scholarly journals Feeding behaviour, risk-sensitivity and response control: effects of 5-HT2Creceptor manipulations

2018 ◽  
Vol 374 (1766) ◽  
pp. 20180144 ◽  
Author(s):  
Trevor Humby ◽  
Yateen Patel ◽  
Jenny Carter ◽  
Laura-Jean G. Stokes ◽  
Robert D. Rogers ◽  
...  
Keyword(s):  
Risk Taking ◽  
Impulse Control ◽  
Delay Condition ◽  
Risk Sensitivity ◽  
Variable Delay ◽  
Theme Issue ◽  
The Past ◽  
Theoretical Perspectives ◽  
Developed World ◽  
The Impact

People, like animals, tend to choose the variable option when given the choice between a fixed and variable delay to reward where, in the variable delay condition, some rewards are available immediately (Laura-Jeanet al. 2019Phil. Trans. R. Soc. B374, 20180141. (doi:10.1098/rstb.2018.0141)). This bias has been suggested to reflect evolutionary pressures resulting from food scarcity in the past placing a premium on obtaining food quickly that can win out against the risks of sometimes sustaining longer delays to food. The psychologies mediating this effect may become maladaptive in the developed world where food is readily available contributing, potentially, to overeating and obesity. Here, we report our development of a novel touchscreen task in mice allowing comparisons of the impact of food delay and food magnitude across species. We show that mice exhibit the typical preference, as shown by humans, for variable over fixed delays to rewards but no preference when it comes to fixed versus variable reward amounts and further show that this bias is sensitive to manipulations of the 5-HT2Creceptor, a key mediator of feeding and impulse control. We discuss the data in terms of the utility of the task to model the psychologies and underlying brain mechanisms impacting on feeding behaviours.This article is part of the theme issue ‘Risk taking and impulsive behaviour: fundamental discoveries, theoretical perspectives and clinical implications’.

scholarly journals Inferring recent evolutionary changes in speech sounds

2021 ◽  
Vol 376 (1824) ◽  
Author(s):  
Steven Moran ◽  
Nicholas A. Lester ◽  
Eitan Grossman
Keyword(s):  
Language Contact ◽  
Language Evolution ◽  
Speech Sounds ◽  
Theme Issue ◽  
Short Term ◽  
The Past ◽  
Evolutionary Changes ◽  
The One ◽  
The Impact

In this paper, we investigate evolutionarily recent changes in the distributions of speech sounds in the world's languages. In particular, we explore the impact of language contact in the past two millennia on today's distributions. Based on three extensive databases of phonological inventories, we analyse the discrepancies between the distribution of speech sounds of ancient and reconstructed languages, on the one hand, and those in present-day languages, on the other. Furthermore, we analyse the degree to which the diffusion of speech sounds via language contact played a role in these discrepancies. We find evidence for substantive differences between ancient and present-day distributions, as well as for the important role of language contact in shaping these distributions over time. Moreover, our findings suggest that the distributions of speech sounds across geographic macro-areas were homogenized to an observable extent in recent millennia. Our findings suggest that what we call the Implicit Uniformitarian Hypothesis, at least with respect to the composition of phonological inventories, cannot be held uncritically. Linguists who would like to draw inferences about human language based on present-day cross-linguistic distributions must consider their theories in light of even short-term language evolution. This article is part of the theme issue ‘Reconstructing prehistoric languages’.

scholarly journals Conquering the inner couch potato: precommitment is an effective strategy to enhance motivation for effortful actions

2018 ◽  
Vol 374 (1766) ◽  
pp. 20180131 ◽  
Author(s):  
Bettina Studer ◽  
Carolin Koch ◽  
Stefan Knecht ◽  
Tobias Kalenscher
Keyword(s):  
Risk Taking ◽  
Small Reward ◽  
Computational Modelling ◽  
Self Control ◽  
Clinical Implications ◽  
Theme Issue ◽  
Choice Behaviour ◽  
Impulsive Behaviour ◽  
Theoretical Perspectives ◽  
Regulatory Measure

Letting effort-free gratification derail us from effort-requiring goals is one reason why we fail to realize health-relevant intentions like ‘exercise regularly’. We tested the effectiveness of the self-control strategy precommitment in such effort-related conflicts, using a novel laboratory choice paradigm, where participants could precommit to an effort-requiring large reward by pre-eliminating an effort-free small reward from their choice set. Our participants used precommitment frequently and effectively, such that they reached effort-requiring large rewards more often. Using computational modelling and Bayesian model comparisons, we assessed whether participants employed precommitment to avoid anticipated willpower failures (i.e. as a self-regulatory measure) or to maximize their motivation to choose the effort-requiring option (i.e. as a self-motivational measure). Observed choices and precommitment decisions were consistent with the motivation maximization hypothesis, but not the willpower hypothesis. Our findings show that offering precommitment is effective in helping individuals optimize their motivation and choice behaviour and thereby achieve effort-requiring goals, and strongly encourage application of precommitment schemes in exercise and rehabilitation interventions. This article is part of the theme issue ‘Risk taking and impulsive behaviour: fundamental discoveries, theoretical perspectives and clinical implications’.

scholarly journals Why has evolution not selected for perfect self-control?

2018 ◽  
Vol 374 (1766) ◽  
pp. 20180139 ◽  
Author(s):  
Benjamin Y. Hayden
Keyword(s):  
Cognitive Control ◽  
Risk Taking ◽  
Decision Makers ◽  
Self Control ◽  
Subjective Feeling ◽  
Theme Issue ◽  
Theoretical Perspectives ◽  
Obvious Reason ◽  
Control Failures

Self-control refers to the ability to deliberately reject tempting options and instead select ones that produce greater long-term benefits. Although some apparent failures of self-control are, on closer inspection, reward maximizing, at least some self-control failures are clearly disadvantageous and non-strategic. The existence of poor self-control presents an important evolutionary puzzle because there is no obvious reason why good self-control should be more costly than poor self-control. After all, a rock is infinitely patient. I propose that self-control failures result from cases in which well-learned (and thus routinized) decision-making strategies yield suboptimal choices. These mappings persist in the decision-makers’ repertoire because they result from learning processes that are adaptive in the broader context, either on the timescale of learning or of evolution. Self-control, then, is a form of cognitive control and the subjective feeling of effort likely reflects the true costs of cognitive control. Poor self-control, in this view, is ultimately a result of bounded optimality. This article is part of the theme issue ‘Risk taking and impulsive behaviour: fundamental discoveries, theoretical perspectives and clinical implications.

scholarly journals Risk taking and impulsive behaviour: fundamental discoveries, theoretical perspectives and clinical implications

2018 ◽  
Vol 374 (1766) ◽  
pp. 20180128 ◽  
Author(s):  
Anthony R. Isles ◽  
Catharine A. Winstanley ◽  
Trevor Humby
Keyword(s):  
Obsessive Compulsive Disorder ◽  
Risk Taking ◽  
Neurodegenerative Disorders ◽  
Human Population ◽  
Clinical Implications ◽  
Theme Issue ◽  
Obsessive Compulsive ◽  
Compulsive Disorder ◽  
Impulsive Behaviour ◽  
Theoretical Perspectives

Our willingness to take risks, our ability to wait or the speed with which to make decisions are central features of our personality. However, it is now recognized that impulsive and risk-taking behaviours are not a unitary construct, and different aspects can be both psychologically and neurally dissociated. The range of neurochemicals and brain systems that govern these behaviours is extensive, and this may be a contributing factor to the phenotypic range seen in the human population. However, this variety can also be pathological as extremes in risk-taking and impulsive behaviours are characteristics of many neuropsychiatric and indeed neurodegenerative disorders. This spans obsessive–compulsive disorder, where behaviour becomes ridged and non-spontaneous, to the nonsensical risk-taking seen in gambling and drug taking. This article is part of the theme issue ‘Risk taking and impulsive behaviour: fundamental discoveries, theoretical perspectives and clinical implications'.

scholarly journals Decolonizing the criminal question

2021 ◽  
pp. 146247452110205
Author(s):  
Ana Aliverti ◽  
Henrique Carvalho ◽  
Anastasia Chamberlen ◽  
Máximo Sozzo
Keyword(s):  
Criminal Justice ◽  
Crime Control ◽  
Intimate Relationship ◽  
Production Of Knowledge ◽  
The Past ◽  
Theoretical Perspectives ◽  
Critical Account ◽  
Justice Practice ◽  
The Impact

In the last years there has been a growing effort from different theoretical perspectives to interrogate critically the impact of colonialism in the past and present of institutions and practices of crime control, both at the central and peripheral contexts, as well as in the production of knowledge in the criminological field. In this feature piece we examine this debate. We offer a critical account of key themes and problems that emerge from the intimate relationship between colonialism and punishment that directly challenge the persistent neglect of these dimensions in mainstream criminological scholarship. We aim to foreground the relevance of this relationship to contemporary enquiries. We highlight that decolonization did not dismantle the colonial roots of the cultural, social and political mechanisms informing contemporary punishment. They are still very much part of criminal justice practice and are thus also central to criminological knowledge productions.

scholarly journals Computational psychiatry of impulsivity and risk: how risk and time preferences interact in health and disease

2018 ◽  
Vol 374 (1766) ◽  
pp. 20180135 ◽  
Author(s):  
Silvia Lopez-Guzman ◽  
Anna B. Konova ◽  
Paul W. Glimcher
Keyword(s):  
Risk Taking ◽  
Temporal Discounting ◽  
Time Preferences ◽  
Clinical Implications ◽  
Mathematical Relationship ◽  
Theme Issue ◽  
Impulsive Behaviour ◽  
Theoretical Perspectives ◽  
Subjective Value ◽  
Health And Disease

Choice impulsivity is an important subcomponent of the broader construct of impulsivity and is a key feature of many psychiatric disorders. Choice impulsivity is typically quantified as temporal discounting , a well-documented phenomenon in which a reward's subjective value diminishes as the delay to its delivery is increased. However, an individual's proclivity to—or more commonly aversion to— risk can influence nearly all of the standard experimental tools available for measuring temporal discounting. Despite this interaction, risk preference is a behaviourally and neurobiologically distinct construct that relates to the economic notion of utility or subjective value. In this opinion piece, we discuss the mathematical relationship between risk preferences and time preferences, their neural implementation, and propose ways that research in psychiatry could, and perhaps should, aim to account for this relationship experimentally to better understand choice impulsivity and its clinical implications. This article is part of the theme issue ‘Risk taking and impulsive behaviour: fundamental discoveries, theoretical perspectives and clinical implications’.

scholarly journals Interactions of immediate and long-term action regulation in the course and complications of bipolar disorder

2018 ◽  
Vol 374 (1766) ◽  
pp. 20180132 ◽  
Author(s):  
Marijn Lijffijt ◽  
Brittany O'Brien ◽  
Ramiro Salas ◽  
Sanjay J. Mathew ◽  
Alan C. Swann
Keyword(s):  
Bipolar Disorder ◽  
Risk Taking ◽  
Treatment Strategies ◽  
Behavioural Disorders ◽  
Theme Issue ◽  
Impulsive Behaviour ◽  
Behavioural Sensitization ◽  
Theoretical Perspectives ◽  
Clinical Consequences

Immediate and long-term mechanisms interact in the regulation of action. We will examine neurobiology and practical clinical consequences of these interactions. Long-term regulation of immediate behavioural control is based on analogous responses to highly rewarding or stressful stimuli: (i) impulsivity is a failure of the balance between activation and inhibition in the immediate regulation of action. (ii) Sensitization is a persistently exaggerated behavioural or physiological response to highly salient stimuli, such as addictive stimuli or inescapable stress. Sensitization can generalize across classes of stimuli. (iii) Impulsivity, possibly related to poor modulation of catecholaminergic and glutamatergic functions, may facilitate development of long-term sensitized responses to stressful or addictive stimuli. In turn, impulsivity is prominent in sensitized behaviour. (iv) While impulsivity and sensitization are general components of behaviour, their interactions are prominent in the course of bipolar disorder, emphasizing roles of substance-use, recurrent course and stressors. (v) Suicide is a complex and severe behaviour that exemplifies the manner in which impulsivity facilitates behavioural sensitization and is, in turn, increased by it, leading to inherently unpredictable behaviour. (vi) Interactions between impulsivity and sensitization can provide targets for complementary preventive and treatment strategies for severe immediate and long-term behavioural disorders. Progress along these lines will be facilitated by predictors of susceptibility to behavioural sensitization. This article is part of the theme issue ‘Risk taking and impulsive behaviour: fundamental discoveries, theoretical perspectives and clinical implications’.

scholarly journals Intestinal helminths as a biomolecular complex in archaeological research

2020 ◽  
Vol 375 (1812) ◽  
pp. 20190570 ◽  
Author(s):  
Patrik G. Flammer ◽  
Adrian L. Smith
Keyword(s):  
High Impact ◽  
Archaeological Research ◽  
Intestinal Helminths ◽  
Theme Issue ◽  
The Past ◽  
Helminth Eggs ◽  
Large Numbers ◽  
Health And Disease ◽  
The Impact ◽  
Microscopic Techniques

Enteric helminths are common parasites in many parts of the world and in the past were much more widespread both geographically and socially. Many enteric helminths are relatively long-lived in the human host, often benign or of low pathogenicity while producing large numbers of environmentally resistant eggs voided in the faeces or found associated with individual remains (skeletons and mummies). The combination of helminth characters offers opportunities to the field of historical pathogen research that are quite different to that of some of the more intensively studied high impact pathogens. Historically, a wealth of studies has employed microscopic techniques to diagnose infection using the morphology of the helminth eggs. More recently, various ancient DNA (aDNA) approaches have been applied in the archaeoparasitological context and these are revolutionizing the field, allowing much more specific diagnosis as well as interrogating the epidemiology of helminths. These advances have enhanced the potential for the field to provide unique information on past populations including using diseases to consider many aspects of life (e.g. sanitation, hygiene, diet, culinary practices and other aspects of society). Here, we consider the impact of helminth archaeoparasitology and more specifically the impact and potential for application of aDNA technologies as a part of the archaeologists' toolkit. This article is part of the theme issue ‘Insights into health and disease from ancient biomolecules’.

scholarly journals Neural circuitry and mechanisms of waiting impulsivity: relevance to addiction

2018 ◽  
Vol 374 (1766) ◽  
pp. 20180145 ◽  
Author(s):  
Jeffrey W. Dalley ◽  
Karen D. Ersche
Keyword(s):  
Translational Research ◽  
Drug Addiction ◽  
Risk Taking ◽  
Impulse Control ◽  
Biomarker Discovery ◽  
Monetary Incentives ◽  
Negative Consequences ◽  
Hyperactivity Disorder ◽  
Theoretical Perspectives ◽  
Personal Harm

Impatience—the failure to wait or tolerate delayed rewards (e.g. food, drug and monetary incentives)—is a common behavioural tendency in humans. However, when rigidly and rapidly expressed with limited regard for future, often negative consequences, impatient or impulsive actions underlie and confer susceptibility for such diverse brain disorders as drug addiction, attention-deficit hyperactivity disorder (ADHD) and major depressive disorder. Consequently, ‘waiting’ impulsivity has emerged as a candidate endophenotype to inform translational research on underlying neurobiological mechanisms and biomarker discovery for many of the so-called impulse-control disorders. Indeed, as reviewed in this article, this research enterprise has revealed a number of unexpected targets and mechanisms for intervention. However, in the context of drug addiction, impulsive decisions that maximize short-term gains (e.g. acute drug consumption) over longer-term punishment (e.g. unemployment, homelessness, personal harm) defines one aspect of impulsivity, which may or may not be related to rapid, unrestrained actions over shorter timescales. We discuss the relevance of this distinction in impulsivity subtypes for drug addiction with reference to translational research in humans and other animals. This article is part of the theme issue ‘Risk taking and impulsive behaviour: fundamental discoveries, theoretical perspectives and clinical implications’.

scholarly journals Optimize the Banker’s Multi-Stage Decision-Making and the Mechanism of Pay Contract Influencing on Bank Default Risk in the Long-Term Model

2020 ◽  
Vol 12 (4) ◽  
pp. 1400
Author(s):  
Tianyi Ma ◽  
Minghui Jiang ◽  
Xuchuan Yuan
Keyword(s):  
Decision Making ◽  
Risk Taking ◽  
Default Risk ◽  
Optimal Decision ◽  
Risk Level ◽  
The Past ◽  
Multi Stage ◽  
Using Data ◽  
The Impact

In recent years, researchers have been devoted to illustrating the correlation between bankers’ pay contracts and a bank’s risk-taking behavior where corporate governance is concerned, especially throughout the past four decades and by using empirical analysis. Despite being a widespread concern, the causality of this relationship is not thoroughly understood. We initiate this research by modeling bankers’ multi-stage decisions of option investment and bond investment from the perspective of theoretical analysis, and by analyzing the function image results using data from Wells Fargo & Co. from the ExecuComp, BvD Orbis, and CRSP-COMPUSTAT databases. We aim to deeply explore the mechanism of how compensation influencing on risk. We are the first to find that it has a “risk cap”, which is the optimal risk level to maximize the return of decision-making. We are also the first to discover the optimal decision coefficient level to maximize the decision return, during which the internal causes and mechanisms of the impact of bankers’ compensation on a bank’s default risk are revealed. We also illustrate the influence of the number of periods. We expect our findings to provide advice for establishing policies when designing pay contracts.

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