Welcome to the Nexus of Ethics, Psychology, Morality, Philosophy and Health Care

Welcome to the nexus of ethics, psychology, morality, technology, health care, and philosophy
Showing posts with label Neurochemistry. Show all posts
Showing posts with label Neurochemistry. Show all posts

Thursday, September 22, 2022

Freezing revisited: coordinated autonomic and central optimization of threat coping

Roelofs, K., Dayan, P. 
Nat Rev Neurosci 23, 568–580 (2022).
https://doi.org/10.1038/s41583-022-00608-2

Abstract

Animals have sophisticated mechanisms for coping with danger. Freezing is a unique state that, upon threat detection, allows evidence to be gathered, response possibilities to be previsioned and preparations to be made for worst-case fight or flight. We propose that — rather than reflecting a passive fear state — the particular somatic and cognitive characteristics of freezing help to conceal overt responses, while optimizing sensory processing and action preparation. Critical for these functions are the neurotransmitters noradrenaline and acetylcholine, which modulate neural information processing and also control the sympathetic and parasympathetic branches of the autonomic nervous system. However, the interactions between autonomic systems and the brain during freezing, and the way in which they jointly coordinate responses, remain incompletely explored. We review the joint actions of these systems and offer a novel computational framework to describe their temporally harmonized integration. This reconceptualization of freezing has implications for its role in decision-making under threat and for psychopathology.

Conclusions and future directions

Considering the post encounter threat state from neural, psychological and computational perspectives has shown how the most obvious external characteristic of this state — a particular form of active freezing arising from co-activation of the normally opposed sympathetic and parasympathetic branches of the ANS — could have various advantages from the viewpoints of both information processing and fast Pavlovian or instrumental action. Descending control of this state is quite well understood, and the potential benefits of expending effort on enhancing unbiased, bottom-up, sensory processing and engaging in planning are easy to observe. However, the roles of ascending neuromodulators in engaging these forms of appropriate information processing are less clear.  Certainly, various of the modes of action of ACh and NA in the CNS are in a position to achieve some of this; but much remains to be discovered by precisely recording and manipulating the candidate circuits within the timeframes of the detection, evaluation and action stages.

One important source of ideas is evolutionary theory. For instance, the polyvagal theory of the phylogeny of the ANS suggests that it progressed in three stages. The first, associated with an unmyelinated vagus nerve, allowed metabolic activity to be depressed in response to threat and also controlled aspects of digestion. The second stage was associated with the sympathetic nervous system, which organized energized behaviour for fight or flight. The third stage was associated with a myelinated vagus nerve and allowed for more flexible and sophisticated responding. It has been suggested that the last stage is particularly involved in the evolution of somatic regulation in a social context; but the evolutionary layering of the competition and cooperation between the inhibitory and activating aspects of the different branches of the ANS is notable. It would be interesting to understand the parallel evolution of cholinergic and noradrenergic neuromodulation in the CNS. 


Note: We are primates subject to the principles of biology and evolution.

Friday, July 12, 2019

The Troubled History of Psychiatry

Jerome Groopman
The New Yorker
Originally posted May 20, 2019

Here is an excerpt:

Yet, despite the phenomenal success of Prozac, and of other SSRIs, no one has been able to produce definitive experimental proof establishing neurochemical imbalances as the pathogenesis of mental illness. Indeed, quite a lot of evidence calls the assumption into question. Clinical trials have stirred up intense controversy about whether antidepressants greatly outperform the placebo effect. And, while SSRIs do boost serotonin, it doesn’t appear that people with depression have unusually low serotonin levels. What’s more, advances in psychopharmacology have been incremental at best; Harrington quotes the eminent psychiatrist Steven Hyman’s assessment that “no new drug targets or therapeutic mechanisms of real significance have been developed for more than four decades.” This doesn’t mean that the available psychiatric medication isn’t beneficial. But some drugs seem to work well for some people and not others, and a patient who gets no benefit from one may do well on another. For a psychiatrist, writing a prescription remains as much an art as a science.

Harrington’s book closes on a sombre note. In America, the final decade of the twentieth century was declared the Decade of the Brain. But, in 2010, the director of the National Institute of Mental Health reflected that the initiative hadn’t produced any marked increase in rates of recovery from mental illness. Harrington calls for an end to triumphalist claims and urges a willingness to acknowledge what we don’t know.

Although psychiatry has yet to find the pathogenesis of most mental illness, it’s important to remember that medical treatment is often beneficial even when pathogenesis remains unknown. After all, what I was taught about peptic ulcers and stress wasn’t entirely useless; though we now know that stress doesn’t cause ulcers, it can exacerbate their symptoms. Even in instances where the discovery of pathogenesis has produced medical successes, it has often worked in tandem with other factors. Without the discovery of H.I.V. we would not have antiretroviral drugs, and yet the halt in the spread of the disease owes much to simple innovations, such as safe-sex education and the distribution of free needles and condoms.

The info is here.

Wednesday, June 8, 2016

Are You Morally Modified?: The Moral Effects of Widely Used Pharmaceuticals

Neil Levy, Thomas Douglas, Guy Kahane, Sylvia Terbeck, Philip J. Cowen, Miles
Hewstone, and Julian Savulescu
Philos Psychiatr Psychol. 2014 June 1; 21(2): 111–125.
doi:10.1353/ppp.2014.0023.

Abstract

A number of concerns have been raised about the possible future use of pharmaceuticals designed
to enhance cognitive, affective, and motivational processes, particularly where the aim is to
produce morally better decisions or behavior. In this article, we draw attention to what is arguably
a more worrying possibility: that pharmaceuticals currently in widespread therapeutic use are
already having unintended effects on these processes, and thus on moral decision making and
morally significant behavior. We review current evidence on the moral effects of three widely
used drugs or drug types: (i) propranolol, (ii) selective serotonin reuptake inhibitors, and (iii)
drugs that effect oxytocin physiology. This evidence suggests that the alterations to moral decision
making and behavior caused by these agents may have important and difficult-to-evaluate
consequences, at least at the population level. We argue that the moral effects of these and other
widely used pharmaceuticals warrant further empirical research and ethical analysis.

The paper is here.

Soon we’ll use science to make people more moral

By James J. Hughes
The Washington Post
Originally posted May 19, 2016

Here is an excerpt:

he emerging debate over the use of drugs and devices for moral enhancement has had three principal viewpoints: those who focus on boosting moral sentiments such as empathy; those who would just boost moral reasoning; and the skeptics. While the former two groups accept the goal of moral enhancement — and differ over the best method — the skeptics reject the project. They argue that moral enhancement therapies are overhyped, and that even if morality drugs were effective, they would be bad for our character to rely on them.

It is certainly true that the initial enthusiasm for certain moral enhancement therapies has been tempered by subsequent research. Dozens of studies have suggested that genes that regulate oxytocin, the “cuddle hormone,” affect trust and empathy, and that empathy is boosted when subjects snort oxytocin. But it now appears that the effects of boosting oxytocin were over-reported and that some of the hormone’s effects are less than cuddly — oxytocin tends to boost empathy only for people like us, increasing ethnocentric “in-group bias.”

The article is here.

Tuesday, July 28, 2015

Parkinson’s and depression drugs can alter moral judgment

By Hannah Devlin
The Guardian
Originally posted July 2, 2015

Common drugs for depression and Parkinson’s can sway people’s moral judgments about harming others, according to research that raises ethical questions about the use of the drugs.

The study found that when healthy people were given a one-off dose of a serotonin-boosting drug widely used to treat depression they became more protective of others, paying almost twice as much to prevent them receiving an electric shock in a laboratory experiment. They also became more reluctant to expose themselves to pain.

The scientists also found that the dopamine-enhancing Parkinson’s drug, levodopa, made healthy people more selfish, wiping out the normal tendency to prefer to receive an electric shock themselves, while sparing those around them.

The entire article is here.

Dopamine Modulates Egalitarian Behavior in Humans

Ignacio Sáez, Lusha Zhu, Eric Set, Andrew Kayser, Ming Hsu
Current Biology (2015) March, Volume 25, Issue 7, p. 912–919

Summary

Egalitarian motives form a powerful force in promoting prosocial behavior and enabling large-scale cooperation in the human species. At the neural level, there is substantial, albeit correlational, evidence suggesting a link between dopamine and such behavior. However, important questions remain about the specific role of dopamine in setting or modulating behavioral sensitivity to prosocial concerns. Here, using a combination of pharmacological tools and economic games, we provide critical evidence for a causal involvement of dopamine in human egalitarian tendencies. Specifically, using the brain penetrant catechol-O-methyl transferase (COMT) inhibitor tolcapone, we investigated the causal relationship between dopaminergic mechanisms and two prosocial concerns at the core of a number of widely used economic games: (1) the extent to which individuals directly value the material payoffs of others, i.e., generosity, and (2) the extent to which they are averse to differences between their own payoffs and those of others, i.e., inequity. We found that dopaminergic augmentation via COMT inhibition increased egalitarian tendencies in participants who played an extended version of the dictator game. Strikingly, computational modeling of choice behavior revealed that tolcapone exerted selective effects on inequity aversion, and not on other computational components such as the extent to which individuals directly value the material payoffs of others. Together, these data shed light on the causal relationship between neurochemical systems and human prosocial behavior and have potential implications for our understanding of the complex array of social impairments accompanying neuropsychiatric disorders involving dopaminergic dysregulation.

The entire article is here.

Saturday, July 25, 2015

Economic Games and Social Neuroscience Methods Can Help Elucidate The Psychology of Parochial Altruism

Everett Jim A.C., Faber Nadira S., Crockett Molly J, De Dreu Carsten K W
Opinion Article
Front. Psychol. | doi: 10.3389/fpsyg.2015.00861

The success of Homo sapiens can in large part be attributed to their highly social nature, and particularly their ability to live and work together in extended social groups. Throughout history, humans have undergone sacrifices to both advance and defend the interests of fellow group members against non-group members. Intrigued by this, researchers from multiple disciplines have attempted to explain the psychological origins and processes of parochial altruism: the well-documented tendency for increased cooperation and prosocial behavior within the boundaries of a group (akin to ingroup love, and ingroup favoritism), and second, the propensity to reject, derogate, and even harm outgroup members (akin to ‘outgroup hate’, e.g. Brewer, 1999; Choi & Bowles, 2007; De Dreu, Balliet, & Halevy, 2014, Hewstone, Rubin, & Willis, 2002; Rusch, 2014; Tajfel & Turner, 1979). Befitting its centrality to a wide range of human social endeavors, parochial altruism is manifested in a large variety of contexts that may differ psychologically. Sometimes, group members help others to achieve a positive outcome (e.g. gain money); and sometimes group members help others avoid a negative outcome (e.g. avoid being robbed). Sometimes, group members conflict over a new resource (e.g. status; money; land) that is currently ‘unclaimed’; and sometimes they conflict over a resource that is already held by one group.

The entire article is here.