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John O'Doherty

John P O'Doherty, Jeffrey Cockburn, Wolfgang M Pauli
In this review, we summarize findings supporting the existence of multiple behavioral strategies for controlling reward-related behavior, including a dichotomy between the goal-directed or model-based system and the habitual or model-free system in the domain of instrumental conditioning and a similar dichotomy in the realm of Pavlovian conditioning. We evaluate evidence from neuroscience supporting the existence of at least partly distinct neuronal substrates contributing to the key computations necessary for the function of these different control systems...
September 28, 2016: Annual Review of Psychology
Jean-Claude Dreher, Simon Dunne, Agnieszka Pazderska, Thomas Frodl, John J Nolan, John P O'Doherty
Although popular discussion of testosterone's influence on males often centers on aggression and antisocial behavior, contemporary theorists have proposed that it instead enhances behaviors involved in obtaining and maintaining a high social status. Two central distinguishing but untested predictions of this theory are that testosterone selectively increases status-relevant aggressive behaviors, such as responses to provocation, but that it also promotes nonaggressive behaviors, such as generosity toward others, when they are appropriate for increasing status...
October 11, 2016: Proceedings of the National Academy of Sciences of the United States of America
Olugbeminiyi Fadeyi, Mihir Parikh, Ming Chen, Robert Kyne, Alexandria Taylor, Inish O'Doherty, Stephen Kaiser, Sabrina Barbas, Sherry Niessen, Manli Shi, Scott L Weinrich, John Kath, Lyn Jones, Ralph Pelton Robinson
Sulfonyl fluoride (SF)-based activity probes have become important tools in chemical biology. Herein, exploiting the relative chemical stability of SF to carry out a number of unprecedented SF-sparing functional group manipulations, we report the chemoselective synthesis of a toolbox of highly functionalized aryl SF monomers that we have used to quickly prepare SF chemical biology probes. In addition to SF, the monomers bear an embedded click handle (a terminal alkyne that can perform copper(I)-mediated azide alkyne cycloaddition)...
August 9, 2016: Chembiochem: a European Journal of Chemical Biology
Aoife Hayes, Sarah Duffy, Michael O'Grady, Jette Jakobsen, Karen Galvin, Joanna Teahan-Dillon, Joseph Kerry, Alan Kelly, John O'Doherty, Siobhan Higgins, Kelly M Seamans, Kevin D Cashman
BACKGROUND: Despite numerous animal studies that have illustrated the impact of additional vitamin D in the diet of hens on the resulting egg vitamin D content, the effect of the consumption of such eggs on vitamin D status of healthy individuals has not, to our knowledge, been tested. OBJECTIVE: We performed a randomized controlled trial (RCT) to investigate the effect of the consumption of vitamin D-enhanced eggs (produced by feeding hens at the maximum concentration of vitamin D3 or serum 25-hydroxyvitamin D [25(OH)D3] lawfully allowed in feed) on winter serum 25(OH)D in healthy adults...
September 2016: American Journal of Clinical Nutrition
Bojlul Bahar, John V O'Doherty, Stafford Vigors, Torres Sweeney
The technique of challenging post-mortem tissue explant with inflammation inducer such as LPS followed by gene expression analysis is widely used for evaluating the immune suppressing effect of bioactives. Using porcine colonic tissue as an ex-vivo model of mammalian intestinal gut, this study evaluated the effect of incubation time on the integrity of gene transcripts and activation of inflammatory immune gene cascade by LPS treatment. Post-slaughter colon was surgically removed and explants were incubated for 0, 3, 6 and 12 h and the abundance of mRNA transcripts of a panel of 92 immune genes were evaluated using quantitative PCR (qPCR) arrays...
July 12, 2016: Clinical and Experimental Immunology
Karl Friston, Thomas FitzGerald, Francesco Rigoli, Philipp Schwartenbeck, John O'Doherty, Giovanni Pezzulo
This paper offers an active inference account of choice behaviour and learning. It focuses on the distinction between goal-directed and habitual behaviour and how they contextualise each other. We show that habits emerge naturally (and autodidactically) from sequential policy optimisation when agents are equipped with state-action policies. In active inference, behaviour has explorative (epistemic) and exploitative (pragmatic) aspects that are sensitive to ambiguity and risk respectively, where epistemic (ambiguity-resolving) behaviour enables pragmatic (reward-seeking) behaviour and the subsequent emergence of habits...
September 2016: Neuroscience and Biobehavioral Reviews
Peter Johnson, Massimo Federico, Amy Kirkwood, Alexander Fosså, Leanne Berkahn, Angelo Carella, Francesco d'Amore, Gunilla Enblad, Antonella Franceschetto, Michael Fulham, Stefano Luminari, Michael O'Doherty, Pip Patrick, Thomas Roberts, Gamal Sidra, Lindsey Stevens, Paul Smith, Judith Trotman, Zaid Viney, John Radford, Sally Barrington
BACKGROUND: We tested interim positron-emission tomography-computed tomography (PET-CT) as a measure of early response to chemotherapy in order to guide treatment for patients with advanced Hodgkin's lymphoma. METHODS: Patients with newly diagnosed advanced classic Hodgkin's lymphoma underwent a baseline PET-CT scan, received two cycles of ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) chemotherapy, and then underwent an interim PET-CT scan. Images were centrally reviewed with the use of a 5-point scale for PET findings...
June 23, 2016: New England Journal of Medicine
Wolfgang M Pauli, John P O'Doherty
No abstract text is available yet for this article.
June 1, 2016: Biological Psychiatry
Simon Dunne, Arun D'Souza, John P O'Doherty
A major open question is whether computational strategies thought to be used during experiential learning, specifically model-based and model-free reinforcement learning, also support observational learning. Furthermore, the question of how observational learning occurs when observers must learn about the value of options from observing outcomes in the absence of choice has not been addressed. In the present study we used a multi-armed bandit task that encouraged human participants to employ both experiential and observational learning while they underwent functional magnetic resonance imaging (fMRI)...
June 1, 2016: Journal of Neurophysiology
Shinsuke Suzuki, Emily L S Jensen, Peter Bossaerts, John P O'Doherty
Our attitude toward risk plays a crucial role in influencing our everyday decision-making. Despite its importance, little is known about how human risk-preference can be modulated by observing risky behavior in other agents at either the behavioral or the neural level. Using fMRI combined with computational modeling of behavioral data, we show that human risk-preference can be systematically altered by the act of observing and learning from others' risk-related decisions. The contagion is driven specifically by brain regions involved in the assessment of risk: the behavioral shift is implemented via a neural representation of risk in the caudate nucleus, whereas the representations of other decision-related variables such as expected value are not affected...
April 5, 2016: Proceedings of the National Academy of Sciences of the United States of America
Áine M Egan, John V O'Doherty, Stafford Vigors, Torres Sweeney
The crustacean shells-derived polysaccharide chitosan has received much attention for its anti-obesity potential. Dietary supplementation of chitosan has been linked with reductions in feed intake, suggesting a potential link between chitosan and appetite control. Hence the objective of this experiment was to investigate the appetite suppressing potential of prawn shell derived chitosan in a pig model. Pigs (70 ± 0.90 kg, 125 days of age, SD 2.0) were fed either T1) basal diet or T2) basal diet plus 1000 ppm chitosan (n = 20 gilts per group) for 63 days...
2016: PloS One
Stafford Vigors, John V O'Doherty, Alan K Kelly, Cormac J O'Shea, Torres Sweeney
Feed efficiency is an important trait in pig production, with evidence to suggest that the efficiencies of a variety of biological systems contribute to variation in this trait. Little work has been conducted on the contribution of the intestinal innate immune response to divergence in feed efficiency. Hence, the objective of this study was to examine select bacterial populations and gene expression profiles of a range of targets relating to gut health and immunity in the intestine of pigs phenotypically divergent in feed efficiency in: a) the basal state; and (b) following an ex-vivo lipopolysaccharide (LPS) challenge of ileal and colonic tissue...
2016: PloS One
Sally F Barrington, Amy A Kirkwood, Antonella Franceschetto, Michael J Fulham, Thomas H Roberts, Helén Almquist, Eva Brun, Karin Hjorthaug, Zaid N Viney, Lucy C Pike, Massimo Federico, Stefano Luminari, John Radford, Judith Trotman, Alexander Fosså, Leanne Berkahn, Daniel Molin, Francesco D'Amore, Donald A Sinclair, Paul Smith, Michael J O'Doherty, Lindsey Stevens, Peter W Johnson
International guidelines recommend that positron emission tomography-computed tomography (PET-CT) should replace CT in Hodgkin lymphoma (HL). The aims of this study were to compare PET-CT with CT for staging and measure agreement between expert and local readers, using a 5-point scale (Deauville criteria), to adapt treatment in a clinical trial: Response-Adapted Therapy in Advanced Hodgkin Lymphoma (RATHL). Patients were staged using clinical assessment, CT, and bone marrow biopsy (RATHL stage). PET-CT was performed at baseline (PET0) and after 2 chemotherapy cycles (PET2) in a response-adapted design...
March 24, 2016: Blood
Áine M Egan, Torres Sweeney, Maria Hayes, John V O'Doherty
The potential of natural products to prevent obesity have been investigated, with evidence to suggest that chitosan has anti-obesity effects. The current experiment investigated the anti-obesity potential of prawn shell derived chitosan on a range of variables relevant to obesity in a pig model. The two dietary treatment groups included in this 63 day study were: T1) basal diet and T2) basal diet plus 1000 ppm chitosan (n = 20 gilts per group (70 ± 0.90 kg). The parameter categories which were assessed included: performance, nutrient digestibility, serum leptin concentrations, nutrient transporter and digestive enzyme gene expression and gut microbial populations...
2015: PloS One
Dimitrije Marković, Jan Gläscher, Peter Bossaerts, John O'Doherty, Stefan J Kiebel
For making decisions in everyday life we often have first to infer the set of environmental features that are relevant for the current task. Here we investigated the computational mechanisms underlying the evolution of beliefs about the relevance of environmental features in a dynamical and noisy environment. For this purpose we designed a probabilistic Wisconsin card sorting task (WCST) with belief solicitation, in which subjects were presented with stimuli composed of multiple visual features. At each moment in time a particular feature was relevant for obtaining reward, and participants had to infer which feature was relevant and report their beliefs accordingly...
October 2015: PLoS Computational Biology
Wolfgang M Pauli, Tobias Larsen, Sven Collette, Julian M Tyszka, Ben Seymour, John P O'Doherty
UNLABELLED: The role of neurons in the substantia nigra (SN) and ventral tegmental area (VTA) of the midbrain in contributing to the elicitation of reward prediction errors during appetitive learning has been well established. Less is known about the differential contribution of these midbrain regions to appetitive versus aversive learning, especially in humans. Here we scanned human participants with high-resolution fMRI focused on the SN and VTA while they participated in a sequential Pavlovian conditioning paradigm involving an appetitive outcome (a pleasant juice), as well as an aversive outcome (an unpleasant bitter and salty flavor)...
October 21, 2015: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Fátima O Martins, Teresa C Delgado, Joana Viegas, Joana M Gaspar, Donald K Scott, Robert M O'Doherty, M Paula Macedo, John G Jones
BACKGROUND AND PURPOSE: Thiazolidinediones (TZD) are known to ameliorate fatty liver in type 2 diabetes. To date, the underlying mechanisms of their hepatic actions remain unclear. EXPERIMENTAL APPROACH: Hepatic triglyceride content and export rates were assessed in 2 week high-sucrose-fed Wistar rats treated with troglitazone and compared with untreated high-sucrose rodent controls. Fractional de novo lipogenesis (DNL) contributions to hepatic triglyceride were quantified by analysis of triglyceride enrichment from deuterated water...
January 2016: British Journal of Pharmacology
John P O'Doherty
In this chapter, we will review evidence about the role of multiple distinct systems in driving the motivation to perform actions in humans. Specifically, we will consider the contribution of goal-directed action selection mechanisms, habitual action selection mechanisms and the influence of Pavlovian predictors on instrumental action selection. We will further evaluate evidence for the contribution of multiple brain areas including ventral frontal and dorsal cortical areas and several distinct parts of the striatum in these processes...
2016: Current Topics in Behavioral Neurosciences
Friedrich Wetterling, Hazel McCarthy, Leonardo Tozzi, Norbert Skokauskas, John P O'Doherty, Aisling Mulligan, James Meaney, Andrew J Fagan, Michael Gill, Thomas Frodl
Symptoms of attention deficit hyperactivity disorder (ADHD) in children often persist into adulthood and can lead to severe antisocial behavior. However, to-date it remains unclear whether neuro-functional abnormalities cause ADHD, which in turn can then provide a marker of persistent ADHD. Using event-related functional magnetic resonance imaging (fMRI), we measured blood oxygenation level dependent (BOLD) signal changes in subjects during a reversal learning task in which choice of the correct stimulus led to a probabilistically determined 'monetary' reward or punishment...
November 2015: Human Brain Mapping
Jan P Gläscher, John P O'Doherty
The combination of functional magnetic resonance imaging (fMRI) with computational models for a given cognitive process provides a powerful framework for testing hypotheses about the neural computations underlying such processes in the brain. Here, we outline the steps involved in implementing this approach with reference to the application of reinforcement learning (RL) models that can account for human choice behavior during value-based decision making. The model generates internal variables which can be used to construct fMRI predictor variables and regressed against individual subjects' fMRI data...
July 2010: Wiley Interdisciplinary Reviews. Cognitive Science
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