PhD student in Biological Anthropology, specializing in the behavior and evolution of monkeys.
What can neuroscience teach us about ethics? Is there a 'morality center' in the brain
Some of the earliest philosophy deals with this question - what does it mean to lead a good, decent human life, and how can we go about doing it?
Although the answers to this question have varied widely across history and across cultures, there are some common threads that nearly all cultures share - be honest, cultivate good relationships with friends and neighbors, treat others with empathy and compassion - that sort of stuff. The world's philosophical traditions are so consistent on these points that some neuroscientists argue it points to an innate moral sense, hardwired by evolution into the human brain.
Although the brain is intensely involved in moral behavior, there's no single region or nucleus that we can point to as the 'morality center.' Instead, it seems that different moral problems are processed in very different ways. For example, when we think about abstract moral dilemmas like how to spend money so that we save the maximum number of lives, we use the prefrontal cortex - a region involved in planning, calculation, etc. But there are also much more visceral, intuitive moral situations that activate deeper structures of the brain. These include direct, face-to-face encounters where we help or harm another being.
Primatologists have been arguing for years that apes and monkeys have social behaviors analogous to human morality (we call these behaviors 'prosocial'). Chimpanzees, for example, take care of aging relatives once they are too weak to take care of themselves; similarly, tamarins and marmosets have been observed sharing food with both relatives and unrelated individuals.
It seems that human beings, like other social primates, are endowed by their biology with a capacity for compassion and caring behavior. What makes humans different is that we can use language, ritual, technology, and storytelling to amplify these abilities. Unfortunately, we can also use these same tools to override our innate moral senses.
Abstract: Neural underpinnings of morality are not yet well understood. Researchers in moral neuroscience have tried to find specific structures and processes that shed light on how morality works. Here, we review the main brain areas that have been associated with morality at both structural and functional levels and speculate about how it can be studied. Orbital and ventromedial prefrontal cortices are implicated in emotionally-driven moral decisions, while dorsolateral prefrontal cortex appears to moderate its response. These competing processes may be mediated by the anterior cingulate cortex. Parietal and temporal structures play important roles in the attribution of others' beliefs and intentions. The insular cortex is engaged during empathic processes. Other regions seem to play a more complementary role in morality. Morality is supported not by a single brain circuitry or structure, but by several circuits overlapping with other complex processes. The identification of the core features of morality and moral-related processes is needed. Neuroscience can provide meaningful insights in order to delineate the boundaries of morality in conjunction with moral psychology.
Pub.: 26 Sep '13, Pinned: 08 May '17
Abstract: Oxytocin- and vasopressin-related systems are present in invertebrate and vertebrate bilaterian animals, including humans, and exhibit conserved neuroanatomical and functional properties. In vertebrates, these systems innervate conserved neural networks that regulate social learning and behavior, including conspecific recognition, social attachment, and parental behavior. Individual and species-level variation in central organization of oxytocin and vasopressin systems has been linked to individual and species variation in social learning and behavior. In humans, genetic polymorphisms in the genes encoding oxytocin and vasopressin peptides and/or their respective target receptors have been associated with individual variation in social recognition, social attachment phenotypes, parental behavior, and psychiatric phenotypes such as autism. Here we describe both conserved and variable features of central oxytocin and vasopressin systems in the context of social behavioral diversity, with a particular focus on neural networks that modulate social learning, behavior, and salience of sociosensory stimuli during species-typical social contexts.
Pub.: 25 Apr '17, Pinned: 08 May '17
Abstract: Synchrony in social groups may confer significant evolutionary advantages by improving group cohesion and social interaction. However, the neurobiological mechanisms translating social synchrony into refined social information transmission between interacting individuals are still elusive. In two successively conducted experiments involving a total of 199 healthy volunteers, we explored the involvement of the neuropeptide oxytocin (OXT) in reciprocal social interaction. First, we show that synchronous social interactions evoke heightened endogenous OXT release in dyadic partners. In a second step, we examined the consequences of elevated OXT concentrations on emotion transmission by intranasally administering synthetic OXT before recording emotional expressions. Intriguingly, our data demonstrate that the subjects' facial and vocal expressiveness of fear and happiness is enhanced after OXT compared to placebo administration. Collectively, our findings point to a central role of social synchrony in facilitating reciprocal communication between individuals via heightened OXT signaling. Elevated OXT concentrations among synchronized individuals seem to augment the partners' emotional expressiveness, thereby contributing to improved transmission of emotional information in social communication.
Pub.: 27 Apr '17, Pinned: 08 May '17
Abstract: Oxytocin is an important messenger in the brain that has been linked to a variety of social functions in pharmacological studies. Besides, functional genetic variations on the oxytocin receptor gene have been repeatedly associated with social processing and functioning. Despite this knowledge, there are very few studies investigating the mechanisms that may explain the link between oxytocin and social functions. In the endeavor to fill this gap in the literature, the current study searches for associations between the prominent rs2268498 polymorphism on the oxytocin receptor gene and participants' ability to perceive and store implicit social information, which is a fundamental function in social information processing. N=121 healthy participants were experimentally tested with an implicit learning paradigm, answered questionnaires assessing empathy and autistic traits, and were genotyped for the rs2268498 polymorphism. T-allele carriers (TT and TC genotypes) exhibited significantly better implicit learning performance than carriers of the CC-genotype, and learning performance was positively associated with self-reported empathy and negatively with self-reported autistic traits. Results indicate that differences in implicit perception and storing of environmental details while watching social interactions could be an important mechanism to explain the association between differences in endogenous oxytocin activity and social functioning. m.
Pub.: 27 Apr '17, Pinned: 08 May '17
Abstract: To provide new preclinical evidence toward improving the efficacy of oxytocin (OT) in treating social dysfunction, we tested the benefit of administering OT under simultaneously induced opioid antagonism during dyadic gaze interactions in monkeys. OT coadministered with a μ-opioid receptor antagonist, naloxone, invoked a supralinear enhancement of prolonged and selective social attention, producing a stronger effect than the summed effects of each administered separately. These effects were consistently observed when averaging over entire sessions, as well as specifically following events of particular social importance, including mutual eye contact and mutual reward receipt. Furthermore, attention to various facial regions was differentially modulated depending on social context. Using the Allen Institute’s transcriptional atlas, we further established the colocalization of μ-opioid and κ-opioid receptor genes and OT genes at the OT-releasing sites in the human brain. These data across monkeys and humans support a regulatory relationship between the OT and opioid systems and suggest that administering OT under opioid antagonism may boost the therapeutic efficacy of OT for enhancing social cognition.
Pub.: 01 May '17, Pinned: 08 May '17
Abstract: Jonathan Haidt's Moral Foundations Theory is an influential scientific account of morality incorporating psychological, developmental, and evolutionary perspectives. The theory proposes that morality is built upon five innate "foundations," each of which is believed to have been selected for during human evolution and, subsequently, tuned-up by learning during development. We argue here that although some general elements of Haidt's theory are plausible, many other important aspects of his account are seriously flawed. First, innateness and modularity figure centrally in Haidt's account, but terminological and conceptual problems foster confusion and ambiguities. Second, both the theory's proposed number of moral foundations and its taxonomy of the moral domain appear contrived, ignoring equally good candidate foundations and the possibility of substantial intergroup differences in the foundations' contents. Third, the mechanisms (viz., modules) and categorical distinctions (viz., between foundations) proposed by the theory are not consilient with discoveries in contemporary neuroscience concerning the organization, functioning, and development of the brain. In light of these difficulties, we suggest that Haidt's theory is inadequate as a scientific account of morality. Nevertheless, the theory's weaknesses are instructive, and hence, criticism may be useful to psychologists, neuroscientists, and philosophers attempting to advance theories of morality, as well as to researchers wishing to invoke concepts such as innateness and modularity more generally.
Pub.: 05 Feb '11, Pinned: 08 May '17
Abstract: Oxytocin (OXT), synthesized in the hypothalamic paraventricular nucleus (PVN) and then released into different brain areas, may play a crucial role in various behaviors and neuropsychiatric disorders, including depression. Testosterone has been proposed by clinical studies to have the opposite effect of oxytocin in these disorders. We began by studying, in the postmortem hypothalamus of fifteen patients with mood disorders and fifteen matched controls, the expression of OXT in the PVN by means of immunocytochemistry (ICC) and the co-localization of OXT and androgen receptor (AR) by means of double labeling ICC. Subsequently, the regulatory effect of AR on OXT gene expression was studied in vitro. We found a higher expression of PVN OXT in the mood disorder patients than in the control subjects, and observed a clear co-localization of AR in OXT-expressing neurons, both in the cytoplasm and in the nucleus. In addition, a significant decrease in OXT-mRNA levels was observed after pre-incubation of the SK-N-SH cells with testosterone. A further potential androgen-responsive element in the human OXT gene promotor was revealed by electrophoretic mobility shift assays and co-transfections in neuroblastoma cells. Finally, in vitro studies demonstrated that AR mediated the down-regulation of OXT gene expression. These results suggest that the fact that OXT and testosterone appear to have opposite effects in neuropsychiatric disorders might be based upon a direct inhibition of AR on OXT transcription, which may provide a novel target for therapeutic strategies in depression.Neuropsychopharmacology accepted article preview online, 27 April 2017. doi:10.1038/npp.2017.76.
Pub.: 28 Apr '17, Pinned: 08 May '17
Abstract: There is growing evidence that the number and quality of social relationships have substantial impacts on health, well-being, and longevity, and, at least in animals, on reproductive fitness. Although it is widely recognized that these outcomes are mediated by a number of neuropeptides, the roles these play remain debated. We suggest that an overemphasis on one neuropeptide (oxytocin), combined with a failure to distinguish between different social domains, has obscured the complexity involved. We use variation in 33 SNPs for the receptor genes for six well-known social neuropeptides in relation to three separate domains of sociality (social disposition, dyadic relationships, and social networks) to show that three neuropeptides (β-endorphin, oxytocin, and dopamine) play particularly important roles, with each being associated predominantly with a different social domain. However, endorphins and dopamine have a much wider compass than oxytocin (whose effects are confined to romantic/reproductive relationships and often do not survive control for other neuropeptides). In contrast, vasopressin, serotonin, and testosterone play only limited roles.
Pub.: 01 May '17, Pinned: 08 May '17
Abstract: Prior research suggests that parenting affects children's relationships, including those with teachers, although there is variation across individuals in such effects. Given evidence suggesting that oxytocin may be particularly important for the quality of social relationships, we tested the hypotheses (a) that change in parenting from 4 to 6 years of age influences and predicts change in the student-teacher relationship from 6 to 8 years of age and (b) that this effect is moderated by a polymorphism related to the child's oxytocin receptor gene (OXTR), rs53576. In 2 studies, participants included, respectively, 652 socioeconomically diverse Norwegian children from a community sample (50.8% male; mean age of 54.9 months at first assessment) and 559 such children from 8 different U.S. locales (49.0% male; approximately 54 months at the first assessment). Norwegian results showed that change in parenting predicted change in student-teacher relationships, but only in the case of children homozygous for the A allele of rs53576 and in a manner consistent with differential-susceptibility theory: for AA carriers, when parenting changed for the worse, so did children's relationship with teachers, whereas when parenting changed for the better, the teacher-child relationships improved accordingly. Such G×E findings could not be replicated in the American sample. Results are discussed in terms of 2 contrasting models of Person-×-Environment interaction (differential susceptibility and diathesis stress) and potential reasons for failure to replicate. (PsycINFO Database Record
Pub.: 05 May '17, Pinned: 08 May '17
Abstract: Accurate interpretation and appropriate expression of emotions are key aspects of social-cognition. Several mental disorders are characterised by transdiagnostic difficulties in these areas and, recently, there has been increasing interest in exploring the effects of oxytocin on social-emotional functioning. This review consists of 33 studies. Fifteen of the studies included people with autism spectrum disorder, schizophrenia, borderline personality disorder, frontotemporal dementia, anorexia nervosa, bulimia nervosa, post-traumatic stress disorder, depression, and opioid and alcohol dependence. We conducted ten meta-analyses examining the effects of intranasal oxytocin on expression of emotions, emotional theory of mind, sensitivity to recognise basic emotions, and recognition of basic emotions. A single dose of intranasal oxytocin significantly improved the recognition of basic emotions, particularly fear, and increased the expression of positive emotions among the healthy individuals. Oxytocin did not significantly influence theory of mind or the expression of negative emotions among the healthy individuals. Finally, intranasal oxytocin did not significantly influence interpretation or expression of emotions among the clinical populations.
Pub.: 04 May '17, Pinned: 08 May '17
Abstract: We critically review themushrooming literature addressing the neuralmechanisms of moral cognition (NMMC), reachingthe following broad conclusions: (1) researchmainly focuses on three inter-relatedcategories: the moral emotions, moral socialcognition, and abstract moral reasoning. (2)Research varies in terms of whether it deploysecologically valid or experimentallysimplified conceptions of moral cognition. Themore ecologically valid the experimentalregime, the broader the brain areas involved.(3) Much of the research depends on simplifyingassumptions about the domain of moral reasoningthat are motivated by the need to makeexperimental progress. This is a valuablebeginning, but as more is understood about theneural mechanisms of decision-making, morerealistic conceptions will need to replace thesimplified conceptions. (4) The neuralcorrelates of real-life moral cognition areunlikely to consist in anything remotely like a``moral module'' or a ``morality center.'' Moralrepresentations, deliberations and decisionsare probably highly distributed and notconfined to any particular brainsub-system. Discovering the basic neuralprinciples governing planning, judgment anddecision-making will require vastly more basicresearch in neuroscience, but correlatingactivity in certain brain regions withwell-defined psychological conditions helpsguide neural level research. Progress on socialphenomena will also require theoreticalinnovation in understanding the brain'sdistinctly biological form of computationthat is anchored by emotions, needs, drives,and the instinct for survival.
Pub.: 01 Jan '03, Pinned: 08 May '17
Abstract: In the last two decades, neuroscience has profoundly transformed how we understand learning, decision making, self, and social attachment. Consequently, traditional philosophical questions about mind and morality have been steered in new directions.
Pub.: 11 Nov '08, Pinned: 08 May '17
Abstract: Among its many roles in body and brain, oxytocin influences social behavior. Understanding the precise nature of this influence is crucial, both within the broader theoretical context of neurobiology, social neuroscience and brain evolution, but also within a clinical context of disorders such as anxiety, schizophrenia, and autism. Research exploring oxytocin's role in human social behavior is difficult owing to its release in both body and brain and its interactive effects with other hormones and neuromodulators. Additional difficulties are due to the intricacies of the blood-brain barrier and oxytocin's instability, which creates measurement issues. Questions concerning how to interpret behavioral results of human experiments manipulating oxytocin are thus made all the more pressing. The current paper discusses several such questions. We highlight unresolved fundamental issues about what exactly happens when oxytocin is administered intranasally, whether such oxytocin does in fact reach appropriate receptors in brain, and whether central or peripheral influences account for the observed behavioral effects. We also highlight the deeper conceptual issue of whether the human data should be narrowly interpreted as implicating a specific role for oxytocin in complex social cognition, such a generosity, trust, or mentalizing, or more broadly interpreted as implicating a lower-level general effect on general states and dispositions, such as anxiety and social motivation. Using several influential studies, we show how seemingly specific, higher-level social-cognitive effects can emerge via a process by which oxytocin's broad influence is channeled into a specific social behavior in a context of an appropriate social and research setting. This article is part of a Special Issue entitled Oxytocin, Vasopressin, and Social Behavior.
Pub.: 27 Dec '11, Pinned: 08 May '17