Showing papers by "Trevor W. Robbins published in 2012"
TL;DR: It is argued that a biological approach to psychiatry based on 'neurocognitive endophenotypes', whereby changes in behavioural or cognitive processes are associated with discrete deficits in defined neural systems, has important implications for the future classification of psychiatric disorders, genetics and therapeutics.
802 citations
TL;DR: Evidence points to a dissociation between the relatively slow, linear development of impulse control and response inhibition during adolescence versus the nonlinear development of the reward system, which is often hyper-responsive to rewards in adolescence.
Abstract: This review compares and contrasts decision-making processes in adults versus adolescents, to highlight how adolescent decision-making is particularly susceptible to modulation by emotional and social factors (such as peer pressure).
550 citations
TL;DR: Brain abnormalities discovered in fronto-striatal brain systems implicated in self-control in both stimulant-dependent individuals and their biological siblings who have no history of chronic drug abuse support the idea of an underlying neurocognitive endophenotype for stimulant drug addiction.
Abstract: Addiction to drugs is a major contemporary public health issue, characterized by maladaptive behavior to obtain and consume an increasing amount of drugs at the expense of the individual's health and social and personal life. We discovered abnormalities in fronto-striatal brain systems implicated in self-control in both stimulant-dependent individuals and their biological siblings who have no history of chronic drug abuse; these findings support the idea of an underlying neurocognitive endophenotype for stimulant drug addiction.
480 citations
University of Vermont1, Université de Montréal2, King's College London3, French Alternative Energies and Atomic Energy Commission4, University of Queensland5, Trinity College, Dublin6, Heidelberg University7, Charité8, German National Metrology Institute9, Paris Descartes University10, French Institute of Health and Medical Research11, University of Nottingham12, McGill University13, University of Toronto14, Dresden University of Technology15, University of Sussex16, University of Cambridge17
TL;DR: The results indicate that both neural endophenotypes and genetic variation give rise to the various manifestations of impulsive behavior.
Abstract: The impulsive behavior that is often characteristic of adolescence may reflect underlying neurodevelopmental processes. Moreover, impulsivity is a multi-dimensional construct, and it is plausible that distinct brain networks contribute to its different cognitive, clinical and behavioral aspects. As these networks have not yet been described, we identified distinct cortical and subcortical networks underlying successful inhibitions and inhibition failures in a large sample (n = 1,896) of 14-year-old adolescents. Different networks were associated with drug use (n = 1,593) and attention-deficit hyperactivity disorder symptoms (n = 342). Hypofunctioning of a specific orbitofrontal cortical network was associated with likelihood of initiating drug use in early adolescence. Right inferior frontal activity was related to the speed of the inhibition process (n = 826) and use of illegal substances and associated with genetic variation in a norepinephrine transporter gene (n = 819). Our results indicate that both neural endophenotypes and genetic variation give rise to the various manifestations of impulsive behavior.
394 citations
TL;DR: Deficits in executive function and response regulation as well as anxious-impulsive personality traits may represent endophenotypes associated with the risk of developing cocaine or amphetamine dependence and may be useful in facilitating the rational development of therapeutic and preventive strategies.
Abstract: ObjectiveNot everyone who takes drugs becomes addicted, but the likelihood of developing drug addiction is greater in people with a family history of drug or alcohol dependence. Relatively little is known about how genetic risk mediates the development of drug dependence. By comparing the phenotypic profile of individuals with and without a family history of addiction, the authors sought to clarify the extent to which cognitive dysfunction and personality traits are shared by family members—and therefore likely to have predated drug dependence—and which aspects are specific to drug-dependent individuals.MethodThe authors assessed cognitive function and personality traits associated with drug dependence in stimulant-dependent individuals (N=50), their biological siblings without a history of drug dependence (N=50), and unrelated healthy volunteers (N=50).ResultsCognitive function was significantly impaired in the stimulant-dependent individuals across a range of domains. Deficits in executive function and ...
209 citations
TL;DR: Risk taking and functional and structural properties of the reward system in adolescents are strongly linked prior to a possible onset of substance abuse, emphasizing their potential role in the predisposition to drug abuse.
Abstract: Objective:Increased risk-taking behavior has been associated with addiction, a disorder also linked to abnormalities in reward processing. Specifically, an attenuated response of reward-related areas (e.g., the ventral striatum) to nondrug reward cues has been reported in addiction. One unanswered question is whether risk-taking preference is associated with striatal reward processing in the absence of substance abuse. Method:Functional and structural MRI was performed in 266 healthy young adolescents and in 31 adolescents reporting potentially problematic substance use. Activation during reward anticipation (using the monetary incentive delay task) and to gray matter density were measured. Risk-taking bias was assessed by the Cambridge Gamble Task. Results:With increasing risk-taking bias, the ventral striatum showed decreased activation bilaterally during reward anticipation. Voxel-based morphometry showed that greater risk-taking bias was also associated with and partially mediated by lower gray matter...
140 citations
Heidelberg University1, Florida State University2, University of Hamburg3, Université de Montréal4, University of Vermont5, Trinity College, Dublin6, Charité7, French Institute of Health and Medical Research8, Paris Descartes University9, University of Nottingham10, Montreal Neurological Institute and Hospital11, University of Toronto12, French Alternative Energies and Atomic Energy Commission13, University of Cambridge14, Dresden University of Technology15
TL;DR: With up to 26% of explained variance, the interrelation of reward-related personality traits, behavior, and neural response patterns may convey risk for later alcohol abuse in adolescence, and thus may be identified as a vulnerability factor for the development of substance use disorders.
138 citations
TL;DR: It is shown that manipulating 5-HT via acute tryptophan depletion (ATD) causes variable effects on brain responses to a variety of emotional stimuli, but it remains unclear whether ATD affects functional connectivity in neural networks involved in processing social signals of aggression.
136 citations
TL;DR: High impulsivity can be ameliorated in rats by drugs that mimic the effects of DA and NA, just as in ADHD, and that activation of D2/3 receptors selectively decreases high impulsivity on the 5CSRTT.
Abstract: Rationale
Impulsivity is associated with a number of psychiatric disorders, most notably attention deficit/hyperactivity disorder (ADHD). Drugs that augment catecholamine function (e.g. methylphenidate and the selective noradrenaline reuptake inhibitor atomoxetine) have clinical efficacy in ADHD, but their precise mechanism of action is unclear.
127 citations
TL;DR: Findings indicate an apparently ‘opponent’ modulation of premature responses by NE and DA in the NAcb shell or core, respectively, and suggest that the symptom clusters of hyperactive-impulsive type ADHD may have distinct neural and neurochemical substrates.
113 citations
TL;DR: These findings implicate glutamatergic and GABAergic mechanisms in the IL in the expression of impulsivity and suggest that excessive glutamate release may not underlie increased impulsivity induced by local NMDA receptor antagonism.
Abstract: Rationale
Previous work has demonstrated a profound effect of N-methyl-d-aspartic acid receptor (NMDAR) antagonism in the infralimbic cortex (IL) to selectively elevate impulsive responding in a rodent reaction time paradigm. However, the mechanism underlying this effect is unclear.
TL;DR: Selective μ-opioid receptor antagonism by GSK1521498 may have utility as a treatment for reducing maladaptive, palatability-driven eating behavior by reducing the motivational properties of stimuli that elicit the binge eating commonly associated with obesity.
TL;DR: Direct evidence is provided that the balance between goal-directed and habitual control in humans is dopamine dependent, and in light of gender differences in dopamine function and psychopathologies.
Abstract: Rationale Dopamine is well known to play an important role in learning and motivation. Recent animal studies have implicated dopamine in the reinforcement of stimulus– response habits, as well as in flexible, goal-directed action. However, the role of dopamine in human action control is still not well understood. Objectives We present the first investigation of the effect of reducing dopamine function in healthy volunteers on the balance between habitual and goal-directed action control. Methods The dietary intervention of acute dietary phenylalanine and tyrosine depletion (APTD) was adopted to study the effects of reduced global dopamine function on action control. Participants were randomly assigned to either the APTD or placebo group (ns=14) to allow for a between-subjects comparison of performance on a novel three-stage experimental paradigm. In the initial learning phase, participants learned to respond to different stimuli in order to gain rewarding outcomes. Subsequently, an outcome-devaluation test and a slips-of-action test were conducted to assess whether participants were able to flexibly adjust their behaviour to changes in the desirability of the outcomes. Results APTD did not prevent stimulus–response learning, nor did we find evidence for impaired response–outcome learning in the subsequent outcome-devaluation test. However, when goal-directed and habitual systems competed for control in the slips-of-action test, APTD tipped the balance
21 Sep 2012
TL;DR: This book examines the evolution and adaptive functions of search; the neural underpinnings of goal-searching mechanisms across species; psychological models of search in memory, decision making, and visual scenes; and applications of search behavior in highly complex environments such as the Internet.
Abstract: Over a century ago, William James proposed that people search through memory much as they rummage through a house looking for lost keys. We scour our environments for territory, food, mates, and information. We search for items in visual scenes, for historical facts, and for the best deals on Internet sites; we search for new friends to add to our social networks, and for solutions to novel problems. What we find is always governed by how we search and by the structure of the environment. This book explores how we search for resources in our minds and in the world. The authors examine the evolution and adaptive functions of search; the neural underpinnings of goal-searching mechanisms across species; psychological models of search in memory, decision making, and visual scenes; and applications of search behavior in highly complex environments such as the Internet. As the range of information, social contacts, and goods continues to expand, how well we are able to search and successfully find what we seek becomes increasingly important. At the same time, search offers cross-disciplinary insights to the scientific study of human cognition and its evolution. Combining perspectives from researchers across numerous domains, this book furthers our understanding of the relationship between search and the human mind.
TL;DR: Findings confirm that the positive modulation of mGlu5 receptors may have beneficial effects in the treatment of certain aspects of cognitive impairment associated with schizophrenia and illustrates the importance of studying putative cognitive enhancing drug effects in a number of models which may have implications for the future development of the compound.
TL;DR: Tryptophan depletion removed the bias against responding on the punished button, and abolished slowing in the presence of punished stimuli, irrespective of response, suggesting additional specificity for the influence of 5-HT on aversively motivated behavioral inhibition.
TL;DR: It is found that functional connectivity of right inferior and superior orbitofrontal cortex (OFC) was abnormally reduced in both disorders and may serve as a human brain systems biomarker for compulsivity across diagnostic categories.
TL;DR: It is suggested that high anxiety predisposes rats to lose control over cocaine—but not heroin—intake, and high anxiety may be a vulnerability trait for the escalation of stimulant but not opiate self-administration.
Abstract: Although high anxiety is commonly associated with drug addiction, its causal role in this disorder is unclear. In light of strong evidence for dissociable neural mechanisms underlying heroin and cocaine addiction, the present study investigated whether high anxiety predicts the propensity of rats to lose control over intravenous cocaine or heroin self-administration. Sixty-four rats were assessed for anxiety in the elevated plus-maze, prior to extended access to intravenous cocaine or heroin self-administration. High-anxious rats, identified in the lower quartile of the population, showed a greater escalation of cocaine, but not heroin, self-administration compared with low-anxious rats selected in the upper quartile of the population. Anxiety scores were also positively correlated with the extent of escalation of cocaine self-administration. The present data suggest that high anxiety predisposes rats to lose control over cocaine—but not heroin—intake. High anxiety may therefore be a vulnerability trait for the escalation of stimulant but not opiate self-administration.
National Institutes of Health1, University of Cambridge2, Johnson & Johnson3, Andrews University4, GlaxoSmithKline5, University of Oxford6, Royal College of Psychiatrists7, University of Pittsburgh8, Medical Research Council9, Center for Global Development10, Imperial College London11, University of California, San Diego12, Eli Lilly and Company13, Wellcome Trust14
TL;DR: The Royal Society International Seminar Consortium describes what the next decade of mental-health drug development should look like.
Abstract: The Royal Society International Seminar Consortium describes what the next decade of mental-health drug development should look like.
TL;DR: Converging translational findings support a central role for brain 5-HT in ATD's effects on cognition and behavior, and challenge whether ATD exerts its effects through serotonergic mechanisms goes too far.
Abstract: Acute tryptophan depletion (ATD), a dietary technique for manipulating brain serotonin (5-HT) function, has advanced our understanding of 5-HT mechanisms in the etiology and treatment of depression and other affective disorders.1 A recent review article in Molecular Psychiatry questioned the validity of ATD.2 Although we agree that ATD's effects on 5-HT activity at the molecular level need further clarification, van Donkelaar et al.2 goes too far in challenging whether ATD exerts its effects through serotonergic mechanisms. There is strong evidence that ATD reduces brain 5-HT and disrupts stimulated 5-HT release,3, 4 and converging translational findings support a central role for brain 5-HT in ATD's effects on cognition and behavior.
TL;DR: In vivo changes in presynaptic dopamine storage in patients with idiopathic Parkinson's disease as a function of the catechol-O-methyltransferase Val(158)Met polymorphism are investigated using (18)F-DOPA positron emission tomography to help explain how this genotypic variation may influence the fronto-striatal cognitive deficits of Parkinson’s disease.
Abstract: Cognitive deficits occur in up to 30% of patients with early Parkinson's disease, some of which are thought to result from dysfunction within the fronto-striatal dopaminergic network. Recently, it has been shown that a common functional polymorphism (Val(158)Met) in the catechol-O-methyltransferase (COMT) gene is associated with changes in executive performance in tasks that have a fronto-striatal basis. This is thought to relate to changes in cortical dopamine levels as catechol-O-methyltransferase is the main mode of inactivation for dopamine in frontal areas. However to date, no study has investigated dopamine turnover as a function of this genetic polymorphism in Parkinson's disease. We, therefore, set out to investigate in vivo changes in presynaptic dopamine storage in patients with idiopathic Parkinson's disease as a function of the catechol-O-methyltransferase Val(158)Met polymorphism using (18)F-DOPA positron emission tomography. Twenty patients with Parkinson's disease (10 homozygous for Val/Val and 10 for Met/Met catechol-O-methyltransferase polymorphisms) underwent (18)F-DOPA positron emission tomography using a prolonged imaging protocol. The first dynamic scan was acquired from 0 to 90 min (early), and the second scan (late) from 150 to 210 min post-intravenous radioligand administration. Patients were matched for age, sex, verbal IQ, disease duration and severity of motor features. (18)F-DOPA influx constants (Ki) were calculated and compared for frontal and striatal regions. Late scan mean frontal and striatal Ki values were significantly reduced in both Parkinson's disease groups relative to early scan Ki values. Met/Met patients had significantly higher late scan Ki values compared with their Val/Val counterparts in anterior cingulate, superior frontal and mid-frontal regions but early frontal Ki values were not different between the two groups. As late Ki values reflect rates of dopamine metabolism to 3,4-dihydroxyphenylacetic acid and homovanillic acid, our results indicate that Met homozygotes have higher presynaptic dopamine levels in frontal regions than Val homozygotes, which may help to explain how this genotypic variation may influence the fronto-striatal cognitive deficits of Parkinson's disease.
TL;DR: Neuronal ensembles in rat hippocampus and VS were simultaneously recorded during a conditioning task in which navigation depended on path integration, revealing strong differences in spatial processing between hippocampal area CA1 and VS, but similarities in how discrete cues impact on this processing.
Abstract: Forming place-reward associations critically depends on the integrity of the hippocampal-ventral striatal system. The ventral striatum (VS) receives a strong hippocampal input conveying spatial-contextual information, but it is unclear how this structure integrates this information to invigorate reward-directed behavior. Neuronal ensembles in rat hippocampus (HC) and VS were simultaneously recorded during a conditioning task in which navigation depended on path integration. In contrast to HC, ventral striatal neurons showed low spatial selectivity, but rather coded behavioral task phases toward reaching goal sites. Outcome-predicting cues induced a remapping of firing patterns in the HC, consistent with its role in episodic memory. VS remapped in conjunction with the HC, indicating that remapping can take place in multiple brain regions engaged in the same task. Subsets of ventral striatal neurons showed a "flip" from high activity when cue lights were illuminated to low activity in intertrial intervals, or vice versa. The cues induced an increase in spatial information transmission and sparsity in both structures. These effects were paralleled by an enhanced temporal specificity of ensemble coding and a more accurate reconstruction of the animal's position from population firing patterns. Altogether, the results reveal strong differences in spatial processing between hippocampal area CA1 and VS, but indicate similarities in how discrete cues impact on this processing.
01 Jan 2012
TL;DR: Evidence is discussed which suggests that all types of cognitive search—be it in searching for perceptual events, for suitable actions, or through memory—share the characteristic of following a fixed sequence of cognitive operations: divergent search followed by convergence search.
Abstract: Human goal-directed action emerges from the interaction between stimulus-driven sensorimotor online systems and slower-working control systems that relate highly processed perceptual information to the construction of goal-related action plans This distribution of labor requires the acquisition of enduring action representations; that is, of memory traces which capture the main characteristics of successful actions and their consequences It is argued here that these traces provide the building blocks for off-line prospective action planning, which renders the search through stored action representations an essential part of action control Hence, action planning requires cognitive search (through possible options) and might have led to the evolution of cognitive search routines that humans have learned to employ for other purposes as well, such as searching for perceptual events and through memory Thus, what is commonly considered to represent different types of search operations may all have evolved from action planning and share the same characteristics Evidence is discussed which suggests that all types of cognitive search—be it in searching for perceptual events, for suitable actions, or through memory—share the characteristic of following a fixed sequence of cognitive operations: divergent search followed by convergent search
TL;DR: The results indicate an important role of the IPC in human decision-making under risk and help to integrate neuropsychological data of risk-taking following vmPFC and insula damage with models of choice derived from human neuroimaging and monkey electrophysiology.
Abstract: Gambling is a widespread recreational activity and requires pitting the values of potential wins and losses against their probability of occurrence. Neuropsychological research showed that betting behavior on laboratory gambling tasks is highly sensitive to focal lesions to the ventromedial prefrontal cortex (vmPFC) and insula. In the current study, we assessed the neural basis of betting choices in healthy participants, using functional magnetic resonance imaging of the Roulette Betting Task. In half of the trials, participants actively chose their bets; in the other half, the computer dictated the bet size. Our results highlight the impact of volitional choice upon gambling-related brain activity: Neural activity in a distributed network – including key structures of the reward circuitry (midbrain, striatum) – was higher during active compared to computer-dictated bet selection. In line with neuropsychological data, the anterior insula and vmPFC were more activated during self-directed bet selection, and responses in these areas were differentially modulated by the odds of winning in the two choice conditions. In addition, responses in the vmPFC and ventral striatum were modulated by the bet size. Convergent with electrophysiological research in macaques, our results further implicate the inferior parietal cortex (IPC) in the processing of the likelihood of potential outcomes: Neural responses in the IPC bilaterally reflected the probability of winning during bet selection. Moreover, the IPC was particularly sensitive to the odds of winning in the active-choice condition, when the processing of this information was required to guide bet selection. Our results indicate an important role of the IPC in human decision-making under risk and help to integrate neuropsychological data of risk-taking following vmPFC and insula damage with models of choice derived from human neuroimaging and monkey electrophysiology.
TL;DR: This ‘Special issue on impulsivity and compulsivity’ revisits a theme first explored by Psychopharmacology in 1999, and provides a detailed and timely review of the considerable and exciting work in mice on the same five-choice serial reaction attentional task used by Dalley etal.
Abstract: This ‘Special issue on impulsivity and compulsivity’revisits a theme first explored by Psychopharmacology in1999 (146, 339–491). That issue of the journal focused onimpulsivity and represented somewhat of a landmark forthis topic in Psychopharmacology and perhaps for the fieldin general. It contained several now highly cited papers byseveral notable researchers in the field, including twoseminal theoretical reviews. One was by John Evenden(‘Varieties of impulsivity’ Evenden 1999) and has beencited 481 times at last count on the ISI Web of Knowledge.The other, on impulsivity, frontostriatal dysfunction anddrug abuse, was by David Jentsch and Jane Taylor (1999)and has been cited no fewer than 555 times.As Evenden’s review presciently anticipated, impulsivitycan be defined in several ways, reflecting what may be amultifaceted construct, engaging several distinct neuralsystems (Dalley et al. 2011). Most definitions emphasisethe tendency towards maladaptive premature behaviour, theloss of motor or response inhibition, the performance of‘automatic urges or impulses’, the tendency to avoid delayand rapidly discount the value of delayed rewards (‘impul-sive choice’) and the lack of reflection in making decisions,often of a highly ‘risky’ type. In general, advances inunderstanding of impulsivity have stemmed from advancesin its measurement in both humans and experimentalanimals, which may often proceed in parallel, usinganalogous tests such as the temporal discounting of rewardor stop signal inhibition. Many of these methods arerepresented in this special issue. Roige et al. provide adetailed and timely review of the considerable and excitingrecent work in mice (including genetic strains) on the samefive-choice serial reaction attentional task used by Dalley etal. to measure impulsivity in rats.Impulsivity refers to a constellation of traits that may befound in several neuropsychiatric disorders, includingattention deficit/hyperactivity disorder (ADHD), substanceabuse including alcoholism and cigarette smoking, mania,antisocial behaviour, as well as pathological aggression anddepression (i.e. suicide). There have been suggestions thatforms of impulsivity can be endophenotypes or intermedi-ate phenotypes for some disorders. For example, rats thatexhibit premature behaviour in the five-choice task appearto have a propensity for compulsive cocaine-seekingbehaviour, even before they are actually exposed to thedrug (Dalley et al. 2011). It is also possible that someabused drugs themselves may also cause impulsive behav-iours (Perry and Carroll 2008). Impulsive behaviour mayalso be especially important in the relapse to drug seeking,as they may share overlapping neural mechanisms (see inthis issue the study by Verdejo-Garcia et al.). Several formsof impulsivity are also prominent in ADHD, which oftenresponds to treatment with the indirect catecholamine
TL;DR: The results are consistent with recent theoretical work that characterises 5-HT as pruning a tree of potential decisions, eliminating options expected to lead to aversive outcomes, potentially at the expense of more globally construed future losses.
Abstract: Rationale
The neurotransmitter serotonin (5-HT) has been implicated in both aversive processing and impulsivity. Reconciling these accounts, recent studies have demonstrated that 5-HT is important for punishment-induced behavioural inhibition. These studies focused on situations where actions lead directly to punishments. However, decision-making often involves making tradeoffs between small ‘local’ costs and larger ‘global’ losses.
TL;DR: Assessment of differences in motor impulsivity in the 5‐choice serial reaction time task (5‐CSRTT) in strains of mice that differ in the expression of the alpha‐synuclein gene suggests alpha‐ synuclein may contribute to impulsivity and potentially, to ICDs which arise in some PD patients treated with dopaminergic medication.
Abstract: The presynaptic protein alpha-synuclein, associated with Parkinson's Disease (PD), plays a role in dopaminergic neurotransmission and is implicated in impulse control disorders (ICDs) such as drug addiction. In this study we investigated a potential causal relationship between alpha-synuclein and impulsivity, by evaluating differences in motor impulsivity in the 5-choice serial reaction time task (5-CSRTT) in strains of mice that differ in the expression of the alpha-synuclein gene. C57BL/6JOlaHsd mice differ from their C57BL/6J ancestors in possessing a chromosomal deletion resulting in the loss of two genes, snca, encoding alpha-synuclein, and mmrn1, encoding multimerin-1. C57BL/6J mice displayed higher impulsivity (more premature responding) than C57BL/6JOlaHsd mice when the pre-stimulus waiting interval was increased in the 5-CSRTT. In order to ensure that the reduced impulsivity was indeed related to snca, and not adjacent gene deletion, wild type (WT) and mice with targeted deletion of alpha-synuclein (KO) were tested in the 5-CSRTT. Similarly, WT mice were more impulsive than mice with targeted deletion of alpha-synuclein. Interrogation of our ongoing analysis of impulsivity in BXD recombinant inbred mouse lines revealed an association of impulsive responding with levels of alpha-synuclein expression in hippocampus. Expression of beta- and gamma-synuclein, members of the synuclein family that may substitute for alpha-synuclein following its deletion, revealed no differential compensations among the mouse strains. These findings suggest that alpha-synuclein may contribute to impulsivity and potentially, to ICDs which arise in some PD patients treated with dopaminergic medication.
Max Planck Society1, Charité2, Humboldt University of Berlin3, French Alternative Energies and Atomic Energy Commission4, King's College London5, German National Metrology Institute6, University of Cambridge7, Trinity College, Dublin8, French Institute of Health and Medical Research9, Paris Descartes University10, Dresden University of Technology11
TL;DR: Cerebellar GM volumes in the right Lobule VI predict manual dexterity in healthy untrained humans when cerebellum-optimized VBM is employed, indicating that previous studies might have underestimated the importance of cerebellar in manual dexterity.
Book•
01 Feb 2012
TL;DR: In this article, the authors consider some of the key advances in neuroscience, such as neuropharmacology, functional neuroimaging and neural interface systems, which could impact upon these developments and the policy implications for the international community, the UK government and the scientific community.
Abstract: Neuroscience is a rapidly advancing field encompassing a range of applications and technologies that are likely to provide significant benefits to society, particularly in the treatment of neurological impairment, disease, and psychiatric illness. However, this new knowledge suggests a number of potential military and law enforcement applications. These can be divided into two main goals: performance enhancement, i.e. improving the efficiency of one’s own forces, and performance degradation, i.e. diminishing the performance of one’s enemy. In this report we consider some of the key advances in neuroscience, such as neuropharmacology, functional neuroimaging and neural interface systems, which could impact upon these developments and the policy implications for the international community, the UK government and the scientific community.
01 Jan 2012
TL;DR: This chapter integrates data on search in three distinct domains—physical movement, attention to external information, and locating items in memory—to highlight the remarkable similarities between these three domains.
Abstract: Search can be defined as an attempt to arrive at a goal at an unknown location in the physical environment, as well as in time, memory, or any other space Search is necessary because the quantity and quality of resources essential to survival and reproduction vary in space and time In addition to exploration through actual body movement in their environment, animals search their external information space through selective allocation of attention and their internal information space to retrieve relevant items from memory This chapter integrates data on search in three distinct domains—physical movement, attention to external information, and locating items in memory—to highlight the remarkable similarities between these three domains First, resources in all three domains are typically distributed in patches Second, in each of the three domains, animals typically keep searching in patches where they have recently found resources and leave areas when none are found or where they have already depleted the resources Third, the neurobiological mechanisms modulating the exploration for and exploitation of resources in all three domains involve dopamine as well as, in many vertebrates, regions of the prefrontal cortex and striatum It is suggested that, throughout evolution, animals co-opted existing strategies and mechanisms used to search their physical space for exploring and exploiting internal and external information spaces The cross-disciplinary integration of theory and data about search can be used to guide future research on the mechanisms underlying cognitive search