance, when the fixation unit is activated it increases the target's decision signal (that represents probability) in a fixed proportion, speeding responses. In contrast, when the fixation target remains present, the fixation unit is not activated, and responses are slower. Both these effects generate characteristic changes in the shapes of the latency distributions that can be accurately predicted by the model.

People show empathic responses to others’ pain, yet how they choose to apportion pain between themselves and others is not well understood. To address this question, we observed choices to reapportion social allocations of painful stimuli and, for comparison, also elicited equivalent choices with money. On average people sought to equalize allocations of both pain and money, in a manner which indicated that inequality carried an increasing marginal cost. Preferences for pain were more altruistic than for money, with several participants assigning more than half the pain to themselves. Our data indicate that, given concern for others, the fundamental principle of diminishing marginal utility motivates spreading costs across individuals. A model incorporating this assumption outperformed existing models of social utility in explaining the data. By implementing selected allocations for real, we also found that while inequality per se did not influence pain perception, altruistic behavior had an intrinsic analgesic effect for the recipient.

The second author's name was spelled incorrectly. The correct name is: Ivo Vlaev. The citation is unaffected by this change.

Studies using conventional consoles have suggested a possible link between video-gaming and laparoscopic skill. The authors hypothesized that the Nintendo Wii, with its motion-sensing interface, would provide a better model for laparoscopic tasks. This study investigated the relationship between Nintendo Wii skill, prior gaming experience, and laparoscopic skill. In this study, 20 participants who had minimal experience with either laparoscopic surgery or Nintendo Wii performed three tasks on a Webcam-based laparoscopic simulator and were assessed on three games on the Wii. The participants completed a questionnaire assessing prior gaming experience. The score for each of the three Wii games correlated positively with the laparoscopic score (r = 0.78, 0.63, 0.77; P

Red or processed meat, but not white meat or fish, is associated with colorectal cancer. The endogenous formation of nitroso compounds is a possible explanation, as red or processed meat--but not white meat or fish--causes a dose-dependent increase in fecal apparent total N-nitroso compounds (ATNC) and the formation of nitroso-compound-specific DNA adducts. Red meat is particularly rich in heme and heme has also been found to promote the formation of ATNC. To investigate the underlying mechanism of ATNC formation, fecal and ileal samples of volunteers fed a high red meat or a vegetarian diet were analyzed for nitrosyl iron, nitrosothiols, and heme. To simulate the processes in the stomach, food homogenates and hemoglobin were incubated under simulated gastric conditions. Nitrosyl iron and nitrosothiols were significantly (p < 0.0001) increased in ileal and fecal samples after a high red meat diet compared with a vegetarian diet; significantly more nitrosyl iron than nitrosothiols was detectable in ileal (p < 0.0001) and fecal (p < 0.001) samples. The strong correlation between fecal nitrosyl iron and heme (0.776; p < 0.0001) suggested that nitrosyl heme is the main source of nitrosyl iron, and ESR confirmed the presence of nitrosyl heme in fecal samples after a high red meat diet. Under simulated gastric conditions, mainly nitrosothiols were formed, suggesting that acid-catalyzed thionitrosation is the initial step in the endogenous formation of nitroso compounds. Nitrosyl heme and other nitroso compounds can then form under the alkaline and reductive conditions of the small and large bowel.

Standard theories of decision-making involving delayed outcomes predict that people should defer a punishment, whilst advancing a reward. In some cases, such as pain, people seem to prefer to expedite punishment, implying that its anticipation carries a cost, often conceptualized as ‘dread’. Despite empirical support for the existence of dread, whether and how it depends on prospective delay is unknown. Furthermore, it is unclear whether dread represents a stable component of value, or is modulated by biases such as framing effects. Here, we examine choices made between different numbers of painful shocks to be delivered faithfully at different time points up to 15 minutes in the future, as well as choices between hypothetical painful dental appointments at time points of up to approximately eight months in the future, to test alternative models for how future pain is disvalued. We show that future pain initially becomes increasingly aversive with increasing delay, but does so at a decreasing rate. This is consistent with a value model in which moment-by-moment dread increases up to the time of expected pain, such that dread becomes equivalent to the discounted expectation of pain. For a minority of individuals pain has maximum negative value at intermediate delay, suggesting that the dread function may itself be prospectively discounted in time. Framing an outcome as relief reduces the overall preference to expedite pain, which can be parameterized by reducing the rate of the dread-discounting function. Our data support an account of disvaluation for primary punishments such as pain, which differs fundamentally from existing models applied to financial punishments, in which dread exerts a powerful but time-dependent influence over choice., Author Summary People often prefer to ‘get pain out of the way’, treating pain in the future as more significant than pain now. One explanation, termed ‘dread’, is that anticipating pain is unpleasant or disadvantageous, rather like pain itself. Human brain imaging studies support the existence of dread, though it is unknown whether and how dread depends on the timing of future pain. We address this question by offering people decisions between moderately painful stimuli, and separately between imagined painful dental appointments occurring at different time points in the future, and use their choices to estimate dread. We show that future pain initially becomes more unpleasant when it is delayed, but as pain is moved further into the future, the effect of delay decreases. This is consistent with dread increasing as anticipated pain draws nearer, which is then combined with a general (and opposing) tendency to down-weight the significance of future events. We also show that dread can be attenuated by describing pain in terms of relief from an imagined even more severe pain. These observations reveal important principles about how people estimate the value of anticipated pain – relevant to a diverse range of human emotion and behavior.