A Monetary Reward Alters Pacing but Not Performance in Competitive Cyclists.

Science.gov (United States)

Skorski, Sabrina; Thompson, Kevin G; Keegan, Richard J; Meyer, Tim; Abbiss, Chris R

2017-01-01

Money has frequently been used as an extrinsic motivator since it is assumed that humans are willing to invest more effort for financial reward. However, the influence of a monetary reward on pacing and performance in trained athletes is not well-understood. Therefore, the aim of this study was to analyse the influence of a monetary reward in well-trained cyclists on their pacing and performance during short and long cycling time trials (TT). Twentythree cyclists (6 ♀, 17 ♂) completed 4 self-paced time trials (TTs, 2 short: 4 km and 6 min; 2 long: 20 km and 30 min); in a randomized order. Participants were separated into parallel, non-randomized "rewarded" and "non-rewarded" groups. Cyclists in the rewarded group received a monetary reward based on highest mean power output across all TTs. Cyclists in the non-rewarded group did not receive a monetary reward. Overall performance was not significantly different between groups in short or long TTs ( p > 0.48). Power output showed moderatly lower effect sizes at comencement of the short TTs ( P meandiff = 36.6 W; d > 0.44) and the 20 km TT ( P meandiff = 22.6 W; d = 0.44) in the rewarded group. No difference was observed in pacing during the 30 min TT ( p = 0.95). An external reward seems to have influenced pacing at the commencement of time trials. Participants in the non-rewarded group adopted a typical parabolic shaped pattern, whereas participants in the rewarded group started trials more conservatively. Results raise the possibility that using money as an extrinsic reward may interfere with regulatory processes required for effective pacing.

Paying for performance: Performance incentives increase desire for the reward object.

Science.gov (United States)

Hur, Julia D; Nordgren, Loran F

2016-09-01

The current research examines how exposure to performance incentives affects one's desire for the reward object. We hypothesized that the flexible nature of performance incentives creates an attentional fixation on the reward object (e.g., money), which leads people to become more desirous of the rewards. Results from 5 laboratory experiments and 1 large-scale field study provide support for this prediction. When performance was incentivized with monetary rewards, participants reported being more desirous of money (Study 1), put in more effort to earn additional money in an ensuing task (Study 2), and were less willing to donate money to charity (Study 4). We replicated the result with nonmonetary rewards (Study 5). We also found that performance incentives increased attention to the reward object during the task, which in part explains the observed effects (Study 6). A large-scale field study replicated these findings in a real-world setting (Study 7). One laboratory experiment failed to replicate (Study 3). (PsycINFO Database Record (c) 2016 APA, all rights reserved).

A Monetary Reward Alters Pacing but Not Performance in Competitive Cyclists

Directory of Open Access Journals (Sweden)

Sabrina Skorski

2017-09-01

Full Text Available Money has frequently been used as an extrinsic motivator since it is assumed that humans are willing to invest more effort for financial reward. However, the influence of a monetary reward on pacing and performance in trained athletes is not well-understood. Therefore, the aim of this study was to analyse the influence of a monetary reward in well-trained cyclists on their pacing and performance during short and long cycling time trials (TT. Twentythree cyclists (6 ♀, 17 ♂ completed 4 self-paced time trials (TTs, 2 short: 4 km and 6 min; 2 long: 20 km and 30 min; in a randomized order. Participants were separated into parallel, non-randomized “rewarded” and “non-rewarded” groups. Cyclists in the rewarded group received a monetary reward based on highest mean power output across all TTs. Cyclists in the non-rewarded group did not receive a monetary reward. Overall performance was not significantly different between groups in short or long TTs (p > 0.48. Power output showed moderatly lower effect sizes at comencement of the short TTs (Pmeandiff = 36.6 W; d > 0.44 and the 20 km TT (Pmeandiff = 22.6 W; d = 0.44 in the rewarded group. No difference was observed in pacing during the 30 min TT (p = 0.95. An external reward seems to have influenced pacing at the commencement of time trials. Participants in the non-rewarded group adopted a typical parabolic shaped pattern, whereas participants in the rewarded group started trials more conservatively. Results raise the possibility that using money as an extrinsic reward may interfere with regulatory processes required for effective pacing.

State-based versus reward-based motivation in younger and older adults.

Science.gov (United States)

Worthy, Darrell A; Cooper, Jessica A; Byrne, Kaileigh A; Gorlick, Marissa A; Maddox, W Todd

2014-12-01

Recent decision-making work has focused on a distinction between a habitual, model-free neural system that is motivated toward actions that lead directly to reward and a more computationally demanding goal-directed, model-based system that is motivated toward actions that improve one's future state. In this article, we examine how aging affects motivation toward reward-based versus state-based decision making. Participants performed tasks in which one type of option provided larger immediate rewards but the alternative type of option led to larger rewards on future trials, or improvements in state. We predicted that older adults would show a reduced preference for choices that led to improvements in state and a greater preference for choices that maximized immediate reward. We also predicted that fits from a hybrid reinforcement-learning model would indicate greater model-based strategy use in younger than in older adults. In line with these predictions, older adults selected the options that maximized reward more often than did younger adults in three of the four tasks, and modeling results suggested reduced model-based strategy use. In the task where older adults showed similar behavior to younger adults, our model-fitting results suggested that this was due to the utilization of a win-stay-lose-shift heuristic rather than a more complex model-based strategy. Additionally, within older adults, we found that model-based strategy use was positively correlated with memory measures from our neuropsychological test battery. We suggest that this shift from state-based to reward-based motivation may be due to age related declines in the neural structures needed for more computationally demanding model-based decision making.

Reward-based spatial crowdsourcing with differential privacy preservation

Science.gov (United States)

Xiong, Ping; Zhang, Lefeng; Zhu, Tianqing

2017-11-01

In recent years, the popularity of mobile devices has transformed spatial crowdsourcing (SC) into a novel mode for performing complicated projects. Workers can perform tasks at specified locations in return for rewards offered by employers. Existing methods ensure the efficiency of their systems by submitting the workers' exact locations to a centralised server for task assignment, which can lead to privacy violations. Thus, implementing crowsourcing applications while preserving the privacy of workers' location is a key issue that needs to be tackled. We propose a reward-based SC method that achieves acceptable utility as measured by task assignment success rates, while efficiently preserving privacy. A differential privacy model ensures rigorous privacy guarantee, and Laplace noise is introduced to protect workers' exact locations. We then present a reward allocation mechanism that adjusts each piece of the reward for a task using the distribution of the workers' locations. Through experimental results, we demonstrate that this optimised-reward method is efficient for SC applications.

Decrement in manual arm performance during whole body cooling.

Science.gov (United States)

Giesbrecht, G G; Bristow, G K

1992-12-01

Six subjects performed three manual arm tasks: 1) prior to immersion in 8 degrees C water; 2) soon after immersion to the neck, but prior to any decrease in core temperature; and 3) every 15 min until core temperatures decreased 2-4.5 degrees C. The tasks were speed of flexion and extension of the fingers, handgrip strength and manual dexterity. There was no immediate effect of cold immersion; however, all scores decreased significantly after core temperature decreased 0.5 degrees C. Further decrease in core temperature was associated with a progressive impairment of performance, although at a slower rate than during the first 0.5 degrees C decrease. Flexion and extension of the fingers was affected relatively more than handgrip strength or manual dexterity. Decrement in performance is a result of peripheral cooling on sensorimotor function with a probable additional effect of central cooling on cerebral function.

Impairment of probabilistic reward-based learning in schizophrenia.

Science.gov (United States)

Weiler, Julia A; Bellebaum, Christian; Brüne, Martin; Juckel, Georg; Daum, Irene

2009-09-01

Recent models assume that some symptoms of schizophrenia originate from defective reward processing mechanisms. Understanding the precise nature of reward-based learning impairments might thus make an important contribution to the understanding of schizophrenia and the development of treatment strategies. The present study investigated several features of probabilistic reward-based stimulus association learning, namely the acquisition of initial contingencies, reversal learning, generalization abilities, and the effects of reward magnitude. Compared to healthy controls, individuals with schizophrenia exhibited attenuated overall performance during acquisition, whereas learning rates across blocks were similar to the rates of controls. On the group level, persons with schizophrenia were, however, unable to learn the reversal of the initial reward contingencies. Exploratory analysis of only the subgroup of individuals with schizophrenia who showed significant learning during acquisition yielded deficits in reversal learning with low reward magnitudes only. There was further evidence of a mild generalization impairment of the persons with schizophrenia in an acquired equivalence task. In summary, although there was evidence of intact basic processing of reward magnitudes, individuals with schizophrenia were impaired at using this feedback for the adaptive guidance of behavior.

The Dilemmas of Adopting Performance Related Pay as a Reward ...

African Journals Online (AJOL)

The Dilemmas of Adopting Performance Related Pay as a Reward Strategy for ... over automatic pay increase (formal and transparent reward systems linked to ... of reward and compensation, and low level of motivation and performance.

Providing Extrinsic Reward for Test Performance Undermines Long-Term Memory Acquisition

Directory of Open Access Journals (Sweden)

Christof eKuhbandner

2016-02-01

Full Text Available Based on numerous studies showing that testing studied material can improve long-term retention more than restudying the same material, it is often suggested that the number of tests in education should be increased to enhance knowledge acquisition. However, testing in real-life educational settings often entails a high degree of extrinsic motivation of learners due to the common practice of placing important consequences on the outcome of a test. Such an effect on the motivation of learners may undermine the beneficial effects of testing on long-term memory because it has been shown that extrinsic motivation can reduce the quality of learning. To examine this issue, participants learned foreign language vocabulary words, followed by an immediate test in which one third of the words were tested and one third restudied. To manipulate extrinsic motivation during immediate testing, participants received either monetary reward contingent on test performance or no reward. After one week, memory for all words was tested. In the immediate test, reward reduced correct recall and increased commission errors, indicating that reward reduced the number of items that can benefit from successful retrieval. The results in the delayed test revealed that reward additionally reduced the gain received from successful retrieval because memory for initially successfully retrieved words was lower in the reward condition. However, testing was still more effective than restudying under reward conditions because reward undermined long-term memory for concurrently restudied material as well. These findings indicate that providing performance-contingent reward in a test can undermine long-term knowledge acquisition.

Providing Extrinsic Reward for Test Performance Undermines Long-Term Memory Acquisition.

Science.gov (United States)

Kuhbandner, Christof; Aslan, Alp; Emmerdinger, Kathrin; Murayama, Kou

2016-01-01

Based on numerous studies showing that testing studied material can improve long-term retention more than restudying the same material, it is often suggested that the number of tests in education should be increased to enhance knowledge acquisition. However, testing in real-life educational settings often entails a high degree of extrinsic motivation of learners due to the common practice of placing important consequences on the outcome of a test. Such an effect on the motivation of learners may undermine the beneficial effects of testing on long-term memory because it has been shown that extrinsic motivation can reduce the quality of learning. To examine this issue, participants learned foreign language vocabulary words, followed by an immediate test in which one-third of the words were tested and one-third restudied. To manipulate extrinsic motivation during immediate testing, participants received either monetary reward contingent on test performance or no reward. After 1 week, memory for all words was tested. In the immediate test, reward reduced correct recall and increased commission errors, indicating that reward reduced the number of items that can benefit from successful retrieval. The results in the delayed test revealed that reward additionally reduced the gain received from successful retrieval because memory for initially successfully retrieved words was lower in the reward condition. However, testing was still more effective than restudying under reward conditions because reward undermined long-term memory for concurrently restudied material as well. These findings indicate that providing performance-contingent reward in a test can undermine long-term knowledge acquisition.

Advances in Computational High-Resolution Mechanical Spectroscopy HRMS Part I: Logarithmic Decrement

International Nuclear Information System (INIS)

Majewski, M; Magalas, L B; Piłat, A

2012-01-01

The comparison between different methods used to compute the logarithmic decrement in high-resolution mechanical spectroscopy (HRMS) is analyzed. The performance of parametric OMI method (Optimization in Multiple Intervals) and interpolated discrete Fourier transform (IpDFT) methods are investigated as a function of the sampling frequency used to digitize free decaying oscillations in low-frequency resonant mechanical spectrometers. It is clearly demonstrated that a new Yoshida-Magalas (YM) method is the most powerful IpDFT-based method which outperforms the standard Yoshida (Y) method and other DFT-based methods. Four IpDFT methods and the OMI method are carefully analyzed as a function of the sampling frequency. The results presented in this work clearly show that the relative error in the estimation of the logarithmic decrement depends both on the length of free decaying signal and on the sampling frequency. The effect of the sampling frequency was not yet reported in the literature. The performance of different methods used in the computations of the logarithmic decrement can be listed in the following order: (1) the OMI, (2) the Yoshida-Magalas YM, (3) the Yoshida-Magalas YMC, and finally (4) the Yoshida Y.

Performability assessment by model checking of Markov reward models

NARCIS (Netherlands)

Baier, Christel; Cloth, L.; Haverkort, Boudewijn R.H.M.; Hermanns, H.; Katoen, Joost P.

2010-01-01

This paper describes efficient procedures for model checking Markov reward models, that allow us to evaluate, among others, the performability of computer-communication systems. We present the logic CSRL (Continuous Stochastic Reward Logic) to specify performability measures. It provides flexibility

Overt and covert attention to location-based reward.

Science.gov (United States)

McCoy, Brónagh; Theeuwes, Jan

2018-01-01

Recent research on the impact of location-based reward on attentional orienting has indicated that reward factors play an influential role in spatial priority maps. The current study investigated whether and how reward associations based on spatial location translate from overt eye movements to covert attention. If reward associations can be tied to locations in space, and if overt and covert attention rely on similar overlapping neuronal populations, then both overt and covert attentional measures should display similar spatial-based reward learning. Our results suggest that location- and reward-based changes in one attentional domain do not lead to similar changes in the other. Specifically, although we found similar improvements at differentially rewarded locations during overt attentional learning, this translated to the least improvement at a highly rewarded location during covert attention. We interpret this as the result of an increased motivational link between the high reward location and the trained eye movement response acquired during learning, leading to a relative slowing during covert attention when the eyes remained fixated and the saccade response was suppressed. In a second experiment participants were not required to keep fixated during the covert attention task and we no longer observed relative slowing at the high reward location. Furthermore, the second experiment revealed no covert spatial priority of rewarded locations. We conclude that the transfer of location-based reward associations is intimately linked with the reward-modulated motor response employed during learning, and alternative attentional and task contexts may interfere with learned spatial priorities. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

The role of memory representation in the vigilance decrement.

Science.gov (United States)

Caggiano, Daniel M; Parasuraman, Raja

2004-10-01

Working memory load is critically important for the overall level of performance on vigilance tasks. However, its role in a key aspect of vigilance-sensitivity decrement over time-is unclear. We used a dual-task procedure in which either a spatial or a nonspatial working memory task was performed simultaneously with a spatial vigilance task for 20 min. Sensitivity in the vigilance task declined over time when the concurrent task involved spatial working memory. In contrast, there was no sensitivity decrement with a nonspatial working memory task. The results provide the first evidence of a specific role for working memory representation in vigilance decrement. The findings are also consistent with a multiple resource theory in which separate resources for memory representation and cognitive control operations are differentially susceptible to depletion over time, depending on the demands of the task at hand.

A new semantic vigilance task: vigilance decrement, workload, and sensitivity to dual-task costs.

Science.gov (United States)

Epling, Samantha L; Russell, Paul N; Helton, William S

2016-01-01

Cognitive resource theory is a common explanation for both the performance decline in vigilance tasks, known as the vigilance decrement, and the limited ability to perform multiple tasks simultaneously. The limited supply of cognitive resources may be utilized faster than they are replenished resulting in a performance decrement, or may need to be allocated among multiple tasks with some performance cost. Researchers have proposed both domain-specific, for example spatial versus verbal processing resources, and domain general cognitive resources. One challenge in testing the domain specificity of cognitive resources in vigilance is the current lack of difficult semantic vigilance tasks which reliably produce a decrement. In the present research, we investigated whether the vigilance decrement was found in a new abbreviated semantic discrimination vigilance task, and whether there was a performance decrement in said vigilance task when paired with a word recall task, as opposed to performed individually. As hypothesized, a vigilance decrement in the semantic vigilance task was found in both the single-task and dual-task conditions, along with reduced vigilance performance in the dual-task condition and reduced word recall in the dual-task condition. This is consistent with cognitive resource theory. The abbreviated semantic vigilance task will be a useful tool for researchers interested in determining the specificity of cognitive resources utilized in vigilance tasks.

The rewarding value of good motor performance in the context of monetary incentives.

Science.gov (United States)

Lutz, Kai; Pedroni, Andreas; Nadig, Karin; Luechinger, Roger; Jäncke, Lutz

2012-07-01

Whether an agent receives positive task feedback or a monetary reward, neural activity in their striatum increases. In the latter case striatal activity reflects extrinsic reward processing, while in the former, striatal activity reflects the intrinsically rewarding effects of performing well. There can be a "hidden cost of reward", which is a detrimental effect of extrinsic on intrinsic reward value. This raises the question how these two types of reward interact. To address this, we applied a monetary incentive delay task: in all trials participants received feedback depending on their performance. In half of the trials they could additionally receive monetary reward if they performed well. This resulted in high performance trials, which were monetarily rewarded and high performance trials that were not. This made it possible to dissociate the neural correlates of performance feedback from the neural correlates of monetary reward that comes with high performance. Performance feedback alone elicits activation increases in the ventral striatum. This activation increases due to additional monetary reward. Neural response in the dorsal striatum on the other hand is only significantly increased by feedback when a monetary incentive is present. The quality of performance does not significantly influence dorsal striatum activity. In conclusion, our results indicate that the dorsal striatum is primarily sensitive to optional or actually received external rewards, whereas the ventral striatum may be coding intrinsic reward due to positive performance feedback. Thus the ventral striatum is suggested to be involved in the processing of intrinsically motivated behavior. Copyright © 2012 Elsevier Ltd. All rights reserved.

Application of Vector Triggering Random Decrement

DEFF Research Database (Denmark)

Asmussen, J. C.; Ibrahim, S. R.; Brincker, Rune

result is a Random Decrement function from each measurement. In traditional Random Decrement estimation the triggering condition is a scalar condition, which should only be fulfilled in a single measurement. In vector triggering Random Decrement the triggering condition is a vector condition......This paper deals with applications of the vector triggering Random Decrement technique. This technique is new and developed with the aim of minimizing estimation time and identification errors. The theory behind the technique is discussed in an accompanying paper. The results presented...... in this paper should be regarded as a further documentation of the technique. The key point in Random Decrement estimation is the formulation of a triggering condition. If the triggering condition is fulfilled a time segment from each measurement is picked out and averaged with previous time segments. The final...

Application of Vector Triggering Random Decrement

DEFF Research Database (Denmark)

Asmussen, J. C.; Ibrahim, S. R.; Brincker, Rune

1997-01-01

result is a Random Decrement function from each measurement. In traditional Random Decrement estimation the triggering condition is a scalar condition, which should only be fulfilled in a single measurement. In vector triggering Random Decrement the triggering condition is a vector condition......This paper deals with applications of the vector triggering Random Decrement technique. This technique is new and developed with the aim of minimizing estimation time and identification errors. The theory behind the technique is discussed in an accompanying paper. The results presented...... in this paper should be regarded as a further documentation of the technique. The key point in Random Decrement estimation is the formulation of a triggering condition. If the triggering condition is fulfilled a time segment from each measurement is picked out and averaged with previous time segments. The final...

Community-based faculty: motivation and rewards.

Science.gov (United States)

Fulkerson, P K; Wang-Cheng, R

1997-02-01

The reasons why practicing physicians precept students in their offices, and the rewards they wish to receive for this work, have not been clearly elucidated. This study determined the reasons for precepting and the rewards expected among a network of preceptors in Milwaukee. A questionnaire was mailed to 120 community-based physician preceptors in a required, third-year ambulatory care clerkship. Respondents were asked to identify why they volunteered and what they considered appropriate recognition or reward. The personal satisfaction derived from the student-teacher interaction was, by far, the most important motivator for preceptors (84%). The most preferred rewards for teaching included clinical faculty appointment, CME and bookstore discounts, computer networking, and workshops for improving skills in clinical teaching. Community-based private physicians who participate in medical student education programs are primarily motivated by the personal satisfaction that they derive from the teaching encounter. An effective preceptor recognition/reward program can be developed using input from the preceptors themselves.

A new perspective on human reward research: How consciously and unconsciously perceived reward information influences performance.

NARCIS (Netherlands)

Zedelius, Claire; Veling, Harm; Custers, Ruud; Bijleveld, Erik; Chiew, K.S.; Aarts, Henk

2014-01-01

The question of how human performance can be improved through rewards is a recurrent topic of interest in psychology and neuroscience. Traditional, cognitive approaches to this topic have focused solely on consciously communicated rewards. Recently, a largely neuroscience-inspired perspective has

A new perspective on human reward research: How consciously and unconsciously perceived reward information influences performance

NARCIS (Netherlands)

Zedelius, C.M.; Veling, H.P.; Custers, R.; Bijleveld, E.H.; Chiew, K.S.; Aarts, H.A.G.

2014-01-01

The question of how human performance can be improved through rewards is a recurrent topic of interest in psychology and neuroscience. Traditional, cognitive approaches to this topic have focused solely on consciously communicated rewards. Recently, a largely neuroscience-inspired perspective has

The reward-based eating drive scale: a self-report index of reward-based eating.

Directory of Open Access Journals (Sweden)

Elissa S Epel

Full Text Available Why are some individuals more vulnerable to persistent weight gain and obesity than are others? Some obese individuals report factors that drive overeating, including lack of control, lack of satiation, and preoccupation with food, which may stem from reward-related neural circuitry. These are normative and common symptoms and not the sole focus of any existing measures. Many eating scales capture these common behaviors, but are confounded with aspects of dysregulated eating such as binge eating or emotional overeating. Across five studies, we developed items that capture this reward-based eating drive (RED. Study 1 developed the items in lean to obese individuals (n = 327 and examined changes in weight over eight years. In Study 2, the scale was further developed and expert raters evaluated the set of items. Study 3 tested psychometric properties of the final 9 items in 400 participants. Study 4 examined psychometric properties and race invariance (n = 80 women. Study 5 examined psychometric properties and age/gender invariance (n = 381. Results showed that RED scores correlated with BMI and predicted earlier onset of obesity, greater weight fluctuations, and greater overall weight gain over eight years. Expert ratings of RED scale items indicated that the items reflected characteristics of reward-based eating. The RED scale evidenced high internal consistency and invariance across demographic factors. The RED scale, designed to tap vulnerability to reward-based eating behavior, appears to be a useful brief tool for identifying those at higher risk of weight gain over time. Given the heterogeneity of obesity, unique brief profiling of the reward-based aspect of obesity using a self-report instrument such as the RED scale may be critical for customizing effective treatments in the general population.

Myopia for the future or hypersensitivity to reward? Age-related changes in decision making on the Iowa Gambling Task.

Science.gov (United States)

Bauer, A S; Timpe, J; Edmonds, E C; Bechara, A; Tranel, D; Denburg, N L

2013-02-01

It has been shown that older adults perform less well than younger adults on the Iowa Gambling Task (IGT), a real-world type decision-making task that factors together reward, punishment, and uncertainty. To explore the reasons behind this age-related decrement, we administered to an adult life span sample of 265 healthy participants (Mdn age = 62.00 +/- 16.17 years; range [23-88]) 2 versions of the IGT, which have different contingencies for successful performance: A'B'C'D' requires choosing lower immediate reward (paired with lower delayed punishment); E'F'G'H' requires choosing higher immediate punishment (paired with higher delayed reward). There was a significant negative correlation between age and performance on the A'B'C'D' version of the IGT (r = -.16, p = .01), while there was essentially no correlation between age and performance on the E'F'G'H' version (r = -.07, p = .24). In addition, the rate of impaired performance in older participants was significantly higher for the A'B'C'D' version (23%) compared with the E'F'G'H' version (13%). A parsimonious account of these findings is an age-related increase in hypersensitivity to reward, whereby the decisions of older adults are disproportionately influenced by prospects of receiving reward, irrespective of the presence or degree of punishment. PsycINFO Database Record (c) 2013 APA, all rights reserved.

MYOPIA FOR THE FUTURE OR HYPERSENSITIVITY TO REWARD? AGE-RELATED CHANGES IN DECISION-MAKING ON THE IOWA GAMBLING TASK

OpenAIRE

Bauer, A. S.; Timpe, J.; Edmonds, E.C.; Bechara, A.; Tranel, D.; Denburg, N.L.

2012-01-01

It has been shown that older adults perform less well than younger adults on the Iowa Gambling Task (IGT), a real-world type decision-making task that factors together reward, punishment, and uncertainty. To explore the reasons behind this age-related decrement, we administered to an adult life-span sample of 265 healthy participants (median age = 62.00 +/− 16.17 years; range [23–88]) two versions of the IGT, which have different contingencies for successful performance: A'B'C'D' requires cho...

Combining Correlation-Based and Reward-Based Learning in Neural Control for Policy Improvement

DEFF Research Database (Denmark)

Manoonpong, Poramate; Kolodziejski, Christoph; Wörgötter, Florentin

2013-01-01

Classical conditioning (conventionally modeled as correlation-based learning) and operant conditioning (conventionally modeled as reinforcement learning or reward-based learning) have been found in biological systems. Evidence shows that these two mechanisms strongly involve learning about...... associations. Based on these biological findings, we propose a new learning model to achieve successful control policies for artificial systems. This model combines correlation-based learning using input correlation learning (ICO learning) and reward-based learning using continuous actor–critic reinforcement...... learning (RL), thereby working as a dual learner system. The model performance is evaluated by simulations of a cart-pole system as a dynamic motion control problem and a mobile robot system as a goal-directed behavior control problem. Results show that the model can strongly improve pole balancing control...

Neurocognitive decrements are present in intellectually superior schizophrenia

Directory of Open Access Journals (Sweden)

Anja eVaskinn

2014-05-01

Full Text Available Data suggests that individuals with schizophrenia (SZ and superior intelligence can present without specific neurocognitive deficits. However, neurocognitive decrements, defined as worse cognition than expected, have been reported in practically all schizophrenia cases. This study investigated if neurocognitive decrements are present in intellectually superior SZ by comparing the neuropsychological profile of SZ cases with IQ-matched healthy controls (HC across intellectual level. Participants with SZ and HCs were stratified into three IQ-groups; intellectually low (IQ 80-95; SZ n = 65 & HC n = 13, intellectually normal (IQ = 100-115; SZ n = 111 & HC n = 115 and intellectually superior (IQ > 120; SZ n = 20 & HC n = 50. A repeated measures multivariate analysis of co-variance compared performance on eight selected neuropsychological tests across IQ-strata and diagnostic group. Differences in clinical characteristics and social functioning in SZ across IQ-strata were investigated with multivariate and univariate analyses of variance. Intellectually superior SZ participants scored within normal limits, but had neurocognitive decrements compared to superior HCs. Decrements were of the same magnitude as in the low and normal IQ-strata. Levels of functional impairments and clinical characteristics in participants with SZ did not differ significantly across IQ-strata. Results indicate that neurocognitive decrements are present in intellectually superior SZ to the same extent as in intellectually low and intellectually normal SZ, supporting the notion that SZ is a neurocognitive disorder. Similar levels of social functional deficits and clinical symptoms suggest similar disease processes in SZ across intellectual level.

Neural correlates of reward-based spatial learning in persons with cocaine dependence.

Science.gov (United States)

Tau, Gregory Z; Marsh, Rachel; Wang, Zhishun; Torres-Sanchez, Tania; Graniello, Barbara; Hao, Xuejun; Xu, Dongrong; Packard, Mark G; Duan, Yunsuo; Kangarlu, Alayar; Martinez, Diana; Peterson, Bradley S

2014-02-01

Dysfunctional learning systems are thought to be central to the pathogenesis of and impair recovery from addictions. The functioning of the brain circuits for episodic memory or learning that support goal-directed behavior has not been studied previously in persons with cocaine dependence (CD). Thirteen abstinent CD and 13 healthy participants underwent MRI scanning while performing a task that requires the use of spatial cues to navigate a virtual-reality environment and find monetary rewards, allowing the functional assessment of the brain systems for spatial learning, a form of episodic memory. Whereas both groups performed similarly on the reward-based spatial learning task, we identified disturbances in brain regions involved in learning and reward in CD participants. In particular, CD was associated with impaired functioning of medial temporal lobe (MTL), a brain region that is crucial for spatial learning (and episodic memory) with concomitant recruitment of striatum (which normally participates in stimulus-response, or habit, learning), and prefrontal cortex. CD was also associated with enhanced sensitivity of the ventral striatum to unexpected rewards but not to expected rewards earned during spatial learning. We provide evidence that spatial learning in CD is characterized by disturbances in functioning of an MTL-based system for episodic memory and a striatum-based system for stimulus-response learning and reward. We have found additional abnormalities in distributed cortical regions. Consistent with findings from animal studies, we provide the first evidence in humans describing the disruptive effects of cocaine on the coordinated functioning of multiple neural systems for learning and memory.

OXYGEN UPTAKE KINETICS DURING INCREMENTAL- AND DECREMENTAL-RAMP CYCLE ERGOMETRY

Directory of Open Access Journals (Sweden)

Fadıl Özyener

2011-09-01

Full Text Available The pulmonary oxygen uptake (VO2 response to incremental-ramp cycle ergometry typically demonstrates lagged-linear first-order kinetics with a slope of ~10-11 ml·min-1·W-1, both above and below the lactate threshold (ӨL, i.e. there is no discernible VO2 slow component (or "excess" VO2 above ӨL. We were interested in determining whether a reverse ramp profile would yield the same response dynamics. Ten healthy males performed a maximum incremental -ramp (15-30 W·min-1, depending on fitness. On another day, the work rate (WR was increased abruptly to the incremental maximum and then decremented at the same rate of 15-30 W.min-1 (step-decremental ramp. Five subjects also performed a sub-maximal ramp-decremental test from 90% of ӨL. VO2 was determined breath-by-breath from continuous monitoring of respired volumes (turbine and gas concentrations (mass spectrometer. The incremental-ramp VO2-WR slope was 10.3 ± 0.7 ml·min-1·W-1, whereas that of the descending limb of the decremental ramp was 14.2 ± 1.1 ml·min-1·W-1 (p < 0.005. The sub-maximal decremental-ramp slope, however, was only 9. 8 ± 0.9 ml·min-1·W-1: not significantly different from that of the incremental-ramp. This suggests that the VO2 response in the supra-ӨL domain of incremental-ramp exercise manifest not actual, but pseudo, first-order kinetics

Children's agenda-based regulation: The effects of prior performance and reward on elementary school children's study choices.

Science.gov (United States)

Lipowski, Stacy; Ariel, Robert; Tauber, Sarah K; Dunlosky, John

2017-12-01

The main goal of the current experiments was to examine the influence of monitoring and reward on elementary school children's study decisions. First and third graders studied names for 10 animals (e.g., "The elephant's name is Suzy") and then were given a cued recall test on which they were shown the animal and needed to recall the name. Next, they were given an opportunity to restudy the animal-name pairs, and some of these pairs were slated to earn a reward (a sticker) if correctly recalled. In Experiment 1, both groups of children were (a) more likely to restudy previously unrecalled pairs than previously recalled pairs and (b) more likely to restudy pairs that were slated to receive a reward. In Experiment 2, we further explored children's use of reward using a forced-choice selection task. Namely, during selection, pairs were presented in dyads where one pair was slated for a reward and the other pair was not, and the children could choose only one pair from each dyad for restudy. Both first and third graders chose to restudy pairs slated for a reward. Thus, even young elementary school children consider both rewards and performance monitoring when regulating their learning. Copyright © 2017 Elsevier Inc. All rights reserved.

Random Decrement

DEFF Research Database (Denmark)

Asmussen, J.C.; Ibrahim, S.R.; Brincker, Rune

Abstraet Thispaper demansirates how to use the Random Decrement (RD) technique for identification o flinear structures subjected to ambient excitation. The theory behind the technique will be presented and guidelines how to choose the different variables will be given. This is done by introducing...

Effect of intrinsic rewards on task performance of employees: Mediating role of motivation

Directory of Open Access Journals (Sweden)

Rizwan Qaiser Danish

2015-02-01

Full Text Available The basic purpose of this study was to examine the effect of reward management system, especially intrinsic rewards on task performance with the mediating role of extrinsic and intrinsic motivation of employees working in the banks in the capital of Punjab, Lahore, Pakistan. The secondary purpose of this study was to explore what level of performance these employees demonstrate towards their organizations when they are rewarded intrinsically and when they are motivated due to these reward management system accordingly. In this study, we collected data through self-administered questionnaires applying correlational explanatory research design. We distributed 300 questionnaires among which 290 were returned resulting in a response rate of 96%. The analysis of the data revealed that intrinsic rewards have positive impact on task performance of employees working in banks and motivation and its dimensions, i.e., intrinsic motivation, extrinsic motivation, and job satisfaction mediated this relationship. Considering the importance of appreciations received by bankers in the form of rewards and their effect on extra role performance and sophisticated management, policy makers should take necessary steps for improving the reward management system which will increase the task performance of employees because they will be motivated by these performance appraisal techniques.

Random Decrement

DEFF Research Database (Denmark)

Asmussen, J. C.; Ibrahim, S. R.; Brincker, Rune

This paper demonstrates how to use the Random Decrement (RD) technique for identification of linear structures subjected to ambient excitation. The theory behind the technique will be presented and guidelines how to choose the different variables will be given. This is done by introducing a new...

Random Decrement

DEFF Research Database (Denmark)

Asmussen, J. C.; Ibrahim, R.; Brincker, Rune

1998-01-01

This paper demonstrates how to use the Random Decrement (RD) technique for identification of linear structures subjected to ambient excitation. The theory behind the technique will be presented and guidelines how to choose the different variables will be given. This is done by introducing a new...

Statistical Theory of the Vector Random Decrement Technique

DEFF Research Database (Denmark)

Asmussen, J. C.; Brincker, Rune; Ibrahim, S. R.

1999-01-01

decays. Due to the speed and/or accuracy of the Vector Random Decrement technique, it was introduced as an attractive alternative to the Random Decrement technique. In this paper, the theory of the Vector Random Decrement technique is extended by applying a statistical description of the stochastic...

Choking under pressure: The neuropsychological mechanisms for incentives induced performance decrements

Directory of Open Access Journals (Sweden)

Rongjun eYu

2015-02-01

Full Text Available In contrast to the assumption of efficiency wage models, which state that wage incentives should be positively correlated with productivity, high incentives may produce performance decrements in real life scenarios. Such a choking under pressure phenomenon exemplifies how psychological stress can profoundly shape human behavior, for good or for bad. Previous theories suggest that individual choking under pressure because that high pressure may distract individuals’ attention away from the task (the distraction account, raise the attention paid to step-by-step skill processes (the explicit monitoring account, or elevate the arousal in general (the over-arousal account. Recent neuroimaging studies have shown that several brain regions implicated in motivation and top-down control of attention also play a key role in stress-induced choking, supporting for the over-arousal and distraction theories of choking. This review aims to identify psychological factors that determine choking and the neural underpinnings of these processes. Insights into how incentives influence performance may aid engineering training regimens and interventions that equip individuals to better handle high-stakes-induced psychological stress, and to thrive under stress.

Reward learning and negative emotion during rapid attentional competition

Directory of Open Access Journals (Sweden)

Takemasa eYokoyama

2015-03-01

Full Text Available Learned stimulus-reward associations influence how attention is allocated, such that stimuli rewarded in the past are favored in situations involving limited resources and competition. At the same time, task-irrelevant, high-arousal negative stimuli capture attention and divert resources away from tasks resulting in poor behavioral performance. Yet, investigations of how reward learning and negative stimuli affect perceptual and attentional processing have been conducted in a largely independent fashion. We have recently reported that performance-based monetary rewards reduce negative stimuli interference during perception. The goal of the present study was to investigate how stimuli associated with past monetary rewards compete with negative stimuli during a subsequent attentional task when, critically, no performance-based rewards were at stake. Across two experiments, we found that target stimuli that were associated with high reward reduced the interference effect of potent, negative distractors. Similar to our recent findings with performance-based rewards, our results demonstrate that reward-associated stimuli reduce the deleterious impact of negative stimuli on behavior.

Estimation of Correlation Functions by Random Decrement

DEFF Research Database (Denmark)

Asmussen, J. C.; Brincker, Rune

This paper illustrates how correlation functions can be estimated by the random decrement technique. Several different formulations of the random decrement technique, estimating the correlation functions are considered. The speed and accuracy of the different formulations of the random decrement...... and the length of the correlation functions. The accuracy of the estimates with respect to the theoretical correlation functions and the modal parameters are both investigated. The modal parameters are extracted from the correlation functions using the polyreference time domain technique....

Dopamine selectively remediates 'model-based' reward learning: a computational approach.

Science.gov (United States)

Sharp, Madeleine E; Foerde, Karin; Daw, Nathaniel D; Shohamy, Daphna

2016-02-01

Patients with loss of dopamine due to Parkinson's disease are impaired at learning from reward. However, it remains unknown precisely which aspect of learning is impaired. In particular, learning from reward, or reinforcement learning, can be driven by two distinct computational processes. One involves habitual stamping-in of stimulus-response associations, hypothesized to arise computationally from 'model-free' learning. The other, 'model-based' learning, involves learning a model of the world that is believed to support goal-directed behaviour. Much work has pointed to a role for dopamine in model-free learning. But recent work suggests model-based learning may also involve dopamine modulation, raising the possibility that model-based learning may contribute to the learning impairment in Parkinson's disease. To directly test this, we used a two-step reward-learning task which dissociates model-free versus model-based learning. We evaluated learning in patients with Parkinson's disease tested ON versus OFF their dopamine replacement medication and in healthy controls. Surprisingly, we found no effect of disease or medication on model-free learning. Instead, we found that patients tested OFF medication showed a marked impairment in model-based learning, and that this impairment was remediated by dopaminergic medication. Moreover, model-based learning was positively correlated with a separate measure of working memory performance, raising the possibility of common neural substrates. Our results suggest that some learning deficits in Parkinson's disease may be related to an inability to pursue reward based on complete representations of the environment. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Performance analysis of chi models using discrete-time probabilistic reward graphs

NARCIS (Netherlands)

Trcka, N.; Georgievska, S.; Markovski, J.; Andova, S.; Vink, de E.P.

2008-01-01

We propose the model of discrete-time probabilistic reward graphs (DTPRGs) for performance analysis of systems exhibiting discrete deterministic time delays and probabilistic behavior, via their interpretation as discrete-time Markov reward chains, full-fledged platform for qualitative and

Effects of leader contingent and noncontingent reward and punishment behaviors on subordinate performance and satisfaction.

Science.gov (United States)

Podsakoff, P M; Todor, W D; Skov, R

1982-12-01

This study investigated the nature of the relationships between leader reward and punishment behaviors and subordinate performance and satisfaction. Only performance-contingent reward behavior was found to affect subordinate performance significantly. Positive relationships were found between leader contingent reward behavior and employee satisfaction. Contingent punishment had no effects on subordinate performance or satisfaction.

Reward Anticipation in Ventral Striatum and Individual Sensitivity to Reward: A Pilot Study of a Child-Friendly fMRI Task.

Science.gov (United States)

van Hulst, Branko M; de Zeeuw, Patrick; Lupas, Kellina; Bos, Dienke J; Neggers, Sebastiaan F W; Durston, Sarah

2015-01-01

Reward processing has been implicated in developmental disorders. However, the classic task to probe reward anticipation, the monetary incentive delay task, has an abstract coding of reward and no storyline and may therefore be less appropriate for use with developmental populations. We modified the task to create a version appropriate for use with children. We investigated whether this child-friendly version could elicit ventral striatal activation during reward anticipation in typically developing children and young adolescents (aged 9.5-14.5). In addition, we tested whether our performance-based measure of reward sensitivity was associated with anticipatory activity in ventral striatum. Reward anticipation was related to activity in bilateral ventral striatum. Moreover, we found an association between individual reward sensitivity and activity in ventral striatum. We conclude that this task assesses ventral striatal activity in a child-friendly paradigm. The combination with a performance-based measure of reward sensitivity potentially makes the task a powerful tool for developmental imaging studies of reward processing.

Perception of performance management and rewards in selected ...

African Journals Online (AJOL)

... rewards in selected public sector organisations in Ghana: a test of the systems theory. ... products and services for customers inside and outside the organization. ... of performance management effectiveness and also establish a relationship ...

Reward-based spatial learning in unmedicated adults with obsessive-compulsive disorder.

Science.gov (United States)

Marsh, Rachel; Tau, Gregory Z; Wang, Zhishun; Huo, Yuankai; Liu, Ge; Hao, Xuejun; Packard, Mark G; Peterson, Bradley S; Simpson, H Blair

2015-04-01

The authors assessed the functioning of mesolimbic and striatal areas involved in reward-based spatial learning in unmedicated adults with obsessive-compulsive disorder (OCD). Functional MRI blood-oxygen-level-dependent response was compared in 33 unmedicated adults with OCD and 33 healthy, age-matched comparison subjects during a reward-based learning task that required learning to use extramaze cues to navigate a virtual eight-arm radial maze to find hidden rewards. The groups were compared in their patterns of brain activation associated with reward-based spatial learning versus a control condition in which rewards were unexpected because they were allotted pseudorandomly to experimentally prevent learning. Both groups learned to navigate the maze to find hidden rewards, but group differences in neural activity during navigation and reward processing were detected in mesolimbic and striatal areas. During navigation, the OCD group, unlike the healthy comparison group, exhibited activation in the left posterior hippocampus. Unlike healthy subjects, participants in the OCD group did not show activation in the left ventral putamen and amygdala when anticipating rewards or in the left hippocampus, amygdala, and ventral putamen when receiving unexpected rewards (control condition). Signal in these regions decreased relative to baseline during unexpected reward receipt among those in the OCD group, and the degree of activation was inversely associated with doubt/checking symptoms. Participants in the OCD group displayed abnormal recruitment of mesolimbic and ventral striatal circuitry during reward-based spatial learning. Whereas healthy comparison subjects exhibited activation in this circuitry in response to the violation of reward expectations, unmedicated OCD participants did not and instead over-relied on the posterior hippocampus during learning. Thus, dopaminergic innervation of reward circuitry may be altered, and future study of anterior/posterior hippocampal

Reward-related behavioral paradigms for addiction research in the mouse: performance of common inbred strains.

Directory of Open Access Journals (Sweden)

Lauren Lederle

2011-01-01

Full Text Available The mouse has emerged as a uniquely valuable species for studying the molecular and genetic basis of complex behaviors and modeling neuropsychiatric disease states. While valid and reliable preclinical assays for reward-related behaviors are critical to understanding addiction-related processes, and various behavioral procedures have been developed and characterized in rats and primates, there have been relatively few studies using operant-based addiction-relevant behavioral paradigms in the mouse. Here we describe the performance of the C57BL/6J inbred mouse strain on three major reward-related paradigms, and replicate the same procedures in two other commonly used inbred strains (DBA/2J, BALB/cJ. We examined Pavlovian-instrumental transfer (PIT by measuring the ability of an auditory cue associated with food reward to promote an instrumental (lever press response. In a separate experiment, we assessed the acquisition and extinction of a simple stimulus-reward instrumental behavior on a touch screen based task. Reinstatement of this behavior was then examined following either continuous exposure to cues (conditioned reinforcers, CRs associated with reward, brief reward and CR exposure, or brief reward exposure followed by continuous CR exposure. The third paradigm examined sensitivity of an instrumental (lever press response to devaluation of food reward (a probe for outcome insensitive, habitual behavior by repeated pairing with malaise. Results showed that C57BL/6J mice displayed robust PIT, as well as clear extinction and reinstatement, but were insensitive to reinforcer devaluation. DBA/2J mice showed good PIT and (rewarded reinstatement, but were slow to extinguish and did not show reinforcer devaluation or significant CR-reinstatement. BALB/cJ mice also displayed good PIT, extinction and reinstatement, and retained instrumental responding following devaluation, but, unlike the other strains, demonstrated reduced Pavlovian approach

Reward-related behavioral paradigms for addiction research in the mouse: performance of common inbred strains.

Science.gov (United States)

Lederle, Lauren; Weber, Susanna; Wright, Tara; Feyder, Michael; Brigman, Jonathan L; Crombag, Hans S; Saksida, Lisa M; Bussey, Timothy J; Holmes, Andrew

2011-01-10

The mouse has emerged as a uniquely valuable species for studying the molecular and genetic basis of complex behaviors and modeling neuropsychiatric disease states. While valid and reliable preclinical assays for reward-related behaviors are critical to understanding addiction-related processes, and various behavioral procedures have been developed and characterized in rats and primates, there have been relatively few studies using operant-based addiction-relevant behavioral paradigms in the mouse. Here we describe the performance of the C57BL/6J inbred mouse strain on three major reward-related paradigms, and replicate the same procedures in two other commonly used inbred strains (DBA/2J, BALB/cJ). We examined Pavlovian-instrumental transfer (PIT) by measuring the ability of an auditory cue associated with food reward to promote an instrumental (lever press) response. In a separate experiment, we assessed the acquisition and extinction of a simple stimulus-reward instrumental behavior on a touch screen based task. Reinstatement of this behavior was then examined following either continuous exposure to cues (conditioned reinforcers, CRs) associated with reward, brief reward and CR exposure, or brief reward exposure followed by continuous CR exposure. The third paradigm examined sensitivity of an instrumental (lever press) response to devaluation of food reward (a probe for outcome insensitive, habitual behavior) by repeated pairing with malaise. Results showed that C57BL/6J mice displayed robust PIT, as well as clear extinction and reinstatement, but were insensitive to reinforcer devaluation. DBA/2J mice showed good PIT and (rewarded) reinstatement, but were slow to extinguish and did not show reinforcer devaluation or significant CR-reinstatement. BALB/cJ mice also displayed good PIT, extinction and reinstatement, and retained instrumental responding following devaluation, but, unlike the other strains, demonstrated reduced Pavlovian approach behavior (food

Reward associations magnify memory-based biases on perception.

Science.gov (United States)

Doallo, Sonia; Patai, Eva Zita; Nobre, Anna Christina

2013-02-01

Long-term spatial contextual memories are a rich source of predictions about the likely locations of relevant objects in the environment and should enable tuning of neural processing of unfolding events to optimize perception and action. Of particular importance is whether and how the reward outcome of past events can impact perception. We combined behavioral measures with recordings of brain activity with high temporal resolution to test whether the previous reward outcome associated with a memory could modulate the impact of memory-based biases on perception, and if so, the level(s) at which visual neural processing is biased by reward-associated memory-guided attention. Data showed that past rewards potentiate the effects of spatial memories upon the discrimination of target objects embedded within complex scenes starting from early perceptual stages. We show that a single reward outcome of learning impacts on how we perceive events in our complex environments.

Chewing gum moderates the vigilance decrement.

OpenAIRE

Morgan, K.; Johnson, A.J.; Miles, C..

2014-01-01

We examine the impact of chewing gum on a Bakan-type vigilance task that requires the continual updating of short-term order memory. Forty participants completed a 30-min auditory Bakan-task either with, or without, the requirement to chew gum. Self-rated measures of mood were taken both pre- and post-task. As expected, the vigilance task produced a time-dependent performance decrement indexed via decreases in target detections and lengthened correct reaction times (RTs), and a reduction in p...

Reinforcement, Behavior Constraint, and the Overjustification Effect.

Science.gov (United States)

Williams, Bruce W.

1980-01-01

Four levels of the behavior constraint-reinforcement variable were manipulated: attractive reward, unattractive reward, request to perform, and a no-reward control. Only the unattractive reward and request groups showed the performance decrements that suggest the overjustification effect. It is concluded that reinforcement does not cause the…

Learned reward association improves visual working memory.

Science.gov (United States)

Gong, Mengyuan; Li, Sheng

2014-04-01

Statistical regularities in the natural environment play a central role in adaptive behavior. Among other regularities, reward association is potentially the most prominent factor that influences our daily life. Recent studies have suggested that pre-established reward association yields strong influence on the spatial allocation of attention. Here we show that reward association can also improve visual working memory (VWM) performance when the reward-associated feature is task-irrelevant. We established the reward association during a visual search training session, and investigated the representation of reward-associated features in VWM by the application of a change detection task before and after the training. The results showed that the improvement in VWM was significantly greater for items in the color associated with high reward than for those in low reward-associated or nonrewarded colors. In particular, the results from control experiments demonstrate that the observed reward effect in VWM could not be sufficiently accounted for by attentional capture toward the high reward-associated item. This was further confirmed when the effect of attentional capture was minimized by presenting the items in the sample and test displays of the change detection task with the same color. The results showed significantly larger improvement in VWM performance when the items in a display were in the high reward-associated color than those in the low reward-associated or nonrewarded colors. Our findings suggest that, apart from inducing space-based attentional capture, the learned reward association could also facilitate the perceptual representation of high reward-associated items through feature-based attentional modulation.

Baseline frontostriatal-limbic connectivity predicts reward-based memory formation.

Science.gov (United States)

Hamann, Janne M; Dayan, Eran; Hummel, Friedhelm C; Cohen, Leonardo G

2014-12-01

Reward mediates the acquisition and long-term retention of procedural skills in humans. Yet, learning under rewarded conditions is highly variable across individuals and the mechanisms that determine interindividual variability in rewarded learning are not known. We postulated that baseline functional connectivity in a large-scale frontostriatal-limbic network could predict subsequent interindividual variability in rewarded learning. Resting-state functional MRI was acquired in two groups of subjects (n = 30) who then trained on a visuomotor procedural learning task with or without reward feedback. We then tested whether baseline functional connectivity within the frontostriatal-limbic network predicted memory strength measured immediately, 24 h and 1 month after training in both groups. We found that connectivity in the frontostriatal-limbic network predicted interindividual variability in the rewarded but not in the unrewarded learning group. Prediction was strongest for long-term memory. Similar links between connectivity and reward-based memory were absent in two control networks, a fronto-parieto-temporal language network and the dorsal attention network. The results indicate that baseline functional connectivity within the frontostriatal-limbic network successfully predicts long-term retention of rewarded learning. © 2014 Wiley Periodicals, Inc.

Rewards boost sustained attention through higher effort: A value-based decision making approach.

Science.gov (United States)

Massar, Stijn A A; Lim, Julian; Sasmita, Karen; Chee, Michael W L

2016-10-01

Maintaining sustained attention over time is an effortful process limited by finite cognitive resources. Recent theories describe the role of motivation in the allocation of such resources as a decision process: the costs of effortful performance are weighed against its gains. We examined this hypothesis by combining methods from attention research and decision neuroscience. Participants first performed a sustained attention task at different levels of reward. They then performed a reward-discounting task, measuring the subjective costs of performance. Results demonstrated that higher rewards led to improved performance (Exp 1-3), and enhanced attentional effort (i.e. pupil diameter; Exp 2 & 3). Moreover, discounting curves constructed from the choice task indicated that subjects devalued rewards that came at the cost of staying vigilant for a longer duration (Exp 1 & 2). Motivation can thus boost sustained attention through increased effort, while sustained performance is regarded as a cost against which rewards are discounted. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Achievement-Based Rewards and Intrinsic Motivation: A Test of Cognitive Mediators

Science.gov (United States)

Cameron, Judy; Pierce, W. David; Banko, Katherine M.; Gear, Amber

2005-01-01

This study assessed how rewards impacted intrinsic motivation when students were rewarded for achievement while learning an activity, for performing at a specific level on a test, or for both. Undergraduate university students engaged in a problem-solving activity. The design was a 2 * 2 factorial with 2 levels of reward in a learning phase…

The merit of cogeneration: Measuring and rewarding performance

International Nuclear Information System (INIS)

Verbruggen, Aviel

2008-01-01

Cogeneration or combined heat and power (CHP) is a thermal power generation cycle with the merit of recovering part or all of the heat that is fatally discarded by such cycles. This merit of higher efficiency is subject of rewarding by public authorities. When the EU enacts CHP promotion in a Directive (1997-2004), crucial measurement and qualification issues remain unsolved. CEN (coordinator of the European Bureaus of Standards) contributes in clarifying the measurement of CHP activities, but shortfalls remain, while CEN bypasses the debate on qualifying CHP performance. This article offers appropriate methods for measuring CHP activities based on design characteristics of the plants. The co-generated electric output is a necessary and sufficient indicator of CHP merit and performance. Regulators can extend this indicator, but should avoid the perverse effects of biased external benchmarking as the EU Directive entails

Performance Trends During Sleep Deprivation on a Tilt-Based Control Task.

Science.gov (United States)

Bolkhovsky, Jeffrey B; Ritter, Frank E; Chon, Ki H; Qin, Michael

2018-07-01

Understanding human behavior under the effects of sleep deprivation allows for the mitigation of risk due to reduced performance. To further this goal, this study investigated the effects of short-term sleep deprivation using a tilt-based control device and examined whether existing user models accurately predict targeting performance. A task in which the user tilts a surface to roll a ball into a target was developed to examine motor performance. A model was built to predict human performance for this task under various levels of sleep deprivation. Every 2 h, 10 subjects completed the task until they reached 24 h of wakefulness. Performance measurements of this task, which were based on Fitts' law, included movement time, task throughput, and time intercept. The model predicted significant performance decrements over the 24-h period with an increase in movement time (R2 = 0.61), a decrease in throughput (R2 = 0.57), and an increase in time intercept (R2 = 0.60). However, it was found that in experimental trials there was no significant change in movement time (R2 = 0.11), throughput (R2 = 0.15), or time intercept (R2 = 0.27). The results found were unexpected as performance decrement is frequently reported during sleep deprivation. These findings suggest a reexamination of the initial thought of sleep loss leading to a decrement in all aspects of performance.Bolkovsky JB, Ritter FE, Chon KH, Qin M. Performance trends during sleep deprivation on a tilt-based control task. Aerosp Med Hum Perform. 2018; 89(7):626-633.

Managing Reward Strategy to Enhance Employee Performance

African Journals Online (AJOL)

Prof

strategy in organizations with a view to ascertaining its efficacy on ... (contingent or variable pay), or for their services in the job (service-related pay). ... The concepts of rewards and incentives are interchangeably used by .... employee's base salary or in most cases organization use a combination of ... to the market values.

Instant messaging addiction among teenagers in China: shyness, alienation, and academic performance decrement.

Science.gov (United States)

Huang, Hanyun; Leung, Louis

2009-12-01

This exploratory research proposes the concept of instant messaging (IM) addiction and examines (a) whether IM addiction exists among Chinese teenagers and, if so, who the addicts are, what their symptoms are, and to what extent they are addicted; (b) whether psychological variables such as shyness and alienation can predict IM use or addiction among teenagers; and (c) whether IM use or IM addiction can impair the academic performance of teenagers. Using Young's classic definition of Internet addiction, results of a stratified random sample of 330 teenagers in China in 2007 found 95.8% of participants use IM, and 9.8% of them can be classified as IM addicts. Factor analysis identified four major IM addiction symptoms among teenagers: preoccupation with IM, loss of relationships due to overuse, loss of control, and escape. Results also showed that shyness and alienation from family, peers, and school are significantly and positively associated with levels of IM addiction. As expected, both the level of IM use and level of IM addiction are significantly linked to teenagers' academic performance decrement.

Results-based Rewards - Leveraging Wage Increases?

DEFF Research Database (Denmark)

Bregn, Kirsten

2005-01-01

A good seven years ago, as a part of a large-scale pay reform, the Danish public sector introduced results-based rewards (RBR), i.e. a pay component awarded for achieving or exceeding targets set in advance. RBR represent a possibility for combining wage-earners interests in higher wages with a g......A good seven years ago, as a part of a large-scale pay reform, the Danish public sector introduced results-based rewards (RBR), i.e. a pay component awarded for achieving or exceeding targets set in advance. RBR represent a possibility for combining wage-earners interests in higher wages...... limited use of RBR, illustrated with examples. The Danish experiences should give food for thought, given that pay systems used by the public sector are currently under transformation in practically all OECD countries....

Effects of frequency and duration on psychometric functions for detection of increments and decrements in sinusoids in noise.

Science.gov (United States)

Moore, B C; Peters, R W; Glasberg, B R

1999-12-01

Psychometric functions for detecting increments or decrements in level of sinusoidal pedestals were measured for increment and decrement durations of 5, 10, 20, 50, 100, and 200 ms and for frequencies of 250, 1000, and 4000 Hz. The sinusoids were presented in background noise intended to mask spectral splatter. A three-interval, three-alternative procedure was used. The results indicated that, for increments, the detectability index d' was approximately proportional to delta I/I. For decrements, d' was approximately proportional to delta L. The slopes of the psychometric functions increased (indicating better performance) with increasing frequency for both increments and decrements. For increments, the slopes increased with increasing increment duration up to 200 ms at 250 and 1000 Hz, but at 4000 Hz they increased only up to 50 ms. For decrements, the slopes increased for durations up to 50 ms, and then remained roughly constant, for all frequencies. For a center frequency of 250 Hz, the slopes of the psychometric functions for increment detection increased with duration more rapidly than predicted by a "multiple-looks" hypothesis, i.e., more rapidly than the square root of duration, for durations up to 50 ms. For center frequencies of 1000 and 4000 Hz, the slopes increased less rapidly than predicted by a multiple-looks hypothesis, for durations greater than about 20 ms. The slopes of the psychometric functions for decrement detection increased with decrement duration at a rate slightly greater than the square root of duration, for durations up to 50 ms, at all three frequencies. For greater durations, the increase in slope was less than proportional to the square root of duration. The results were analyzed using a model incorporating a simulated auditory filter, a compressive nonlinearity, a sliding temporal integrator, and a decision device based on a template mechanism. The model took into account the effects of both the external noise and an assumed internal

Understanding Performance Decrements in a Letter-Canceling Task: Overcoming Habits or Inhibition of Reading.

Science.gov (United States)

Myers, Larry; Downie, Steven; Taylor, Grant; Marrington, Jessica; Tehan, Gerald; Ireland, Michael J

2018-01-01

The importance of self-regulation in human behavior is readily apparent and diverse theoretical accounts for explaining self-regulation failures have been proposed. Typically, these accounts are based on a sequential task methodology where an initial task is presented to deplete self-regulatory resources, and carryover effects are then examined on a second outcome task. In the aftermath of high profile replication failures using a popular letter-crossing task as a means of depleting self-regulatory resources and subsequent criticisms of that task, current research into self-control is currently at an impasse. This is largely due to the lack of empirical research that tests explicit assumptions regarding the initial task. One such untested assumption is that for resource depletion to occur, the initial task must first establish an habitual response and then this habitual response must be inhibited, with behavioral inhibition being the causal factor in inducing depletion. This study reports on four experiments exploring performance on a letter-canceling task, where the rules for target identification remained constant but the method of responding differed (Experiment 1) and the coherence of the text was manipulated (Experiments 1-4). Experiment 1 established that habit forming and behavioral inhibition did not produce any performance decrement when the targets were embedded in random letter strings. Experiments 2-4 established that target detection was sensitive to language characteristics and the coherence of the background text, suggesting that participants' automatic reading processes is a key driver of performance in the letter-e task.

Identification of System Parameters by the Random Decrement Technique

DEFF Research Database (Denmark)

Brincker, Rune; Kirkegaard, Poul Henning; Rytter, Anders

-Walker equations and finally least square fitting of the theoretical correlation function. The results are compared to the results of fitting an Auto Regressive Moving Average(ARMA) model directly to the system output. All investigations are performed on the simulated output from a single degree-off-freedom system......The aim of this paper is to investigate and illustrate the possibilities of using correlation functions estimated by the Random Decrement Technique as a basis for parameter identification. A two-stage system identification method is used: first the correlation functions are estimated by the Random...... Decrement technique and then the system parameters are identified from the correlation function estimates. Three different techniques are used in the parameters identification process: a simple non-paramatic method, estimation of an Auto Regressive(AR) model by solving an overdetermined set of Yule...

Effects of Motivation: Rewarding Hackers for Undetected Attacks Cause Analysts to Perform Poorly.

Science.gov (United States)

Maqbool, Zahid; Makhijani, Nidhi; Pammi, V S Chandrasekhar; Dutt, Varun

2017-05-01

The aim of this study was to determine how monetary motivations influence decision making of humans performing as security analysts and hackers in a cybersecurity game. Cyberattacks are increasing at an alarming rate. As cyberattacks often cause damage to existing cyber infrastructures, it is important to understand how monetary rewards may influence decision making of hackers and analysts in the cyber world. Currently, only limited attention has been given to this area. In an experiment, participants were randomly assigned to three between-subjects conditions ( n = 26 for each condition): equal payoff, where the magnitude of monetary rewards for hackers and defenders was the same; rewarding hacker, where the magnitude of monetary reward for hacker's successful attack was 10 times the reward for analyst's successful defense; and rewarding analyst, where the magnitude of monetary reward for analyst's successful defense was 10 times the reward for hacker's successful attack. In all conditions, half of the participants were human hackers playing against Nash analysts and half were human analysts playing against Nash hackers. Results revealed that monetary rewards for human hackers and analysts caused a decrease in attack and defend actions compared with the baseline. Furthermore, rewarding human hackers for undetected attacks made analysts deviate significantly from their optimal behavior. If hackers are rewarded for their undetected attack actions, then this causes analysts to deviate from optimal defend proportions. Thus, analysts need to be trained not become overenthusiastic in defending networks. Applications of our results are to networks where the influence of monetary rewards may cause information theft and system damage.

Model-free and model-based reward prediction errors in EEG.

Science.gov (United States)

Sambrook, Thomas D; Hardwick, Ben; Wills, Andy J; Goslin, Jeremy

2018-05-24

Learning theorists posit two reinforcement learning systems: model-free and model-based. Model-based learning incorporates knowledge about structure and contingencies in the world to assign candidate actions with an expected value. Model-free learning is ignorant of the world's structure; instead, actions hold a value based on prior reinforcement, with this value updated by expectancy violation in the form of a reward prediction error. Because they use such different learning mechanisms, it has been previously assumed that model-based and model-free learning are computationally dissociated in the brain. However, recent fMRI evidence suggests that the brain may compute reward prediction errors to both model-free and model-based estimates of value, signalling the possibility that these systems interact. Because of its poor temporal resolution, fMRI risks confounding reward prediction errors with other feedback-related neural activity. In the present study, EEG was used to show the presence of both model-based and model-free reward prediction errors and their place in a temporal sequence of events including state prediction errors and action value updates. This demonstration of model-based prediction errors questions a long-held assumption that model-free and model-based learning are dissociated in the brain. Copyright © 2018 Elsevier Inc. All rights reserved.

The effect of REM sleep deprivation on motivation for food reward.

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Hanlon, Erin C; Andrzejewski, Matthew E; Harder, Bridgette K; Kelley, Ann E; Benca, Ruth M

2005-08-30

Prolonged sleep deprivation in rats produces a characteristic syndrome consisting of an increase in food intake yet a decrease in weight. Moreover, the increase in food intake generally precedes the weight loss, suggesting that sleep deprivation may affect appetitive behaviors. Using the multiple platform method to produce rapid eye movement (REM) sleep deprivation, we investigated the effect of REM sleep deprivation (REMSD) on motivation for food reward utilizing food-reinforced operant tasks. In acquisition or maintenance of an operant task, REM sleep-deprived rats, with or without simultaneous food restriction, decreased responding for sucrose pellet reward in comparison to controls, despite the fact that all REM sleep-deprived rats lost weight. Furthermore, the overall response deficit of the REM sleep-deprived rats was due to a within-session decline in responding. REM sleep-deprived rats showed evidence of understanding the contingency of the task comparable to controls throughout deprivation period, suggesting that the decrements in responding were not primarily related to deficits in learning or memory. Rather, REM sleep deprivation appears to alter systems involved in motivational processes, reward, and/or attention.

Hilbert-Twin – A Novel Hilbert Transform-Based Method To Compute Envelope Of Free Decaying Oscillations Embedded In Noise, And The Logarithmic Decrement In High-Resolution Mechanical Spectroscopy HRMS

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Magalas L.B.

2015-06-01

Full Text Available In this work, we present a novel Hilbert-twin method to compute an envelope and the logarithmic decrement, δ, from exponentially damped time-invariant harmonic strain signals embedded in noise. The results obtained from five computing methods: (1 the parametric OMI (Optimization in Multiple Intervals method, two interpolated discrete Fourier transform-based (IpDFT methods: (2 the Yoshida-Magalas (YM method and (3 the classic Yoshida (Y method, (4 the novel Hilbert-twin (H-twin method based on the Hilbert transform, and (5 the conventional Hilbert transform (HT method are analyzed and compared. The fundamental feature of the Hilbert-twin method is the efficient elimination of intrinsic asymmetrical oscillations of the envelope, aHT (t, obtained from the discrete Hilbert transform of analyzed signals. Excellent performance in estimation of the logarithmic decrement from the Hilbert-twin method is comparable to that of the OMI and YM for the low- and high-damping levels. The Hilbert-twin method proved to be robust and effective in computing the logarithmic decrement and the resonant frequency of exponentially damped free decaying signals embedded in experimental noise. The Hilbert-twin method is also appropriate to detect nonlinearities in mechanical loss measurements of metals and alloys.

Ambient Modal Testing of the Vestvej Bridge using Random Decrement

DEFF Research Database (Denmark)

Asmussen, J. C.; Brincker, Rune; Rytter, A.

This paper presents an ambient vibration study of the Vestvej Bridge. The bridge is a typically Danish two-span concrete bridge which crosses a highway. The purpose of the study is to perform a pre-investigation of the dynamic behavior to obtain information for the design of a demonstration project...... concerning application of vibration based inspection of bridges. The data analysis process of ambient vribration testing of bridges has traditionally been based on auto and cross spectral densities estimated using an FFT algorithm. In the pre-analysis state the spectral densities are all averaged to obtain...... measurements might have a low signal to noise ratio. Thus, it might be difficult clearly to identify physical modes from the spectral densities. The Random Decrement (RD) technique is another method to perform the data analysis process in the time domain only. It is basically a very simple and very easily...

Ambient Modal Testing of the Vestvej Bridge using Random Decrement

DEFF Research Database (Denmark)

Asmussen, J. C.; Brincker, Rune; Rytter, A.

1998-01-01

This paper presents an ambient vibration study of the Vestvej Bridge. The bridge is a typically Danish two-span concrete bridge which crosses a highway. The purpose of the study is to perform a pre-investigation of the dynamic behavior to obtain information for the design of a demonstration project...... concerning application of vibration based inspection of bridges. The data analysis process of ambient vribration testing of bridges has traditionally been based on auto and cross spectral densities estimated using an FFT algorithm. In the pre-analysis state the spectral densities are all averaged to obtain...... measurements might have a low signal to noise ratio. Thus, it might be difficult clearly to identify physical modes from the spectral densities. The Random Decrement (RD) technique is another method to perform the data analysis process in the time domain only. It is basically a very simple and very easily...

The Use of Player-centered Positive Reinforcement to Schedule In-game Rewards Increases Enjoyment and Performance in a Serious Game

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Aniket Nagle

2014-10-01

Full Text Available Among the methods used to increase enjoyment and performance in serious games, reward schedules, i.e., determining when in-game rewards should be given, have not been sufficiently explored. In the present study, we designed a simple memory training serious game and compared two methods of scheduling rewards, both based on the paradigm of positive reinforcement: fixed ratio schedule, in which rewards were given after a fixed number of correct responses, and variable ratio schedule, in which rewards were given after an unpredictable number of correct responses. To account for the variability in player preference for rewards, a player-centered sub-mode was included in both schedules by adjusting the schedule ratio according to player preference for rewards. The effectiveness of this approach was tested by comparing it against two more sub-modes: one which used a predetermined ratio, and another which set the ratio to the opposite of player preference. The game was put online and tested with 210 participants. Enjoyment, performance, duration of gameplay, and likelihood to play again were significantly higher in the player-centered sub-mode than the other sub-modes. On average, the variable-ratio schedule was better in the outcome measures than the fixed-ratio schedule. The results highlight the importance of in-game rewards, and indicate that giving rewards according to a player-centered variable-ratio schedule has the potential to make serious games more effective.

Reward and attitudes: The unintended outcomes of an effective performance appraisal

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Solomon M. Semakula-Katende

2013-10-01

Full Text Available Orientation: Focus was on the role of reward and attitudes as major determinants in enhancing the effectiveness of performance appraisal systems. Research purpose: To develop a structural model from the qualitative and quantitative findings from which to address the identified gaps in order to improve the effectiveness of appraisals. Motivation for the study: The attention that role players tended to give to the rewarding of employees during the appraisal process made it appear as the only important determinant of an appraisal’s success. In appraisals in many public institutions, reward has been given unnecessary prominence over other drivers, such as management and development. That led most key role players (leaders, managers and employees to perceive the current employee performance management and development system (EPMDS to be purely for monetary (salary increments and cash bonuses and non-monetary (promotion purposes, which, in turn, compromised its effectiveness. Research design, approach and method: Structural equation modelling (SEM was utilised as a statistical technique for testing and estimating causal relations using a combination of statistical data and qualitative causal assumptions. This allowed both confirmatory and exploratory modelling to be undertaken, which is suited to both theory testing and theory development. A triangulation of quantitative (questionnaire and qualitative (interview study was conducted. A total of 300 questionnaires were distributed to nine government hospitals in the Free State province, namely Mofumahadi Manapo Mopeli, Dihlabeng, and Boitumelo regional hospitals, as well as Elizabeth Ross, Thebe, Phekolong, Mpumelelo, Reitz and Ficksburg district hospitals. There was a high response rate of 96 per cent, a total of 287 completed questionnaires. Respondents ranged from top executives, middle management, line management, to employees of all categories. Main findings: Reward and attitudes were found to

Reward-based training of recurrent neural networks for cognitive and value-based tasks.

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Song, H Francis; Yang, Guangyu R; Wang, Xiao-Jing

2017-01-13

Trained neural network models, which exhibit features of neural activity recorded from behaving animals, may provide insights into the circuit mechanisms of cognitive functions through systematic analysis of network activity and connectivity. However, in contrast to the graded error signals commonly used to train networks through supervised learning, animals learn from reward feedback on definite actions through reinforcement learning. Reward maximization is particularly relevant when optimal behavior depends on an animal's internal judgment of confidence or subjective preferences. Here, we implement reward-based training of recurrent neural networks in which a value network guides learning by using the activity of the decision network to predict future reward. We show that such models capture behavioral and electrophysiological findings from well-known experimental paradigms. Our work provides a unified framework for investigating diverse cognitive and value-based computations, and predicts a role for value representation that is essential for learning, but not executing, a task.

Reactivation of Reward-Related Patterns from Single Past Episodes Supports Memory-Based Decision Making.

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Wimmer, G Elliott; Büchel, Christian

2016-03-09

Rewarding experiences exert a strong influence on later decision making. While decades of neuroscience research have shown how reinforcement gradually shapes preferences, decisions are often influenced by single past experiences. Surprisingly, relatively little is known about the influence of single learning episodes. Although recent work has proposed a role for episodes in decision making, it is largely unknown whether and how episodic experiences contribute to value-based decision making and how the values of single episodes are represented in the brain. In multiple behavioral experiments and an fMRI experiment, we tested whether and how rewarding episodes could support later decision making. Participants experienced episodes of high reward or low reward in conjunction with incidental, trial-unique neutral pictures. In a surprise test phase, we found that participants could indeed remember the associated level of reward, as evidenced by accurate source memory for value and preferences to re-engage with rewarded objects. Further, in a separate experiment, we found that high-reward objects shown as primes before a gambling task increased financial risk taking. Neurally, re-exposure to objects in the test phase led to significant reactivation of reward-related patterns. Importantly, individual variability in the strength of reactivation predicted value memory performance. Our results provide a novel demonstration that affect-related neural patterns are reactivated during later experience. Reactivation of value information represents a mechanism by which memory can guide decision making. Copyright © 2016 the authors 0270-6474/16/362868-13$15.00/0.

Task complexity and task, goal, and reward interdependence in group performance : a prescriptive model

NARCIS (Netherlands)

Vijfeijken, van H.T.G.A.; Kleingeld, P.A.M.; Tuijl, van H.F.J.M.; Algera, J.A.; Thierry, H.

2002-01-01

A prescriptive model on how to design effective combinations of goal setting and contingent rewards for group performance management is presented. The model incorporates the constructs task complexity, task interdependence, goal interdependence, and reward interdependence and specifies optimal fit

Reward Systems and Performance of Sales: A Descriptive Study among the Ghanaian Insurance Industry

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Joshua Ohene-Danso

2015-04-01

Full Text Available Ghanaian managers over recent years have taken a steady pattern of organizational policies, aimed specifically at enhancing employees’ development and management. Significant among these measures are recognition and rewards management. The system of rewards at selected Ghanaian Insurance Companies within it Southern Sector operations affected the performance of employees in the sales and marketing of products. Descriptive results indicate that, reward strategies are significant in providing an incentive to employees to work. It is recommended that total rewards should be extended to cover job security and other benefits in the form of recognition.

Motion-Induced Blindness Using Increments and Decrements of Luminance

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Stine Wm Wren

2017-10-01

Full Text Available Motion-induced blindness describes the disappearance of stationary elements of a scene when other, perhaps non-overlapping, elements of the scene are in motion. We measured the effects of increment (200.0 cd/m2 and decrement targets (15.0 cd/m2 and masks presented on a grey background (108.0 cd/m2, tapping into putative ON- and OFF-channels, on the rate of target disappearance psychophysically. We presented two-frame motion, which has coherent motion energy, and dynamic Glass patterns and dynamic anti-Glass patterns, which do not have coherent motion energy. Using the method of constant stimuli, participants viewed stimuli of varying durations (3.1 s, 4.6 s, 7.0 s, 11 s, or 16 s in a given trial and then indicated whether or not the targets vanished during that trial. Psychometric function midpoints were used to define absolute threshold mask duration for the disappearance of the target. 95% confidence intervals for threshold disappearance times were estimated using a bootstrap technique for each of the participants across two experiments. Decrement masks were more effective than increment masks with increment targets. Increment targets were easier to mask than decrement targets. Distinct mask pattern types had no effect, suggesting that perceived coherence contributes to the effectiveness of the mask. The ON/OFF dichotomy clearly carries its influence to the level of perceived motion coherence. Further, the asymmetry in the effects of increment and decrement masks on increment and decrement targets might lead one to speculate that they reflect the ‘importance’ of detecting decrements in the environment.

Modeling Multioperator Multi-UAV Operator Attention Allocation Problem Based on Maximizing the Global Reward

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Yuhang Wu

2016-01-01

Full Text Available This paper focuses on the attention allocation problem (AAP in modeling multioperator multi-UAV (MOMU, with the operator model and task properties taken into consideration. The model of MOMU operator AAP based on maximizing the global reward is established and used to allocate tasks to all operators as well as set work time and rest time to each task simultaneously for operators. The proposed model is validated in Matlab simulation environment, using the immune algorithm and dynamic programming algorithm to evaluate the performance of the model in terms of the reward value with regard to the work time, rest time, and task allocation. The result shows that the total reward of the proposed model is larger than the one obtained from previously published methods using local maximization and the total reward of our method has an exponent-like relation with the task arrival rate. The proposed model can improve the operators’ task processing efficiency in the MOMU command and control scenarios.

Blunted striatal response to monetary reward anticipation during smoking abstinence predicts lapse during a contingency-managed quit attempt.

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Sweitzer, Maggie M; Geier, Charles F; Denlinger, Rachel; Forbes, Erika E; Raiff, Bethany R; Dallery, Jesse; McClernon, F J; Donny, Eric C

2016-03-01

Tobacco smoking is associated with dysregulated reward processing within the striatum, characterized by hypersensitivity to smoking rewards and hyposensitivity to non-smoking rewards. This bias toward smoking reward at the expense of alternative rewards is further exacerbated by deprivation from smoking, which may contribute to difficulty maintaining abstinence during a quit attempt. We examined whether abstinence-induced changes in striatal processing of rewards predicted lapse likelihood during a quit attempt supported by contingency management (CM), in which abstinence from smoking was reinforced with money. Thirty-six non-treatment-seeking smokers participated in two functional MRI (fMRI) sessions, one following 24-h abstinence and one following smoking as usual. During each scan, participants completed a rewarded guessing task designed to elicit striatal activation in which they could earn smoking and monetary rewards delivered after the scan. Participants then engaged in a 3-week CM-supported quit attempt. As previously reported, 24-h abstinence was associated with increased striatal activation in anticipation of smoking reward and decreased activation in anticipation of monetary reward. Individuals exhibiting greater decrements in right striatal activation to monetary reward during abstinence (controlling for activation during non-abstinence) were more likely to lapse during CM (p reward. These results are consistent with a growing number of studies indicating the specific importance of disrupted striatal processing of non-drug reward in nicotine dependence and highlight the importance of individual differences in abstinence-induced deficits in striatal function for smoking cessation.

The role of memory representation in the vigilance decrement

OpenAIRE

CAGGIANO, DANIEL M.; PARASURAMAN, RAJA

2004-01-01

Working memory load is critically important for the overall level of performance on vigilance tasks. However, its role in a key aspect of vigilance—sensitivity decrement over time—is unclear. We used a dual-task procedure in which either a spatial or a nonspatial working memory task was performed simultaneously with a spatial vigilance task for 20 min. Sensitivity in the vigilance task declined over time when the concurrent task involved spatial working memory. In contrast, there was no sensi...

Methylphenidate and brain activity in a reward/conflict paradigm: role of the insula in task performance.

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Ivanov, Iliyan; Liu, Xun; Clerkin, Suzanne; Schulz, Kurt; Fan, Jin; Friston, Karl; London, Edythe D; Schwartz, Jeffrey; Newcorn, Jeffrey H

2014-06-01

Psychostimulants, such as methylphenidate, are thought to improve information processing in motivation-reward and attention-activation networks by enhancing the effects of more relevant signals and suppressing those of less relevant ones; however the nature of such reciprocal influences remains poorly understood. To explore this question, we tested the effect of methylphenidate on performance and associated brain activity in the Anticipation, Conflict, Reward (ACR) task. Sixteen healthy adult volunteers, ages 21-45, were scanned twice using functional magnetic resonance imaging (fMRI) as they performed the ACR task under placebo and methylphenidate conditions. A three-way repeated measures analysis of variance, with cue (reward vs. non-reward), target (congruent vs. incongruent) and medication condition (methylphenidate vs. placebo) as the factors, was used to analyze behaviors on the task. Blood oxygen level dependent (BOLD) signals, reflecting task-related neural activity, were evaluated using linear contrasts. Participants exhibited significantly greater accuracy in the methylphenidate condition than the placebo condition. Compared with placebo, the methylphenidate condition also was associated with lesser task-related activity in components of attention-activation systems irrespective of the reward cue, and less task-related activity in components of the reward-motivation system, particularly the insula, during reward trials irrespective of target difficulty. These results suggest that methylphenidate enhances task performance by improving efficiency of information processing in both reward-motivation and in attention-activation systems. Published by Elsevier B.V.

Incremental effects of reward on creativity.

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Eisenberger, R; Rhoades, L

2001-10-01

The authors examined 2 ways reward might increase creativity. First, reward contingent on creativity might increase extrinsic motivation. Studies 1 and 2 found that repeatedly giving preadolescent students reward for creative performance in 1 task increased their creativity in subsequent tasks. Study 3 reported that reward promised for creativity increased college students' creative task performance. Second, expected reward for high performance might increase creativity by enhancing perceived self-determination and, therefore, intrinsic task interest. Study 4 found that employees' intrinsic job interest mediated a positive relationship between expected reward for high performance and creative suggestions offered at work. Study 5 found that employees' perceived self-determination mediated a positive relationship between expected reward for high performance and the creativity of anonymous suggestions for helping the organization.

Long-lasting effects of performance-contingent unconscious and conscious reward incentives during cued task-switching.

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Capa, Rémi L; Bouquet, Cédric A; Dreher, Jean-Claude; Dufour, André

2013-01-01

Motivation is often thought to interact consciously with executive control, although recent studies have indicated that motivation can also be unconscious. To date, however, the effects of unconscious motivation on high-order executive control functions have not been explored. Only a few studies using subliminal stimuli (i.e., those not related to motivation, such as an arrow to prime a response) have reported short-lived effects on high-order executive control functions. Here, building on research on unconscious motivation, in which a behavior of perseverance is induced to attain a goal, we hypothesized that subliminal motivation can have long-lasting effects on executive control processes. We investigated the impact of unconscious/conscious monetary reward incentives on evoked potentials and neural activity dynamics during cued task-switching performance. Participants performed long runs of task-switching. At the beginning of each run, a reward (50 cents or 1 cent) was displayed, either subliminally or supraliminally. Participants earned the reward contingent upon their correct responses to each trial of the run. A higher percentage of runs was achieved with higher (conscious and unconscious) than lower rewards, indicating that unconscious high rewards have long-lasting behavioral effects. Event-related potential (ERP) results indicated that unconscious and conscious rewards influenced preparatory effort in task preparation, as suggested by a greater fronto-central contingent negative variation (CNV) starting at cue-onset. However, a greater parietal P3 associated with better reaction times (RTs) was observed only under conditions of conscious high reward, suggesting a larger amount of working memory invested during task performance. Together, these results indicate that unconscious and conscious motivations are similar at early stages of task-switching preparation but differ during task performance. Copyright © 2012 Elsevier Ltd. All rights reserved.

Counteracting effect of threat on reward enhancements during working memory.

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Choi, Jong Moon; Padmala, Srikanth; Pessoa, Luiz

2015-01-01

Cognitive performance has been shown to be enhanced when performance-based rewards are at stake. On the other hand, task-irrelevant threat processing has been shown to have detrimental effects during several cognitive tasks. Crucially, the impact of reward and threat on cognition has been studied largely independently of one another. Hence, our understanding of how reward and threat simultaneously contribute to performance is incomplete. To fill in this gap, the present study investigated how reward and threat interact with one another during a cognitive task. We found that threat of shock counteracted the beneficial effect of reward during a working memory task. Furthermore, individual differences in self-reported reward-sensitivity and anxiety were linked to the extent to which reward and threat interacted during behaviour. Together, the current findings contribute to a limited but growing literature unravelling how positive and negative information processing jointly influence cognition.

Feedback associated with expectation for larger-reward improves visuospatial working memory performances in children with ADHD.

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Hammer, Rubi; Tennekoon, Michael; Cooke, Gillian E; Gayda, Jessica; Stein, Mark A; Booth, James R

2015-08-01

We tested the interactive effect of feedback and reward on visuospatial working memory in children with ADHD. Seventeen boys with ADHD and 17 Normal Control (NC) boys underwent functional magnetic resonance imaging (fMRI) while performing four visuospatial 2-back tasks that required monitoring the spatial location of letters presented on a display. Tasks varied in reward size (large; small) and feedback availability (no-feedback; feedback). While the performance of NC boys was high in all conditions, boys with ADHD exhibited higher performance (similar to those of NC boys) only when they received feedback associated with large-reward. Performance pattern in both groups was mirrored by neural activity in an executive function neural network comprised of few distinct frontal brain regions. Specifically, neural activity in the left and right middle frontal gyri of boys with ADHD became normal-like only when feedback was available, mainly when feedback was associated with large-reward. When feedback was associated with small-reward, or when large-reward was expected but feedback was not available, boys with ADHD exhibited altered neural activity in the medial orbitofrontal cortex and anterior insula. This suggests that contextual support normalizes activity in executive brain regions in children with ADHD, which results in improved working memory. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Using food as a reward: An examination of parental reward practices.

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Roberts, Lindsey; Marx, Jenna M; Musher-Eizenman, Dara R

2018-01-01

Eating patterns and taste preferences are often established early in life. Many studies have examined how parental feeding practices may affect children's outcomes, including food intake and preference. The current study focused on a common food parenting practice, using food as a reward, and used Latent Profile Analysis (LPA) to examine whether mothers (n = 376) and fathers (n = 117) of children ages 2.8 to 7.5 (M = 4.7; SD = 1.1) grouped into profiles (i.e., subgroups) based on how they use of food as a reward. The 4-class model was the best-fitting LPA model, with resulting classes based on both the frequency and type of reward used. Classes were: infrequent reward (33%), tangible reward (21%), food reward (27%), and frequent reward (19%). The current study also explored whether children's eating styles (emotional overeating, rood fussiness, food responsiveness, and satiety responsiveness) and parenting style (Authoritative, Authoritarian, and Permissive) varied by reward profile. Analyses of Variance (ANOVA) revealed that the four profiles differed significantly for all outcome variables except satiety responsiveness. It appears that the use of tangible and food-based rewards have important implications in food parenting. More research is needed to better understand how the different rewarding practices affect additional child outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

An empirical study of the reward preferences of South African employees

Directory of Open Access Journals (Sweden)

Robin J. Snelgar

2013-04-01

Full Text Available Orientation: Adapting traditional reward systems to focus on employee preferences has become a necessity as companies strive to attract, motivate and retain a skilled and high performing workforce. Research purpose: The aim of the study was to identify certain categories of rewards that employees consider to be most important, including base pay, contingency pay, benefits, performance and career management, quality work environment, and work–home integration. The impact of these reward categories on an organisation’s ability to attract, motivate and retain employees was explored, together with the influence of demographic variables on reward preferences. Motivation for the study: There is much debate over whether reward packages should be tailor-made to suit individual employees. It has been argued that a ‘one-size-fits-all’ approach with regard to rewards is no longer effective. Research design, approach and method: A structured questionnaire, based on the total rewards model, was used to achieve the objectives of the study. A sample of 250 employees from 11 medium-sized to large-sized organisations participated in the study. Main findings: The results showed that base pay is deemed to be the most preferred reward component amongst respondents; however, they are most dissatisfied with the level at which this reward is provided by their current employers. Base pay is also the most important reward when attracting and retaining employees. Differences between reward preferences and demographic variables, including age, gender and job level, were found. Practical/managerial implications: Organisations should design their reward systems according to the preferences of their employees by focusing on base pay and contingency or variable pay. These rewards will also serve to retain them; although, to motivate employees, non-cash awards and recognition should be emphasised. Contribution/value-add: This study contributes to literature on reward

BOLD responses in reward regions to hypothetical and imaginary monetary rewards.

Science.gov (United States)

Miyapuram, Krishna P; Tobler, Philippe N; Gregorios-Pippas, Lucy; Schultz, Wolfram

2012-01-16

Monetary rewards are uniquely human. Because money is easy to quantify and present visually, it is the reward of choice for most fMRI studies, even though it cannot be handed over to participants inside the scanner. A typical fMRI study requires hundreds of trials and thus small amounts of monetary rewards per trial (e.g. 5p) if all trials are to be treated equally. However, small payoffs can have detrimental effects on performance due to their limited buying power. Hypothetical monetary rewards can overcome the limitations of smaller monetary rewards but it is less well known whether predictors of hypothetical rewards activate reward regions. In two experiments, visual stimuli were associated with hypothetical monetary rewards. In Experiment 1, we used stimuli predicting either visually presented or imagined hypothetical monetary rewards, together with non-rewarding control pictures. Activations to reward predictive stimuli occurred in reward regions, namely the medial orbitofrontal cortex and midbrain. In Experiment 2, we parametrically varied the amount of visually presented hypothetical monetary reward keeping constant the amount of actually received reward. Graded activation in midbrain was observed to stimuli predicting increasing hypothetical rewards. The results demonstrate the efficacy of using hypothetical monetary rewards in fMRI studies. Copyright © 2011 Elsevier Inc. All rights reserved.

Prefrontal neurons encode context-based response execution and inhibition in reward seeking and extinction

Science.gov (United States)

Moorman, David E.; Aston-Jones, Gary

2015-01-01

The prefrontal cortex (PFC) guides execution and inhibition of behavior based on contextual demands. In rodents, the dorsal/prelimbic (PL) medial PFC (mPFC) is frequently considered essential for execution of goal-directed behavior (“go”) whereas ventral/infralimbic (IL) mPFC is thought to control behavioral suppression (“stop”). This dichotomy is commonly seen for fear-related behaviors, and for some behaviors related to cocaine seeking. Overall, however, data for reward-directed behaviors are ambiguous, and few recordings of PL/IL activity have been performed to demonstrate single-neuron correlates. We recorded neuronal activity in PL and IL during discriminative stimulus driven sucrose seeking followed by multiple days of extinction of the reward-predicting stimulus. Contrary to a generalized PL-go/IL-stop hypothesis, we found cue-evoked activity in PL and IL during reward seeking and extinction. Upon analyzing this activity based on resultant behavior (lever press or withhold), we found that neurons in both areas encoded contextually appropriate behavioral initiation (during reward seeking) and withholding (during extinction), where context was dictated by response–outcome contingencies. Our results demonstrate that PL and IL signal contextual information for regulation of behavior, irrespective of whether that involves initiation or suppression of behavioral responses, rather than topographically encoding go vs. stop behaviors. The use of context to optimize behavior likely plays an important role in maximizing utility-promoting exertion of activity when behaviors are rewarded and conservation of energy when not. PMID:26170333

Task complexity and task, goal, and reward interdependence in group performance management : A prescriptive model

NARCIS (Netherlands)

van Vijfeijken, H.; Kleingeld, A.; van Tuijl, H.; Algera, J.A.; Thierry, Hk.

2002-01-01

A prescriptive model on how to design effective combinations of goal setting and contingent rewards for group performance management is presented. The model incorporates the constructs task complexity, task interdependence, goal interdependence, and reward interdependence and specifies optimal fit

A reward optimization method based on action subrewards in hierarchical reinforcement learning.

Science.gov (United States)

Fu, Yuchen; Liu, Quan; Ling, Xionghong; Cui, Zhiming

2014-01-01

Reinforcement learning (RL) is one kind of interactive learning methods. Its main characteristics are "trial and error" and "related reward." A hierarchical reinforcement learning method based on action subrewards is proposed to solve the problem of "curse of dimensionality," which means that the states space will grow exponentially in the number of features and low convergence speed. The method can reduce state spaces greatly and choose actions with favorable purpose and efficiency so as to optimize reward function and enhance convergence speed. Apply it to the online learning in Tetris game, and the experiment result shows that the convergence speed of this algorithm can be enhanced evidently based on the new method which combines hierarchical reinforcement learning algorithm and action subrewards. The "curse of dimensionality" problem is also solved to a certain extent with hierarchical method. All the performance with different parameters is compared and analyzed as well.

Impaired associative learning with food rewards in obese women.

Science.gov (United States)

Zhang, Zhihao; Manson, Kirk F; Schiller, Daniela; Levy, Ifat

2014-08-04

Obesity is a major epidemic in many parts of the world. One of the main factors contributing to obesity is overconsumption of high-fat and high-calorie food, which is driven by the rewarding properties of these types of food. Previous studies have suggested that dysfunction in reward circuits may be associated with overeating and obesity. The nature of this dysfunction, however, is still unknown. Here, we demonstrate impairment in reward-based associative learning specific to food in obese women. Normal-weight and obese participants performed an appetitive reversal learning task in which they had to learn and modify cue-reward associations. To test whether any learning deficits were specific to food reward or were more general, we used a between-subject design in which half of the participants received food reward and the other half received money reward. Our results reveal a marked difference in associative learning between normal-weight and obese women when food was used as reward. Importantly, no learning deficits were observed with money reward. Multiple regression analyses also established a robust negative association between body mass index and learning performance in the food domain in female participants. Interestingly, such impairment was not observed in obese men. These findings suggest that obesity may be linked to impaired reward-based associative learning and that this impairment may be specific to the food domain. Copyright © 2014 Elsevier Ltd. All rights reserved.

Students' perceptions of rewards for academic performance by parents and teachers: relations with achievement and motivation in college.

Science.gov (United States)

Davis, Kelly D; Winsler, Adam; Middleton, Michael

2006-06-01

In the present study, the authors examined college students' (N= 136) perceptions of the provision of extrinsic rewards given by parents and teachers for academic performance from elementary school through high school. They also examined the relations between reward history and present student motivational orientation. External rewards for students' grades were common at all levels of schooling. Reward history related significantly to students' motivational orientation and performance in college, and these relations were generally stronger for boys than for girls. The authors discuss implications of these findings.

Fast concurrent array-based stacks, queues and deques using fetch-and-increment-bounded, fetch-and-decrement-bounded and store-on-twin synchronization primitives

Science.gov (United States)

Chen, Dong; Gara, Alana; Heidelberger, Philip; Kumar, Sameer; Ohmacht, Martin; Steinmacher-Burow, Burkhard; Wisniewski, Robert

2014-09-16

Implementation primitives for concurrent array-based stacks, queues, double-ended queues (deques) and wrapped deques are provided. In one aspect, each element of the stack, queue, deque or wrapped deque data structure has its own ticket lock, allowing multiple threads to concurrently use multiple elements of the data structure and thus achieving high performance. In another aspect, new synchronization primitives FetchAndIncrementBounded (Counter, Bound) and FetchAndDecrementBounded (Counter, Bound) are implemented. These primitives can be implemented in hardware and thus promise a very fast throughput for queues, stacks and double-ended queues.

Monetary rewards modulate inhibitory control

Directory of Open Access Journals (Sweden)

Paula Marcela Herrera

2014-05-01

Full Text Available The ability to override a dominant response, often referred to as behavioural inhibiton, is considered a key element of executive cognition. Poor behavioural inhibition is a defining characteristic of several neurological and psychiatric populations. Recently, there has been increasing interest in the motivational dimension of behavioural inhibition, with some experiments incorporating emotional contingencies in classical inhibitory paradigms such as the Go/Nogo and Stop Signal Tasks. Several studies have reported a positive modulatory effect of reward on the performance of such tasks in pathological conditions such as substance abuse, pathological gambling, and ADHD. However, experiments that directly investigate the modulatory effects of reward magnitudes on the performance of inhibitory paradigms are rare and consequently, little is known about the finer grained relationship between motivation and self-control. Here, we probed the effect of reward and reward magnitude on behavioural inhibition using two modified version of the widely used Stop Signal Task. The first task compared no reward with reward, whilst the other compared two different reward magnitudes. The reward magnitude effect was confirmed by the second study, whereas it was less compelling in the first study, possibly due to the effect of having no reward in some conditions. In addition, our results showed a kick start effect over global performance measures. More specifically, there was a long lasting improvement in performance throughout the task, when participants received the highest reward magnitudes at the beginning of the protocol. These results demonstrate that individuals’ behavioural inhibition capacities are dynamic not static because they are modulated by the reward magnitude and initial reward history of the task at hand.

Challenges in the Detection of Working Memory and Attention Decrements among Overweight Adolescent Girls.

Science.gov (United States)

Bauer, Lance O; Manning, Kevin J

2016-01-01

The present study is unique in employing unusually difficult attention and working memory tasks to reveal subtle cognitive decrements among overweight/obese adolescents. It evaluated novel measures of background electroencephalographic (EEG) activity during one of the tasks and tested correlations of these and other measures with psychological and psychiatric predictors of obesity maintenance or progression. Working memory and sustained attention tasks were presented to 158 female adolescents who were rated on dichotomous (body mass index percentile working memory task. During the sustained attention task, overweight/obese adolescents exhibited more EEG frontal beta power as well as greater intraindividual variability in reaction time and beta power across task periods than their normal-weight peers. Secondary analyses showed that frontal beta power during the sustained attention task was positively correlated with anxiety, panic, borderline personality features, drug abuse, and loss of control over food intake. The findings suggest that working memory and sustained attention decrements do exist among overweight/obese adolescent girls. The reliable detection of the decrements may depend on the difficulty of the tasks as well as the manner in which performance and brain activity are measured. Future studies should examine the relevance of these decrements to dietary education efforts and treatment response. © 2016 S. Karger AG, Basel.

Use of the accelerating rotarod for assessment of motor performance decrement induced by potential anticonvulsant compounds in nerve agent poisoning. (Reannouncement with new availability information)

Energy Technology Data Exchange (ETDEWEB)

Capacio, B.R.; Harris, L.W.; Anderson, D.R.; Lennox, W.J.; Gales, V.

1992-12-31

The accelerating rotarod was used to assess motor performance decrement in rats after administration of candidate anticonvulsant compounds (acetazolamide, amitriptyline, chlordiazepoxide, diazepan, diazepam-lysine, lorazepam, loprazolam, midazolam, phenobarbital and scopolamine) against nerve agent poisoning. AH compounds were tested as the commercially available injectable preparation except for diazepam-lysine and loprazolam, which are not FDA approved. A peak effect time, as well as a dose to decrease performance time by 50% from control (PDD50), was determined. The calculated PDD50 (micrometer ol/kg) values and peak effect tunes were midazolam, 1.16 at 15 min; loprazolam, 1.17 at 15 min; diazepam-lysine, 4.17 at 30 min; lorazepwn, 4.98 at 15 min; diazepam, 5.27 at 15 min; phenobarbital, 101.49 at 45 min; chlordiazepoxide, 159.21 at 30 min; scopolamine, amitriptyline and acetazolamide did not demonstrate a performance decrement at any of the doses tested. The PDD50 values were compared with doses which have been utilized against nerve agent-induced convulsions or published ED50 values from standard anticonvulsant screening tests (maximal electroshock MES and subcutaneous pentylenetetrazol (scMET)). I serve agents, anticonvulsants, diazepam, accelerating rotarod, motor performance.

Reward positivity: Reward prediction error or salience prediction error?

Science.gov (United States)

Heydari, Sepideh; Holroyd, Clay B

2016-08-01

The reward positivity is a component of the human ERP elicited by feedback stimuli in trial-and-error learning and guessing tasks. A prominent theory holds that the reward positivity reflects a reward prediction error signal that is sensitive to outcome valence, being larger for unexpected positive events relative to unexpected negative events (Holroyd & Coles, 2002). Although the theory has found substantial empirical support, most of these studies have utilized either monetary or performance feedback to test the hypothesis. However, in apparent contradiction to the theory, a recent study found that unexpected physical punishments also elicit the reward positivity (Talmi, Atkinson, & El-Deredy, 2013). The authors of this report argued that the reward positivity reflects a salience prediction error rather than a reward prediction error. To investigate this finding further, in the present study participants navigated a virtual T maze and received feedback on each trial under two conditions. In a reward condition, the feedback indicated that they would either receive a monetary reward or not and in a punishment condition the feedback indicated that they would receive a small shock or not. We found that the feedback stimuli elicited a typical reward positivity in the reward condition and an apparently delayed reward positivity in the punishment condition. Importantly, this signal was more positive to the stimuli that predicted the omission of a possible punishment relative to stimuli that predicted a forthcoming punishment, which is inconsistent with the salience hypothesis. © 2016 Society for Psychophysiological Research.

Use of multiple-site performance-contingent SEMG reward programming in pediatric rehabilitation: a retrospective review.

Science.gov (United States)

Bolek, Jeffrey E

2006-09-01

We completed a retrospective review of the effectiveness of multi-site, performance-contingent reward programming on functional change in motor performance of 16 treatment resistant children. Patients were previously treated in physical or occupational therapy for head control, standing balance training, sitting and upper extremity use (brachial plexus injury). They then participated in a program that utilized multiple surface electromyography sites the use of which was rewarded with videos for performing the correct constellation of recruitment pattern (e.g., contracting some muscles while relaxing others). Onset of reward was calibrated for each patient and transfer of skill to outside the clinic was encouraged by linking a verbal cue to the correct motor plan. Fourteen of the 16 patients improved. The implications of the use of this technique in the treatment of motor dysfunction is discussed.

How Performance-Contingent Reward Prospect Modulates Cognitive Control: Increased Cue Maintenance at the Cost of Decreased Flexibility

Science.gov (United States)

Hefer, Carmen; Dreisbach, Gesine

2017-01-01

Growing evidence suggests that reward prospect promotes cognitive stability in terms of increased context or cue maintenance. In 3 Experiments, using different versions of the AX-continuous performance task, we investigated whether this reward effect comes at the cost of decreased cognitive flexibility. Experiment 1 shows that the reward induced…

Influence of reward system on job performance of librarians in ...

African Journals Online (AJOL)

The surest way to ensure and maintain high job performance in academic libraries is adequate use of reward system. Salaries, awards, allowances and recognitions are agents of satisfaction and motivation which helps in sustaining and transforming the entire workforce in the library. This study therefore analyzed the ...

Risk of Adverse Health Outcomes and Decrements in Performance Due to In-flight Medical Conditions

Science.gov (United States)

Antonsen,Erik

2017-01-01

The drive to undertake long-duration space exploration missions at greater distances from Earth gives rise to many challenges concerning human performance under extreme conditions. At NASA, the Human Research Program (HRP) has been established to investigate the specific risks to astronaut health and performance presented by space exploration, in addition to developing necessary countermeasures and technology to reduce risk and facilitate safer, more productive missions in space (NASA Human Research Program 2009). The HRP is divided into five subsections, covering behavioral health, space radiation, habitability, and other areas of interest. Within this structure is the ExMC Element, whose research contributes to the overall development of new technologies to overcome the challenges of expanding human exploration and habitation of space. The risk statement provided by the HRP to the ExMC Element states: "Given that medical conditions/events will occur during human spaceflight missions, there is a possibility of adverse health outcomes and decrements in performance in mission and for long term health" (NASA Human Research Program 2016). Within this risk context, the Exploration Medical Capabilities (ExMC) Element is specifically concerned with establishing evidenced-based methods of monitoring and maintaining astronaut health. Essential to completing this task is the advancement in techniques that identify, prevent, and treat any health threats that may occur during space missions. The ultimate goal of the ExMC Element is to develop and demonstrate a pathway for medical system integration into vehicle and mission design to mitigate the risk of medical issues. Integral to this effort is inclusion of an evidence-based medical and data handling system appropriate for long-duration, exploration-class missions. This requires a clear Concept of Operations, quantitative risk metrics or other tools to address changing risk throughout a mission, and system scoping and system

Memory load as a cognitive antidote to performance decrements in data entry.

Science.gov (United States)

Chapman, Mary J; Healy, Alice F; Kole, James A

2016-10-01

In two experiments, subjects trained in data entry, typing one 4-digit number at a time. At training, subjects either typed the numbers immediately after they appeared (immediate) or typed the previous number from memory while viewing the next number (delayed). In Experiment 2 stimulus presentation time was limited and either nothing or a space (gap) was inserted between the second and third digits. In both experiments after training, all subjects completed a test with no gap and typed numbers immediately. Training with a memory load improved speed across training blocks (Experiment 1) and eliminated the decline in accuracy across training blocks (Experiment 2), thus serving as a cognitive antidote to performance decrements. An analysis of each keystroke revealed different underlying processes and strategies for the two training conditions, including when encoding took place. Chunking (in which the first and last two digits are treated separately) was more evident in the immediate than in the delayed condition and was exaggerated with a gap, even at test when there was no gap. These results suggest that such two-digit chunking is due to stimulus encoding and motor planning processes as well as memory, and those processes transferred from training to testing.

Methodological issues underlying multiple decrement life table analysis.

Science.gov (United States)

Mode, C J; Avery, R C; Littman, G S; Potter, R G

1977-02-01

In this paper, the actuarial method of multiple decrement life table analysis of censored, longitudinal data is examined. The discussion is organized in terms of the first segment of usage of an intrauterine device. Weaknesses of the actuarial approach are pointed out, and an alternative approach, based on the classical model of competing risks, is proposed. Finally, the actuarial and the alternative method of analyzing censored data are compared, using data from the Taichung Medical Study on Intrauterine Devices.

Value and probability coding in a feedback-based learning task utilizing food rewards.

Science.gov (United States)

Tricomi, Elizabeth; Lempert, Karolina M

2015-01-01

For the consequences of our actions to guide behavior, the brain must represent different types of outcome-related information. For example, an outcome can be construed as negative because an expected reward was not delivered or because an outcome of low value was delivered. Thus behavioral consequences can differ in terms of the information they provide about outcome probability and value. We investigated the role of the striatum in processing probability-based and value-based negative feedback by training participants to associate cues with food rewards and then employing a selective satiety procedure to devalue one food outcome. Using functional magnetic resonance imaging, we examined brain activity related to receipt of expected rewards, receipt of devalued outcomes, omission of expected rewards, omission of devalued outcomes, and expected omissions of an outcome. Nucleus accumbens activation was greater for rewarding outcomes than devalued outcomes, but activity in this region did not correlate with the probability of reward receipt. Activation of the right caudate and putamen, however, was largest in response to rewarding outcomes relative to expected omissions of reward. The dorsal striatum (caudate and putamen) at the time of feedback also showed a parametric increase correlating with the trialwise probability of reward receipt. Our results suggest that the ventral striatum is sensitive to the motivational relevance, or subjective value, of the outcome, while the dorsal striatum codes for a more complex signal that incorporates reward probability. Value and probability information may be integrated in the dorsal striatum, to facilitate action planning and allocation of effort. Copyright © 2015 the American Physiological Society.

Models of brachial to finger pulse wave distortion and pressure decrement

NARCIS (Netherlands)

Gizdulich, P.; Prentza, A.; Wesseling, K.H.

1997-01-01

Objective: To model the pulse wave distortion and pressure decrement occurring between brachial and finger arteries. Distortion reversion and decrement correction were also our aims. Methods: Brachial artery pressure was recorded intra-arterially and finger pressure was recorded non-invasively by

Nursing Performance and Mobile Phone Use: Are Nurses Aware of Their Performance Decrements?

Science.gov (United States)

McBride, Deborah; LeVasseur, Sandra A; Li, Dongmei

2015-04-23

Prior research has documented the effect of concurrent mobile phone use on medical care. This study examined the extent of hospital registered nurses' awareness of their mobile-phone-associated performance decrements. The objective of this study was to compare self-reported performance with reported observed performance of others with respect to mobile phone use by hospital registered nurses. In March 2014, a previously validated survey was emailed to the 10,978 members of the Academy of Medical Surgical Nurses. The responses were analyzed using a two-proportion z test (alpha=.05, two-tailed) to examine whether self-reported and observed rates of error were significantly different. All possible demographic and employment confounders which could potentially contribute to self-reported and observed performance errors were tested for significance. Of the 950 respondents, 825 (8.68%, 825/950) met the inclusion criteria for analysis. The representativeness of the sample relative to the US nursing workforce was assessed using a two-proportion z test. This indicated that sex and location of primary place of employment (urban/rural) were represented appropriately in the study sample. Respondents in the age groups 55 years old were overrepresented. Whites, American Indians/Alaskan natives, and Native Hawaiian or Pacific Islanders were underrepresented, while Hispanic and multiple/other ethnicities were overrepresented. It was decided to report the unweighted, rather than the weighted survey data, with the recognition that the results, while valuable, may not be generalizable to the entire US registered nursing workforce. A significant difference was found between registered nurses' self-reported and observed rates of errors associated with concurrent mobile phone use in following three categories (1) work performance (z=-26.6142, Pmobile phone use by nurses at work was a serious distraction; always (13%, 107/825), often (29.6%, 244/825), sometimes (44.6%, 368/825), rarely

Heterogeneity in the Effects of Reward- and Deposit-based Financial Incentives on Smoking Cessation.

Science.gov (United States)

Halpern, Scott D; French, Benjamin; Small, Dylan S; Saulsgiver, Kathryn; Harhay, Michael O; Audrain-McGovern, Janet; Loewenstein, George; Asch, David A; Volpp, Kevin G

2016-10-15

Targeting different smoking cessation programs to smokers most likely to quit when using them could reduce the burden of lung disease. To identify smokers most likely to quit using pure reward-based financial incentives or incentive programs requiring refundable deposits to become eligible for rewards. We conducted prespecified secondary analyses of a randomized trial in which 2,538 smokers were assigned to an $800 reward contingent on sustained abstinence from smoking, a refundable $150 deposit plus a $650 reward, or usual care. Using logistic regression, we identified characteristics of smokers that were most strongly associated with accepting their assigned intervention and ceasing smoking for 6 months. We assessed modification of the acceptance, efficacy, and effectiveness of reward and deposit programs by 11 prospectively selected demographic, smoking-related, and psychological factors. Predictors of sustained smoking abstinence differed among participants assigned to reward- versus deposit-based incentives. However, greater readiness to quit and less steep discounting of future rewards were consistently among the most important predictors. Deposit-based programs were uniquely effective relative to usual care among men, higher-income participants, and participants who more commonly failed to pay their bills (all interaction P values rewards, deposits were more effective among black persons (P = 0.022) and those who more commonly failed to pay their bills (P = 0.082). Relative to rewards, deposits were more commonly accepted by higher-income participants, men, white persons, and those who less commonly failed to pay their bills (all P incentives suggests potential benefits of targeting behavior-change interventions based on patient characteristics. Clinical trial registered with www.clinicaltrials.gov (NCT 01526265).

Commitment to Self-Rewards

OpenAIRE

Koch, Alexander K.; Nafziger, Julia

2009-01-01

Self-administered rewards are ubiquitous. They serve as incentives for personal accomplish¬ments and are widely recommended as tools for overcoming self-control problems. However, it seems puzzling why self-rewards can work: the prospect of a reward has a motivating force only if the threat of self-denial of the reward after low performance is credible. We explain how a rational forward-looking individual may achieve commitment to self-rewards, by applying Köszegi and Rabin's (2006) model of ...

Adults with autism spectrum disorders exhibit decreased sensitivity to reward parameters when making effort-based decisions

Directory of Open Access Journals (Sweden)

Damiano Cara R

2012-05-01

Full Text Available Abstract Background Efficient effort expenditure to obtain rewards is critical for optimal goal-directed behavior and learning. Clinical observation suggests that individuals with autism spectrum disorders (ASD may show dysregulated reward-based effort expenditure, but no behavioral study to date has assessed effort-based decision-making in ASD. Methods The current study compared a group of adults with ASD to a group of typically developing adults on the Effort Expenditure for Rewards Task (EEfRT, a behavioral measure of effort-based decision-making. In this task, participants were provided with the probability of receiving a monetary reward on a particular trial and asked to choose between either an “easy task” (less motoric effort for a small, stable reward or a “hard task” (greater motoric effort for a variable but consistently larger reward. Results Participants with ASD chose the hard task more frequently than did the control group, yet were less influenced by differences in reward value and probability than the control group. Additionally, effort-based decision-making was related to repetitive behavior symptoms across both groups. Conclusions These results suggest that individuals with ASD may be more willing to expend effort to obtain a monetary reward regardless of the reward contingencies. More broadly, results suggest that behavioral choices may be less influenced by information about reward contingencies in individuals with ASD. This atypical pattern of effort-based decision-making may be relevant for understanding the heightened reward motivation for circumscribed interests in ASD.

Dose Dependent Dopaminergic Modulation of Reward-Based Learning in Parkinson's Disease

Science.gov (United States)

van Wouwe, N. C.; Ridderinkhof, K. R.; Band, G. P. H.; van den Wildenberg, W. P. M.; Wylie, S. A.

2012-01-01

Learning to select optimal behavior in new and uncertain situations is a crucial aspect of living and requires the ability to quickly associate stimuli with actions that lead to rewarding outcomes. Mathematical models of reinforcement-based learning to select rewarding actions distinguish between (1) the formation of stimulus-action-reward…

The Impact of Performance Appraisal, Reward System, Job Stress, and Work Life Conflict to Employee Performance

OpenAIRE

Rumambie, Yuliana Fransisca

2014-01-01

Employee Performance is an important part in a company or organization. It plays a very important role in an organization because performance of the company or organization largely depends on the performance of its employee. Recently, organizations realize that there are several factors that can affect employee performance. Several factors that can considered as the major determinants of employee performance, such as Performance Appraisal, Reward System, Job Stress, and Work life conflict. Th...

The Influence of Performance on Bargaining and Distribution of Rewards.

Science.gov (United States)

Landau, Samuel B.

Performance variables were manipulated to elicit differential outcomes of success and failure for dyad members in an attempt to investigate resultant bargaining and distribution of rewards. Seventy, 10-12-year old children (36 female, 34 males) were placed into dyads controlling for age, sex, I.Q., and friendship choices. Self-allocations were…

Risk of Performance Decrement and Crew Illness Due to an Inadequate Food System

Science.gov (United States)

Douglas, Grace L.; Cooper, Maya; Bermudez-Aguirre, Daniela; Sirmons, Takiyah

2016-01-01

evidence for the Risk of Performance Decrement and Crew Illness Due to an Inadequate Food System and the gaps in relation to exploration, as identified by the NASA Human Research Program (HRP). The research reviewed here indicates strategies to establish methods, technologies, and requirements that increase food stability, support adequate nutrition, quality, and variety, enable supplementation with grow-pick-and-eat salad crops, ensure safety, and reduce resource use. Obtaining the evidence to establish an adequate food system is essential, as the resources allocated to the food system may be defined based on the data relating nutritional stability and food quality requirements to crew performance and health.

Performance in a 12-hour, 300-rad profile

International Nuclear Information System (INIS)

Yochmowitz, M.G.; Brown, G.C.

1977-01-01

A discrete behavioral task was initiated to study the effects of a 300-rad variable dose rate exposure profile upon positively (food reward) and negatively (mild shock) reinforced groups of primates. Animals performed the task for 12 h. Performance decrements were readily apparent in 2 of 8 shock and 2 of 7 food animals, while delayed reaction times were found in 3 of 8 shock and 3 of 7 food animals. Of the 7 food animals, 4 exhibited emesis, while 1 of 8 shock animals vomited. Such information is useful to military planners who need guidelines to indicate potential aircrew nuclear vulnerability and survivability

Heterogeneity in the Effects of Reward- and Deposit-based Financial Incentives on Smoking Cessation

Science.gov (United States)

French, Benjamin; Small, Dylan S.; Saulsgiver, Kathryn; Harhay, Michael O.; Audrain-McGovern, Janet; Loewenstein, George; Asch, David A.; Volpp, Kevin G.

2016-01-01

Rationale: Targeting different smoking cessation programs to smokers most likely to quit when using them could reduce the burden of lung disease. Objectives: To identify smokers most likely to quit using pure reward-based financial incentives or incentive programs requiring refundable deposits to become eligible for rewards. Methods: We conducted prespecified secondary analyses of a randomized trial in which 2,538 smokers were assigned to an $800 reward contingent on sustained abstinence from smoking, a refundable $150 deposit plus a $650 reward, or usual care. Measurements and Main Results: Using logistic regression, we identified characteristics of smokers that were most strongly associated with accepting their assigned intervention and ceasing smoking for 6 months. We assessed modification of the acceptance, efficacy, and effectiveness of reward and deposit programs by 11 prospectively selected demographic, smoking-related, and psychological factors. Predictors of sustained smoking abstinence differed among participants assigned to reward- versus deposit-based incentives. However, greater readiness to quit and less steep discounting of future rewards were consistently among the most important predictors. Deposit-based programs were uniquely effective relative to usual care among men, higher-income participants, and participants who more commonly failed to pay their bills (all interaction P values patient characteristics. Clinical trial registered with www.clinicaltrials.gov (NCT 01526265). PMID:27064456

Effects of reward and punishment on task performance, mood and autonomic nervous function, and the interaction with personality.

Science.gov (United States)

Sakuragi, Sokichi; Sugiyama, Yoshiki

2009-06-01

The effects of reward and punishment are different, and there are individual differences in sensitivity to reward and punishment. The purpose of this study was to investigate the effects of reward and punishment on task performance, mood, and autonomic nervous function, along with the interaction with personality. Twenty-one healthy female subjects volunteered for the experiment. The task performance was evaluated by required time and total errors while performing a Wisconsin Card Sorting Test. We assessed their personalities using the Minnesota Multiphasic Personality Inventory (MMPI) questionnaire, and mood states by a profile of mood states. Autonomic nervous function was estimated by a spectral analysis of heart rate variability, baroreflex sensitivity, and blood pressure. Repeated measures analysis of variance (ANOVA) revealed significant interaction of condition x time course on mood and autonomic nervous activity, which would indicate a less stressed state under the rewarding condition, but revealed no significant interaction of condition x time course on the task performance. The interactions with personality were further analyzed by repeated measures ANOVA applying the clinical scales of MMPI as independent variables, and significant interactions of condition x time course x Pt (psychasthenia) on task performance, mood, and blood pressure, were revealed. That is, the high Pt group, whose members tend to be sensitive and prone to worry, showed gradual improvement of task performance under the punishing situation with slight increase in systolic blood pressure, while showed no improvement under the rewarding situation with fatigue sense attenuation. In contrast, the low Pt group, whose members tend to be adaptive and self-confident, showed gradual improvement under the rewarding situation. Therefore, we should carefully choose the strategy of reward or punishment, considering the interaction with personality as well as the context in which it is given.

Students' Perceptions of Rewards for Academic Performance by Parents and Teachers: Relations with Achievement and Motivation in College

Science.gov (United States)

Davis, Kelly D.; Winsler, Adam; Middleton, Michael

2006-01-01

In the present study, the authors examined college students' (N = 136) perceptions of the provision of extrinsic rewards given by parents and teachers for academic performance from elementary school through high school. They also examined the relations between reward history and present student motivational orientation. External rewards for…

Modulation of neural activity by reward in medial intraparietal cortex is sensitive to temporal sequence of reward

Science.gov (United States)

Rajalingham, Rishi; Stacey, Richard Greg; Tsoulfas, Georgios

2014-01-01

To restore movements to paralyzed patients, neural prosthetic systems must accurately decode patients' intentions from neural signals. Despite significant advancements, current systems are unable to restore complex movements. Decoding reward-related signals from the medial intraparietal area (MIP) could enhance prosthetic performance. However, the dynamics of reward sensitivity in MIP is not known. Furthermore, reward-related modulation in premotor areas has been attributed to behavioral confounds. Here we investigated the stability of reward encoding in MIP by assessing the effect of reward history on reward sensitivity. We recorded from neurons in MIP while monkeys performed a delayed-reach task under two reward schedules. In the variable schedule, an equal number of small- and large-rewards trials were randomly interleaved. In the constant schedule, one reward size was delivered for a block of trials. The memory period firing rate of most neurons in response to identical rewards varied according to schedule. Using systems identification tools, we attributed the schedule sensitivity to the dependence of neural activity on the history of reward. We did not find schedule-dependent behavioral changes, suggesting that reward modulates neural activity in MIP. Neural discrimination between rewards was less in the variable than in the constant schedule, degrading our ability to decode reach target and reward simultaneously. The effect of schedule was mitigated by adding Haar wavelet coefficients to the decoding model. This raises the possibility of multiple encoding schemes at different timescales and reinforces the potential utility of reward information for prosthetic performance. PMID:25008408

Modulation of neural activity by reward in medial intraparietal cortex is sensitive to temporal sequence of reward.

Science.gov (United States)

Rajalingham, Rishi; Stacey, Richard Greg; Tsoulfas, Georgios; Musallam, Sam

2014-10-01

To restore movements to paralyzed patients, neural prosthetic systems must accurately decode patients' intentions from neural signals. Despite significant advancements, current systems are unable to restore complex movements. Decoding reward-related signals from the medial intraparietal area (MIP) could enhance prosthetic performance. However, the dynamics of reward sensitivity in MIP is not known. Furthermore, reward-related modulation in premotor areas has been attributed to behavioral confounds. Here we investigated the stability of reward encoding in MIP by assessing the effect of reward history on reward sensitivity. We recorded from neurons in MIP while monkeys performed a delayed-reach task under two reward schedules. In the variable schedule, an equal number of small- and large-rewards trials were randomly interleaved. In the constant schedule, one reward size was delivered for a block of trials. The memory period firing rate of most neurons in response to identical rewards varied according to schedule. Using systems identification tools, we attributed the schedule sensitivity to the dependence of neural activity on the history of reward. We did not find schedule-dependent behavioral changes, suggesting that reward modulates neural activity in MIP. Neural discrimination between rewards was less in the variable than in the constant schedule, degrading our ability to decode reach target and reward simultaneously. The effect of schedule was mitigated by adding Haar wavelet coefficients to the decoding model. This raises the possibility of multiple encoding schemes at different timescales and reinforces the potential utility of reward information for prosthetic performance. Copyright © 2014 the American Physiological Society.

Commitment to self-rewards

DEFF Research Database (Denmark)

Koch, Alexander; Nafziger, Julia

People often overcome self-control problems by promising to reward themselves for accomplishing a task. Such strategies based on self-administered rewards however require the person to believe that she would indeed deny herself the reward if she should fail to achieve the desired outcome. Drawing...... on Koszegi and Rabin's (2006) model of endogenous reference point formation, we show how a rational forward-looking individual can achieve such internal commitment. But our results also demonstrate the limitations of self regulation based on self-rewards....

Accelerated iTBS treatment in depressed patients differentially modulates reward system activity based on anhedonia.

Science.gov (United States)

Duprat, Romain; Wu, Guo-Rong; De Raedt, Rudi; Baeken, Chris

2017-08-09

Accelerated intermittent theta-burst stimulation (aiTBS) anti-depressive working mechanisms are still unclear. Because aiTBS may work through modulating the reward system and the level of anhedonia may influence this modulation, we investigated the effect of aiTBS on reward responsiveness in high and low anhedonic MDD patients. In this registered RCT (NCT01832805), 50 MDD patients were randomised to a sham-controlled cross-over aiTBS treatment protocol over the left dorsolateral prefrontal cortex (DLPFC). Patients performed a probabilistic learning task in fMRI before and after each week of stimulation. Task performance analyses did not show any significant effects of aiTBS on reward responsiveness, nor differences between both groups of MDD patients. However, at baseline, low anhedonic patients displayed higher neural activity in the caudate and putamen. After the first week of aiTBS treatment, in low anhedonic patients we found a decreased neural activity within the reward system, in contrast to an increased activity observed in high anhedonic patients. No changes were observed in reward related neural regions after the first week of sham stimulation. Although both MDD groups showed no differences in task performance, our brain imaging findings suggest that left DLPFC aiTBS treatment modulates the reward system differently according to anhedonia severity.

Sleep spindles during a nap correlate with post sleep memory performance for highly rewarded word-pairs.

Science.gov (United States)

Studte, Sara; Bridger, Emma; Mecklinger, Axel

2017-04-01

The consolidation of new associations is thought to depend in part on physiological processes engaged during non-REM (NREM) sleep, such as slow oscillations and sleep spindles. Moreover, NREM sleep is thought to selectively benefit associations that are adaptive for the future. In line with this, the current study investigated whether different reward cues at encoding are associated with changes in sleep physiology and memory retention. Participants' associative memory was tested after learning a list of arbitrarily paired words both before and after taking a 90-min nap. During learning, word-pairs were preceded by a cue indicating either a high or a low reward for correct memory performance at test. The motivation manipulation successfully impacted retention such that memory declined to a greater extent from pre- to post sleep for low rewarded than for high rewarded word-pairs. In line with previous studies, positive correlations between spindle density during NREM sleep and general memory performance pre- and post-sleep were found. In addition to this, however, a selective positive relationship between memory performance for highly rewarded word-pairs at posttest and spindle density during NREM sleep was also observed. These results support the view that motivationally salient memories are preferentially consolidated and that sleep spindles may be an important underlying mechanism for selective consolidation. Copyright © 2016 Elsevier Inc. All rights reserved.

Reward/Punishment reversal learning in older suicide attempters.

Science.gov (United States)

Dombrovski, Alexandre Y; Clark, Luke; Siegle, Greg J; Butters, Meryl A; Ichikawa, Naho; Sahakian, Barbara J; Szanto, Katalin

2010-06-01

Suicide rates are high in old age, and the contribution of cognitive risk factors remains poorly understood. Suicide may be viewed as an outcome of an altered decision process. The authors hypothesized that impairment in reward/punishment-based learning, a component of affective decision making, is associated with attempted suicide in late-life depression. They expected that suicide attempters would discount past reward/punishment history, focusing excessively on the most recent rewards and punishments. The authors further hypothesized that this impairment could be dissociated from executive abilities, such as forward planning. The authors assessed reward/punishment-based learning using the probabilistic reversal learning task in 65 individuals age 60 and older: suicide attempters, suicide ideators, nonsuicidal depressed elderly, and nondepressed comparison subjects. The authors used a reinforcement learning computational model to decompose reward/punishment processing over time. The Stockings of Cambridge test served as a control measure of executive function. Suicide attempters but not suicide ideators showed impaired probabilistic reversal learning compared to both nonsuicidal depressed elderly and nondepressed comparison subjects, after controlling for effects of education, global cognitive function, and substance use. Model-based analyses revealed that suicide attempters discounted previous history to a higher degree relative to comparison subjects, basing their choice largely on reward/punishment received on the last trial. Groups did not differ in their performance on the Stockings of Cambridge test. Older suicide attempters display impaired reward/punishment-based learning. The authors propose a hypothesis that older suicide attempters make overly present-focused decisions, ignoring past experiences. Modification of this "myopia for the past" may have therapeutic potential.

Role of delay-based reward in the spatial cooperation

Science.gov (United States)

Wang, Xu-Wen; Nie, Sen; Jiang, Luo-Luo; Wang, Bing-Hong; Chen, Shi-Ming

2017-01-01

Strategy selection in games, a typical decision making, usually brings noticeable reward for players which have discounted value if the delay appears. The discounted value is measure: earning sooner with a small reward or later with a delayed larger reward. Here, we investigate effects of delayed rewards on the cooperation in structured population. It is found that delayed reward supports the spreading of cooperation in square lattice, small-world and random networks. In particular, intermediate reward differences between delays impel the highest cooperation level. Interestingly, cooperative individuals with the same delay time steps form clusters to resist the invasion of defects, and cooperative individuals with lowest delay reward survive because they form the largest clusters in the lattice.

Dopamine, reward learning, and active inference.

Science.gov (United States)

FitzGerald, Thomas H B; Dolan, Raymond J; Friston, Karl

2015-01-01

Temporal difference learning models propose phasic dopamine signaling encodes reward prediction errors that drive learning. This is supported by studies where optogenetic stimulation of dopamine neurons can stand in lieu of actual reward. Nevertheless, a large body of data also shows that dopamine is not necessary for learning, and that dopamine depletion primarily affects task performance. We offer a resolution to this paradox based on an hypothesis that dopamine encodes the precision of beliefs about alternative actions, and thus controls the outcome-sensitivity of behavior. We extend an active inference scheme for solving Markov decision processes to include learning, and show that simulated dopamine dynamics strongly resemble those actually observed during instrumental conditioning. Furthermore, simulated dopamine depletion impairs performance but spares learning, while simulated excitation of dopamine neurons drives reward learning, through aberrant inference about outcome states. Our formal approach provides a novel and parsimonious reconciliation of apparently divergent experimental findings.

A measurement-based performability model for a multiprocessor system

Science.gov (United States)

Ilsueh, M. C.; Iyer, Ravi K.; Trivedi, K. S.

1987-01-01

A measurement-based performability model based on real error-data collected on a multiprocessor system is described. Model development from the raw errror-data to the estimation of cumulative reward is described. Both normal and failure behavior of the system are characterized. The measured data show that the holding times in key operational and failure states are not simple exponential and that semi-Markov process is necessary to model the system behavior. A reward function, based on the service rate and the error rate in each state, is then defined in order to estimate the performability of the system and to depict the cost of different failure types and recovery procedures.

Model Seleksi Premi Asuransi Jiwa Dwiguna untuk Kasus Multiple Decrement

OpenAIRE

Cita, Devi Ramana; Pane, Rolan; ', Harison

2015-01-01

This article discusses a select survival model for the case of multiple decrements in evaluating endowment life insurance premium for person currently aged ( + ) years, who is selected at age with ℎ years selection period. The case of multiple decrements in this case is limited to two cases. The calculation of the annual premium is done by prior evaluating of the single premium, and the present value of annuity depends on theconstant force assumption.

Reward and punishment enhance motor adaptation in stroke.

Science.gov (United States)

Quattrocchi, Graziella; Greenwood, Richard; Rothwell, John C; Galea, Joseph M; Bestmann, Sven

2017-09-01

The effects of motor learning, such as motor adaptation, in stroke rehabilitation are often transient, thus mandating approaches that enhance the amount of learning and retention. Previously, we showed in young individuals that reward and punishment feedback have dissociable effects on motor adaptation, with punishment improving adaptation and reward enhancing retention. If these findings were able to generalise to patients with stroke, they would provide a way to optimise motor learning in these patients. Therefore, we tested this in 45 patients with chronic stroke allocated in three groups. Patients performed reaching movements with their paretic arm with a robotic manipulandum. After training (day 1), day 2 involved adaptation to a novel force field. During the adaptation phase, patients received performance-based feedback according to the group they were allocated: reward, punishment or no feedback (neutral). On day 3, patients readapted to the force field but all groups now received neutral feedback. All patients adapted, with reward and punishment groups displaying greater adaptation and readaptation than the neutral group, irrespective of demographic, cognitive or functional differences. Remarkably, the reward and punishment groups adapted to similar degree as healthy controls. Finally, the reward group showed greater retention. This study provides, for the first time, evidence that reward and punishment can enhance motor adaptation in patients with stroke. Further research on reinforcement-based motor learning regimes is warranted to translate these promising results into clinical practice and improve motor rehabilitation outcomes in patients with stroke. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Self-stimulating rats combine subjective reward magnitude and subjective reward rate multiplicatively.

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Leon, M I; Gallistel, C R

1998-07-01

For rats that bar pressed for intracranial electrical stimulation in a 2-lever matching paradigm with concurrent variable interval schedules of reward, the authors found that the time allocation ratio is based on a multiplicative combination of the ratio of subjective reward magnitudes and the ratio of the rates of reward. Multiplicative combining was observed in a range covering approximately 2 orders of magnitude in the ratio of the rates of reward from about 1:10 to 10:1) and an order of magnitude change in the size of rewards. After determining the relation between the pulse frequency of stimulation and subjective reward magnitude, the authors were able to predict from knowledge of the subjective magnitudes of the rewards and the obtained relative rates of reward the subject's time allocation ratio over a range in which it varied by more than 3 orders of magnitude.

Response-only modal identification using random decrement algorithm with time-varying threshold level

International Nuclear Information System (INIS)

Lin, Chang Sheng; Tseng, Tse Chuan

2014-01-01

Modal Identification from response data only is studied for structural systems under nonstationary ambient vibration. The topic of this paper is the estimation of modal parameters from nonstationary ambient vibration data by applying the random decrement algorithm with time-varying threshold level. In the conventional random decrement algorithm, the threshold level for evaluating random dec signatures is defined as the standard deviation value of response data of the reference channel. The distortion of random dec signatures may be, however, induced by the error involved in noise from the original response data in practice. To improve the accuracy of identification, a modification of the sampling procedure in random decrement algorithm is proposed for modal-parameter identification from the nonstationary ambient response data. The time-varying threshold level is presented for the acquisition of available sample time history to perform averaging analysis, and defined as the temporal root-mean-square function of structural response, which can appropriately describe a wide variety of nonstationary behaviors in reality, such as the time-varying amplitude (variance) of a nonstationary process in a seismic record. Numerical simulations confirm the validity and robustness of the proposed modal-identification method from nonstationary ambient response data under noisy conditions.

Bio-robots automatic navigation with graded electric reward stimulation based on Reinforcement Learning.

Science.gov (United States)

Zhang, Chen; Sun, Chao; Gao, Liqiang; Zheng, Nenggan; Chen, Weidong; Zheng, Xiaoxiang

2013-01-01

Bio-robots based on brain computer interface (BCI) suffer from the lack of considering the characteristic of the animals in navigation. This paper proposed a new method for bio-robots' automatic navigation combining the reward generating algorithm base on Reinforcement Learning (RL) with the learning intelligence of animals together. Given the graded electrical reward, the animal e.g. the rat, intends to seek the maximum reward while exploring an unknown environment. Since the rat has excellent spatial recognition, the rat-robot and the RL algorithm can convergent to an optimal route by co-learning. This work has significant inspiration for the practical development of bio-robots' navigation with hybrid intelligence.

The effectiveness of loyalty rewards to promote the use of an Internet-based heart health program.

Science.gov (United States)

Liu, Sam; Hodgson, Corinne; Zbib, Ahmad M; Payne, Ada Y M; Nolan, Robert P

2014-07-02

Internet-based health programs have been shown to be effective in reducing risk for cardiovascular disease. However, their rates of enrollment and engagement remain low. It is currently unclear whether rewards from established loyalty programs can serve as a conditioned stimulus to improve the use of a freely available Internet-based program. The objectives of the study were to (1) examine enrollment rates and levels of engagement with the My Health eSupport program between a Conditioned Reward group and a Control group, and (2) investigate the influence of loyalty rewards and participant characteristics on levels of enrollment and program engagement. The study sample (n=142,726) consisted of individuals who were offered enrollment in an Internet-based health intervention (My Health eSupport) after completing the Heart&Stroke Risk Assessment on the Heart and Stroke Foundation website. My Health eSupport programs provided encouragement and tips for lifestyle change. This is a free, self-guided, fully automated program that proactively delivers tailored email messages at 2-week intervals based on the participant's stage of motivational "readiness" and priority for lifestyle change. Participants in the Conditioned Reward group were offered a single exposure of 20 loyalty reward points from the Air Miles loyalty program for completing the Heart&Stroke Risk Assessment (10 reward points) and enrolling in the Internet-based program (10 reward points). Meanwhile, no rewards were given to the Control group participants. All data were collected between February 1, 2011 and February 10, 2012. In total, 51.38% (73,327/142,726) of individuals in the Conditioned Reward group and 48.62% (69,399/142,726) of individuals in the Control group completed the Heart&Stroke Risk Assessment. Subsequently, significantly more individuals from the Conditioned Reward group (52.96%, 38,835/73,327) enrolled in the My Health eSupport program than Controls (4.07%, 2826/69,399). Regression analyses

Dopamine, reward learning, and active inference

Directory of Open Access Journals (Sweden)

Thomas eFitzgerald

2015-11-01

Full Text Available Temporal difference learning models propose phasic dopamine signalling encodes reward prediction errors that drive learning. This is supported by studies where optogenetic stimulation of dopamine neurons can stand in lieu of actual reward. Nevertheless, a large body of data also shows that dopamine is not necessary for learning, and that dopamine depletion primarily affects task performance. We offer a resolution to this paradox based on an hypothesis that dopamine encodes the precision of beliefs about alternative actions, and thus controls the outcome-sensitivity of behaviour. We extend an active inference scheme for solving Markov decision processes to include learning, and show that simulated dopamine dynamics strongly resemble those actually observed during instrumental conditioning. Furthermore, simulated dopamine depletion impairs performance but spares learning, while simulated excitation of dopamine neurons drives reward learning, through aberrant inference about outcome states. Our formal approach provides a novel and parsimonious reconciliation of apparently divergent experimental findings.

Maximizing Performance: Augmented Feedback, Focus of Attention, and/or Reward?

Science.gov (United States)

Wälchli, Michael; Ruffieux, Jan; Bourquin, Yann; Keller, Martin; Taube, Wolfgang

2016-04-01

Different approaches like providing augmented feedback (aF), applying an external focus of attention (EF), or rewarding participants with money (RE) have been shown to instantly enhance motor performance. So far, these approaches have been tested either in separate studies or directly against each other. However, there is no study that combined aF, EF, and/or RE to test whether this provokes additional benefits. The aim of the present study was therefore to identify the most powerful combination. Eighteen participants performed maximal countermovement jumps in six different conditions: neutral (NE), aF, RE, aF + EF, aF + RE, and aF + EF + RE. Participants demonstrated the highest jump heights with aF + EF, followed by aF + EF + RE, aF + RE, aF, RE, and finally, NE. Activity of the M. rectus femoris differed significantly between conditions resulting in lower muscular activity in aF + EF and aF + EF + RE compared with NE. All other parameters, such as ground reaction forces and joint angles, were comparable across conditions. This is the first study showing superior performance when combining aF with EF. As reduced muscular activity was found only in conditions with EF, it is argued in line with the constrained action hypothesis that adopting an EF improves movement efficiency. In contrast, aF seems to rather enhance (intrinsic) motivation. However, monetary reward did not further amplify performance.

Monetary rewards influence retrieval orientations.

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Halsband, Teresa M; Ferdinand, Nicola K; Bridger, Emma K; Mecklinger, Axel

2012-09-01

Reward anticipation during learning is known to support memory formation, but its role in retrieval processes is so far unclear. Retrieval orientations, as a reflection of controlled retrieval processing, are one aspect of retrieval that might be modulated by reward. These processes can be measured using the event-related potentials (ERPs) elicited by retrieval cues from tasks with different retrieval requirements, such as via changes in the class of targeted memory information. To determine whether retrieval orientations of this kind are modulated by reward during learning, we investigated the effects of high and low reward expectancy on the ERP correlates of retrieval orientation in two separate experiments. The reward manipulation at study in Experiment 1 was associated with later memory performance, whereas in Experiment 2, reward was directly linked to accuracy in the study task. In both studies, the participants encoded mixed lists of pictures and words preceded by high- or low-reward cues. After 24 h, they performed a recognition memory exclusion task, with words as the test items. In addition to a previously reported material-specific effect of retrieval orientation, a frontally distributed, reward-associated retrieval orientation effect was found in both experiments. These findings suggest that reward motivation during learning leads to the adoption of a reward-associated retrieval orientation to support the retrieval of highly motivational information. Thus, ERP retrieval orientation effects not only reflect retrieval processes related to the sought-for materials, but also relate to the reward conditions with which items were combined during encoding.

Adaptive neural reward processing during anticipation and receipt of monetary rewards in mindfulness meditators.

Science.gov (United States)

Kirk, Ulrich; Brown, Kirk Warren; Downar, Jonathan

2015-05-01

Reward seeking is ubiquitous and adaptive in humans. But excessive reward seeking behavior, such as chasing monetary rewards, may lead to diminished subjective well-being. This study examined whether individuals trained in mindfulness meditation show neural evidence of lower susceptibility to monetary rewards. Seventy-eight participants (34 meditators, 44 matched controls) completed the monetary incentive delay task while undergoing functional magnetic resonance imaging. The groups performed equally on the task, but meditators showed lower neural activations in the caudate nucleus during reward anticipation, and elevated bilateral posterior insula activation during reward anticipation. Meditators also evidenced reduced activations in the ventromedial prefrontal cortex during reward receipt compared with controls. Connectivity parameters between the right caudate and bilateral anterior insula were attenuated in meditators during incentive anticipation. In summary, brain regions involved in reward processing-both during reward anticipation and receipt of reward-responded differently in mindfulness meditators than in nonmeditators, indicating that the former are less susceptible to monetary incentives. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

BOLD responses in reward regions to hypothetical and imaginary monetary rewards.

OpenAIRE

Miyapuram Krishna P; Tobler Philippe N; Gregorios-Pippas Lucy; Schultz Wolfram

2012-01-01

Monetary rewards are uniquely human. Because money is easy to quantify and present visually, it is the reward of choice for most fMRI studies, even though it cannot be handed over to participants inside the scanner. A typical fMRI study requires hundreds of trials and thus small amounts of monetary rewards per trial (e.g. 5p) if all trials are to be treated equally. However, small payoffs can have detrimental effects on performance due to their limited buying power. Hypothetical monetary rewa...

Reward contingencies and the recalibration of task monitoring and reward systems: a high-density electrical mapping study.

Science.gov (United States)

Morie, K P; De Sanctis, P; Foxe, J J

2014-07-25

Task execution almost always occurs in the context of reward-seeking or punishment-avoiding behavior. As such, ongoing task-monitoring systems are influenced by reward anticipation systems. In turn, when a task has been executed either successfully or unsuccessfully, future iterations of that task will be re-titrated on the basis of the task outcome. Here, we examined the neural underpinnings of the task-monitoring and reward-evaluation systems to better understand how they govern reward-seeking behavior. Twenty-three healthy adult participants performed a task where they accrued points that equated to real world value (gift cards) by responding as rapidly as possible within an allotted timeframe, while success rate was titrated online by changing the duration of the timeframe dependent on participant performance. Informative cues initiated each trial, indicating the probability of potential reward or loss (four levels from very low to very high). We manipulated feedback by first informing participants of task success/failure, after which a second feedback signal indicated actual magnitude of reward/loss. High-density electroencephalography (EEG) recordings allowed for examination of event-related potentials (ERPs) to the informative cues and in turn, to both feedback signals. Distinct ERP components associated with reward cues, task-preparatory and task-monitoring processes, and reward feedback processes were identified. Unsurprisingly, participants displayed increased ERP amplitudes associated with task-preparatory processes following cues that predicted higher chances of reward. They also rapidly updated reward and loss prediction information dependent on task performance after the first feedback signal. Finally, upon reward receipt, initial reward probability was no longer taken into account. Rather, ERP measures suggested that only the magnitude of actual reward or loss was now processed. Reward and task-monitoring processes are clearly dissociable, but

Neural basis of the undermining effect of monetary reward on intrinsic motivation.

Science.gov (United States)

Murayama, Kou; Matsumoto, Madoka; Izuma, Keise; Matsumoto, Kenji

2010-12-07

Contrary to the widespread belief that people are positively motivated by reward incentives, some studies have shown that performance-based extrinsic reward can actually undermine a person's intrinsic motivation to engage in a task. This "undermining effect" has timely practical implications, given the burgeoning of performance-based incentive systems in contemporary society. It also presents a theoretical challenge for economic and reinforcement learning theories, which tend to assume that monetary incentives monotonically increase motivation. Despite the practical and theoretical importance of this provocative phenomenon, however, little is known about its neural basis. Herein we induced the behavioral undermining effect using a newly developed task, and we tracked its neural correlates using functional MRI. Our results show that performance-based monetary reward indeed undermines intrinsic motivation, as assessed by the number of voluntary engagements in the task. We found that activity in the anterior striatum and the prefrontal areas decreased along with this behavioral undermining effect. These findings suggest that the corticobasal ganglia valuation system underlies the undermining effect through the integration of extrinsic reward value and intrinsic task value.

The Effects of Extrinsic Rewards on Admissions Counselors' Performance

Science.gov (United States)

Gardner-Engel, Miriam

2010-01-01

This study examines the best ways to motivate college admissions counselors. A review of literature revealed multiple perspectives on intrinsic and extrinsic as well as tangible and intangible rewards. Primary research was designed to examine the impact of tangible rewards and verbal reinforcements with a convenience sample of nine college…

Reinforcement learning signals in the human striatum distinguish learners from nonlearners during reward-based decision making.

Science.gov (United States)

Schönberg, Tom; Daw, Nathaniel D; Joel, Daphna; O'Doherty, John P

2007-11-21

The computational framework of reinforcement learning has been used to forward our understanding of the neural mechanisms underlying reward learning and decision-making behavior. It is known that humans vary widely in their performance in decision-making tasks. Here, we used a simple four-armed bandit task in which subjects are almost evenly split into two groups on the basis of their performance: those who do learn to favor choice of the optimal action and those who do not. Using models of reinforcement learning we sought to determine the neural basis of these intrinsic differences in performance by scanning both groups with functional magnetic resonance imaging. We scanned 29 subjects while they performed the reward-based decision-making task. Our results suggest that these two groups differ markedly in the degree to which reinforcement learning signals in the striatum are engaged during task performance. While the learners showed robust prediction error signals in both the ventral and dorsal striatum during learning, the nonlearner group showed a marked absence of such signals. Moreover, the magnitude of prediction error signals in a region of dorsal striatum correlated significantly with a measure of behavioral performance across all subjects. These findings support a crucial role of prediction error signals, likely originating from dopaminergic midbrain neurons, in enabling learning of action selection preferences on the basis of obtained rewards. Thus, spontaneously observed individual differences in decision making performance demonstrate the suggested dependence of this type of learning on the functional integrity of the dopaminergic striatal system in humans.

Two spatiotemporally distinct value systems shape reward-based learning in the human brain.

Science.gov (United States)

Fouragnan, Elsa; Retzler, Chris; Mullinger, Karen; Philiastides, Marios G

2015-09-08

Avoiding repeated mistakes and learning to reinforce rewarding decisions is critical for human survival and adaptive actions. Yet, the neural underpinnings of the value systems that encode different decision-outcomes remain elusive. Here coupling single-trial electroencephalography with simultaneously acquired functional magnetic resonance imaging, we uncover the spatiotemporal dynamics of two separate but interacting value systems encoding decision-outcomes. Consistent with a role in regulating alertness and switching behaviours, an early system is activated only by negative outcomes and engages arousal-related and motor-preparatory brain structures. Consistent with a role in reward-based learning, a later system differentially suppresses or activates regions of the human reward network in response to negative and positive outcomes, respectively. Following negative outcomes, the early system interacts and downregulates the late system, through a thalamic interaction with the ventral striatum. Critically, the strength of this coupling predicts participants' switching behaviour and avoidance learning, directly implicating the thalamostriatal pathway in reward-based learning.

External Goal Setting in Reward-Based Crowdfunding - Inventor, Marathoner, Sprinter and Extreme Sprinter

OpenAIRE

Haug, Jonas; Haslum, Mikkel Hilde

2016-01-01

Purpose In recent years, crowdfunding has emerged as a popular method to finance entrepreneurial ventures. Entrepreneurs appeal directly to the general public, e.g. the crowd, for help getting their innovative ideas off the ground. Within the world of reward-based crowdfunding, the authors of how to -literature (practitioners) and the authors of theoretical reward-based crowdfunding literature (theoreticians) disagree on strategies for setting the external (i.e. public) funding goal. ...

Modelling comonotonic group-life under dependent decrement causes

OpenAIRE

Wang, Dabuxilatu

2011-01-01

Comonotonicity had been a extreme case of dependency between random variables. This article consider an extension of single life model under multiple dependent decrement causes to the case of comonotonic group-life.

Egalitarian reward contingency in competitive games and primate prefrontal neuronal activity.

Science.gov (United States)

Hosokawa, Takayuki; Watanabe, Masataka

2015-01-01

How people work to obtain a reward depends on the context of the reward delivery, such as the presence/absence of competition and the contingency of reward delivery. Since resources are limited, winning a competition is critically important for organisms' obtaining a reward. People usually expect ordinary performance-reward contingency, with better performers obtaining better rewards. Unordinary reward contingency, such as egalitarianism (equal rewards/no-rewards to both good and poor performers), dampens people's motivation. We previously reported that monkeys were more motivated, and neurons in the lateral prefrontal cortex (LPFC) showed higher outcome-related activity in a competitive than in a noncompetitive game (Hosokawa and Watanabe, 2012). However, monkey's behavior and LPFC neuronal activity have not been examined in a competitive situation with an unordinary performance-reward contingency. Also, the fixed performance-reward contingency in the previous study did not allow us to examine effects of win/loss separately from those of reward/no-reward on prefrontal neuronal activity. Here, we employed the egalitarian competitive situation in which both the winner and loser, or neither of them, got a reward as well as the normal competitive situation in which only the winner got a reward. Monkey's behavioral performance greatly deteriorated in trials with the egalitarian outcome conditions. LPFC neurons showed activities that reflected the normal or egalitarian outcome condition while very few neurons coded win/loss independent of reward/no-reward. Importantly, we found neurons that showed reward-related activity in the normal, but not in the egalitarian outcome conditions, even though the same reward was given to the animal. These results indicate that LPFC may play an important role in monitoring the current reward contingency and integrating it with the performance outcome (win-loss) for better performing the competitive game, and thus for better survival.

A tribute to Charlie Chaplin: Induced positive affect improves reward-based decision-learning in Parkinson’s Disease

Directory of Open Access Journals (Sweden)

K. Richard eRidderinkhof

2012-06-01

Full Text Available Reward-based decision-learning refers to the process of learning to select those actions that lead to rewards while avoiding actions that lead to punishments. This process, known to rely on dopaminergic activity in striatal brain regions, is compromised in Parkinson’s disease (PD. We hypothesized that such decision-learning deficits are alleviated by induced positive affect, which is thought to incur transient boosts in midbrain and striatal dopaminergic activity. Computational measures of probabilistic reward-based decision-learning were determined for 51 patients diagnosed with PD. Previous work has shown these measures to rely on the nucleus caudatus (outcome evaluation during the early phases of learning and the putamen (reward prediction during later phases of learning. We observed that induced positive affect facilitated learning, through its effects on reward prediction rather than outcome evaluation. Viewing a few minutes of comedy clips served to remedy dopamine-related problems in putamen-based frontostriatal circuitry and, consequently, in learning to predict which actions will yield reward.

Models of brachial to finger pulse wave distortion and pressure decrement.

Science.gov (United States)

Gizdulich, P; Prentza, A; Wesseling, K H

1997-03-01

To model the pulse wave distortion and pressure decrement occurring between brachial and finger arteries. Distortion reversion and decrement correction were also our aims. Brachial artery pressure was recorded intra-arterially and finger pressure was recorded non-invasively by the Finapres technique in 53 adult human subjects. Mean pressure was subtracted from each pressure waveform and Fourier analysis applied to the pulsations. A distortion model was estimated for each subject and averaged over the group. The average inverse model was applied to the full finger pressure waveform. The pressure decrement was modelled by multiple regression on finger systolic and diastolic levels. Waveform distortion could be described by a general, frequency dependent model having a resonance at 7.3 Hz. The general inverse model has an anti-resonance at this frequency. It converts finger to brachial pulsations thereby reducing average waveform distortion from 9.7 (s.d. 3.2) mmHg per sample for the finger pulse to 3.7 (1.7) mmHg for the converted pulse. Systolic and diastolic level differences between finger and brachial arterial pressures changed from -4 (15) and -8 (11) to +8 (14) and +8 (12) mmHg, respectively, after inverse modelling, with pulse pressures correct on average. The pressure decrement model reduced both the mean and the standard deviation of systolic and diastolic level differences to 0 (13) and 0 (8) mmHg. Diastolic differences were thus reduced most. Brachial to finger pulse wave distortion due to wave reflection in arteries is almost identical in all subjects and can be modelled by a single resonance. The pressure decrement due to flow in arteries is greatest for high pulse pressures superimposed on low means.

The role of the dorsal raphé nucleus in reward-seeking behavior

Directory of Open Access Journals (Sweden)

Kae eNakamura

2013-08-01

Full Text Available Pharmacological experiments have shown that the modulation of brain serotonin levels has a strong impact on value-based decision making. Anatomical and physiological evidence also revealed that the dorsal raphé nucleus (DRN, a major source of serotonin, and the dopamine system receive common inputs from brain regions associated with appetitive and aversive information processing. The serotonin and dopamine systems also have reciprocal functional influences on each other. However, the specific mechanism by which serotonin affects value-based decision making is not clear.To understand the information carried by the DRN for reward-seeking behavior, we measured single neuron activity in the primate DRN during the performance of saccade tasks to obtain different amounts of a reward. We found that DRN neuronal activity was characterized by tonic modulation that was altered by the expected and received reward value. Consistent reward-dependent modulation across different task periods suggested that DRN activity kept track of the reward value throughout a trial. The DRN was also characterized by modulation of its activity in the opposite direction by different neuronal subgroups, one firing strongly for the prediction and receipt of large rewards, with the other firing strongly for small rewards. Conversely, putative dopamine neurons showed positive phasic responses to reward-indicating cues and the receipt of an unexpected reward amount, which supports the reward prediction error signal hypothesis of dopamine.I suggest that the tonic reward monitoring signal of the DRN, possibly together with its interaction with the dopamine system, reports a continuous level of motivation throughout the performance of a task. Such a signal may provide reward context information to the targets of DRN projections, where it may be integrated further with incoming motivationally salient information.

Carotid flow pulsatility is higher in women with greater decrement in gait speed during multi-tasking.

Science.gov (United States)

Gonzales, Joaquin U; James, C Roger; Yang, Hyung Suk; Jensen, Daniel; Atkins, Lee; Al-Khalil, Kareem; O'Boyle, Michael

2017-05-01

Central arterial hemodynamics is associated with cognitive impairment. Reductions in gait speed during walking while performing concurrent tasks known as dual-tasking (DT) or multi-tasking (MT) is thought to reflect the cognitive cost that exceeds neural capacity to share resources. We hypothesized that central vascular function would associate with decrements in gait speed during DT or MT. Gait speed was measured using a motion capture system in 56 women (30-80y) without mild-cognitive impairment. Dual-tasking was considered walking at a fast-pace while balancing a tray. Multi-tasking was the DT condition plus subtracting by serial 7's. Applanation tonometry was used for measurement of aortic stiffness and central pulse pressure. Doppler-ultrasound was used to measure blood flow velocity and β-stiffness index in the common carotid artery. The percent change in gait speed was larger for MT than DT (14.1±11.2 vs. 8.7±9.6%, p decrement (third tertile) as compared to women with less decrement (first tertile) in gait speed during MT after adjusting for age, gait speed, and task error. Carotid pulse pressure and β-stiffness did not contribute to these tertile differences. Elevated carotid flow pulsatility and resistance are characteristics found in healthy women that show lower cognitive capacity to walk and perform multiple concurrent tasks. Copyright © 2017 Elsevier B.V. All rights reserved.

cfDNA as an Earlier Predictor of Exercise-Induced Performance Decrement Related to Muscle Damage.

Science.gov (United States)

Andreatta, Michely V; Curty, Victor M; Coutinho, João Victor S; Santos, Miguel Ângelo A; Vassallo, Paula F; de Sousa, Nuno F; Barauna, Valério G

2017-11-28

The aims of this study were: a) to evaluate whether cell-free DNA (cfDNA) levels increase immediately after an acute light and heavy resistance exercise (RE) bout, and b) to whether cfDNA levels are associated with functional muscle capacity until 48hrs after exercise session. Twenty healthy volunteers performed 3 sets of the leg press resistance exercise with 80% of 1RM (RE80) or 40% of 1RM (RE40) with similar exercise volume. Blood lactate was measured after completion of the 3 sets. Creatine kinase (CK), cfDNA and jump performance were evaluated before (pre) exercise, immediately post-exercise (Post-0) and every 24hrs until 48hrs. Lactate concentration increased similarly in both groups (RE40, 4.0±1.3mmol/L; RE80, 4.8±1.3mmol/L). No changes were observed in squat jump and countermovement jump performance after RE40, however both jumps remained reduced until 48h in RE80 group. CK concentration increased post-24h only in the RE80 group (Pre: 128.8±73.7U/L to Post-24h: 313.8±116.4U/L). cfDNA concentration increased post-0h only in the RE80 group (Pre, 249.8±82.3ng/mL; Post-0h, 406.3±67.2ng/mL). There was a negative correlation between post-0h cfDNA concentration and post-24h squat jump (r=-0.521; p=0.01) and post-0h cfDNA concentration and post-24h countermovement jump (r=-0.539; p=0.01). cfDNA increases in responsive to RE intensity even when not performed until exhaustion. cfDNA measured immediately after RE is a promising biomarker for muscle performance decrement until 48hrs of a RE bout.

Reward-based learning under hardware constraints-using a RISC processor embedded in a neuromorphic substrate.

Science.gov (United States)

Friedmann, Simon; Frémaux, Nicolas; Schemmel, Johannes; Gerstner, Wulfram; Meier, Karlheinz

2013-01-01

In this study, we propose and analyze in simulations a new, highly flexible method of implementing synaptic plasticity in a wafer-scale, accelerated neuromorphic hardware system. The study focuses on globally modulated STDP, as a special use-case of this method. Flexibility is achieved by embedding a general-purpose processor dedicated to plasticity into the wafer. To evaluate the suitability of the proposed system, we use a reward modulated STDP rule in a spike train learning task. A single layer of neurons is trained to fire at specific points in time with only the reward as feedback. This model is simulated to measure its performance, i.e., the increase in received reward after learning. Using this performance as baseline, we then simulate the model with various constraints imposed by the proposed implementation and compare the performance. The simulated constraints include discretized synaptic weights, a restricted interface between analog synapses and embedded processor, and mismatch of analog circuits. We find that probabilistic updates can increase the performance of low-resolution weights, a simple interface between analog synapses and processor is sufficient for learning, and performance is insensitive to mismatch. Further, we consider communication latency between wafer and the conventional control computer system that is simulating the environment. This latency increases the delay, with which the reward is sent to the embedded processor. Because of the time continuous operation of the analog synapses, delay can cause a deviation of the updates as compared to the not delayed situation. We find that for highly accelerated systems latency has to be kept to a minimum. This study demonstrates the suitability of the proposed implementation to emulate the selected reward modulated STDP learning rule. It is therefore an ideal candidate for implementation in an upgraded version of the wafer-scale system developed within the BrainScaleS project.

Electrophysiological indices of anterior cingulate cortex function reveal changing levels of cognitive effort and reward valuation that sustain task performance.

Science.gov (United States)

Umemoto, Akina; Inzlicht, Michael; Holroyd, Clay B

2018-06-14

Successful execution of goal-directed behaviors often requires the deployment of cognitive control, which is thought to require cognitive effort. Recent theories have proposed that anterior cingulate cortex (ACC) regulates control levels by weighing the reward-related benefits of control against its effort-related costs. However, given that the sensations of cognitive effort and reward valuation are available only to introspection, this hypothesis is difficult to investigate empirically. We have proposed that two electrophysiological indices of ACC function, frontal midline theta and the reward positivity (RewP), provide objective measures of these functions. To explore this issue, we recorded the electroencephalogram (EEG) from participants engaged in an extended, cognitively-demanding task. Participants performed a time estimation task for 2hours in which they received reward and error feedback according to their task performance. We observed that the amplitude of the RewP, a feedback-locked component of the event related brain potential associated with reward processing, decreased with time-on-task. Conversely, frontal midline theta power, which consists of 4-8Hz EEG oscillations associated with cognitive effort, increased with time-on-task. We also explored how these phenomena changed over time by conducting within-participant multi-level modeling analyses. Our results suggest that extended execution of a cognitively-demanding task is characterized by an early phase in which high control levels foster rapid improvements in task performance, and a later phase in which high control levels were necessary to maintain stable task performance, perhaps counteracting waning reward valuation. Copyright © 2018. Published by Elsevier Ltd.

Reassessment of the relationship between M-protein decrement and survival in multiple myeloma.

Science.gov (United States)

Palmer, M; Belch, A; Hanson, J; Brox, L

1989-01-01

The relationship between percentage M-protein decrement and survival is assessed in 134 multiple myeloma patients. The correlation did not achieve statistical significance (P = 0.069). Multivariate analysis using the Cox proportional hazards model, including a number of previously recognised prognostic factors, showed only percentage M-protein decrement, creatinine and haemoglobin to be significantly correlated with survival. However, the R'-statistic for each of these variables was low, indicating that their prognostic power is weak. We conclude that neither the percentage M-protein decrement nor the response derived from it can be used as an accurate means of assessing the efficacy of treatment in myeloma. Mature survival data alone should be used for this purpose.

Reassessment of the relationship between M-protein decrement and survival in multiple myeloma.

Science.gov (United States)

Palmer, M.; Belch, A.; Hanson, J.; Brox, L.

1989-01-01

The relationship between percentage M-protein decrement and survival is assessed in 134 multiple myeloma patients. The correlation did not achieve statistical significance (P = 0.069). Multivariate analysis using the Cox proportional hazards model, including a number of previously recognised prognostic factors, showed only percentage M-protein decrement, creatinine and haemoglobin to be significantly correlated with survival. However, the R'-statistic for each of these variables was low, indicating that their prognostic power is weak. We conclude that neither the percentage M-protein decrement nor the response derived from it can be used as an accurate means of assessing the efficacy of treatment in myeloma. Mature survival data alone should be used for this purpose. PMID:2757916

Premotor and Motor Cortices Encode Reward.

Directory of Open Access Journals (Sweden)

Pavan Ramkumar

Full Text Available Rewards associated with actions are critical for motivation and learning about the consequences of one's actions on the world. The motor cortices are involved in planning and executing movements, but it is unclear whether they encode reward over and above limb kinematics and dynamics. Here, we report a categorical reward signal in dorsal premotor (PMd and primary motor (M1 neurons that corresponds to an increase in firing rates when a trial was not rewarded regardless of whether or not a reward was expected. We show that this signal is unrelated to error magnitude, reward prediction error, or other task confounds such as reward consumption, return reach plan, or kinematic differences across rewarded and unrewarded trials. The availability of reward information in motor cortex is crucial for theories of reward-based learning and motivational influences on actions.

Reward speeds up and increases consistency of visual selective attention: a lifespan comparison.

Science.gov (United States)

Störmer, Viola; Eppinger, Ben; Li, Shu-Chen

2014-06-01

Children and older adults often show less favorable reward-based learning and decision making, relative to younger adults. It is unknown, however, whether reward-based processes that influence relatively early perceptual and attentional processes show similar lifespan differences. In this study, we investigated whether stimulus-reward associations affect selective visual attention differently across the human lifespan. Children, adolescents, younger adults, and older adults performed a visual search task in which the target colors were associated with either high or low monetary rewards. We discovered that high reward value speeded up response times across all four age groups, indicating that reward modulates attentional selection across the lifespan. This speed-up in response time was largest in younger adults, relative to the other three age groups. Furthermore, only younger adults benefited from high reward value in increasing response consistency (i.e., reduction of trial-by-trial reaction time variability). Our findings suggest that reward-based modulations of relatively early and implicit perceptual and attentional processes are operative across the lifespan, and the effects appear to be greater in adulthood. The age-specific effect of reward on reducing intraindividual response variability in younger adults likely reflects mechanisms underlying the development and aging of reward processing, such as lifespan age differences in the efficacy of dopaminergic modulation. Overall, the present results indicate that reward shapes visual perception across different age groups by biasing attention to motivationally salient events.

Progressive decrement PWM algorithm for minimum mean square error inverter output voltage

International Nuclear Information System (INIS)

Ghaeb, J.A.; Smadi, M.A.; Ababneh, M.

2011-01-01

Highlights: → The main contribution of this work is to provide a better performance for the power inverter operation. → The proposed technique splits the determined original pulse-width of an inverter operation in to many pulses. → The new approach extends the central pulse and shrinks the exterior pulses. → This is leading to an inverter output cycle close to the sinusoidal form of fewer harmonics. - Abstract: The paper proposes two modulation techniques for the power inverter. These new techniques are named progressive decrement PWM algorithm (PDPA) and progressive increment PWM algorithm (PIPA). Both techniques take the determined original pulse-width of an inverter operation and split it to many pulses. In the PDPA technique, the largest width is given to the middle pulse and the width of the boundary pulses is reduced progressively starting from the first boundary-pulse toward the last boundary-pulse. In the PIPA technique, there is a gradual increment instead of decrement. The two techniques have been proved that it can maintain the original pulse-width of the inverter operation. The new approach PDPA extends the central pulse and shrinks the exterior pulses, leading to an inverter output cycle close to the sinusoidal form of fewer harmonic contents. Simulation results are performed to evaluate the performances of the proposed techniques: PDPA and PIPA and to compare them with the well known methods. The main contribution of the proposed PDPA technique is that it provides a better performance for the most harmonic orders compared to the well established sinusoidal PWM technique.

Rewards and Creative Performance: A Meta-Analytic Test of Theoretically Derived Hypotheses

Science.gov (United States)

Byron, Kris; Khazanchi, Shalini

2012-01-01

Although many scholars and practitioners are interested in understanding how to motivate individuals to be more creative, whether and how rewards affect creativity remain unclear. We argue that the conflicting evidence may be due to differences between studies in terms of reward conditions and the context in which rewards are offered.…

Social reward shapes attentional biases.

Science.gov (United States)

Anderson, Brian A

2016-01-01

Paying attention to stimuli that predict a reward outcome is important for an organism to survive and thrive. When visual stimuli are associated with tangible, extrinsic rewards such as money or food, these stimuli acquire high attentional priority and come to automatically capture attention. In humans and other primates, however, many behaviors are not motivated directly by such extrinsic rewards, but rather by the social feedback that results from performing those behaviors. In the present study, I examine whether positive social feedback can similarly influence attentional bias. The results show that stimuli previously associated with a high probability of positive social feedback elicit value-driven attentional capture, much like stimuli associated with extrinsic rewards. Unlike with extrinsic rewards, however, such stimuli also influence task-specific motivation. My findings offer a potential mechanism by which social reward shapes the information that we prioritize when perceiving the world around us.

Chewing gum moderates the vigilance decrement.

Science.gov (United States)

Morgan, Kate; Johnson, Andrew J; Miles, Christopher

2014-05-01

We examine the impact of chewing gum on a Bakan-type vigilance task that requires the continual updating of short-term order memory. Forty participants completed a 30-min auditory Bakan-task either with, or without, the requirement to chew gum. Self-rated measures of mood were taken both pre- and post-task. As expected, the vigilance task produced a time-dependent performance decrement indexed via decreases in target detections and lengthened correct reaction times (RTs), and a reduction in post-task self-rated alertness scores. The declines in both performance and subjective alertness were attenuated in the chewing-gum group. In particular, correct RTs were significantly shorter following the chewing of gum in the latter stages of the task. Additionally, the gradients of decline for target detection and incline for correct RTs were both attenuated for the chewing-gum group. These findings are consistent with the data of Tucha and Simpson (2011), Appetite, 56, 299-301, who showed beneficial effects of chewing gum in the latter stages of a 30 min visual attention task, and extend their data to a task that necessitates the continuous updating of order memory. It is noteworthy that our data contradict the claim (Kozlov, Hughes, & Jones, 2012, Q. J. Exp. Psychology, 65, 501-513) that chewing gum negatively impacts short-term memory task performance. © 2013 The British Psychological Society.

Reward Inference by Primate Prefrontal and Striatal Neurons

OpenAIRE

Pan, Xiaochuan; Fan, Hongwei; Sawa, Kosuke; Tsuda, Ichiro; Tsukada, Minoru; Sakagami, Masamichi

2014-01-01

The brain contains multiple yet distinct systems involved in reward prediction. To understand the nature of these processes, we recorded single-unit activity from the lateral prefrontal cortex (LPFC) and the striatum in monkeys performing a reward inference task using an asymmetric reward schedule. We found that neurons both in the LPFC and in the striatum predicted reward values for stimuli that had been previously well experienced with set reward quantities in the asymmetric reward task. Im...

Reward-based learning under hardware constraints - Using a RISC processor embedded in a neuromorphic substrate

Directory of Open Access Journals (Sweden)

Simon eFriedmann

2013-09-01

Full Text Available In this study, we propose and analyze in simulations a new, highly flexible method of imple-menting synaptic plasticity in a wafer-scale, accelerated neuromorphic hardware system. Thestudy focuses on globally modulated STDP, as a special use-case of this method. Flexibility isachieved by embedding a general-purpose processor dedicated to plasticity into the wafer. Toevaluate the suitability of the proposed system, we use a reward modulated STDP rule in a spiketrain learning task. A single layer of neurons is trained to fire at specific points in time withonly the reward as feedback. This model is simulated to measure its performance, i.e. the in-crease in received reward after learning. Using this performance as baseline, we then simulatethe model with various constraints imposed by the proposed implementation and compare theperformance. The simulated constraints include discretized synaptic weights, a restricted inter-face between analog synapses and embedded processor, and mismatch of analog circuits. Wefind that probabilistic updates can increase the performance of low-resolution weights, a simpleinterface between analog synapses and processor is sufficient for learning, and performance isinsensitive to mismatch. Further, we consider communication latency between wafer and theconventional control computer system that is simulating the environment. This latency increasesthe delay, with which the reward is sent to the embedded processor. Because of the time continu-ous operation of the analog synapses, delay can cause a deviation of the updates as compared tothe not delayed situation. We find that for highly accelerated systems latency has to be kept to aminimum. This study demonstrates the suitability of the proposed implementation to emulatethe selected reward modulated STDP learning rule. It is therefore an ideal candidate for imple-mentation in an upgraded version of the wafer-scale system developed within the BrainScaleSproject.

Reward-dependent modulation of movement variability.

Science.gov (United States)

Pekny, Sarah E; Izawa, Jun; Shadmehr, Reza

2015-03-04

Movement variability is often considered an unwanted byproduct of a noisy nervous system. However, variability can signal a form of implicit exploration, indicating that the nervous system is intentionally varying the motor commands in search of actions that yield the greatest success. Here, we investigated the role of the human basal ganglia in controlling reward-dependent motor variability as measured by trial-to-trial changes in performance during a reaching task. We designed an experiment in which the only performance feedback was success or failure and quantified how reach variability was modulated as a function of the probability of reward. In healthy controls, reach variability increased as the probability of reward decreased. Control of variability depended on the history of past rewards, with the largest trial-to-trial changes occurring immediately after an unrewarded trial. In contrast, in participants with Parkinson's disease, a known example of basal ganglia dysfunction, reward was a poor modulator of variability; that is, the patients showed an impaired ability to increase variability in response to decreases in the probability of reward. This was despite the fact that, after rewarded trials, reach variability in the patients was comparable to healthy controls. In summary, we found that movement variability is partially a form of exploration driven by the recent history of rewards. When the function of the human basal ganglia is compromised, the reward-dependent control of movement variability is impaired, particularly affecting the ability to increase variability after unsuccessful outcomes. Copyright © 2015 the authors 0270-6474/15/354015-10$15.00/0.

Identification of System Parameters by the Random Decrement Technique

DEFF Research Database (Denmark)

Brincker, Rune; Kirkegaard, Poul Henning; Rytter, Anders

1991-01-01

-Walker equations and finally, least-square fitting of the theoretical correlation function. The results are compared to the results of fitting an Auto Regressive Moving Average (ARMA) model directly to the system output from a single-degree-of-freedom system loaded by white noise.......The aim of this paper is to investigate and illustrate the possibilities of using correlation functions estimated by the Random Decrement Technique as a basis for parameter identification. A two-stage system identification system is used: first, the correlation functions are estimated by the Random...... Decrement Technique, and then the system parameters are identified from the correlation function estimates. Three different techniques are used in the parameter identification process: a simple non-parametric method, estimation of an Auto Regressive (AR) model by solving an overdetermined set of Yule...

Vector Triggering Random Decrement for High Identification Accuracy

DEFF Research Database (Denmark)

Ibrahim, S. R.; Asmussen, J. C.; Brincker, Rune

Using the Random Decrement (RD) technique to obtain free response estimates and combining this with time domain modal identification methods to obtain the poles and the mode shapes is acknowledged as a fast and accurate way of analysing measured responses of structures subject to ambient loads. W...

Monetary reward speeds up voluntary saccades.

Science.gov (United States)

Chen, Lewis L; Chen, Y Mark; Zhou, Wu; Mustain, William D

2014-01-01

Past studies have shown that reward contingency is critical for sensorimotor learning, and reward expectation speeds up saccades in animals. Whether monetary reward speeds up saccades in human remains unknown. Here we addressed this issue by employing a conditional saccade task, in which human subjects performed a series of non-reflexive, visually-guided horizontal saccades. The subjects were (or were not) financially compensated for making a saccade in response to a centrally-displayed visual congruent (or incongruent) stimulus. Reward modulation of saccadic velocities was quantified independently of the amplitude-velocity coupling. We found that reward expectation significantly sped up voluntary saccades up to 30°/s, and the reward modulation was consistent across tests. These findings suggest that monetary reward speeds up saccades in human in a fashion analogous to how juice reward sped up saccades in monkeys. We further noticed that the idiosyncratic nasal-temporal velocity asymmetry was highly consistent regardless of test order, and its magnitude was not correlated with the magnitude of reward modulation. This suggests that reward modulation and the intrinsic velocity asymmetry may be governed by separate mechanisms that regulate saccade generation.

Total rewards that retain: A study of demographic preferences

Directory of Open Access Journals (Sweden)

Monica Pregnolato

2017-01-01

Full Text Available Orientation: Changing workplace demographics and a dearth of employees with scarce skills have forced employers to better understand the various factors that retain talented employees. Research purpose: In this empirical study, the reward preferences and ideal combination of total reward elements (based on an estimation of their relative importance that retain employees from various demographic groups, including employees of different race, gender and age groups, were investigated. Motivation for study: Organisations are competing for talented employees and to benefit from the value these individuals add, it is required of them to stay at the respective businesses. Previous studies have indicated that employees who are offered a reward package that is aligned to their personal preferences are prone to stay longer at the organisation and to be more engaged at work. However, new and novel ways need to be found to identify the reward preferences of employees. Research design, approach and method: A quantitative approach and descriptive research design was employed to estimate the individual reward preferences and identify an ideal mix of total reward elements that retain different cohorts of employees. Three questionnaires were distributed, including a Remuneration Managers Questionnaire (n = 7, a Remuneration Preference Questionnaire (n = 368 and a Choice-based Conjoint Task Questionnaire (n = 368. The latter two questionnaires were distributed as an online questionnaire to South African businesses and consisted of eight choice-based conjoint tasks, as well as a field survey. Main findings: The results of the choice-based conjoint analysis revealed that all respondents considered financial rewards (Benefits, Performance and Recognition, Remuneration, Career, in that order as relatively speaking, the most important components in their total rewards package that would lead to their retention. For most demographic groups, the remaining three places

Reward modulates perception in binocular rivalry.

Science.gov (United States)

Marx, Svenja; Einhäuser, Wolfgang

2015-01-14

Our perception does not provide us with an exact imprint of the outside world, but is continuously adapted to our internal expectations, task sets, and behavioral goals. Although effects of reward-or value in general-on perception therefore seem likely, how valuation modulates perception and how such modulation relates to attention is largely unknown. We probed effects of reward on perception by using a binocular-rivalry paradigm. Distinct gratings drifting in opposite directions were presented to each observer's eyes. To objectify their subjective perceptual experience, the optokinetic nystagmus was used as measure of current perceptual dominance. In a first experiment, one of the percepts was either rewarded or attended. We found that reward and attention similarly biased perception. In a second experiment, observers performed an attentionally demanding task either on the rewarded stimulus, the other stimulus, or both. We found that-on top of an attentional effect on perception-at each level of attentional load, reward still modulated perception by increasing the dominance of the rewarded percept. Similarly, penalizing one percept increased dominance of the other at each level of attentional load. In turn, rewarding-and similarly nonpunishing-a percept yielded performance benefits that are typically associated with selective attention. In conclusion, our data show that value modulates perception in a similar way as the volitional deployment of attention, even though the relative effect of value is largely unaffected by an attention task. © 2015 ARVO.

Prosocial reward learning in children and adolescents

Directory of Open Access Journals (Sweden)

Youngbin Kwak

2016-10-01

Full Text Available Adolescence is a period of increased sensitivity to social contexts. To evaluate how social context sensitivity changes over development – and influences reward learning – we investigated how children and adolescents perceive and integrate rewards for oneself and others during a dynamic risky-decision-making task. Children and adolescents (N=75, 8-16 yrs performed the Social Gambling Task (SGT, (Kwak et al., 2014 and completed a set of questionnaires measuring other-regarding behavior. In the SGT, participants choose amongst four card decks that have different payout structures for oneself and for a charity. We examined patterns of choices, overall decision strategies, and how reward outcomes led to trial-by-trial adjustments in behavior, as estimated using a reinforcement-learning model. Performance of children and adolescents was compared to data from a previously collected sample of adults (N=102 performing the identical task. We found that that children/adolescents were not only more sensitive to rewards directed to the charity than self but also showed greater prosocial tendencies on independent measures of other-regarding behavior. Children and adolescents also showed less use of a strategy that prioritizes rewards for self at the expense of rewards for others. These results support the conclusion that, compared to adults, children and adolescents show greater sensitivity to outcomes for others when making decisions and learning about potential rewards.

Pain and suicidality: insights from reward and addiction neuroscience.

Science.gov (United States)

Elman, Igor; Borsook, David; Volkow, Nora D

2013-10-01

Suicidality is exceedingly prevalent in pain patients. Although the pathophysiology of this link remains unclear, it may be potentially related to the partial congruence of physical and emotional pain systems. The latter system's role in suicide is also conspicuous during setbacks and losses sustained in the context of social attachments. Here we propose a model based on the neural pathways mediating reward and anti-reward (i.e., allostatic adjustment to recurrent activation of the reward circuitry); both are relevant etiologic factors in pain, suicide and social attachments. A comprehensive literature search on neurobiology of pain and suicidality was performed. The collected articles were critically reviewed and relevant data were extracted and summarized within four key areas: (1) physical and emotional pain, (2) emotional pain and social attachments, (3) pain- and suicide-related alterations of the reward and anti-reward circuits as compared to addiction, which is the premier probe for dysfunction of these circuits and (4) mechanistically informed treatments of co-occurring pain and suicidality. Pain-, stress- and analgesic drugs-induced opponent and proponent states of the mesolimbic dopaminergic pathways may render reward and anti-reward systems vulnerable to sensitization, cross-sensitization and aberrant learning of contents and contexts associated with suicidal acts and behaviors. These findings suggest that pain patients exhibit alterations in the brain circuits mediating reward (depressed function) and anti-reward (sensitized function) that may affect their proclivity for suicide and support pain and suicidality classification among other "reward deficiency syndromes" and a new proposal for "enhanced anti-reward syndromes". We suggest that interventions aimed at restoring the balance between the reward and anti-reward networks in patients with chronic pain may help decreasing their suicide risk. Published by Elsevier Ltd.

Distinct Motivational Effects of Contingent and Noncontingent Rewards.

Science.gov (United States)

Manohar, Sanjay G; Finzi, Rebecca Dawn; Drew, Daniel; Husain, Masud

2017-07-01

When rewards are available, people expend more energy, increasing their motivational vigor. In theory, incentives might drive behavior for two distinct reasons: First, they increase expected reward; second, they increase the difference in subjective value between successful and unsuccessful performance, which increases contingency-the degree to which action determines outcome. Previous studies of motivational vigor have never compared these directly. Here, we indexed motivational vigor by measuring the speed of eye movements toward a target after participants heard a cue indicating how outcomes would be determined. Eye movements were faster when the cue indicated that monetary rewards would be contingent on performance than when the cue indicated that rewards would be random. But even when the cue indicated that a reward was guaranteed regardless of speed, movement was still faster than when no reward was available. Motivation by contingent and certain rewards was uncorrelated across individuals, which suggests that there are two separable, independent components of motivation. Contingent motivation generated autonomic arousal, and unlike noncontingent motivation, was effective with penalties as well as rewards.

Stress and reward processing in bipolar disorder: an fMRI study

Science.gov (United States)

Berghorst, Lisa H; Kumar, Poornima; Greve, Doug N; Deckersbach, Thilo; Ongur, Dost; Dutra, Sunny; Pizzagalli, Diego A

2016-01-01

Objectives A link between negative life stress and the onset of mood episodes in bipolar disorder (BD) has been established, but processes underlying such a link remain unclear. Growing evidence suggests that stress can negatively affect reward processing and related neurobiological substrates, indicating that a dysregulated reward system may provide a partial explanation. The aim of this study was to test the impact of stress on reward-related neural functioning in BD. Methods Thirteen euthymic or mildly depressed individuals with BD and 15 controls performed a Monetary Incentive Delay task while undergoing functional magnetic resonance imaging during no-stress and stress (negative psychosocial stressor involving poor performance feedback and threat of monetary deductions) conditions. Results In hypothesis-driven region-of- interest-based analyses, a significant group by condition interaction emerged in the amygdala during reward anticipation. Relative to controls, while anticipating a potential reward, subjects with BD were characterized by amygdalar hyperactivation in the no-stress condition but hypoactivation during stress. Moreover, relative to controls, subjects with BD had significantly larger amygdala volumes. After controlling for structural differences, the effects of stress on amygdalar function remained, whereas groups no longer differed during the no-stress condition. During reward consumption, a group by condition interaction emerged in the putamen due to increased putamen activation to rewards in participants with BD during stress, but an opposite pattern in controls. Conclusions Overall, findings highlight possible impairments in using reward-predicting cues to adaptively engage in goal-directed actions in BD, combined with stress-induced hypersensitivity to reward consumption. Potential clinical implications are discussed. PMID:27870507

Reassessment of the relationship between M-protein decrement and survival in multiple myeloma.

OpenAIRE

Palmer, M.; Belch, A.; Hanson, J.; Brox, L.

1989-01-01

The relationship between percentage M-protein decrement and survival is assessed in 134 multiple myeloma patients. The correlation did not achieve statistical significance (P = 0.069). Multivariate analysis using the Cox proportional hazards model, including a number of previously recognised prognostic factors, showed only percentage M-protein decrement, creatinine and haemoglobin to be significantly correlated with survival. However, the R'-statistic for each of these variables was low, indi...

Time-on-task decrement in vigilance is modulated by inter-individual vulnerability to homeostatic sleep pressure manipulation

Directory of Open Access Journals (Sweden)

Micheline eMaire

2014-03-01

Full Text Available Under sleep loss, vigilance is reduced and attentional failures emerge progressively. It becomes difficult to maintain stable performance over time, leading to growing performance variability (i.e. state instability in an individual and among subjects. Task duration plays a major role in the maintenance of stable vigilance levels, such that the longer the task, the more likely state instability will be observed. Vulnerability to sleep-loss-dependent performance decrements is highly individual and is also modulated by a polymorphism in the human clock gene PERIOD3 (PER3. By combining two different protocols, we manipulated sleep-wake history by once extending wakefulness for 40 h (high sleep pressure condition and once by imposing a short sleep-wake cycle by alternating 160 min of wakefulness and 80 min naps (low sleep pressure condition in a within-subject design. We observed that homozygous carriers of the long repeat allele of PER3 (PER35/5 experienced a greater time-on-task dependent performance decrement (i.e., a steeper increase in the number of lapses in the Psychomotor Vigilance Task compared to the carriers of the short repeat allele (PER34/4. These genotype-dependent effects disappeared under low sleep pressure conditions, and neither motivation, nor perceived effort accounted for these differences. Our data thus suggest that greater sleep-loss related attentional vulnerability based on the PER3 polymorphism is mirrored by a greater state instability under extended wakefulness in the short compared to the long allele carriers. Our results undermine the importance of time-on-task related aspects when investigating inter-individual differences in sleep loss-induced behavioural vulnerability.

Model Checking Markov Reward Models with Impulse Rewards

NARCIS (Netherlands)

Cloth, Lucia; Katoen, Joost-Pieter; Khattri, Maneesh; Pulungan, Reza; Bondavalli, Andrea; Haverkort, Boudewijn; Tang, Dong

This paper considers model checking of Markov reward models (MRMs), continuous-time Markov chains with state rewards as well as impulse rewards. The reward extension of the logic CSL (Continuous Stochastic Logic) is interpreted over such MRMs, and two numerical algorithms are provided to check the

Differential encoding of factors influencing predicted reward value in monkey rostral anterior cingulate cortex.

Science.gov (United States)

Toda, Koji; Sugase-Miyamoto, Yasuko; Mizuhiki, Takashi; Inaba, Kiyonori; Richmond, Barry J; Shidara, Munetaka

2012-01-01

The value of a predicted reward can be estimated based on the conjunction of both the intrinsic reward value and the length of time to obtain it. The question we addressed is how the two aspects, reward size and proximity to reward, influence the responses of neurons in rostral anterior cingulate cortex (rACC), a brain region thought to play an important role in reward processing. We recorded from single neurons while two monkeys performed a multi-trial reward schedule task. The monkeys performed 1-4 sequential color discrimination trials to obtain a reward of 1-3 liquid drops. There were two task conditions, a valid cue condition, where the number of trials and reward amount were associated with visual cues, and a random cue condition, where the cue was picked from the cue set at random. In the valid cue condition, the neuronal firing is strongly modulated by the predicted reward proximity during the trials. Information about the predicted reward amount is almost absent at those times. In substantial subpopulations, the neuronal responses decreased or increased gradually through schedule progress to the predicted outcome. These two gradually modulating signals could be used to calculate the effect of time on the perception of reward value. In the random cue condition, little information about the reward proximity or reward amount is encoded during the course of the trial before reward delivery, but when the reward is actually delivered the responses reflect both the reward proximity and reward amount. Our results suggest that the rACC neurons encode information about reward proximity and amount in a manner that is dependent on utility of reward information. The manner in which the information is represented could be used in the moment-to-moment calculation of the effect of time and amount on predicted outcome value.

Improving control over the impulse for reward: sensitivity of harmful alcohol drinkers to delayed reward but not immediate punishment.

Science.gov (United States)

Rossiter, Sarah; Thompson, Julian; Hester, Robert

2012-09-01

Cognitive control dysfunction has been identified in dependent alcohol users and implicated in the transition from abuse to dependence, although evidence of dyscontrol in chronic but non-dependent 'harmful' alcohol abusers is mixed. The current study examined harmful alcohol users response inhibition over rewarding stimuli in the presence of monetary reward and punishment, to determine whether changes in sensitivity to these factors, noted in imaging studies of dependent users, influences impulse control. Harmful (n=30) and non-hazardous (n=55) alcohol users were administered a Monetary Incentive Go/No-go task that required participants to inhibit a prepotent motor response associated with reward. Harmful alcohol users showed a significantly poorer ability to withhold their impulse for a rewarding stimulus in the presence of immediate monetary punishment for failure, while retaining equivalent response inhibition performance under neutral conditions (associated with neither monetary loss or gain), and significantly better performance under delayed reward conditions. The results of the present study suggest that non-dependent alcohol abusers have altered sensitivity to reward and punishment that influences their impulse control for reward, in the absence of gross dyscontrol that is consistent with past findings in which such performance contingencies were not used. The ability of delayed monetary reward, but not punishment, to increase sustained impulse control in this sample has implications for the mechanism that might underlie the transition from alcohol abuse to dependence, as well as intervention strategies aimed at preventing this transition. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Vascular Risk Factors and Diseases Modulate Deficits of Reward-Based Reversal Learning in Acute Basal Ganglia Stroke.

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Ulla K Seidel

Full Text Available Besides motor function, the basal ganglia have been implicated in feedback learning. In patients with chronic basal ganglia infarcts, deficits in reward-based reversal learning have previously been described.We re-examined the acquisition and reversal of stimulus-stimulus-reward associations and acquired equivalence in eleven patients with acute basal ganglia stroke (8 men, 3 women; 57.8±13.3 years, whose performance was compared eleven healthy subjects of comparable age, sex distribution and education, who were recruited outside the hospital. Eleven hospitalized patients with a similar vascular risk profile as the stroke patients but without stroke history served as clinical control group.In a neuropsychological assessment 7±3 days post-stroke, verbal and spatial short-term and working memory and inhibition control did not differ between groups. Compared with healthy subjects, control patients with vascular risk factors exhibited significantly reduced performance in the reversal phase (F[2,30] = 3.47; p = 0.044; post-hoc comparison between risk factor controls and healthy controls: p = 0.030, but not the acquisition phase (F[2,30] = 1.01; p = 0.376 and the acquired equivalence (F[2,30] = 1.04; p = 0.367 tasks. In all tasks, the performance of vascular risk factor patients closely resembled that of basal ganglia stroke patients. Correlation studies revealed a significant association of the number of vascular risk factors with reversal learning (r = -0.33, p = 0.012, but not acquisition learning (r = -0.20, p = 0.121 or acquired equivalence (r = -0.22, p = 0.096.The previously reported impairment of reward-based learning may be attributed to vascular risk factors and associated diseases, which are enriched in stroke patients. This study emphasizes the necessity of appropriate control subjects in cognition studies.

The Atacama Cosmology Telescope: Detection or Sunyaev-Zel'Dovich Decrement in Groups and Clusters Associated with Luminous Red Galaxies

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Hand, Nick; Appel, John William; Battaglia, Nick; Bond, J. Richard; Das, Sudeep; Devlin, Mark J.; Dunkley, Joanna; Dunner, Rolando; Essinger-Hileman, Thomas; Fowler, Joseph W.;

Effects of material and non-material rewards on remembering to do things for others

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Maria A. Brandimonte

2015-12-01

Full Text Available Recent research has shown that pro-social prospective memory, i.e., remembering to do something for others, is negatively affected by the presence of small material rewards. While this competition between pro-social and self-gain motives leads to poor memory for the intention, people do not seem to be aware of the possible collision effects of competing motives (Brandimonte, Ferrante, Bianco, & Villani, 2010. Extending research on this general topic, in two activity-based prospective memory experiments, we explored the effects of different types and amount of rewards on pro-social prospective remembering. In Experiment 1, participants could receive no reward, a low material reward (1 euro, or a high material reward (20 euro for their pro-social prospective memory action. In Experiment 2, their pro-social prospective memory performance could be rewarded or not with an image reward (publicity of their altruistic behavior. Results revealed that introducing a small material reward (Experiment 1 or a non-material reward (Experiment 2 impaired pro-social prospective memory. However, introducing a high material reward eliminated the impairment (Experiment 1. Importantly, in Experiment 1, ongoing task performance in the pro-social condition was faster than in the No PM condition. However, in Experiment 2, ongoing task costs emerged in the presence of a non-material reward, as compared to the pro-social condition. Also, results from two independent ratings showed that people’s predictions on their future pro-social actions were at odds (Experiment 1 or in line (Experiment 2 with actual PM performance. It is suggested that, according to the nature and amount of rewards, memory for a pro-social future action may be modulated by conscious or unconscious motivational mechanisms.

Adaptive scaling of reward in episodic memory: a replication study.

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Mason, Alice; Ludwig, Casimir; Farrell, Simon

2017-11-01

Reward is thought to enhance episodic memory formation via dopaminergic consolidation. Bunzeck, Dayan, Dolan, and Duzel [(2010). A common mechanism for adaptive scaling of reward and novelty. Human Brain Mapping, 31, 1380-1394] provided functional magnetic resonance imaging (fMRI) and behavioural evidence that reward and episodic memory systems are sensitive to the contextual value of a reward-whether it is relatively higher or lower-as opposed to absolute value or prediction error. We carried out a direct replication of their behavioural study and did not replicate their finding that memory performance associated with reward follows this pattern of adaptive scaling. An effect of reward outcome was in the opposite direction to that in the original study, with lower reward outcomes leading to better memory than higher outcomes. There was a marginal effect of reward context, suggesting that expected value affected memory performance. We discuss the robustness of the reward memory relationship to variations in reward context, and whether other reward-related factors have a more reliable influence on episodic memory.

Abnormal reward functioning across substance use disorders and major depressive disorder: Considering reward as a transdiagnostic mechanism.

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Baskin-Sommers, Arielle R; Foti, Dan

2015-11-01

A common criticism of the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 2013) is that its criteria are based more on behavioral descriptions than on underlying biological mechanisms. Increasingly, calls have intensified for a more biologically-based approach to conceptualizing, studying, and treating psychological disorders, as exemplified by the Research Domain Criteria Project (RDoC). Among the most well-studied neurobiological mechanisms is reward processing. Moreover, individual differences in reward sensitivity are related to risk for substance abuse and depression. The current review synthesizes the available preclinical, electrophysiological, and neuroimaging literature on reward processing from a transdiagnostic, multidimensional perspective. Findings are organized with respect to key reward constructs within the Positive Valence Systems domain of the RDoC matrix, including initial responsiveness to reward (physiological 'liking'), approach motivation (physiological 'wanting'), and reward learning/habit formation. In the current review, we (a) describe the neural basis of reward, (b) elucidate differences in reward activity in substance abuse and depression, and (c) suggest a framework for integrating these disparate literatures and discuss the utility of shifting focus from diagnosis to process for understanding liability and co-morbidity. Ultimately, we believe that an integrative focus on abnormal reward functioning across the full continuum of clinically heterogeneous samples, rather than within circumscribed diagnostic categories, might actually help to refine the phenotypes and improve the prediction of onset and recovery of these disorders. Copyright © 2015 Elsevier B.V. All rights reserved.

Resistance to extinction, generalization decrement, and conditioned reinforcement.

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Dulaney, Alana E; Bell, Matthew C

2008-06-01

This study investigated generalization decrement during an extinction resistance-to-change test for pigeon key pecking using a two-component multiple schedule with equal variable-interval 3-min schedules and different reinforcer amounts (one component presented 2-s access to reinforcement and the other 8s). After establishing baseline responding, subjects were assigned to one of the two extinction conditions: hopper stimuli (hopper and hopper light were activated but no food was available) or Control (inactive hopper and hopper light). Responding in the 8-s component was more resistant to extinction than responding in the 2-s component, the hopper stimuli group was more resistant to extinction compared to the Control group, and an interaction between amount of reinforcement, extinction condition, and session block was present. This finding supports generalization decrement as a factor that influences resistance to extinction. Hopper-time data (the amount of time subjects spent with their heads in the hopper) were compared to resistance-to-change data in an investigation of the role of conditioned reinforcement on resistance to change.

Impaired reward responsiveness in schizophrenia.

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Taylor, Nicholas; Hollis, Jeffrey P; Corcoran, Sarah; Gross, Robin; Cuthbert, Bruce; Swails, Lisette W; Duncan, Erica

2018-03-08

Anhedonia is a core negative symptom of schizophrenia. Schizophrenia patients report largely intact pleasure in consuming rewards, but have impairments in generating motivated behavior to pursue rewards, and show reduced fMRI activation of the reward pathway during presentation of rewarded stimuli. A computer based task measuring the development of a response bias in favor of rewarded stimuli permits assessment of reward-induced motivation. We hypothesized that subjects with schizophrenia would be impaired on this task. 58 schizophrenia subjects (SCZ) and 52 healthy controls (CON) were studied with a signal detection task to assess reward responsiveness. In multiple trials over three blocks subjects were asked to correctly identify two stimuli that were paired with unequal chance of monetary reward. The critical outcome variable was response bias, the development of a greater percent correct identification of the stimulus that was rewarded more often. An ANOVA on response bias with Block as a repeated-measures factor and Diagnosis as a between-group factor indicated that SCZ subjects achieved a lower bias to rewarded stimuli than CON subjects (F(1,105)=8.82, p=0.004, η 2 =0.078). Post hoc tests indicated that SCZ subjects had significantly impaired bias in Block 1 (p=0.002) and Block 2 (p=0.05), indicating that SCZ were slower to achieve normal levels of bias during the session. SCZ subjects were slower to develop response bias to rewarded stimuli than CON subjects. This finding is consonant with the hypothesis that people with schizophrenia have a blunted capacity to modify behavior in response to reward. Copyright © 2018. Published by Elsevier B.V.

Individual differences in sensitivity to reward and punishment and neural activity during reward and avoidance learning.

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Kim, Sang Hee; Yoon, HeungSik; Kim, Hackjin; Hamann, Stephan

2015-09-01

In this functional neuroimaging study, we investigated neural activations during the process of learning to gain monetary rewards and to avoid monetary loss, and how these activations are modulated by individual differences in reward and punishment sensitivity. Healthy young volunteers performed a reinforcement learning task where they chose one of two fractal stimuli associated with monetary gain (reward trials) or avoidance of monetary loss (avoidance trials). Trait sensitivity to reward and punishment was assessed using the behavioral inhibition/activation scales (BIS/BAS). Functional neuroimaging results showed activation of the striatum during the anticipation and reception periods of reward trials. During avoidance trials, activation of the dorsal striatum and prefrontal regions was found. As expected, individual differences in reward sensitivity were positively associated with activation in the left and right ventral striatum during reward reception. Individual differences in sensitivity to punishment were negatively associated with activation in the left dorsal striatum during avoidance anticipation and also with activation in the right lateral orbitofrontal cortex during receiving monetary loss. These results suggest that learning to attain reward and learning to avoid loss are dependent on separable sets of neural regions whose activity is modulated by trait sensitivity to reward or punishment. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Programmed gradient descent biosorption of strontium ions by Saccaromyces cerevisiae and ashing analysis: A decrement solution for nuclide and heavy metal disposal

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Liu, Mingxue [Life Science and Engineering College, Southwest University of Science and Technology, Mianyang, 621010 (China); Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education of China, Mianyang, 621010 (China); Dong, Faqin, E-mail: fqdong@swust.edu.cn [Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education of China, Mianyang, 621010 (China); Zhang, Wei [Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education of China, Mianyang, 621010 (China); Nie, Xiaoqin [Fundamental Science on Nuclear Wastes and Environmental Safety Laboratory, Mianyang, 621010 (China); Sun, Shiyong [Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education of China, Mianyang, 621010 (China); Wei, Hongfu; Luo, Lang; Xiang, Sha; Zhang, Gege [Life Science and Engineering College, Southwest University of Science and Technology, Mianyang, 621010 (China)

2016-08-15

Highlights: • A programmed gradient descent biosorption process was designed. • The adsorption and bioaccumulation quantity of strontium ions by yeast cell were measured. • The decrement of biosorbents after biosorption by ashing was analyzed. • A technological flow process of decrement solution for waste disposal was proposed. - Abstract: One of the waste disposal principles is decrement. The programmed gradient descent biosorption of strontium ions by Saccaromyces cerevisiae regarding bioremoval and ashing process for decrement were studied in present research. The results indicated that S. cerevisiae cells showed valid biosorption for strontium ions with greater than 90% bioremoval efficiency for high concentration strontium ions under batch culture conditions. The S. cerevisiae cells bioaccumulated approximately 10% of strontium ions in the cytoplasm besides adsorbing 90% strontium ions on cell wall. The programmed gradient descent biosorption presented good performance with a nearly 100% bioremoval ratio for low concentration strontium ions after 3 cycles. The ashing process resulted in a huge volume and weight reduction ratio as well as enrichment for strontium in the ash. XRD results showed that SrSO{sub 4} existed in ash. Simulated experiments proved that sulfate could adjust the precipitation of strontium ions. Finally, we proposed a technological flow process that combined the programmed gradient descent biosorption and ashing, which could yield great decrement and allow the supernatant to meet discharge standard. This technological flow process may be beneficial for nuclides and heavy metal disposal treatment in many fields.

An Effective Privacy Architecture to Preserve User Trajectories in Reward-Based LBS Applications

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A S M Touhidul Hasan

2018-02-01

Full Text Available How can training performance data (e.g., running or walking routes be collected, measured, and published in a mobile program while preserving user privacy? This question is becoming important in the context of the growing use of reward-based location-based service (LBS applications, which aim to promote employee training activities and to share such data with insurance companies in order to reduce the healthcare insurance costs of an organization. One of the main concerns of such applications is the privacy of user trajectories, because the applications normally collect user locations over time with identities. The leak of the identified trajectories often results in personal privacy breaches. For instance, a trajectory would expose user interest in places and behaviors in time by inference and linking attacks. This information can be used for spam advertisements or individual-based assaults. To the best of our knowledge, no existing studies can be directly applied to solve the problem while keeping data utility. In this paper, we identify the personal privacy problem in a reward-based LBS application and propose privacy architecture with a bounded perturbation technique to protect user’s trajectory from the privacy breaches. Bounded perturbation uses global location set (GLS to anonymize the trajectory data. In addition, the bounded perturbation will not generate any visiting points that are not possible to visit in real time. The experimental results on real-world datasets demonstrate that the proposed bounded perturbation can effectively anonymize location information while preserving data utility compared to the existing methods.

The brain correlates of the effects of monetary and verbal rewards on intrinsic motivation.

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Albrecht, Konstanze; Abeler, Johannes; Weber, Bernd; Falk, Armin

2014-01-01

Apart from everyday duties, such as doing the laundry or cleaning the house, there are tasks we do for pleasure and enjoyment. We do such tasks, like solving crossword puzzles or reading novels, without any external pressure or force; instead, we are intrinsically motivated: we do the tasks because we enjoy doing them. Previous studies suggest that external rewards, i.e., rewards from the outside, affect the intrinsic motivation to engage in a task: while performance-based monetary rewards are perceived as controlling and induce a business-contract framing, verbal rewards praising one's competence can enhance the perceived self-determination. Accordingly, the former have been shown to decrease intrinsic motivation, whereas the latter have been shown to increase intrinsic motivation. The present study investigated the neural processes underlying the effects of monetary and verbal rewards on intrinsic motivation in a group of 64 subjects applying functional magnetic resonance imaging (fMRI). We found that, when participants received positive performance feedback, activation in the anterior striatum and midbrain was affected by the nature of the reward; compared to a non-rewarded control group, activation was higher while monetary rewards were administered. However, we did not find a decrease in activation after reward withdrawal. In contrast, we found an increase in activation for verbal rewards: after verbal rewards had been withdrawn, participants showed a higher activation in the aforementioned brain areas when they received success compared to failure feedback. We further found that, while participants worked on the task, activation in the lateral prefrontal cortex was enhanced after the verbal rewards were administered and withdrawn.

Reward deficiency and anti-reward in pain chronification

OpenAIRE

Borsook, D.; Linnman, C.; Faria, Vanda; Strassman, A. M.; Becerra, L.; Elman, I.

2016-01-01

Converging lines of evidence suggest that the pathophysiology of pain is mediated to a substantial degree via allostatic neuroadaptations in reward- and stress-related brain circuits. Thus, reward deficiency (RD) represents a within-system neuroadaptation to pain-induced protracted activation of the reward circuits that leads to depletion-like hypodopaminergia, clinically manifested anhedonia, and diminished motivation for natural reinforcers. Anti-reward (AR) conversely pertains to a between...

Rewards.

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Gunderman, Richard B; Kamer, Aaron P

2011-05-01

For much of the 20th century, psychologists and economists operated on the assumption that work is devoid of intrinsic rewards, and the only way to get people to work harder is through the use of rewards and punishments. This so-called carrot-and-stick model of workplace motivation, when applied to medical practice, emphasizes the use of financial incentives and disincentives to manipulate behavior. More recently, however, it has become apparent that, particularly when applied to certain kinds of work, such approaches can be ineffective or even frankly counterproductive. Instead of focusing on extrinsic rewards such as compensation, organizations and their leaders need to devote more attention to the intrinsic rewards of work itself. This article reviews this new understanding of rewards and traces out its practical implications for radiology today. Copyright © 2011. Published by Elsevier Inc.

Pervasive negative effects of rewards on intrinsic motivation: The myth continues.

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Cameron, J; Banko, K M; Pierce, W D

2001-01-01

A major concern in psychology and education is that rewards decrease intrinsic motivation to perform activities. Over the past 30 years, more than 100 experimental studies have been conducted on this topic. In 1994, Cameron and Pierce conducted a meta-analysis of this literature and concluded that negative effects of reward were limited and could be easily prevented in applied settings. A more recent meta-analysis of the literature by Deci, Koestner, and Ryan (1999) shows pervasive negative effects of reward. The purpose of the present article is to resolve differences in previous meta-analytic findings and to provide a meta-analysis of rewards and intrinsic motivation that permits tests of competing theoretical explanations. Our results suggest that in general, rewards are not harmful to motivation to perform a task. Rewards given for low-interest tasks enhance free-choice intrinsic motivation. On high-interest tasks, verbal rewards produce positive effects on free-choice motivation and self-reported task interest. Negative effects are found on high-interest tasks when the rewards are tangible, expected (offered beforehand), and loosely tied to level of performance. When rewards are linked to level of performance, measures of intrinsic motivation increase or do not differ from a nonrewarded control group. Overall, the pattern of results indicates that reward contingencies do not have pervasive negative effects on intrinsic motivation. Theoretical and practical implications of the findings are addressed.

The role of reward and reward uncertainty in episodic memory

OpenAIRE

Mason, Alice; Farrell, Simon; Howard-Jones, Paul; Ludwig, Casimir

2017-01-01

Declarative memory has been found to be sensitive to reward-related changes in the environment. The reward signal can be broken down into information regarding the expected value of the reward, reward uncertainty and the prediction error. Research has established that high as opposed to low reward values enhance declarative memory. Research in neuroscience suggests that high uncertainty activates the reward system, which could lead to enhanced learning and memory. Here we present the results ...

Registered nurses' perceptions of rewarding and its significance.

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Seitovirta, Jaana; Lehtimäki, Aku-Ville; Vehviläinen-Julkunen, Katri; Mitronen, Lasse; Kvist, Tarja

2017-11-07

To examine reward type preferences and their relationships with the significance of rewarding perceived by registered nurses in Finland. Previous studies have found relationships between nurses' rewarding and their motivation at work, job satisfaction and organisational commitment. Data were collected in a cross-sectional, descriptive, questionnaire survey from 402 registered nurses using the Registered Nurses' Perceptions of Rewarding Scale in 2015, and analysed with descriptive and multivariate statistical methods. Registered nurses assigned slightly higher values to several non-financial than to financial rewards. The non-financial reward types appreciation and feedback from work community, worktime arrangements, work content, and opportunity to develop, influence and participate were highly related to the significance of rewarding. We identified various rewards that registered nurses value, and indications that providing an appropriate array of rewards, particularly non-financial rewards, is a highly beneficial element of nursing management. It is important to understand the value of rewards for nursing management. Nurse managers should offer diverse rewards to their registered nurses to promote excellent performance and to help efforts to secure and maintain high-quality, safe patient care. The use of appropriate rewards is especially crucial to improving registered nurses' reward satisfaction and job satisfaction globally in the nursing profession. © 2017 John Wiley & Sons Ltd.

Reward guides vision when it's your thing: trait reward-seeking in reward-mediated visual priming.

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Clayton Hickey

Full Text Available Reward-related mesolimbic dopamine is thought to play an important role in guiding animal behaviour, biasing approach towards potentially beneficial environmental stimuli and away from objects unlikely to garner positive outcome. This is considered to result in part from an impact on perceptual and attentional processes: dopamine initiates a series of cognitive events that result in the priming of reward-associated perceptual features. We have provided behavioural and electrophysiological evidence that this mechanism guides human vision in search, an effect we refer to as reward priming. We have also demonstrated that there is substantial individual variability in this effect. Here we show that behavioural differences in reward priming are predicted remarkably well by a personality index that captures the degree to which a person's behaviour is driven by reward outcome. Participants with reward-seeking personalities are found to be those who allocate visual resources to objects characterized by reward-associated visual features. These results add to a rapidly developing literature demonstrating the crucial role reward plays in attentional control. They additionally illustrate the striking impact personality traits can have on low-level cognitive processes like perception and selective attention.

Modeling effects of intrinsic and extrinsic rewards on the competition between striatal learning systems

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Joschka eBoedecker

2013-10-01

Full Text Available A common assumption in psychology, economics, and other fields holds that higher performance will result if extrinsic rewards (such as money are offered as an incentive. While this principle seems to work well for tasks that require the execution of the same sequence of steps over and over, with little uncertainty about the process, in other cases, especially where creative problem solving is required due to the difficulty in finding the optimal sequence of actions, external rewards can actually be detrimental to task performance. Furthermore, they have the potential to undermine intrinsic motivation to do an otherwise interesting activity. In this work, we extend a computational model of the prefrontal and dorsolateral striatal reinforcement learning systems to account for the effects of extrinsic and intrinsic rewards. The model assumes that the brain employs both a goal-directed and a habitual learning system, and competition between both is based on the trade-off between the cost of the reasoning process and value of information. The goal-directed system elicits internal rewards when its models of the environment improve, while the habitual system, being model-free, does not. Our results account for the phenomena that initial extrinsic reward leads to reduced activity after extinction compared to the case without any initial extrinsic rewards, and that performance in complex task settings drops when higher external rewards are promised. We also test the hypothesis that external rewards bias the competition in favor of the computationally efficient, but cruder and less flexible habitual system, which can negatively influence intrinsic motivation and task performance in the class of tasks we consider.

Modeling effects of intrinsic and extrinsic rewards on the competition between striatal learning systems.

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Boedecker, Joschka; Lampe, Thomas; Riedmiller, Martin

2013-01-01

A common assumption in psychology, economics, and other fields holds that higher performance will result if extrinsic rewards (such as money) are offered as an incentive. While this principle seems to work well for tasks that require the execution of the same sequence of steps over and over, with little uncertainty about the process, in other cases, especially where creative problem solving is required due to the difficulty in finding the optimal sequence of actions, external rewards can actually be detrimental to task performance. Furthermore, they have the potential to undermine intrinsic motivation to do an otherwise interesting activity. In this work, we extend a computational model of the dorsomedial and dorsolateral striatal reinforcement learning systems to account for the effects of extrinsic and intrinsic rewards. The model assumes that the brain employs both a goal-directed and a habitual learning system, and competition between both is based on the trade-off between the cost of the reasoning process and value of information. The goal-directed system elicits internal rewards when its models of the environment improve, while the habitual system, being model-free, does not. Our results account for the phenomena that initial extrinsic reward leads to reduced activity after extinction compared to the case without any initial extrinsic rewards, and that performance in complex task settings drops when higher external rewards are promised. We also test the hypothesis that external rewards bias the competition in favor of the computationally efficient, but cruder and less flexible habitual system, which can negatively influence intrinsic motivation and task performance in the class of tasks we consider.

A focus on reward in anorexia nervosa through the lens of the activity-based anorexia rodent model.

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Foldi, C J; Milton, L K; Oldfield, B J

2017-10-01

Patients suffering anorexia nervosa (AN) become anhedonic, unable or unwilling to derive normal pleasures and tend to avoid rewarding outcomes, most profoundly in food intake. The activity-based anorexia model recapitulates many of the pathophysiological and behavioural hallmarks of the human condition, including a reduction in food intake, excessive exercise, dramatic weight loss, loss of reproductive cycles, hypothermia and anhedonia, and therefore it allows investigation into the underlying neurobiology of anorexia nervosa. The use of this model has directed attention to disruptions in central reward neurocircuitry, which may contribute to disease susceptibility. The purpose of this review is to demonstrate the utility of this unique model to provide insight into the mechanisms of reward relevant to feeding and weight loss, which may ultimately help to unravel the neurobiology of anorexia nervosa and, in a broader sense, the foundation of reward-based feeding. © 2017 British Society for Neuroendocrinology.

PENGARUH GAYA KEPEMIMPINAN, KOMITMEN, ORGANISASI, KUALITAS SUMBER DAYA, REWARD, DAN PUNISHMENT TERHADAP ANGGARAN BERBASIS KINERJA (Studi Empirik Pada Pemerintah Kabupaten Lombok Barat

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Syarifah Massuki Fitri

2014-07-01

Full Text Available Penelitian ini bertujuan untuk menguji secara empiris pengaruh gaya kepemimpinan, komitmen organisasi, kualitas sumber daya, reward dan punishment terhadap implementasi anggaran berbasis kinerja pada Pemerintahan Kabupaten Lombok Barat. Pengambilan sampel dilakukan dengan metode purposive sampling. Metode analisis yang digunakan adalah regresi linier berganda. Hasil dari pengujian hipotesis di dalam penelitian ini menunjukkan bahwa gaya kepemimpinan berpengaruh negatif dan signifikan terhadap anggaran berbasis kinerja. Kualitas sumber daya dan reward berpengaruh signifikan terhadap anggaran berbasis kinerja. Komitmen organisasi dan punishment tidak berpengaruh terhadap anggaran berbasis kinerja. Secara simultan, gaya kepemimpinan, komitmen seluruh komponen organisasi, kualitas sumber daya, reward, dan punishment berpengaruh positif dan signifikan terhadap anggaran berbasis kinerja pada pemerintahan kabupaten Lombok Barat. This research aims to empirically examine the influance of Leadership Style, Organization Commitment, Quality of Resources, Reward, and Punishment regarding the implementation of Performance-Based Budgeting in the West Lombok Regency. Sampling was done with the purposive sampling. Analysis method the used is multiple linear regression. Results of hypothesis testing in this study indicate that leadership style has negative and significant impact of performance-based budgeting. Quality of Resources and reward has positive and significant impact of performance-based budgeting. While, Organization Commitment and Punishment not influence on the implementation of performance-based budgeting in the West Lombok Regency. Simultaneously, Leadership Style, Organization Commitment, Quality of Resources, Reward, and Punishment have a positive and significant influence on the implementation of performance-based budgeting in the West Lombok Regency.

Specificity of Reward Sensitivity and Parasympathetic-Based Regulation among Children with Attention-Deficit/Hyperactivity and Disruptive Behavior Disorders.

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Tenenbaum, Rachel B; Musser, Erica D; Raiker, Joseph S; Coles, Erika K; Gnagy, Elizabeth M; Pelham, William E

2018-07-01

Attention-deficit/hyperactivity disorder (ADHD) is associated with disruptionsin reward sensitivity and regulatory processes. However, it is unclear whether thesedisruptions are better explained by comorbid disruptive behavior disorder (DBD)symptomology. This study sought to examine this question using multiple levels ofanalysis (i.e., behavior, autonomic reactivity). One hundred seventeen children (aged 6 to 12 years; 72.6% male; 69 with ADHD) completed theBalloon-Analogue Risk Task (BART) to assess external reward sensitivity behaviorally.Sympathetic-based internal reward sensitivity and parasympathetic-based regulationwere indexed via cardiac pre-ejection period (PEP) and respiratory sinus arrhythmia(RSA), respectively. Children with ADHD exhibited reduced internal reward sensitivity (i.e.,lengthened PEP; F(1,112)=4.01, p=0.047) compared to healthy controls and werecharacterized by greater parasympathetic-based dysregulation (i.e., reduced RSAaugmentation F(1,112)=10.12, p=0.002). However, follow-up analyses indicated theADHD effect was better accounted for by comorbid DBD diagnoses; that is, childrenwith ADHD and comorbid ODD were characterized by reduced internal rewardsensitivity (i.e., lengthened PEP; t=2.47, p=0.046) and by parasympathetic-baseddysregulation (i.e., reduced RSA augmentation; t=3.51, p=0.002) in response to rewardwhen compared to typically developing youth. Furthermore, children with ADHD and comorbid CD exhibited greater behaviorally-based external reward sensitivity (i.e.,more total pops; F(3,110)= 5.96, p=0.001) compared to children with ADHD only (t=3.87, p=0.001) and children with ADHD and ODD (t=3.56, p=0.003). Results suggest that disruptions in sensitivity to reward may be betteraccounted for, in part, by comorbid DBD.Key Words: attention-deficit/hyperactivity disorder, autonomic nervous system,disruptive behavior disorders, reward sensitivityPowered.

The brain correlates of the effects of monetary and verbal rewards on intrinsic motivation

OpenAIRE

Albrecht, Konstanze; Abeler, Johannes; Weber, Bernd; Falk, Armin

2014-01-01

Apart from everyday duties, such as doing the laundry or cleaning the house, there are tasks we do for pleasure and enjoyment. We do such tasks, like solving crossword puzzles or reading novels, without any external pressure or force; instead, we are intrinsically motivated: we do the tasks because we enjoy doing them. Previous studies suggest that external rewards, i.e., rewards from the outside, affect the intrinsic motivation to engage in a task: while performance-based monetary rewards ar...

THE BRAIN CORRELATES OF THE EFFECTS OF MONETARY AND VERBAL REWARDS ON INTRINSIC MOTIVATION

OpenAIRE

Konstanze eAlbrecht; Johannes eAbeler; Bernd eWeber; Bernd eWeber; Armin eFalk; Armin eFalk

2014-01-01

Apart from everyday duties, such as doing the laundry or cleaning the house, there are tasks we do for pleasure and enjoyment. We do such tasks, like solving crossword puzzles or reading novels, without any external pressure or force; instead, we are intrinsically motivated: We do the tasks because we enjoy doing them. Previous studies suggest that external rewards, i.e., rewards from the outside, affect the intrinsic motivation to engage in a task: While performance-based monetary rewards ar...

Listening to music in a risk-reward context: The roles of the temporoparietal junction and the orbitofrontal/insular cortices in reward-anticipation, reward-gain, and reward-loss.

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Li, Chia-Wei; Chen, Jyh-Horng; Tsai, Chen-Gia

2015-12-10

Artificial rewards, such as visual arts and music, produce pleasurable feelings. Popular songs in the verse-chorus form provide a useful model for understanding the neural mechanisms underlying the processing of artificial rewards, because the chorus is usually the most rewarding element of a song. In this functional magnetic resonance imaging (fMRI) study, the stimuli were excerpts of 10 popular songs with a tensioned verse-to-chorus transition. We examined the neural correlates of three phases of reward processing: (1) reward-anticipation during the verse-to-chorus transition, (2) reward-gain during the first phrase of the chorus, and (3) reward-loss during the unexpected noise followed by the verse-to-chorus transition. Participants listened to these excerpts in a risk-reward context because the verse was followed by either the chorus or noise with equal probability. The results showed that reward-gain and reward-loss were associated with left- and right-biased temporoparietal junction activation, respectively. The bilateral temporoparietal junctions were active during reward-anticipation. Moreover, we observed left-biased lateral orbitofrontal activation during reward-anticipation, whereas the medial orbitofrontal cortex was activated during reward-gain. The findings are discussed in relation to the cognitive and emotional aspects of reward processing. Copyright © 2015 Elsevier B.V. All rights reserved.

A Stochastic Hybrid Systems framework for analysis of Markov reward models

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Dhople, S.V.; DeVille, L.; Domínguez-García, A.D.

2014-01-01

In this paper, we propose a framework to analyze Markov reward models, which are commonly used in system performability analysis. The framework builds on a set of analytical tools developed for a class of stochastic processes referred to as Stochastic Hybrid Systems (SHS). The state space of an SHS is comprised of: (i) a discrete state that describes the possible configurations/modes that a system can adopt, which includes the nominal (non-faulty) operational mode, but also those operational modes that arise due to component faults, and (ii) a continuous state that describes the reward. Discrete state transitions are stochastic, and governed by transition rates that are (in general) a function of time and the value of the continuous state. The evolution of the continuous state is described by a stochastic differential equation and reward measures are defined as functions of the continuous state. Additionally, each transition is associated with a reset map that defines the mapping between the pre- and post-transition values of the discrete and continuous states; these mappings enable the definition of impulses and losses in the reward. The proposed SHS-based framework unifies the analysis of a variety of previously studied reward models. We illustrate the application of the framework to performability analysis via analytical and numerical examples

Changes in Incentives, Rewards and Sanctions.

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Lonsdale, Alan

1993-01-01

A review of the literature over the past decade reflects substantial changes in rewards, incentives, and sanctions used with college faculty. These changes parallel changes in the public sector generally. Increasing emphasis on formal evaluation and on use of money as an incentive and reward for performance is noted. (MSE)

A Dynamic Connectome Supports the Emergence of Stable Computational Function of Neural Circuits through Reward-Based Learning.

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Kappel, David; Legenstein, Robert; Habenschuss, Stefan; Hsieh, Michael; Maass, Wolfgang

2018-01-01

Synaptic connections between neurons in the brain are dynamic because of continuously ongoing spine dynamics, axonal sprouting, and other processes. In fact, it was recently shown that the spontaneous synapse-autonomous component of spine dynamics is at least as large as the component that depends on the history of pre- and postsynaptic neural activity. These data are inconsistent with common models for network plasticity and raise the following questions: how can neural circuits maintain a stable computational function in spite of these continuously ongoing processes, and what could be functional uses of these ongoing processes? Here, we present a rigorous theoretical framework for these seemingly stochastic spine dynamics and rewiring processes in the context of reward-based learning tasks. We show that spontaneous synapse-autonomous processes, in combination with reward signals such as dopamine, can explain the capability of networks of neurons in the brain to configure themselves for specific computational tasks, and to compensate automatically for later changes in the network or task. Furthermore, we show theoretically and through computer simulations that stable computational performance is compatible with continuously ongoing synapse-autonomous changes. After reaching good computational performance it causes primarily a slow drift of network architecture and dynamics in task-irrelevant dimensions, as observed for neural activity in motor cortex and other areas. On the more abstract level of reinforcement learning the resulting model gives rise to an understanding of reward-driven network plasticity as continuous sampling of network configurations.

Measuring and modeling the interaction among reward size, delay to reward, and satiation level on motivation in monkeys.

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Minamimoto, Takafumi; La Camera, Giancarlo; Richmond, Barry J

2009-01-01

Motivation is usually inferred from the likelihood or the intensity with which behavior is carried out. It is sensitive to external factors (e.g., the identity, amount, and timing of a rewarding outcome) and internal factors (e.g., hunger or thirst). We trained macaque monkeys to perform a nonchoice instrumental task (a sequential red-green color discrimination) while manipulating two external factors: reward size and delay-to-reward. We also inferred the state of one internal factor, level of satiation, by monitoring the accumulated reward. A visual cue indicated the forthcoming reward size and delay-to-reward in each trial. The fraction of trials completed correctly by the monkeys increased linearly with reward size and was hyperbolically discounted by delay-to-reward duration, relations that are similar to those found in free operant and choice tasks. The fraction of correct trials also decreased progressively as a function of the satiation level. Similar (albeit noiser) relations were obtained for reaction times. The combined effect of reward size, delay-to-reward, and satiation level on the proportion of correct trials is well described as a multiplication of the effects of the single factors when each factor is examined alone. These results provide a quantitative account of the interaction of external and internal factors on instrumental behavior, and allow us to extend the concept of subjective value of a rewarding outcome, usually confined to external factors, to account also for slow changes in the internal drive of the subject.

THE BRAIN CORRELATES OF THE EFFECTS OF MONETARY AND VERBAL REWARDS ON INTRINSIC MOTIVATION

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Konstanze eAlbrecht

2014-09-01

Full Text Available Apart from everyday duties, such as doing the laundry or cleaning the house, there are tasks we do for pleasure and enjoyment. We do such tasks, like solving crossword puzzles or reading novels, without any external pressure or force; instead, we are intrinsically motivated: We do the tasks because we enjoy doing them. Previous studies suggest that external rewards, i.e., rewards from the outside, affect the intrinsic motivation to engage in a task: While performance-based monetary rewards are perceived as controlling and induce a business-contract framing, verbal rewards praising one’s competence can enhance the perceived self-determination. Accordingly, the former have been shown to decrease intrinsic motivation, whereas the latter have been shown to increase intrinsic motivation. The present study investigated the neural processes underlying the effects of monetary and verbal rewards on intrinsic motivation in a group of 64 subjects applying functional magnetic resonance imaging (fMRI. We found that, when participants received positive performance feedback, activation in the anterior striatum and midbrain was affected by the nature of the reward; compared to a non-rewarded control group, activation was higher while monetary rewards were administered. However, we did not find a decrease in activation after reward withdrawal. In contrast, we found an increase in activation for verbal rewards: After verbal rewards had been withdrawn, participants showed a higher activation in the aforementioned brain areas when they received success compared to failure feedback. We further found that, while participants worked on the task, activation in the lateral prefrontal cortex was enhanced after the verbal rewards were administered and withdrawn.

Reward associations impact both iconic and visual working memory.

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Infanti, Elisa; Hickey, Clayton; Turatto, Massimo

2015-02-01

Reward plays a fundamental role in human behavior. A growing number of studies have shown that stimuli associated with reward become salient and attract attention. The aim of the present study was to extend these results into the investigation of iconic memory and visual working memory. In two experiments we asked participants to perform a visual-search task where different colors of the target stimuli were paired with high or low reward. We then tested whether the pre-established feature-reward association affected performance on a subsequent visual memory task, in which no reward was provided. In this test phase participants viewed arrays of 8 objects, one of which had unique color that could match the color associated with reward during the previous visual-search task. A probe appeared at varying intervals after stimulus offset to identify the to-be-reported item. Our results suggest that reward biases the encoding of visual information such that items characterized by a reward-associated feature interfere with mnemonic representations of other items in the test display. These results extend current knowledge regarding the influence of reward on early cognitive processes, suggesting that feature-reward associations automatically interact with the encoding and storage of visual information, both in iconic memory and visual working memory. Copyright © 2014 Elsevier Ltd. All rights reserved.

Self-choice enhances value in reward-seeking in primates.

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Setogawa, Tsuyoshi; Mizuhiki, Takashi; Matsumoto, Narihisa; Akizawa, Fumika; Shidara, Munetaka

2014-03-01

When an individual chooses one item from two or more alternatives, they compare the values of the expected outcomes. The outcome value can be determined by the associated reward amount, the probability of reward, and the workload required to earn the reward. Rational choice theory states that choices are made to maximize rewards over time, and that the same outcome values lead to an equal likelihood of choices. However, the theory does not distinguish between conditions with the same reward value, even when acquired under different circumstances, and does not always accurately describe real behavior. We have found that allowing a monkey to choose a reward schedule endows the schedule with extra value when compared to performance in an identical schedule that is chosen by another agent (a computer here). This behavior is not consistent with pure rational choice theory. Theoretical analysis using a modified temporal-difference learning model showed an enhanced schedule state value by self-choice. These results suggest that an increased reward value underlies the improved performances by self-choice during reward-seeking behavior. Copyright © 2014 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Employee Reward Systems in Organizations

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Došenović Dragana

2016-06-01

Full Text Available Employee rewarding is one of the activities of human resource management concerning the management of money, goods and services that employees receive from their employer in exchange for their work. Given that a properly designed reward system is one of the conditions for a stable business, successful performance of work activities and the achievement of set objectives in each organization, the basic theme of this paper is the employee reward system, with a special focus on different elements of it. The purpose of this paper is to describe the role and significance of the observed system and to draw attention to its role in employee’s motivation.

Reward deficiency and anti-reward in pain chronification.

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Borsook, D; Linnman, C; Faria, V; Strassman, A M; Becerra, L; Elman, I

2016-09-01

Converging lines of evidence suggest that the pathophysiology of pain is mediated to a substantial degree via allostatic neuroadaptations in reward- and stress-related brain circuits. Thus, reward deficiency (RD) represents a within-system neuroadaptation to pain-induced protracted activation of the reward circuits that leads to depletion-like hypodopaminergia, clinically manifested anhedonia, and diminished motivation for natural reinforcers. Anti-reward (AR) conversely pertains to a between-systems neuroadaptation involving over-recruitment of key limbic structures (e.g., the central and basolateral amygdala nuclei, the bed nucleus of the stria terminalis, the lateral tegmental noradrenergic nuclei of the brain stem, the hippocampus and the habenula) responsible for massive outpouring of stressogenic neurochemicals (e.g., norepinephrine, corticotropin releasing factor, vasopressin, hypocretin, and substance P) giving rise to such negative affective states as anxiety, fear and depression. We propose here the Combined Reward deficiency and Anti-reward Model (CReAM), in which biopsychosocial variables modulating brain reward, motivation and stress functions can interact in a 'downward spiral' fashion to exacerbate the intensity, chronicity and comorbidities of chronic pain syndromes (i.e., pain chronification). Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Reward-dependent modulation of working memory in lateral prefrontal cortex.

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Kennerley, Steven W; Wallis, Jonathan D

2009-03-11

Although research implicates lateral prefrontal cortex (PFC) in executive control and goal-directed behavior, it remains unclear how goals influence executive processes. One possibility is that goal-relevant information, such as expected rewards, could modulate the representation of information relating to executive control, thereby ensuring the efficient allocation of cognitive resources. To investigate this, we examined how reward modulated spatial working memory. Past studies investigating spatial working memory have focused on dorsolateral PFC, but this area only weakly connects with areas processing reward. Ventrolateral PFC has better connections in this regard. Thus, we contrasted the functional properties of single neurons in ventrolateral and dorsolateral PFC as two subjects performed a task that required them to hold spatial information in working memory under different expectancies of reward for correct performance. We balanced the order of presentation of spatial and reward information so we could assess the neuronal encoding of the two pieces of information independently and conjointly. Neurons in ventrolateral PFC encoded both spatial and reward information earlier, stronger and in a more sustained manner than neurons in dorsolateral PFC. Within ventrolateral PFC, spatial selectivity was more prevalent on the inferior convexity than within the principal sulcus. Finally, when reward increased spatial selectivity, behavioral performance improved, whereas when reward decreased spatial selectivity, behavioral performance deteriorated. These results suggest that ventrolateral PFC may be a locus whereby information about expected rewards can modulate information in working memory. The pattern of results is consistent with a role for ventrolateral PFC in attentional control.

The circadian clock, reward and memory

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Urs eAlbrecht

2011-11-01

Full Text Available During our daily activities, we experience variations in our cognitive performance, which is often accompanied by cravings for small rewards, such as consuming coffee or chocolate. This indicates that the time of day, cognitive performance and reward may be related to one another. This review will summarize data that describes the influence of the circadian clock on addiction and mood-related behavior and put the data into perspective in relation to memory processes.

A test of the reward-value hypothesis.

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Smith, Alexandra E; Dalecki, Stefan J; Crystal, Jonathon D

2017-03-01

Rats retain source memory (memory for the origin of information) over a retention interval of at least 1 week, whereas their spatial working memory (radial maze locations) decays within approximately 1 day. We have argued that different forgetting functions dissociate memory systems. However, the two tasks, in our previous work, used different reward values. The source memory task used multiple pellets of a preferred food flavor (chocolate), whereas the spatial working memory task provided access to a single pellet of standard chow-flavored food at each location. Thus, according to the reward-value hypothesis, enhanced performance in the source memory task stems from enhanced encoding/memory of a preferred reward. We tested the reward-value hypothesis by using a standard 8-arm radial maze task to compare spatial working memory accuracy of rats rewarded with either multiple chocolate or chow pellets at each location using a between-subjects design. The reward-value hypothesis predicts superior accuracy for high-valued rewards. We documented equivalent spatial memory accuracy for high- and low-value rewards. Importantly, a 24-h retention interval produced equivalent spatial working memory accuracy for both flavors. These data are inconsistent with the reward-value hypothesis and suggest that reward value does not explain our earlier findings that source memory survives unusually long retention intervals.

Reward inference by primate prefrontal and striatal neurons.

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Pan, Xiaochuan; Fan, Hongwei; Sawa, Kosuke; Tsuda, Ichiro; Tsukada, Minoru; Sakagami, Masamichi

2014-01-22

The brain contains multiple yet distinct systems involved in reward prediction. To understand the nature of these processes, we recorded single-unit activity from the lateral prefrontal cortex (LPFC) and the striatum in monkeys performing a reward inference task using an asymmetric reward schedule. We found that neurons both in the LPFC and in the striatum predicted reward values for stimuli that had been previously well experienced with set reward quantities in the asymmetric reward task. Importantly, these LPFC neurons could predict the reward value of a stimulus using transitive inference even when the monkeys had not yet learned the stimulus-reward association directly; whereas these striatal neurons did not show such an ability. Nevertheless, because there were two set amounts of reward (large and small), the selected striatal neurons were able to exclusively infer the reward value (e.g., large) of one novel stimulus from a pair after directly experiencing the alternative stimulus with the other reward value (e.g., small). Our results suggest that although neurons that predict reward value for old stimuli in the LPFC could also do so for new stimuli via transitive inference, those in the striatum could only predict reward for new stimuli via exclusive inference. Moreover, the striatum showed more complex functions than was surmised previously for model-free learning.

Reward anticipation modulates the effect of stress-related increases in cortisol on episodic memory.

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Quent, Jörn A; McCullough, Andrew M; Sazma, Matt; Wolf, Oliver T; Yonelinas, Andrew P

2018-01-01

When acute stress is experienced shortly after an event is encoded into memory, this can slow the forgetting of the study event, which is thought to reflect the effect of cortisol on consolidation. In addition, when events are encoded under conditions of high reward they tend to be remembered better than those encoded under non-rewarding conditions, and these effects are thought to reflect the operation of the dopaminergic reward system. Although both modulatory systems are believed to impact the medial temporal lobe regions critical for episodic memory, the manner, and even the extent, to which these two systems interact is currently unknown. To address this question in the current study, participants encoded words under reward or non-reward conditions, then one half of the participants were stressed using the social evaluation cold pressor task and the other half completed a non-stress control task. After a two-hour delay, all participants received a free recall and recognition memory test. There were no significant effects of stress or reward on overall memory performance. However, for the non-reward items, increases in stress-related cortisol in stressed participants were related to increases in recall and increases in recollection-based recognition responses. In contrast, for the reward items, increases in stress-related cortisol were not related to increases in memory performance. The results indicate that the stress and the reward systems interact in the way they impact episodic memory. The results are consistent with tag and capture models in the sense that cortisol reactivity can only affect non-reward items because plasticity-related products are already provided by reward anticipation. Copyright © 2017 Elsevier Inc. All rights reserved.

Impact of the Reward System and of the Access to Information on Individual Performance in Psychological Empowerment and its Effect on the Management Effectiveness of a Multinational Company

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Sabrina do Nascimento

2014-04-01

Full Text Available The goal of this study is to investigate the impact of the variables reward system and access to information on individual performance (background in the psychological empowerment according to the model of Spreitzer (1995, and its effect on managerial effectiveness (consequent as measured by the achievement of goals set out in the reward system in a multinational company. The study is based on the psychological empowerment conceptual model of Spreitzer (1995 and its structure uses two independent variables (reward system and access to information as input and a consequent variable (managerial effectiveness as output. The construct of the research is consists of operationalizations done by Spreitzer (1995 and Lawler III (2003. A descriptive research with quantitative approach was performed on a multinational company of American origin, with a factory plant located in southern Brazil. The questionnaire sent to employees of this plant was adapted from Spreitzer (1995, and contains 24 multiple choice questions of seven points in Likert scale. In the data analysis, the statistical technique of linear regression was applied using the Statistical Package for Social Sciences (SPSS. The survey results show the presence of dimensions of the competence, meaning, impact and self-determination of psychological empowerment. The company's managerial effectiveness, as measured by the achievement of goals established in the reward system, showed no significant relationship with the psychological empowerment dimensions. It was conclude that the reward system and the access to information on individual performance impact on the psychological empowerment and are reflected partly in the company's managerial effectiveness.

Rewards, Intrinsic Motivation, and Achievement in Intact Classrooms

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Luis, Melissa Ann

2011-01-01

The purpose of this study was to examine the effects of performance-contingent rewards in a real-world setting, namely the sixth grade math classroom. This study is significant in that it represents a field study on the effects of rewards in the classroom. The purpose of this study was to investigate what effect, if any, the choice of a reward had…

Multiple variables explain the variability in the decrement in VO2max during acute hypobaric hypoxia.

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Robergs, R A; Quintana, R; Parker, D L; Frankel, C C

1998-06-01

We used multiple regression analyses to determine the relationships between the decrement in sea level (SL, 760 Torr) VO2max during hypobaric hypoxia (HH) and variables that could alter or be related to the decrement in VO2max. HH conditions consisted of 682 Torr, 632 Torr, and 566 Torr, and the measured independent variables were SL-VO2max, SL lactate threshold (SL-LT), the change in hemoglobin saturation at VO2max between 760 and 566 Torr (delta SaO2max), lean body mass (LBM), and gender. Male (N = 14) and female (N = 14) subjects of varied fitness, training status, and residential altitude (1,640-2,460 m) completed cycle ergometry tests of VO2max at each HH condition under randomized and single-blinded conditions. VO2max decreased significantly from 760 Torr after 682 Torr (approximately 915 m) (3.5 +/- 0.9 to 3.4 +/- 0.8 L.min-1, P = 0.0003). Across all HH conditions, the slope of the relative decrement in VO2max (%VO2max) during HH was -9.2%/100 mm Hg (-8.1%/1000 m) with an initial decrease from 100% estimated to occur below 705 Torr (610 m). Step-wise multiple regression revealed that SL-VO2max, SL-LT, delta SaO2max, LBM, and gender each significantly combined to account for 89.03% of the variance in the decrement in VO2max (760-566 Torr) (P decrement in VO2max during HH. The unique variance explanation afforded by SL-LT, LBM, and gender suggests that issues pertaining to oxygen diffusion within skeletal muscle may add to the explanation of between subjects variability in the decrement in VO2max during HH.

Influence of reward motivation on human declarative memory.

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Miendlarzewska, Ewa A; Bavelier, Daphne; Schwartz, Sophie

2016-02-01

Motivational relevance can prioritize information for memory encoding and consolidation based on reward value. In this review, we pinpoint the possible psychological and neural mechanisms by which reward promotes learning, from guiding attention to enhancing memory consolidation. We then discuss how reward value can spill-over from one conditioned stimulus to a non-conditioned stimulus. Such generalization can occur across perceptually similar items or through more complex relations, such as associative or logical inferences. Existing evidence suggests that the neurotransmitter dopamine boosts the formation of declarative memory for rewarded information and may also control the generalization of reward values. In particular, temporally-correlated activity in the hippocampus and in regions of the dopaminergic circuit may mediate value-based decisions and facilitate cross-item integration. Given the importance of generalization in learning, our review points to the need to study not only how reward affects later memory but how learned reward values may generalize to related representations and ultimately alter memory structure. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Commonality Between Approaches to Determine Jump Fatigue During Basketball Activity in Junior Players: In-Game Versus Across-Game Decrements.

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Scanlan, Aaron T; Fox, Jordan L; Borges, Nattai R; Dalbo, Vincent J

2017-02-01

Declines in high-intensity activity during game play (in-game approach) and performance tests measured pre- and postgame (across-game approach) have been used to assess player fatigue in basketball. However, a direct comparison of these approaches is not available. Consequently, this study examined the commonality between in- and across-game jump fatigue during simulated basketball game play. Australian, state-level, junior male basketball players (n = 10; 16.6 ± 1.1 y, 182.4 ± 4.3 cm, 68.3 ± 10.2 kg) completed 4 × 10-min standardized quarters of simulated basketball game play. In-game jump height during game play was measured using video analysis, while across-game jump height was determined pre-, mid-, and postgame play using an in-ground force platform. Jump height was determined using the flight-time method, with jump decrement calculated for each approach across the first half, second half, and entire game. A greater jump decrement was apparent for the in-game approach than for the across-game approach in the first half (37.1% ± 11.6% vs 1.7% ± 6.2%; P = .005; d = 3.81, large), while nonsignificant, large differences were evident between approaches in the second half (d = 1.14) and entire game (d = 1.83). Nonsignificant associations were evident between in-game and across-game jump decrement, with shared variances of 3-26%. Large differences and a low commonality were observed between in- and across-game jump fatigue during basketball game play, suggesting that these approaches measure different constructs. Based on our findings, it is not recommended that basketball coaches use these approaches interchangeably to monitor player fatigue across the season.

Reward modulation of hippocampal subfield activation during successful associative encoding and retrieval

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Wolosin, Sasha M.; Zeithamova, Dagmar; Preston, Alison R.

2012-01-01

Emerging evidence suggests that motivation enhances episodic memory formation through interactions between medial temporal lobe (MTL) structures and dopaminergic midbrain. In addition, recent theories propose that motivation specifically facilitates hippocampal associative binding processes, resulting in more detailed memories that are readily reinstated from partial input. Here, we used high-resolution functional magnetic resonance imaging to determine how motivation influences associative encoding and retrieval processes within human MTL subregions and dopaminergic midbrain. Participants intentionally encoded object associations under varying conditions of reward and performed a retrieval task during which studied associations were cued from partial input. Behaviorally, cued recall performance was superior for high-value relative to low-value associations; however, participants differed in the degree to which rewards influenced memory. The magnitude of behavioral reward modulation was associated with reward-related activation changes in dentate gyrus/CA2,3 during encoding and enhanced functional connectivity between dentate gyrus/CA2,3 and dopaminergic midbrain during both the encoding and retrieval phases of the task. These findings suggests that within the hippocampus, reward-based motivation specifically enhances dentate gyrus/CA2,3 associative encoding mechanisms through interactions with dopaminergic midbrain. Furthermore, within parahippocampal cortex and dopaminergic midbrain regions, activation associated with successful memory formation was modulated by reward across the group. During the retrieval phase, we also observed enhanced activation in hippocampus and dopaminergic midbrain for high-value associations that occurred in the absence of any explicit cues to reward. Collectively, these findings shed light on fundamental mechanisms through which reward impacts associative memory formation and retrieval through facilitation of MTL and VTA/SN processing

Decrement in operant performance produced by NMDA receptor antagonists in the rat: tolerance and cross-tolerance.

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Dravolina, O A; Zvartau, E E; Bespalov, A Y

2000-04-01

Current perspectives on the clinical use of NMDA receptor antagonists infer repeated administration schedules for the management of different pathological states. The development of tolerance and cross-tolerance between different NMDA receptor antagonists may be an important factor contributing to the clinical efficacy of these drugs. The present study aimed to characterize the development of tolerance and cross-tolerance to the ability of various site-selective NMDA receptor antagonists to produce a decrement of operant responding (multiple extinction 9 s fixed-interval 1-s schedule of water reinforcement). Acute administration of D-CPPen (SDZ EAA 494; 1-5.6 mg/kg), dizocilpine (MK-801; 0.03-0.3 mg/kg), memantine (0.3-17 mg/kg), ACEA-1021 (10-56 mg/kg), and eliprodil (1-30 mg/kg) differentially affected operant responding. Both increases and decreases in response rates and accuracy of responding were observed. Repeated preexposure to D-CPPen (5.6 mg/kg, once a day for 7 days) attenuated a behavioral disruption produced by an acute challenge with D-CPPen or ACEA-1021, but potentiated the effects of dizocilpine, memantine, and eliprodil. Based on the present results, one can suggest that the repeated administration of a competitive NMDA receptor antagonist differentially affects the functional activity of various sites on NMDA receptor complex.

Effects of monetary reward and punishment on information checking behaviour.

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Li, Simon Y W; Cox, Anna L; Or, Calvin; Blandford, Ann

2016-03-01

Two experiments were conducted to examine whether checking one's own work can be motivated by monetary reward and punishment. Participants were randomly assigned to one of three conditions: a flat-rate payment for completing the task (Control); payment increased for error-free performance (Reward); payment decreased for error performance (Punishment). Experiment 1 (N = 90) was conducted with liberal arts students, using a general data-entry task. Experiment 2 (N = 90) replicated Experiment 1 with clinical students and a safety-critical 'cover story' for the task. In both studies, Reward and Punishment resulted in significantly fewer errors, more frequent and longer checking, than Control. No such differences were obtained between the Reward and Punishment conditions. It is concluded that error consequences in terms of monetary reward and punishment can result in more accurate task performance and more rigorous checking behaviour than errors without consequences. However, whether punishment is more effective than reward, or vice versa, remains inconclusive. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Reward loss and the basolateral amygdala: A function in reward comparisons.

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Kawasaki, Katsuyoshi; Annicchiarico, Iván; Glueck, Amanda C; Morón, Ignacio; Papini, Mauricio R

2017-07-28

The neural circuitry underlying behavior in reward loss situations is poorly understood. We considered two such situations: reward devaluation (from large to small rewards) and reward omission (from large rewards to no rewards). There is evidence that the central nucleus of the amygdala (CeA) plays a role in the negative emotion accompanying reward loss. However, little is known about the function of the basolateral nucleus (BLA) in reward loss. Two hypotheses of BLA function in reward loss, negative emotion and reward comparisons, were tested in an experiment involving pretraining excitotoxic BLA lesions followed by training in four tasks: consummatory successive negative contrast (cSNC), autoshaping (AS) acquisition and extinction, anticipatory negative contrast (ANC), and open field testing (OF). Cell counts in the BLA (but not in the CeA) were significantly lower in animals with lesions vs. shams. BLA lesions eliminated cSNC and ANC, and accelerated extinction of lever pressing in AS. BLA lesions had no effect on OF testing: higher activity in the periphery than in the central area. This pattern of results provides support for the hypothesis that BLA neurons are important for reward comparison. The three affected tasks (cSNC, ANC, and AS extinction) involve reward comparisons. However, ANC does not seem to involve negative emotions and it was affected, whereas OF activity is known to involve negative emotion, but it was not affected. It is hypothesized that a circuit involving the thalamus, insular cortex, and BLA is critically involved in the mechanism comparing current and expected rewards. Copyright © 2017 Elsevier B.V. All rights reserved.

Adolescent development of context-dependent stimulus-reward association memory and its neural correlates.

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Voss, Joel L; O'Neil, Jonathan T; Kharitonova, Maria; Briggs-Gowan, Margaret J; Wakschlag, Lauren S

2015-01-01

Expression of learned stimulus-reward associations based on context is essential for regulation of behavior to meet situational demands. Contextual regulation improves during development, although the developmental progression of relevant neural and cognitive processes is not fully specified. We therefore measured neural correlates of flexible, contextual expression of stimulus-reward associations in pre/early-adolescent children (ages 9-13 years) and young adults (ages 19-22 years). After reinforcement learning using standard parameters, a contextual reversal manipulation was used whereby contextual cues indicated that stimulus-reward associations were the same as previously reinforced for some trials (consistent trials) or were reversed on other trials (inconsistent trials). Subjects were thus required to respond according to original stimulus-reward associations vs. reversed associations based on trial-specific contextual cues. Children and young adults did not differ in reinforcement learning or in relevant functional magnetic resonance imaging (fMRI) correlates. In contrast, adults outperformed children during contextual reversal, with better performance specifically for inconsistent trials. fMRI signals corresponding to this selective advantage included greater activity in lateral prefrontal cortex (LPFC), hippocampus, and dorsal striatum for young adults relative to children. Flexible expression of stimulus-reward associations based on context thus improves via adolescent development, as does recruitment of brain regions involved in reward learning and contextual expression of memory. HighlightsEarly-adolescent children and young adults were equivalent in reinforcement learning.Adults outperformed children in contextual expression of stimulus-reward associations.Adult advantages correlated with increased activity of relevant brain regions.Specific neurocognitive developmental changes support better contextual regulation.

Monetary reward magnitude effects on behavior and brain function during goal-directed behavior.

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Rosell-Negre, P; Bustamante, J C; Fuentes-Claramonte, P; Costumero, V; Benabarre, S; Barrós-Loscertales, A

2017-08-01

Reward may modulate the cognitive processes required for goal achievement, while individual differences in personality may affect reward modulation. Our aim was to test how different monetary reward magnitudes modulate brain activation and performance during goal-directed behavior, and whether individual differences in reward sensitivity affect this modulation. For this purpose, we scanned 37 subjects with a parametric design in which we varied the magnitude of monetary rewards (€0, €0.01, €0.5, €1 or €1.5) in a blocked fashion while participants performed an interference counting-Stroop condition. The results showed that the brain activity of left dorsolateral prefrontal cortex (DLPFC) and the striatum were modulated by increasing and decreasing reward magnitudes, respectively. Behavioral performance improved as the magnitude of monetary reward increased while comparing the non reward (€0) condition to any other reward condition, or the lower €0.01 to any other reward condition, and this improvement was related with individual differences in reward sensitivity. In conclusion, the locus of influence of monetary incentives overlaps the activity of the regions commonly involved in cognitive control.

Neural activation to monetary reward is associated with amphetamine reward sensitivity.

Science.gov (United States)

Crane, Natania A; Gorka, Stephanie M; Weafer, Jessica; Langenecker, Scott A; de Wit, Harriet; Phan, K Luan

2018-03-14

One known risk factor for drug use and abuse is sensitivity to rewarding effects of drugs. It is not known whether this risk factor extends to sensitivity to non-drug rewards. In this study with healthy young adults, we examined the association between sensitivity to the subjective rewarding effects of amphetamine and a neural indicator of anticipation of monetary reward. We hypothesized that greater euphorigenic response to amphetamine would be associated with greater neural activation to anticipation of monetary reward (Win > Loss). Healthy participants (N = 61) completed four laboratory sessions in which they received d-amphetamine (20 mg) and placebo in alternating order, providing self-report measures of euphoria and stimulation at regular intervals. At a separate visit 1-3 weeks later, participants completed the guessing reward task (GRT) during fMRI in a drug-free state. Participants reporting greater euphoria after amphetamine also exhibited greater neural activation during monetary reward anticipation in mesolimbic reward regions, including the bilateral caudate and putamen. This is the first study to show a relationship between neural correlates of monetary reward and sensitivity to the subjective rewarding effects of amphetamine in humans. These findings support growing evidence that sensitivity to reward in general is a risk factor for drug use and abuse, and suggest that sensitivity of drug-induced euphoria may reflect a general sensitivity to rewards. This may be an index of vulnerability for drug use or abuse.

Functional requirements for reward-modulated spike-timing-dependent plasticity.

Science.gov (United States)

Frémaux, Nicolas; Sprekeler, Henning; Gerstner, Wulfram

2010-10-06

Recent experiments have shown that spike-timing-dependent plasticity is influenced by neuromodulation. We derive theoretical conditions for successful learning of reward-related behavior for a large class of learning rules where Hebbian synaptic plasticity is conditioned on a global modulatory factor signaling reward. We show that all learning rules in this class can be separated into a term that captures the covariance of neuronal firing and reward and a second term that presents the influence of unsupervised learning. The unsupervised term, which is, in general, detrimental for reward-based learning, can be suppressed if the neuromodulatory signal encodes the difference between the reward and the expected reward-but only if the expected reward is calculated for each task and stimulus separately. If several tasks are to be learned simultaneously, the nervous system needs an internal critic that is able to predict the expected reward for arbitrary stimuli. We show that, with a critic, reward-modulated spike-timing-dependent plasticity is capable of learning motor trajectories with a temporal resolution of tens of milliseconds. The relation to temporal difference learning, the relevance of block-based learning paradigms, and the limitations of learning with a critic are discussed.

The effects of non-contingent extrinsic and intrinsic rewards on memory consolidation.

Science.gov (United States)

Nielson, Kristy A; Bryant, Ted

2005-07-01

Emotional and arousing treatments given shortly after learning enhance delayed memory retrieval in animal and human studies. Positive affect and reward induced prior to a variety of cognitive tasks enhance performance, but their ability to affect memory consolidation has not been investigated before. Therefore, we investigated the effects of a small, non-contingent, intrinsic or extrinsic reward on delayed memory retrieval. Participants (n=108) studied and recalled a list of 30 affectively neutral, imageable nouns. Experimental groups were then given either an intrinsic reward (e.g., praise) or an extrinsic reward (e.g., US 1 dollar). After a one-week delay, participants' retrieval performance for the word list was significantly better in the extrinsic reward groups, whether the reward was expected or not, than in controls. Those who received the intrinsic reward performed somewhat better than controls, but the difference was not significant. Thus, at least some forms of arousal and reward, even when semantically unrelated to the learned material, can effectively modulate memory consolidation. These types of treatments might be useful for the development of new memory intervention strategies.

Social reward improves the voluntary control over localized brain activity in fMRI-based neurofeedback training

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Krystyna Anna Mathiak

2015-06-01

Full Text Available Neurofeedback (NF based on real-time functional magnetic resonance imaging (rt-fMRI allows voluntary regulation of the activity in a selected brain region. For the training of this regulation, a well-designed feedback system is required. Social reward may serve as an effective incentive in NF paradigms, but its efficiency has not yet been tested. Therefore, we developed a social reward NF paradigm and assessed it in comparison with a typical visual NF paradigm (moving bar.We trained 24 healthy participants, on three consecutive days, to control activation in dorsal anterior cingulate cortex (ACC with fMRI-based NF. In the social feedback group, an avatar gradually smiled when ACC activity increased, whereas in the standard feedback group, a moving bar indicated the activation level. To assess a transfer of the NF training both groups were asked to up-regulate their brain activity without receiving feedback immediately before and after the NF training (pre- and post-test. Finally, the effect of the acquired NF training on ACC function was evaluated in a cognitive interference task (Simon task during the pre- and post-test.Social reward led to stronger activity in the ACC and reward-related areas during the NF training when compared to standard feedback. After the training, both groups were able to regulate ACC without receiving feedback, with a trend for stronger responses in the social feedback group. Moreover, despite a lack of behavioral differences, significant higher ACC activations emerged in the cognitive interference task, reflecting a stronger generalization of the NF training on cognitive interference processing after social feedback.Social reward can increase self-regulation in fMRI-based NF and strengthen its effects on neural processing in related tasks, such as cognitive interference. An advantage of social feedback is that a direct external reward is provided as in natural social interactions, opening perspectives for implicit

Learning to maximize reward rate: a model based on semi-Markov decision processes.

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Khodadadi, Arash; Fakhari, Pegah; Busemeyer, Jerome R

2014-01-01

WHEN ANIMALS HAVE TO MAKE A NUMBER OF DECISIONS DURING A LIMITED TIME INTERVAL, THEY FACE A FUNDAMENTAL PROBLEM: how much time they should spend on each decision in order to achieve the maximum possible total outcome. Deliberating more on one decision usually leads to more outcome but less time will remain for other decisions. In the framework of sequential sampling models, the question is how animals learn to set their decision threshold such that the total expected outcome achieved during a limited time is maximized. The aim of this paper is to provide a theoretical framework for answering this question. To this end, we consider an experimental design in which each trial can come from one of the several possible "conditions." A condition specifies the difficulty of the trial, the reward, the penalty and so on. We show that to maximize the expected reward during a limited time, the subject should set a separate value of decision threshold for each condition. We propose a model of learning the optimal value of decision thresholds based on the theory of semi-Markov decision processes (SMDP). In our model, the experimental environment is modeled as an SMDP with each "condition" being a "state" and the value of decision thresholds being the "actions" taken in those states. The problem of finding the optimal decision thresholds then is cast as the stochastic optimal control problem of taking actions in each state in the corresponding SMDP such that the average reward rate is maximized. Our model utilizes a biologically plausible learning algorithm to solve this problem. The simulation results show that at the beginning of learning the model choses high values of decision threshold which lead to sub-optimal performance. With experience, however, the model learns to lower the value of decision thresholds till finally it finds the optimal values.

Beyond Rewards

Science.gov (United States)

Hall, Philip S.

2009-01-01

Using rewards to impact students' behavior has long been common practice. However, using reward systems to enhance student learning conveniently masks the larger and admittedly more difficult task of finding and implementing the structure and techniques that children with special needs require to learn. More important, rewarding the child for good…

The impact of a total reward system of work engagement

Directory of Open Access Journals (Sweden)

Crystal Hoole

2016-11-01

Research purpose: The overall purpose of this study was to explore the relationship between total rewards and work engagement in a South African context and to determine which reward categories predict work engagement. The study further endeavoured to determine whether gender and age had a moderating effect on the relationship between total rewards and engagement. Motivation for the study: Statistics report that less than 30% of all working people are optimally engaged in their work. Considering that individuals spend more than a third of their lives at work committing themselves emotionally, physically and psychologically – research indicates that employees are no longer satisfied with traditional reward systems and want to feel valued and appreciated. Research approach, design and method: In this quantitative, cross-sectional research design using a non-probability convenience and purposive sampling strategy, 318 questionnaires were collected and analysed from financial institutions in Gauteng in which opinions were sought on the importance of different types of rewards structures and preferences, and how engaged they are in their workplace. The 17-item UWES and Nienaber total reward preference model were the chosen measuring instruments. Main findings: A small statistically significant correlation (r = 0.25; p < 0.05; small effect was found between total rewards and work engagement, and 12% of the variance of work engagement was explained. Only performance and career management significantly predicted work engagement. Practical/Managerial implications: Although small, the significant correlation between total rewards and work engagement implies that total rewards are important motivators for employees in the workplace. Of the total rewards scales tested, only performance and career management significantly predicted work engagement, suggesting that more research is needed. Organisations seeking to implement total reward strategies should pay specific

Random Decrement and Regression Analysis of Traffic Responses of Bridges

DEFF Research Database (Denmark)

Asmussen, J. C.; Ibrahim, S. R.; Brincker, Rune

1996-01-01

The topic of this paper is the estimation of modal parameters from ambient data by applying the Random Decrement technique. The data fro the Queensborough Bridge over the Fraser River in Vancouver, Canada have been applied. The loads producing the dynamic response are ambient, e. g. wind, traffic...

Random Decrement and Regression Analysis of Traffic Responses of Bridges

DEFF Research Database (Denmark)

Asmussen, J. C.; Ibrahim, S. R.; Brincker, Rune

The topic of this paper is the estimation of modal parameters from ambient data by applying the Random Decrement technique. The data from the Queensborough Bridge over the Fraser River in Vancouver, Canada have been applied. The loads producing the dynamic response are ambient, e.g. wind, traffic...

Extinction and renewal of cue-elicited reward-seeking.

Science.gov (United States)

Bezzina, Louise; Lee, Jessica C; Lovibond, Peter F; Colagiuri, Ben

2016-12-01

Reward cues can contribute to overconsumption of food and drugs and can relapse. The failure of exposure therapies to reduce overconsumption and relapse is generally attributed to the context-specificity of extinction. However, no previous study has examined whether cue-elicited reward-seeking (as opposed to cue-reactivity) is sensitive to context renewal. We tested this possibility in 160 healthy volunteers using a Pavlovian-instrumental transfer (PIT) design involving voluntary responding for a high value natural reward (chocolate). One reward cue underwent Pavlovian extinction in the same (Group AAA) or different context (Group ABA) to all other phases. This cue was compared with a second non-extinguished reward cue and an unpaired control cue. There was a significant overall PIT effect with both reward cues eliciting reward-seeking on test relative to the unpaired cue. Pavlovian extinction substantially reduced this effect, with the extinguished reward cue eliciting less reward-seeking than the non-extinguished reward cue. Most interestingly, extinction of cue-elicited reward-seeking was sensitive to renewal, with extinction less effective for reducing PIT when conducted in a different context. These findings have important implications for extinction-based interventions for reducing maladaptive reward-seeking in practice. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reward-based behaviors and emotional processing in human with narcolepsy-cataplexy

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Sophie eBayard

2013-05-01

Full Text Available ajor advances in the past decade have led a better understanding of the pathophysiology of narcolepsy with cataplexy caused by the early loss of hypothalamic hypocretin neurons. Although a role for hypocretin in the regulation of sleep/wakefulness state is widely recognized, other functions, not necessarily related to arousal, have been identified. Hence, the hypocretin system enhances signaling in the mesolimbic pathways regulating reward processing, emotion and mood regulation, and addiction. Although studies on hypocretin-deficient mice have shown that hypocretin plays an essential role in reward-seeking, depression-like behavior and addiction, results in human narcolepsy remained subject to debate. Most of studies revealed that hypocretin-deficient narcolepsy patients either drug-free or medicated with psychostimulant had preferences towards risky choices in a decision-making task under ambiguity together with higher frequency of depressive symptoms and binge eating disorder compared to controls. However, human studies mostly reported the lack of association with pathological impulsivity and gambling, and substance and alcohol abuse in the context of narcolepsy-cataplexy. Prospective larger studies are required to confirm these findings in drug-free and medicated patients with narcolepsy. Inclusion of patients with other central hypersomnias without hypocretin deficiency will provide answer to the major question of the role of the hypocretin system in reward-based behaviors and emotional processing in humans.

Validation and extension of the reward-mountain model.

Science.gov (United States)

Breton, Yannick-André; Mullett, Ada; Conover, Kent; Shizgal, Peter

2013-01-01

The reward-mountain model relates the vigor of reward seeking to the strength and cost of reward. Application of this model provides information about the stage of processing at which manipulations such as drug administration, lesions, deprivation states, and optogenetic interventions act to alter reward seeking. The model has been updated by incorporation of new information about frequency following in the directly stimulated neurons responsible for brain stimulation reward and about the function that maps objective opportunity costs into subjective ones. The behavioral methods for applying the model have been updated and improved as well. To assess the impact of these changes, two related predictions of the model that were supported by earlier work have been retested: (1) altering the duration of rewarding brain stimulation should change the pulse frequency required to produce a reward of half-maximal intensity, and (2) this manipulation should not change the opportunity cost at which half-maximal performance is directed at earning a maximally intense reward. Prediction 1 was supported in all six subjects, but prediction 2 was supported in only three. The latter finding is interpreted to reflect recruitment, at some stimulation sites, of a heterogeneous reward substrate comprising dual, parallel circuits that integrate the stimulation-induced neural signals.

Informationally administered reward enhances intrinsic motivation in schizophrenia.

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Lee, Hyeon-Seung; Jang, Seon-Kyeong; Lee, Ga-Young; Park, Seon-Cheol; Medalia, Alice; Choi, Kee-Hong

2017-10-01

Even when individuals with schizophrenia have an intact ability to enjoy rewarding moments, the means to assist them to translate rewarding experiences into goal-directed behaviors is unclear. The present study sought to determine whether informationally administered rewards enhance intrinsic motivation to foster goal-directed behaviors in individuals with schizophrenia (SZ) and healthy controls (HCs). Eighty-four participants (SZ=43, HCs=41) were randomly assigned to conditions involving either a performance-contingent reward with an informationally administered reward or a task-contingent reward with no feedback. Participants were asked to play two cognitive games of equalized difficulty. Accuracy, self-reported intrinsic motivation, free-choice intrinsic motivation (i.e., game play during a free-choice observation period), and perceived competency were measured. Intrinsic motivation and perceived competency in the cognitive games were similar between the two participant groups. The informationally administered reward significantly enhanced self-reported intrinsic motivation and perceived competency in both the groups. The likelihood that individuals with schizophrenia would play the game during the free-choice observation period was four times greater in the informationally administered reward condition than that in the no-feedback condition. Our findings suggest that, in the context of cognitive remediation, individuals with schizophrenia would benefit from informationally administered rewards. Copyright © 2017 Elsevier B.V. All rights reserved.

The antecedents of satisfaction with pay in teams: do performance-based compensation and autonomy keep team-members satisfied?

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Ana-Maria Godeanu

2012-06-01

Full Text Available This paper aims to investigate the effects performance-based compensation and autonomy on satisfaction with pay in the context of team working. I develop a complex perspective that considers the influence of different monetary and non-monetary rewards on satisfaction with pay. Drawing from the agency theory, equity theory and theory of cooperation I predict that both piece rates and team-based rewards are associated with higher pay satisfaction. Moreover, I claim that both individual and team-based autonomy contribute to increased satisfaction with pay. Using a cross-sectional dataset of randomly selected European employees who are asked about specific working and living conditions, results confirm that both productivity-based rewards and autonomy are important for employee satisfaction. Managers should know when to introduce rewards based only on individual merits and when to give to use autonomy as a buffer to compensate for the potential lack of fairness in the payment system.

Neuromodulatory Adaptive Combination of Correlation-based Learning in Cerebellum and Reward-based Learning in Basal Ganglia for Goal-directed Behavior Control

DEFF Research Database (Denmark)

Dasgupta, Sakyasingha; Wörgötter, Florentin; Manoonpong, Poramate

2014-01-01

Goal-directed decision making in biological systems is broadly based on associations between conditional and unconditional stimuli. This can be further classified as classical conditioning (correlation-based learning) and operant conditioning (reward-based learning). A number of computational...... and experimental studies have well established the role of the basal ganglia in reward-based learning, where as the cerebellum plays an important role in developing specific conditioned responses. Although viewed as distinct learning systems, recent animal experiments point toward their complementary role...... in behavioral learning, and also show the existence of substantial two-way communication between these two brain structures. Based on this notion of co-operative learning, in this paper we hypothesize that the basal ganglia and cerebellar learning systems work in parallel and interact with each other. We...

TOTAL REWARDS MODEL IN ROMANIAN COMPANIES

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Elena-Sabina HODOR

2014-04-01

Full Text Available Total Rewards Management is a subject of major importance for companies, because, by using models for this, firms can achieve their objectives of high performance. In order to analyse a validated total rewards model in Romanian Accounting and Consulting Companies, it is used The WorldatWork Total Rewards Model, which depict what contributes to applicant attraction and employee motivation and retention. Thus, the methodology of the previous survey is adjusted to the local context. The conclusions for the methodological aspects illustrate that the present research involves three strategic steps in order to achieve the objectives presented: the analysis of organizational environment of the companies from the sample, checking if Total Rewards Model proposed in the previous research is applicable for the same romanian companies from the previous survey, the analysing of the differences between results, and, if necessary, the adaptation of the model for Romania.

A new perspective on punishments and rewards in marketing channel relationships

OpenAIRE

Chow, M.W.

2007-01-01

How effective are punishments and rewards in influencing dealer performance in marketing channel relationships? Although often used in managerial practice, academic research on the relationship between punishment/reward and dealer performance has been scarce and demonstrates variable results. The aim of this dissertation is to resolve the indistinctness that currently surrounds academic research on the use of punishments and rewards in marketing channel relationships. The three studies in thi...

Pengaruh Total Reward Terhadap Job Engagement Serta Dampaknya Terhadap Kinerja Pegawai

OpenAIRE

Widodo, Chresno Wahyu

2014-01-01

Total Reward combines Transactional Reward and Relational Reward can meet any level of employee‘s needs therefore will foster employee to invest their Job involvement (cognitive energy), Job satisfaction (emotional reaction), Intrinsic motivation (physical energy) actively into complete work role performance. If employee shows Job Engagement during work in turn will create superior performance that are directly involved in the accomplishment of core job tasks involved in organization‘s =techn...

A modified random decrement technique for modal identification from nonstationary ambient response data only

International Nuclear Information System (INIS)

Lin, Chang Sheng; Chiang, Dar Yun

2012-01-01

Modal identification is considered from response data of structural system under nonstationary ambient vibration. In a previous paper, we showed that by assuming the ambient excitation to be nonstationary white noise in the form of a product model, the nonstationary response signals can be converted into free-vibration data via the correlation technique. In the present paper, if the ambient excitation can be modeled as a nonstationary white noise in the form of a product model, then the nonstationary cross random decrement signatures of structural response evaluated at any fixed time instant are shown theoretically to be proportional to the nonstationary cross-correlation functions. The practical problem of insufficient data samples available for evaluating nonstationary random decrement signatures can be approximately resolved by first extracting the amplitude-modulating function from the response and then transforming the nonstationary responses into stationary ones. Modal-parameter identification can then be performed using the Ibrahim time-domain technique, which is effective at identifying closely spaced modes. The theory proposed can be further extended by using the filtering concept to cover the case of nonstationary color excitations. Numerical simulations confirm the validity of the proposed method for identification of modal parameters from nonstationary ambient response data

Influence of dynamic dislocation drag on amplitude dependences of damping decrement and modulus defect in lead

International Nuclear Information System (INIS)

Soifer, Y.M.; Golosovskii, M.A.; Kobelev, N.P.

1981-01-01

A study was made of the amplitude dependences of the damping decrement and the modulus defect in lead at low temperatures at frequencies of 100 kHz and 5 MHz. It was shown that in pure lead at high frequencies a change in the amplitude dependences of the damping decrement and the modulus defect under the superconducting transition is due mainly to the change in the losses caused by the dynamic drag of dislocations whereas in measurements at low frequencies the influence of the superconducting transition is due to the change in the conditions of dislocation unpinning from point defects. The influence of the dynamic dislocation drag on the amplitude dependences of the damping decrement and the modulus defect is calculated and a method is presented for experimental estimation of the contribution of dynamic effects to the amplitude-dependent internal friction

The Risks and Rewards of Value-Based Reimbursement.

Science.gov (United States)

Henkel, Robert J; Maryland, Patricia A

2015-01-01

As healthcare systems across the country shift to value-based care, they face an enormous challenge. Not only must they reimagine how they identify, engage, and manage the care of patients, they also need to determine new ways of engaging and aligning physicians and other caregivers in creating better-coordinated care across the continuum. This article explores how healthcare systems making the transition from volume to value can maximize their reward while managing their risk. As the largest not-for-profit healthcare system in the United States and the largest Catholic healthcare system in the world, Ascension is committed to making its own transition, marked by broad-based innovation. We call this goal the Quadruple Aim: improving health outcomes, patient experiences, and provider experiences while lowering the overall cost of care. Healthcare systems and providers have many value-based models to choose from, including pay for performance (P4P), shared savings, bundled payments, shared risk, global capitation, and provider-sponsored health plans. Analysis of these options should include an evaluation of market readiness (i.e., the ability of a health system to align with the needs of employers or commercial insurers in a given market). Healthcare systems also must be prepared to invest in resources that facilitate effective transitions and continuity of care--for example, care management. In addition, they need to recognize that as they focus on wellness, inpatient volumes will decline, requiring cost-structure adjustments and added ancillary services to compensate for this decline. Some healthcare systems are even exploring the possibility of becoming their own payer, taking on more risk and responsibility for the health of patients and populations.

Reward-modulated motor information in identified striatum neurons.

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Isomura, Yoshikazu; Takekawa, Takashi; Harukuni, Rie; Handa, Takashi; Aizawa, Hidenori; Takada, Masahiko; Fukai, Tomoki

2013-06-19

It is widely accepted that dorsal striatum neurons participate in either the direct pathway (expressing dopamine D1 receptors) or the indirect pathway (expressing D2 receptors), controlling voluntary movements in an antagonistically balancing manner. The D1- and D2-expressing neurons are activated and inactivated, respectively, by dopamine released from substantia nigra neurons encoding reward expectation. However, little is known about the functional representation of motor information and its reward modulation in individual striatal neurons constituting the two pathways. In this study, we juxtacellularly recorded the spike activity of single neurons in the dorsolateral striatum of rats performing voluntary forelimb movement in a reward-predictable condition. Some of these neurons were identified morphologically by a combination of juxtacellular visualization and in situ hybridization for D1 mRNA. We found that the striatal neurons exhibited distinct functional activations before and during the forelimb movement, regardless of the expression of D1 mRNA. They were often positively, but rarely negatively, modulated by expecting a reward for the correct motor response. The positive reward modulation was independent of behavioral differences in motor performance. In contrast, regular-spiking and fast-spiking neurons in any layers of the motor cortex displayed only minor and unbiased reward modulation of their functional activation in relation to the execution of forelimb movement. Our results suggest that the direct and indirect pathway neurons cooperatively rather than antagonistically contribute to spatiotemporal control of voluntary movements, and that motor information is subcortically integrated with reward information through dopaminergic and other signals in the skeletomotor loop of the basal ganglia.

Differentiating neural reward responsiveness in autism versus ADHD

Directory of Open Access Journals (Sweden)

Gregor Kohls

2014-10-01

Full Text Available Although attention deficit hyperactivity disorders (ADHD and autism spectrum disorders (ASD share certain neurocognitive characteristics, it has been hypothesized to differentiate the two disorders based on their brain's reward responsiveness to either social or monetary reward. Thus, the present fMRI study investigated neural activation in response to both reward types in age and IQ-matched boys with ADHD versus ASD relative to typically controls (TDC. A significant group by reward type interaction effect emerged in the ventral striatum with greater activation to monetary versus social reward only in TDC, whereas subjects with ADHD responded equally strong to both reward types, and subjects with ASD showed low striatal reactivity across both reward conditions. Moreover, disorder-specific neural abnormalities were revealed, including medial prefrontal hyperactivation in response to social reward in ADHD versus ventral striatal hypoactivation in response to monetary reward in ASD. Shared dysfunction was characterized by fronto-striato-parietal hypoactivation in both clinical groups when money was at stake. Interestingly, lower neural activation within parietal circuitry was associated with higher autistic traits across the entire study sample. In sum, the present findings concur with the assumption that both ASD and ADHD display distinct and shared neural dysfunction in response to reward.

Influence of dopaminergically mediated reward on somatosensory decision-making.

Directory of Open Access Journals (Sweden)

Burkhard Pleger

2009-07-01

Full Text Available Reward-related dopaminergic influences on learning and overt behaviour are well established, but any influence on sensory decision-making is largely unknown. We used functional magnetic resonance imaging (fMRI while participants judged electric somatosensory stimuli on one hand or other, before being rewarded for correct performance at trial end via a visual signal, at one of four anticipated financial levels. Prior to the procedure, participants received either placebo (saline, a dopamine agonist (levodopa, or an antagonist (haloperidol.higher anticipated reward improved tactile decisions. Visually signalled reward reactivated primary somatosensory cortex for the judged hand, more strongly for higher reward. After receiving a higher reward on one trial, somatosensory activations and decisions were enhanced on the next trial. These behavioural and neural effects were all enhanced by levodopa and attenuated by haloperidol, indicating dopaminergic dependency. Dopaminergic reward-related influences extend even to early somatosensory cortex and sensory decision-making.

RM-SORN: a reward-modulated self-organizing recurrent neural network.

Science.gov (United States)

Aswolinskiy, Witali; Pipa, Gordon

2015-01-01

Neural plasticity plays an important role in learning and memory. Reward-modulation of plasticity offers an explanation for the ability of the brain to adapt its neural activity to achieve a rewarded goal. Here, we define a neural network model that learns through the interaction of Intrinsic Plasticity (IP) and reward-modulated Spike-Timing-Dependent Plasticity (STDP). IP enables the network to explore possible output sequences and STDP, modulated by reward, reinforces the creation of the rewarded output sequences. The model is tested on tasks for prediction, recall, non-linear computation, pattern recognition, and sequence generation. It achieves performance comparable to networks trained with supervised learning, while using simple, biologically motivated plasticity rules, and rewarding strategies. The results confirm the importance of investigating the interaction of several plasticity rules in the context of reward-modulated learning and whether reward-modulated self-organization can explain the amazing capabilities of the brain.

A test of the reward-contrast hypothesis.

Science.gov (United States)

Dalecki, Stefan J; Panoz-Brown, Danielle E; Crystal, Jonathon D

2017-12-01

Source memory, a facet of episodic memory, is the memory of the origin of information. Whereas source memory in rats is sustained for at least a week, spatial memory degraded after approximately a day. Different forgetting functions may suggest that two memory systems (source memory and spatial memory) are dissociated. However, in previous work, the two tasks used baiting conditions consisting of chocolate and chow flavors; notably, the source memory task used the relatively better flavor. Thus, according to the reward-contrast hypothesis, when chocolate and chow were presented within the same context (i.e., within a single radial maze trial), the chocolate location was more memorable than the chow location because of contrast. We tested the reward-contrast hypothesis using baiting configurations designed to produce reward-contrast. The reward-contrast hypothesis predicts that under these conditions, spatial memory will survive a 24-h retention interval. We documented elimination of spatial memory performance after a 24-h retention interval using a reward-contrast baiting pattern. These data suggest that reward contrast does not explain our earlier findings that source memory survives unusually long retention intervals. Copyright © 2017 Elsevier B.V. All rights reserved.

A new perspective on punishments and rewards in marketing channel relationships

NARCIS (Netherlands)

Chow, M.W.

2007-01-01

How effective are punishments and rewards in influencing dealer performance in marketing channel relationships? Although often used in managerial practice, academic research on the relationship between punishment/reward and dealer performance has been scarce and demonstrates variable results. The

On the search for an appropriate metric for reaction time to suprathreshold increments and decrements.

Science.gov (United States)

Vassilev, Angel; Murzac, Adrian; Zlatkova, Margarita B; Anderson, Roger S

2009-03-01

Weber contrast, DeltaL/L, is a widely used contrast metric for aperiodic stimuli. Zele, Cao & Pokorny [Zele, A. J., Cao, D., & Pokorny, J. (2007). Threshold units: A correct metric for reaction time? Vision Research, 47, 608-611] found that neither Weber contrast nor its transform to detection-threshold units equates human reaction times in response to luminance increments and decrements under selective rod stimulation. Here we show that their rod reaction times are equated when plotted against the spatial luminance ratio between the stimulus and its background (L(max)/L(min), the larger and smaller of background and stimulus luminances). Similarly, reaction times to parafoveal S-cone selective increments and decrements from our previous studies [Murzac, A. (2004). A comparative study of the temporal characteristics of processing of S-cone incremental and decremental signals. PhD thesis, New Bulgarian University, Sofia, Murzac, A., & Vassilev, A. (2004). Reaction time to S-cone increments and decrements. In: 7th European conference on visual perception, Budapest, August 22-26. Perception, 33, 180 (Abstract).], are better described by the spatial luminance ratio than by Weber contrast. We assume that the type of stimulus detection by temporal (successive) luminance discrimination, by spatial (simultaneous) luminance discrimination or by both [Sperling, G., & Sondhi, M. M. (1968). Model for visual luminance discrimination and flicker detection. Journal of the Optical Society of America, 58, 1133-1145.] determines the appropriateness of one or other contrast metric for reaction time.

Abnormal Striatal BOLD Responses to Reward Anticipation and Reward Delivery in ADHD

Science.gov (United States)

Furukawa, Emi; Bado, Patricia; Tripp, Gail; Mattos, Paulo; Wickens, Jeff R.; Bramati, Ivanei E.; Alsop, Brent; Ferreira, Fernanda Meireles; Lima, Debora; Tovar-Moll, Fernanda; Sergeant, Joseph A.; Moll, Jorge

2014-01-01

Altered reward processing has been proposed to contribute to the symptoms of attention deficit hyperactivity disorder (ADHD). The neurobiological mechanism underlying this alteration remains unclear. We hypothesize that the transfer of dopamine release from reward to reward-predicting cues, as normally observed in animal studies, may be deficient in ADHD. Functional magnetic resonance imaging (fMRI) was used to investigate striatal responses to reward-predicting cues and reward delivery in a classical conditioning paradigm. Data from 14 high-functioning and stimulant-naïve young adults with elevated lifetime symptoms of ADHD (8 males, 6 females) and 15 well-matched controls (8 males, 7 females) were included in the analyses. During reward anticipation, increased blood-oxygen-level-dependent (BOLD) responses in the right ventral and left dorsal striatum were observed in controls, but not in the ADHD group. The opposite pattern was observed in response to reward delivery; the ADHD group demonstrated significantly greater BOLD responses in the ventral striatum bilaterally and the left dorsal striatum relative to controls. In the ADHD group, the number of current hyperactivity/impulsivity symptoms was inversely related to ventral striatal responses during reward anticipation and positively associated with responses to reward. The BOLD response patterns observed in the striatum are consistent with impaired predictive dopamine signaling in ADHD, which may explain altered reward-contingent behaviors and symptoms of ADHD. PMID:24586543

Segregated encoding of reward-identity and stimulus-reward associations in human orbitofrontal cortex.

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Klein-Flügge, Miriam Cornelia; Barron, Helen Catharine; Brodersen, Kay Henning; Dolan, Raymond J; Behrens, Timothy Edward John

2013-02-13

A dominant focus in studies of learning and decision-making is the neural coding of scalar reward value. This emphasis ignores the fact that choices are strongly shaped by a rich representation of potential rewards. Here, using fMRI adaptation, we demonstrate that responses in the human orbitofrontal cortex (OFC) encode a representation of the specific type of food reward predicted by a visual cue. By controlling for value across rewards and by linking each reward with two distinct stimuli, we could test for representations of reward-identity that were independent of associative information. Our results show reward-identity representations in a medial-caudal region of OFC, independent of the associated predictive stimulus. This contrasts with a more rostro-lateral OFC region encoding reward-identity representations tied to the predicate stimulus. This demonstration of adaptation in OFC to reward specific representations opens an avenue for investigation of more complex decision mechanisms that are not immediately accessible in standard analyses, which focus on correlates of average activity.

Reward Circuitry in Addiction.

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Cooper, Sarah; Robison, A J; Mazei-Robison, Michelle S

2017-07-01

Understanding the brain circuitry that underlies reward is critical to improve treatment for many common health issues, including obesity, depression, and addiction. Here we focus on insights into the organization and function of reward circuitry and its synaptic and structural adaptations in response to cocaine exposure. While the importance of certain circuits, such as the mesocorticolimbic dopamine pathway, are well established in drug reward, recent studies using genetics-based tools have revealed functional changes throughout the reward circuitry that contribute to different facets of addiction, such as relapse and craving. The ability to observe and manipulate neuronal activity within specific cell types and circuits has led to new insight into not only the basic connections between brain regions, but also the molecular changes within these specific microcircuits, such as neurotrophic factor and GTPase signaling or α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor function, that underlie synaptic and structural plasticity evoked by drugs of abuse. Excitingly, these insights from preclinical rodent work are now being translated into the clinic, where transcranial magnetic simulation and deep brain stimulation therapies are being piloted in human cocaine dependence. Thus, this review seeks to summarize current understanding of the major brain regions implicated in drug-related behaviors and the molecular mechanisms that contribute to altered connectivity between these regions, with the postulation that increased knowledge of the plasticity within the drug reward circuit will lead to new and improved treatments for addiction.

Dopamine reward prediction error coding.

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Schultz, Wolfram

2016-03-01

Reward prediction errors consist of the differences between received and predicted rewards. They are crucial for basic forms of learning about rewards and make us strive for more rewards-an evolutionary beneficial trait. Most dopamine neurons in the midbrain of humans, monkeys, and rodents signal a reward prediction error; they are activated by more reward than predicted (positive prediction error), remain at baseline activity for fully predicted rewards, and show depressed activity with less reward than predicted (negative prediction error). The dopamine signal increases nonlinearly with reward value and codes formal economic utility. Drugs of addiction generate, hijack, and amplify the dopamine reward signal and induce exaggerated, uncontrolled dopamine effects on neuronal plasticity. The striatum, amygdala, and frontal cortex also show reward prediction error coding, but only in subpopulations of neurons. Thus, the important concept of reward prediction errors is implemented in neuronal hardware.

Social and monetary reward processing in autism spectrum disorders.

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Delmonte, Sonja; Balsters, Joshua H; McGrath, Jane; Fitzgerald, Jacqueline; Brennan, Sean; Fagan, Andrew J; Gallagher, Louise

2012-09-26

Social motivation theory suggests that deficits in social reward processing underlie social impairments in autism spectrum disorders (ASD). However, the extent to which abnormalities in reward processing generalize to other classes of stimuli remains unresolved. The aim of the current study was to examine if reward processing abnormalities in ASD are specific to social stimuli or can be generalized to other classes of reward. Additionally, we sought to examine the results in the light of behavioral impairments in ASD. Participants performed adapted versions of the social and monetary incentive delay tasks. Data from 21 unmedicated right-handed male participants with ASD and 21 age- and IQ-matched controls were analyzed using a factorial design to examine the blood-oxygen-level-dependent (BOLD) response during the anticipation and receipt of both reward types. Behaviorally, the ASD group showed less of a reduction in reaction time (RT) for rewarded compared to unrewarded trials than the control group. In terms of the fMRI results, there were no significant group differences in reward circuitry during reward anticipation. During the receipt of rewards, there was a significant interaction between group and reward type in the left dorsal striatum (DS). The ASD group showed reduced activity in the DS compared to controls for social rewards but not monetary rewards and decreased activation for social rewards compared to monetary rewards. Controls showed no significant difference between the two reward types. Increased activation in the DS during social reward processing was associated with faster response times for rewarded trials, compared to unrewarded trials, in both groups. This is in line with behavioral results indicating that the ASD group showed less of a reduction in RT for rewarded compared to unrewarded trials. Additionally, de-activation to social rewards was associated with increased repetitive behavior in ASD. In line with social motivation theory, the ASD

BAS-drive trait modulates dorsomedial striatum activity during reward response-outcome associations.

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Costumero, Víctor; Barrós-Loscertales, Alfonso; Fuentes, Paola; Rosell-Negre, Patricia; Bustamante, Juan Carlos; Ávila, César

2016-09-01

According to the Reinforcement Sensitivity Theory, behavioral studies have found that individuals with stronger reward sensitivity easily detect cues of reward and establish faster associations between instrumental responses and reward. Neuroimaging studies have shown that processing anticipatory cues of reward is accompanied by stronger ventral striatum activity in individuals with stronger reward sensitivity. Even though establishing response-outcome contingencies has been consistently associated with dorsal striatum, individual differences in this process are poorly understood. Here, we aimed to study the relation between reward sensitivity and brain activity while processing response-reward contingencies. Forty-five participants completed the BIS/BAS questionnaire and performed a gambling task paradigm in which they received monetary rewards or punishments. Overall, our task replicated previous results that have related processing high reward outcomes with activation of striatum and medial frontal areas, whereas processing high punishment outcomes was associated with stronger activity in insula and middle cingulate. As expected, the individual differences in the activity of dorsomedial striatum correlated positively with BAS-Drive. Our results agree with previous studies that have related the dorsomedial striatum with instrumental performance, and suggest that the individual differences in this area may form part of the neural substrate responsible for modulating instrumental conditioning by reward sensitivity.

The relationship between personality types and reward preferences

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R. Nienaber

2011-12-01

: This study confirms that there are significant differences in the reward preferences of different segments. Management can more effectively structure reward models according to these preferences without increasing overall costs. Contribution/value-add: The existing body of knowledge on the reward preferences of people with different personality types and personality preferences are enhanced. In addition, the study on the reward preferences of different demographic groups within a South African context adds considerably to the existing body of literature. Based on research results, a total rewards framework, on employee preferences, was designed. Furthermore, an increased understanding of the reward categories that contribute towards .the attraction, retention and motivation of employees as well as preferences for certain reward categories, have been obtained.

Age-related decrements in bone mineral density in women over 65

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Steiger, P.; Cummings, S. R.; Black, D. M.; Spencer, N. E.; Genant, H. K.

1992-01-01

Age-related changes in bone density contribute to the risk of fractures. To describe the relationship between age and bone mass in elderly women, we studied a large cohort of women over age 65 years who were recruited from population-based lists in four cities in the United States. Bone density in g/cm2 was measured by single-photon absorptiometry (SPA) and dual x-ray absorptiometry (DXA) at the distal and proximal radius, the calcaneus, the lumbar spine, and the proximal femur. Centralized data collection was used to control data quality and consistency. We found a strong inverse relationship between bone density and age for most sites. Decrements in bone density between women aged 65-69 years and women 85 years and older exceeded 16% in all regions except the spine, where the difference between the two age groups was 6%. Ward's triangle and the calcaneus exhibited the largest decrements, with 26 and 21%, respectively. The estimates of annual changes in bone mineral density by linear regression at sites other than the spine ranged from -0.82% at the femoral neck and trochanter to -1.30% at Ward's triangle. Correlations between the different regions ranged from r = 0.51 between the proximal radius and Ward's triangle to r = 0.66 between the distal radius and calcaneus. We conclude that the inverse relationship between age and bone mass measured by absorptiometry techniques in white women continues into the ninth decade of life. The relationship is strongest for bone density of Ward's triangle and the calcaneus and weakest for the spine.

When Rewards Go Wrong: A Tale of Five Motivational Misdirects

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Steel, Piers; MacDonnell, Rhiannon

2012-01-01

At the heart of most performance management systems is a reward program. However, even when we are doing everything else right, rewards can go wrong. Here, we explore five ways that external incentives can damage performance, from destroying altruistic behavior to distracting people from the task. Fortunately, most of these downfalls are…

Risk of Performance Decrements and Adverse Health Outcomes Resulting from Sleep Loss, Circadian Desynchronization, and Work Overload

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Flynn-Evans, Erin; Gregory, Kevin; Arsintescu, Lucia; Whitmire, Alexandra

2016-01-01

Sleep loss, circadian desynchronization, and work overload occur to some extent for ground and flight crews, prior to and during spaceflight missions. Ground evidence indicates that such risk factors may lead to performance decrements and adverse health outcomes, which could potentially compromise mission objectives. Efforts are needed to identify the environmental and mission conditions that interfere with sleep and circadian alignment, as well as individual differences in vulnerability and resiliency to sleep loss and circadian desynchronization. Specifically, this report highlights a collection of new evidence to better characterize the risk and reveals new gaps in this risk as follows: Sleep loss is apparent during spaceflight. Astronauts consistently average less sleep during spaceflight relative to on the ground. The causes of this sleep loss remain unknown, however ground-based evidence suggests that the sleep duration of astronauts is likely to lead to performance impairment and short and long-term health consequences. Further research is needed in this area in order to develop screening tools to assess individual astronaut sleep need in order to quantify the magnitude of sleep loss during spaceflight; current and planned efforts in BHP's research portfolio address this need. In addition, it is still unclear whether the conditions of spaceflight environment lead to sleep loss or whether other factors, such as work overload lead to the reduced sleep duration. Future data mining efforts and continued data collection on the ISS will help to further characterize factors contributing to sleep loss. Sleep inertia has not been evaluated during spaceflight. Ground-based studies confirm that it takes two to four hours to achieve optimal performance after waking from a sleep episode. Sleep inertia has been associated with increased accidents and reduced performance in operational environments. Sleep inertia poses considerable risk during spaceflight when emergency

Motivational orientation modulates the neural response to reward.

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Linke, Julia; Kirsch, Peter; King, Andrea V; Gass, Achim; Hennerici, Michael G; Bongers, André; Wessa, Michèle

2010-02-01

Motivational orientation defines the source of motivation for an individual to perform a particular action and can either originate from internal desires (e.g., interest) or external compensation (e.g., money). To this end, motivational orientation should influence the way positive or negative feedback is processed during learning situations and this might in turn have an impact on the learning process. In the present study, we thus investigated whether motivational orientation, i.e., extrinsic and intrinsic motivation modulates the neural response to reward and punishment as well as learning from reward and punishment in 33 healthy individuals. To assess neural responses to reward, punishment and learning of reward contingencies we employed a probabilistic reversal learning task during functional magnetic resonance imaging. Extrinsic and intrinsic motivation were assessed with a self-report questionnaire. Rewarding trials fostered activation in the medial orbitofrontal cortex and anterior cingulate gyrus (ACC) as well as the amygdala and nucleus accumbens, whereas for punishment an increased neural response was observed in the medial and inferior prefrontal cortex, the superior parietal cortex and the insula. High extrinsic motivation was positively correlated to increased neural responses to reward in the ACC, amygdala and putamen, whereas a negative relationship between intrinsic motivation and brain activation in these brain regions was observed. These findings show that motivational orientation indeed modulates the responsiveness to reward delivery in major components of the human reward system and therefore extends previous results showing a significant influence of individual differences in reward-related personality traits on the neural processing of reward. Copyright (c) 2009 Elsevier Inc. All rights reserved.

Reward, Context, and Human Behaviour

Directory of Open Access Journals (Sweden)

Clare L. Blaukopf

2007-01-01

Full Text Available Animal models of reward processing have revealed an extensive network of brain areas that process different aspects of reward, from expectation and prediction to calculation of relative value. These results have been confirmed and extended in human neuroimaging to encompass secondary rewards more unique to humans, such as money. The majority of the extant literature covers the brain areas associated with rewards whilst neglecting analysis of the actual behaviours that these rewards generate. This review strives to redress this imbalance by illustrating the importance of looking at the behavioural outcome of rewards and the context in which they are produced. Following a brief review of the literature of reward-related activity in the brain, we examine the effect of reward context on actions. These studies reveal how the presence of reward vs. reward and punishment, or being conscious vs. unconscious of reward-related actions, differentially influence behaviour. The latter finding is of particular importance given the extent to which animal models are used in understanding the reward systems of the human mind. It is clear that further studies are needed to learn about the human reaction to reward in its entirety, including any distinctions between conscious and unconscious behaviours. We propose that studies of reward entail a measure of the animal's (human or nonhuman knowledge of the reward and knowledge of its own behavioural outcome to achieve that reward.

Heterogeneity of reward mechanisms.

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Lajtha, A; Sershen, H

2010-06-01

The finding that many drugs that have abuse potential and other natural stimuli such as food or sexual activity cause similar chemical changes in the brain, an increase in extracellular dopamine (DA) in the shell of the nucleus accumbens (NAccS), indicated some time ago that the reward mechanism is at least very similar for all stimuli and that the mechanism is relatively simple. The presently available information shows that the mechanisms involved are more complex and have multiple elements. Multiple brain regions, multiple receptors, multiple distinct neurons, multiple transmitters, multiple transporters, circuits, peptides, proteins, metabolism of transmitters, and phosphorylation, all participate in reward mechanisms. The system is variable, is changed during development, is sex-dependent, and is influenced by genetic differences. Not all of the elements participate in the reward of all stimuli. Different set of mechanisms are involved in the reward of different drugs of abuse, yet different mechanisms in the reward of natural stimuli such as food or sexual activity; thus there are different systems that distinguish different stimuli. Separate functions of the reward system such as anticipation, evaluation, consummation and identification; all contain function-specific elements. The level of the stimulus also influences the participation of the elements of the reward system, there are possible reactions to even below threshold stimuli, and excessive stimuli can change reward to aversion involving parts of the system. Learning and memory of past reward is an important integral element of reward and addictive behavior. Many of the reward elements are altered by repeated or chronic stimuli, and chronic exposure to one drug is likely to alter the response to another stimulus. To evaluate and identify the reward stimulus thus requires heterogeneity of the reward components in the brain.

Impaired Flexible Reward-Based Decision-Making in Binge Eating Disorder: Evidence from Computational Modeling and Functional Neuroimaging.

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Reiter, Andrea M F; Heinze, Hans-Jochen; Schlagenhauf, Florian; Deserno, Lorenz

2017-02-01

Despite its clinical relevance and the recent recognition as a diagnostic category in the DSM-5, binge eating disorder (BED) has rarely been investigated from a cognitive neuroscientific perspective targeting a more precise neurocognitive profiling of the disorder. BED patients suffer from a lack of behavioral control during recurrent binge eating episodes and thus fail to adapt their behavior in the face of negative consequences, eg, high risk for obesity. To examine impairments in flexible reward-based decision-making, we exposed BED patients (n=22) and matched healthy individuals (n=22) to a reward-guided decision-making task during functional resonance imaging (fMRI). Performing fMRI analysis informed via computational modeling of choice behavior, we were able to identify specific signatures of altered decision-making in BED. On the behavioral level, we observed impaired behavioral adaptation in BED, which was due to enhanced switching behavior, a putative deficit in striking a balance between exploration and exploitation appropriately. This was accompanied by diminished activation related to exploratory decisions in the anterior insula/ventro-lateral prefrontal cortex. Moreover, although so-called model-free reward prediction errors remained intact, representation of ventro-medial prefrontal learning signatures, incorporating inference on unchosen options, was reduced in BED, which was associated with successful decision-making in the task. On the basis of a computational psychiatry account, the presented findings contribute to defining a neurocognitive phenotype of BED.

Overlapping neural systems represent cognitive effort and reward anticipation.

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Vassena, Eliana; Silvetti, Massimo; Boehler, Carsten N; Achten, Eric; Fias, Wim; Verguts, Tom

2014-01-01

Anticipating a potential benefit and how difficult it will be to obtain it are valuable skills in a constantly changing environment. In the human brain, the anticipation of reward is encoded by the Anterior Cingulate Cortex (ACC) and Striatum. Naturally, potential rewards have an incentive quality, resulting in a motivational effect improving performance. Recently it has been proposed that an upcoming task requiring effort induces a similar anticipation mechanism as reward, relying on the same cortico-limbic network. However, this overlapping anticipatory activity for reward and effort has only been investigated in a perceptual task. Whether this generalizes to high-level cognitive tasks remains to be investigated. To this end, an fMRI experiment was designed to investigate anticipation of reward and effort in cognitive tasks. A mental arithmetic task was implemented, manipulating effort (difficulty), reward, and delay in reward delivery to control for temporal confounds. The goal was to test for the motivational effect induced by the expectation of bigger reward and higher effort. The results showed that the activation elicited by an upcoming difficult task overlapped with higher reward prospect in the ACC and in the striatum, thus highlighting a pivotal role of this circuit in sustaining motivated behavior.

Dopamine reward prediction error coding

OpenAIRE

Schultz, Wolfram

2016-01-01

Reward prediction errors consist of the differences between received and predicted rewards. They are crucial for basic forms of learning about rewards and make us strive for more rewards?an evolutionary beneficial trait. Most dopamine neurons in the midbrain of humans, monkeys, and rodents signal a reward prediction error; they are activated by more reward than predicted (positive prediction error), remain at baseline activity for fully predicted rewards, and show depressed activity with less...

Emphasizing the 'positive' in positive reinforcement: Using non-binary rewarding for training monkeys on cognitive tasks.

Science.gov (United States)

Fischer, Benjamin; Wegener, Detlef

2018-04-04

Non-human primates constitute an indispensable model system for studying higher brain func-tions at the neurophysiological level. Studies involving these animals elucidated the neuronal mechanisms of various cognitive and executive functions, such as visual attention, working memory, and decision-making. Positive Reinforcement Training (PRT) constitutes the gold standard for training animals on the cognitive tasks employed in these studies. In the laboratory, PRT is usually based on applying a liquid reward as the reinforcer to strengthen the desired be-havior, and absence of the reward if the animal's response was wrong. By trial-and-error, the monkey may adopt its behavior and successfully reduces the number of error trials, and eventu-ally learns even very sophisticated tasks. However, progress and success of the training strongly depend on reasonable error rates. If errors get too frequent, they may cause a drop in the ani-mal's motivation to cooperate, or its adaptation to high error rates and poor overall perfor-mance. We here introduce an alternative training regime to minimize errors and base the critical information for learning on graded rewarding. For every new task rule, the feedback to the ani-mal is provided by different amounts of reward to distinguish the desired, optimal behavior from less optimally behavior. We applied this regime in different situations during training of visual attention tasks, and analyzed behavioral performance and reaction times to evaluate its effec-tiveness. For both simple and complex behaviors, graded rewarding was found to constitute a powerful technique allowing for effective training without trade-off in accessible task difficulty or task performance.

The impact of reward and punishment on skill learning depends on task demands.

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Steel, Adam; Silson, Edward H; Stagg, Charlotte J; Baker, Chris I

2016-10-27

Reward and punishment motivate behavior, but it is unclear exactly how they impact skill performance and whether the effect varies across skills. The present study investigated the effect of reward and punishment in both a sequencing skill and a motor skill context. Participants trained on either a sequencing skill (serial reaction time task) or a motor skill (force-tracking task). Skill knowledge was tested immediately after training, and again 1 hour, 24-48 hours, and 30 days after training. We found a dissociation of the effects of reward and punishment on the tasks, primarily reflecting the impact of punishment. While punishment improved serial reaction time task performance, it impaired force-tracking task performance. In contrast to prior literature, neither reward nor punishment benefitted memory retention, arguing against the common assumption that reward ubiquitously benefits skill retention. Collectively, these results suggest that punishment impacts skilled behavior more than reward in a complex, task dependent fashion.

The impact of cognitive load on reward evaluation.

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Krigolson, Olave E; Hassall, Cameron D; Satel, Jason; Klein, Raymond M

2015-11-19

The neural systems that afford our ability to evaluate rewards and punishments are impacted by a variety of external factors. Here, we demonstrate that increased cognitive load reduces the functional efficacy of a reward processing system within the human medial-frontal cortex. In our paradigm, two groups of participants used performance feedback to estimate the exact duration of one second while electroencephalographic (EEG) data was recorded. Prior to performing the time estimation task, both groups were instructed to keep their eyes still and avoid blinking in line with well established EEG protocol. However, during performance of the time-estimation task, one of the two groups was provided with trial-to-trial-feedback about their performance on the time-estimation task and their eye movements to induce a higher level of cognitive load relative to participants in the other group who were solely provided with feedback about the accuracy of their temporal estimates. In line with previous work, we found that the higher level of cognitive load reduced the amplitude of the feedback-related negativity, a component of the human event-related brain potential associated with reward evaluation within the medial-frontal cortex. Importantly, our results provide further support that increased cognitive load reduces the functional efficacy of a neural system associated with reward processing. Copyright © 2015 Elsevier B.V. All rights reserved.

Effects of motivation on reward and attentional networks: an fMRI study.

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Ivanov, Iliyan; Liu, Xun; Clerkin, Suzanne; Schulz, Kurt; Friston, Karl; Newcorn, Jeffrey H; Fan, Jin

2012-11-01

Existing evidence suggests that reward and attentional networks function in concert and that activation in one system influences the other in a reciprocal fashion; however, the nature of these influences remains poorly understood. We therefore developed a three-component task to assess the interaction effects of reward anticipation and conflict resolution on the behavioral performance and the activation of brain reward and attentional systems. Sixteen healthy adult volunteers aged 21-45 years were scanned with functional magnetic resonance imaging (fMRI) while performing the task. A two-way repeated measures analysis of variance (ANOVA) with cue (reward vs. non-reward) and target (congruent vs. incongruent) as within-subjects factors was used to test for main and interaction effects. Neural responses to anticipation, conflict, and reward outcomes were tested. Behaviorally there were main effects of both reward cue and target congruency on reaction time. Neuroimaging results showed that reward anticipation and expected reward outcomes activated components of the attentional networks, including the inferior parietal and occipital cortices, whereas surprising non-rewards activated the frontoinsular cortex bilaterally and deactivated the ventral striatum. In turn, conflict activated a broad network associated with cognitive control and motor functions. Interaction effects showed decreased activity in the thalamus, anterior cingulated gyrus, and middle frontal gyrus bilaterally when difficult conflict trials (e.g., incongruent targets) were preceded by reward cues; in contrast, the ventral striatum and orbitofrontal cortex showed greater activation during congruent targets preceded by reward cues. These results suggest that reward anticipation is associated with lower activation in attentional networks, possibly due to increased processing efficiency, whereas more difficult, conflict trials are associated with lower activity in regions of the reward system, possibly

Strategies for reward-based crowdfunding campaigns

Directory of Open Access Journals (Sweden)

Sascha Kraus

2016-01-01

Full Text Available Crowdfunding represents an alternative way of funding entrepreneurial ventures – and is attracting a high amount of interest in research as well as practice. Against this background, this paper analyzes reward-based crowdfunding campaign strategies and their communication tools. To do this, 446 crowdfunding projects were gathered and empirically analyzed. Three different paths of successful crowdfunding projects could be identified and are described in detail. Practical implications of crowdfunding strategies are derived, and are dependent on the required sales effort and the project added value. The terms communicator, networker and self-runner are created for this crowdfunding strategy and filled with practical examples. This paper contributes to the literature in different ways: first, it sheds more light on the developing concept of crowdfunding, with an overview of current academic discussions on crowdfunding. Furthermore, the analysis of success factors for crowdfunding initiatives adds to an emerging area of research and allows entrepreneurs to extract best practice examples for increasing the probability of successful crowdfunding projects under consideration of the key influencing factors of communication.

Reward Motivation Enhances Task Coding in Frontoparietal Cortex.

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Etzel, Joset A; Cole, Michael W; Zacks, Jeffrey M; Kay, Kendrick N; Braver, Todd S

2016-04-01

Reward motivation often enhances task performance, but the neural mechanisms underlying such cognitive enhancement remain unclear. Here, we used a multivariate pattern analysis (MVPA) approach to test the hypothesis that motivation-related enhancement of cognitive control results from improved encoding and representation of task set information. Participants underwent two fMRI sessions of cued task switching, the first under baseline conditions, and the second with randomly intermixed reward incentive and no-incentive trials. Information about the upcoming task could be successfully decoded from cue-related activation patterns in a set of frontoparietal regions typically associated with task control. More critically, MVPA classifiers trained on the baseline session had significantly higher decoding accuracy on incentive than non-incentive trials, with decoding improvement mediating reward-related enhancement of behavioral performance. These results strongly support the hypothesis that reward motivation enhances cognitive control, by improving the discriminability of task-relevant information coded and maintained in frontoparietal brain regions. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

A study of non-monetary rewards as a motivation tool for employee performance in Tesco

OpenAIRE

Alegbejo, Titilayo B.

2013-01-01

2013 dissertation for MSc in Human Resource Management. Selected by academic staff as a good example of a masters level dissertation. \\ud \\ud \\ud The aim of this study was to critically evaluate the impact of non-monetary rewards on employee motivation, to determine which non-monetary reward motivates employees in Tesco and to investigate the value of non-monetary rewards to employees. The survey design was adopted in this study and data was collected through the distribution of questionnaire...

Noise masking of S-cone increments and decrements.

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Wang, Quanhong; Richters, David P; Eskew, Rhea T

2014-11-12

S-cone increment and decrement detection thresholds were measured in the presence of bipolar, dynamic noise masks. Noise chromaticities were the L-, M-, and S-cone directions, as well as L-M, L+M, and achromatic (L+M+S) directions. Noise contrast power was varied to measure threshold Energy versus Noise (EvN) functions. S+ and S- thresholds were similarly, and weakly, raised by achromatic noise. However, S+ thresholds were much more elevated by S, L+M, L-M, L- and M-cone noises than were S- thresholds, even though the noises consisted of two symmetric chromatic polarities of equal contrast power. A linear cone combination model accounts for the overall pattern of masking of a single test polarity well. L and M cones have opposite signs in their effects upon raising S+ and S- thresholds. The results strongly indicate that the psychophysical mechanisms responsible for S+ and S- detection, presumably based on S-ON and S-OFF pathways, are distinct, unipolar mechanisms, and that they have different spatiotemporal sampling characteristics, or contrast gains, or both. © 2014 ARVO.

Scaling prediction errors to reward variability benefits error-driven learning in humans.

Science.gov (United States)

Diederen, Kelly M J; Schultz, Wolfram

2015-09-01

Effective error-driven learning requires individuals to adapt learning to environmental reward variability. The adaptive mechanism may involve decays in learning rate across subsequent trials, as shown previously, and rescaling of reward prediction errors. The present study investigated the influence of prediction error scaling and, in particular, the consequences for learning performance. Participants explicitly predicted reward magnitudes that were drawn from different probability distributions with specific standard deviations. By fitting the data with reinforcement learning models, we found scaling of prediction errors, in addition to the learning rate decay shown previously. Importantly, the prediction error scaling was closely related to learning performance, defined as accuracy in predicting the mean of reward distributions, across individual participants. In addition, participants who scaled prediction errors relative to standard deviation also presented with more similar performance for different standard deviations, indicating that increases in standard deviation did not substantially decrease "adapters'" accuracy in predicting the means of reward distributions. However, exaggerated scaling beyond the standard deviation resulted in impaired performance. Thus efficient adaptation makes learning more robust to changing variability. Copyright © 2015 the American Physiological Society.

Real time wide area radiation surveillance system (REWARD) based on 3d silicon and (CD,ZN)Te for neutron and gamma-ray detection

Science.gov (United States)

Disch, C.

2014-09-01

Mobile surveillance systems are used to find lost radioactive sources and possible nuclear threats in urban areas. The REWARD collaboration [1] aims to develop such a complete radiation monitoring system that can be installed in mobile or stationary setups across a wide area. The scenarios include nuclear terrorism threats, lost radioactive sources, radioactive contamination and nuclear accidents. This paper will show the performance capabilities of the REWARD system in different scnarios. The results include both Monte Carlo simulations as well as neutron and gamma-ray detection performances in terms of efficiency and nuclide identification. The outcomes of several radiation mapping survey with the entire REWARD system will also be presented.

Disentangling reward anticipation with simultaneous pupillometry / fMRI.

Science.gov (United States)

Schneider, Max; Leuchs, Laura; Czisch, Michael; Sämann, Philipp G; Spoormaker, Victor I

2018-05-05

The reward system may provide an interesting intermediate phenotype for anhedonia in affective disorders. Reward anticipation is characterized by an increase in arousal, and previous studies have linked the anterior cingulate cortex (ACC) to arousal responses such as dilation of the pupil. Here, we examined pupil dynamics during a reward anticipation task in forty-six healthy human subjects and evaluated its neural correlates using functional magnetic resonance imaging (fMRI). Pupil size showed a strong increase during monetary reward anticipation, a moderate increase during verbal reward anticipation and a decrease during control trials. For fMRI analyses, average pupil size and pupil change were computed in 1-s time bins during the anticipation phase. Activity in the ventral striatum was inversely related to the pupil size time course, indicating an early onset of activation and a role in reward prediction processing. Pupil dilations were linked to increased activity in the salience network (dorsal ACC and bilateral insula), which likely triggers an increase in arousal to enhance task performance. Finally, increased pupil size preceding the required motor response was associated with activity in the ventral attention network. In sum, pupillometry provides an effective tool for disentangling different phases of reward anticipation, with relevance for affective symptomatology. Copyright © 2018 Elsevier Inc. All rights reserved.

A Computer-Assisted Learning Model Based on the Digital Game Exponential Reward System

Science.gov (United States)

Moon, Man-Ki; Jahng, Surng-Gahb; Kim, Tae-Yong

2011-01-01

The aim of this research was to construct a motivational model which would stimulate voluntary and proactive learning using digital game methods offering players more freedom and control. The theoretical framework of this research lays the foundation for a pedagogical learning model based on digital games. We analyzed the game reward system, which…

Trial-by-Trial Modulation of Associative Memory Formation by Reward Prediction Error and Reward Anticipation as Revealed by a Biologically Plausible Computational Model.

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Aberg, Kristoffer C; Müller, Julia; Schwartz, Sophie

2017-01-01

Anticipation and delivery of rewards improves memory formation, but little effort has been made to disentangle their respective contributions to memory enhancement. Moreover, it has been suggested that the effects of reward on memory are mediated by dopaminergic influences on hippocampal plasticity. Yet, evidence linking memory improvements to actual reward computations reflected in the activity of the dopaminergic system, i.e., prediction errors and expected values, is scarce and inconclusive. For example, different previous studies reported that the magnitude of prediction errors during a reinforcement learning task was a positive, negative, or non-significant predictor of successfully encoding simultaneously presented images. Individual sensitivities to reward and punishment have been found to influence the activation of the dopaminergic reward system and could therefore help explain these seemingly discrepant results. Here, we used a novel associative memory task combined with computational modeling and showed independent effects of reward-delivery and reward-anticipation on memory. Strikingly, the computational approach revealed positive influences from both reward delivery, as mediated by prediction error magnitude, and reward anticipation, as mediated by magnitude of expected value, even in the absence of behavioral effects when analyzed using standard methods, i.e., by collapsing memory performance across trials within conditions. We additionally measured trait estimates of reward and punishment sensitivity and found that individuals with increased reward (vs. punishment) sensitivity had better memory for associations encoded during positive (vs. negative) prediction errors when tested after 20 min, but a negative trend when tested after 24 h. In conclusion, modeling trial-by-trial fluctuations in the magnitude of reward, as we did here for prediction errors and expected value computations, provides a comprehensive and biologically plausible description of

Reward-enhanced memory in younger and older adults.

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Spaniol, Julia; Schain, Cécile; Bowen, Holly J

2014-09-01

We investigated how the anticipation of remote monetary reward modulates intentional episodic memory formation in younger and older adults. On the basis of prior findings of preserved reward-cognition interactions in aging, we predicted that reward anticipation would be associated with enhanced memory in both younger and older adults. On the basis of previous demonstrations of a time-dependent effect of reward anticipation on memory, we expected the memory enhancement to increase with study-test delay. In Experiment 1, younger and older participants encoded a series of picture stimuli associated with high- or low-reward values. At test (24-hr postencoding), recognition hits resulted in either high or low monetary rewards, whereas false alarms were penalized to discourage guessing. Experiment 2 was similar to Experiment 1, but the study-test delay was manipulated within subjects (immediate vs 24hr). In Experiment 1, younger and older adults showed enhanced recognition for high-reward pictures compared with low-reward pictures. Experiment 2 replicated this finding and additionally showed that the effect did not extend to immediate recognition. The current findings provide support for a time-dependent mechanism of reward-based memory enhancement. They also suggest that aging leaves intact the positive influence of reward anticipation on intentional long-term memory formation. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Perceptions of rewards among volunteer caregivers of people living with AIDS working in faith-based organizations in South Africa: a qualitative study.

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Akintola, Olagoke

2010-06-14

Volunteer caregivers are a critical source of support for the majority of people living with HIV and AIDS in southern Africa, which has extremely high HIV/AIDS prevalence rates. While studies have shown that volunteer caregiving is associated with negative health and socio-economic outcomes, little is known about the positive experiences of volunteers in the home-based care context in South Africa. The purpose of this study is to explore the perception of rewards among volunteers working in home-based care settings. This study uses a qualitative design. Qualitative interviews were conducted with a purposively selected sample of 55 volunteer caregivers using an interview schedule containing open-ended questions. Volunteer caregivers derived intrinsic rewards related to self-growth and personal (emotional and psychological) development on the job; they also derived satisfaction from community members taking a liking for them and expressing a need for their services. Volunteers felt gratified by the improvements in their health behaviours, which were a direct consequence of the experiences of caring for terminally ill patients with AIDS. Extrinsic rewards came from appreciation and recognition shown by patients and community members. Extrinsic rewards also accrued to volunteers when the services they rendered made their patients happy. Perhaps the greatest sources of extrinsic rewards are skills and competencies acquired from training and experience while caring for their patients, and volunteers' ability to make a difference in the community. Insights into volunteer caregiver rewards provide opportunities for policy makers and programme managers to develop a model of home-based care that facilitates the accrual of rewards to volunteers alongside volunteers' traditional duties of patient care. Programme managers could employ these insights in recruiting and assisting volunteers to identify and reflect on rewards in the caregiving situation as a means of reducing the

Situational moderators of leader reward and punishment behaviors: fact or fiction?

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Podsakoff, P M; Todor, W D; Grover, R A; Huber, V L

1984-08-01

One assumption shared by many contemporary models of leadership is that situational variables moderate the relationships between leader behaviors and subordinate responses. Recently, however, R. J. House and J. L. Baetz (1979 in B. Staw & L. Cummings, Eds., Research in Organizational Behavior (Vol. 1), Greenwich, Connecticut, JAI Press) have suggested that the effects of some leader traits and behaviors may be relatively invariant; that is, have the same effects in a variety of situations. One possible class of leader behaviors which may have relatively consistent effects across situations are those known as leader reward and punishment behaviors. The first goal of the research reported here was to increase our understanding of the relationships between leader contingent and noncontingent reward and punishment behaviors and subordinate responses. Contingent reward behavior was found to have the most pronounced relationships with subordinate performance and satisfaction, followed by noncontingent punishment behavior. Neither leader noncontingent reward nor contingent punishment behavior were found to be related to either subordinate performance or satisfaction, with the exception that noncontingent reward behavior was negatively related to subordinates' satisfaction with work. The second goal of the research was to examine the effects of a variety of potential moderators on the relationships between leader reward and punishment behaviors and subordinate responses. The results of this study suggest that the relationships between leader reward and punishment behaviors and subordinates' performance are relatively free of moderating effects.

Random reward priming is task-contingent: The robustness of the 1-trial reward priming effect

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Árni Gunnar Ásgeirsson

2014-04-01

Full Text Available Consistent financial reward of particular features influences the allocation of visual attention in many ways. More surprising are 1-trial reward priming effects on attention where reward schedules are random and reward on one trial influences attentional allocation on the next. Those findings are thought to reflect that rewarded features become more salient than unrewarded ones on the subsequent trial. Here we attempt to conceptually replicate this effect, testing its generalizability. In three versions of an analogous paradigm to the additional singleton paradigm involving singleton search for a Gabor patch of odd spatial frequency we found no evidence of reward priming, while we only partially replicate the reward priming in the exact original paradigm tested by Hickey and colleagues. The results cast doubt on the proposal that random reward enhances salience, suggested in the original papers, and highlight the need for a more nuanced account. In many other paradigms reward effects have been found to progress gradually, becoming stronger as they build up, and we argue that for robust reward priming, reward schedules need to be more consistent than in the original 1-trial reward priming paradigm.

The alcoholic brain: neural bases of impaired reward-based decision-making in alcohol use disorders.

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Galandra, Caterina; Basso, Gianpaolo; Cappa, Stefano; Canessa, Nicola

2018-03-01

Neuroeconomics is providing insights into the neural bases of decision-making in normal and pathological conditions. In the neuropsychiatric domain, this discipline investigates how abnormal functioning of neural systems associated with reward processing and cognitive control promotes different disorders, and whether such evidence may inform treatments. This endeavor is crucial when studying different types of addiction, which share a core promoting mechanism in the imbalance between impulsive subcortical neural signals associated with immediate pleasurable outcomes and inhibitory signals mediated by a prefrontal reflective system. The resulting impairment in behavioral control represents a hallmark of alcohol use disorders (AUDs), a chronic relapsing disorder characterized by excessive alcohol consumption despite devastating consequences. This review aims to summarize available magnetic resonance imaging (MRI) evidence on reward-related decision-making alterations in AUDs, and to envision possible future research directions. We review functional MRI (fMRI) studies using tasks involving monetary rewards, as well as MRI studies relating decision-making parameters to neurostructural gray- or white-matter metrics. The available data suggest that excessive alcohol exposure affects neural signaling within brain networks underlying adaptive behavioral learning via the implementation of prediction errors. Namely, weaker ventromedial prefrontal cortex activity and altered connectivity between ventral striatum and dorsolateral prefrontal cortex likely underpin a shift from goal-directed to habitual actions which, in turn, might underpin compulsive alcohol consumption and relapsing episodes despite adverse consequences. Overall, these data highlight abnormal fronto-striatal connectivity as a candidate neurobiological marker of impaired choice in AUDs. Further studies are needed, however, to unveil its implications in the multiple facets of decision-making.

A correction term for the covariance of renewal-reward processes with multivariate rewards

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Patch, B.; Nazarathy, Y.; Taimre, T.

We consider a renewal-reward process with multivariate rewards. Such a process is constructed from an i.i.d. sequence of time periods, to each of which there is associated a multivariate reward vector. The rewards in each time period may depend on each other and on the period length, but not on the

Utilization of reward-prospect enhances preparatory attention and reduces stimulus conflict.

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van den Berg, Berry; Krebs, Ruth M; Lorist, Monicque M; Woldorff, Marty G

2014-06-01

The prospect of gaining money is an incentive widely at play in the real world. Such monetary motivation might have particularly strong influence when the cognitive system is challenged, such as when needing to process conflicting stimulus inputs. Here, we employed manipulations of reward-prospect and attentional-preparation levels in a cued-Stroop stimulus conflict task, along with the high temporal resolution of electrical brain recordings, to provide insight into the mechanisms by which reward-prospect and attention interact and modulate cognitive task performance. In this task, the cue indicated whether or not the participant needed to prepare for an upcoming Stroop stimulus and, if so, whether there was the potential for monetary reward (dependent on performance on that trial). Both cued attention and cued reward-prospect enhanced preparatory neural activity, as reflected by increases in the hallmark attention-related negative-polarity ERP slow wave (contingent negative variation [CNV]) and reductions in oscillatory Alpha activity, which was followed by enhanced processing of the subsequent Stroop stimulus. In addition, similar modulations of preparatory neural activity (larger CNVs and reduced Alpha) predicted shorter versus longer response times (RTs) to the subsequent target stimulus, consistent with such modulations reflecting trial-to-trial variations in attention. Particularly striking were the individual differences in the utilization of reward-prospect information. In particular, the size of the reward effects on the preparatory neural activity correlated across participants with the degree to which reward-prospect both facilitated overall task performance (shorter RTs) and reduced conflict-related behavioral interference. Thus, the prospect of reward appears to recruit attentional preparation circuits to enhance processing of task-relevant target information.

Ventral striatal activity links adversity and reward processing in children

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Niki H. Kamkar

2017-08-01

Full Text Available Adversity impacts many aspects of psychological and physical development including reward-based learning and decision-making. Mechanisms relating adversity and reward processing in children, however, remain unclear. Here, we show that adversity is associated with potentiated learning from positive outcomes and impulsive decision-making, but unrelated to learning from negative outcomes. We then show via functional magnetic resonance imaging that the link between adversity and reward processing is partially mediated by differences in ventral striatal response to rewards. The findings suggest that early-life adversity is associated with alterations in the brain’s sensitivity to rewards accounting, in part, for the link between adversity and altered reward processing in children.

Developmental continuity in reward-related enhancement of cognitive control.

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Strang, Nicole M; Pollak, Seth D

2014-10-01

Adolescents engage in more risky behavior than children or adults. The most prominent hypothesis for this phenomenon is that brain systems governing reward sensitivity and brain systems governing self-regulation mature at different rates. Those systems governing reward sensitivity mature in advance of those governing self-control. This hypothesis has substantial empirical support, however, the evidence supporting this theory has been exclusively derived from contexts where self-control systems are required to regulate reward sensitivity in order to promote adaptive behavior. In adults, reward promotes a shift to a proactive control strategy and better cognitive control performance. It is unclear whether children and adolescents will respond to reward in the same way. Using fMRI methodology, we explored whether children and adolescents would demonstrate a shift to proactive control in the context of reward. We tested 22 children, 20 adolescents, and 23 adults. In contrast to our hypothesis, children, adolescents, and adults all demonstrated a shift to proactive cognitive control in the context of reward. In light of the results, current neurobiological theories of adolescent behavior need to be refined to reflect that in certain contexts there is continuity in the manner reward and cognitive control systems interact across development. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Markov counting and reward processes for analysing the performance of a complex system subject to random inspections

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Ruiz-Castro, Juan Eloy

2016-01-01

In this paper, a discrete complex reliability system subject to internal failures and external shocks, is modelled algorithmically. Two types of internal failure are considered: repairable and non-repairable. When a repairable failure occurs, the unit goes to corrective repair. In addition, the unit is subject to external shocks that may produce an aggravation of the internal degradation level, cumulative damage or extreme failure. When a damage threshold is reached, the unit must be removed. When a non-repairable failure occurs, the device is replaced by a new, identical one. The internal performance and the external damage are partitioned in performance levels. Random inspections are carried out. When an inspection takes place, the internal performance of the system and the damage caused by external shocks are observed and if necessary the unit is sent to preventive maintenance. If the inspection observes minor state for the internal performance and/or external damage, then these states remain in memory when the unit goes to corrective or preventive maintenance. Transient and stationary analyses are performed. Markov counting and reward processes are developed in computational form to analyse the performance and profitability of the system with and without preventive maintenance. These aspects are implemented computationally with Matlab. - Highlights: • A multi-state device is modelled in an algorithmic and computational form. • The performance is partitioned in multi-states and degradation levels. • Several types of failures with repair times according to degradation levels. • Preventive maintenance as response to random inspection is introduced. • The performance-profitable is analysed through Markov counting and reward processes.

A simple solution for model comparison in bold imaging: the special case of reward prediction error and reward outcomes.

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Erdeniz, Burak; Rohe, Tim; Done, John; Seidler, Rachael D

2013-01-01

Conventional neuroimaging techniques provide information about condition-related changes of the BOLD (blood-oxygen-level dependent) signal, indicating only where and when the underlying cognitive processes occur. Recently, with the help of a new approach called "model-based" functional neuroimaging (fMRI), researchers are able to visualize changes in the internal variables of a time varying learning process, such as the reward prediction error or the predicted reward value of a conditional stimulus. However, despite being extremely beneficial to the imaging community in understanding the neural correlates of decision variables, a model-based approach to brain imaging data is also methodologically challenging due to the multicollinearity problem in statistical analysis. There are multiple sources of multicollinearity in functional neuroimaging including investigations of closely related variables and/or experimental designs that do not account for this. The source of multicollinearity discussed in this paper occurs due to correlation between different subjective variables that are calculated very close in time. Here, we review methodological approaches to analyzing such data by discussing the special case of separating the reward prediction error signal from reward outcomes.

Acute Stress Influences Neural Circuits of Reward Processing

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Anthony John Porcelli

2012-11-01

Full Text Available People often make decisions under aversive conditions such as acute stress. Yet, less is known about the process in which acute stress can influence decision-making. A growing body of research has established that reward-related information associated with the outcomes of decisions exerts a powerful influence over the choices people make and that an extensive network of brain regions, prominently featuring the striatum, is involved in the processing of this reward-related information. Thus, an important step in research on the nature of acute stress’ influence over decision-making is to examine how it may modulate responses to rewards and punishments within reward-processing neural circuitry. In the current experiment, we employed a simple reward processing paradigm – where participants received monetary rewards and punishments – known to evoke robust striatal responses. Immediately prior to performing each of two task runs, participants were exposed to acute stress (i.e., cold pressor or a no stress control procedure in a between-subjects fashion. No stress group participants exhibited a pattern of activity within the dorsal striatum and orbitofrontal cortex consistent with past research on outcome processing – specifically, differential responses for monetary rewards over punishments. In contrast, acute stress group participants’ dorsal striatum and orbitofrontal cortex demonstrated decreased sensitivity to monetary outcomes and a lack of differential activity. These findings provide insight into how neural circuits may process rewards and punishments associated with simple decisions under acutely stressful conditions.

Reward and Attentional Control in Visual Search

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Anderson, Brian A.; Wampler, Emma K.; Laurent, Patryk A.

2015-01-01

It has long been known that the control of attention in visual search depends both on voluntary, top-down deployment according to context-specific goals, and on involuntary, stimulus-driven capture based on the physical conspicuity of perceptual objects. Recent evidence suggests that pairing target stimuli with reward can modulate the voluntary deployment of attention, but there is little evidence that reward modulates the involuntary deployment of attention to task-irrelevant distractors. We report several experiments that investigate the role of reward learning on attentional control. Each experiment involved a training phase and a test phase. In the training phase, different colors were associated with different amounts of monetary reward. In the test phase, color was not task-relevant and participants searched for a shape singleton; in most experiments no reward was delivered in the test phase. We first show that attentional capture by physically salient distractors is magnified by a previous association with reward. In subsequent experiments we demonstrate that physically inconspicuous stimuli previously associated with reward capture attention persistently during extinction—even several days after training. Furthermore, vulnerability to attentional capture by high-value stimuli is negatively correlated across individuals with working memory capacity and positively correlated with trait impulsivity. An analysis of intertrial effects reveals that value-driven attentional capture is spatially specific. Finally, when reward is delivered at test contingent on the task-relevant shape feature, recent reward history modulates value-driven attentional capture by the irrelevant color feature. The influence of learned value on attention may provide a useful model of clinical syndromes characterized by similar failures of cognitive control, including addiction, attention-deficit/hyperactivity disorder, and obesity. PMID:23437631

Offshore wind energy : balancing risk and reward

International Nuclear Information System (INIS)

Nerland, C.

2010-01-01

Offshore wind energy developments are expected to increase as the demand for renewable energy sources grows. This poster presentation described a method of balancing risk and reward in offshore wind energy projects. The method was based on risk assessment strategies used by the oil and gas industry. The dedicated framework considered schedules; budgets; performance; and operating and maintenance costs. A value chain assessment method was used to optimize the balance between risk and reward by evaluating uncertainties and risk related to each project element and its relationship to other elements within an integrated dynamic model designed to determine the net present value of a project. The decision-making criteria included the RISKEX risk expenditure strategy designed to consider the balance between risk exposure, capital expenditures, and operational expenditures in relation to the statistical cost of unplanned repairs, and lost production capacity. A case study of a large offshore wind farm was used to demonstrate the method. tabs., figs.

Decision-making and addiction (part II): myopia for the future or hypersensitivity to reward?

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Bechara, Antoine; Dolan, Sara; Hindes, Andrea

2002-01-01

On a decision-making instrument known as the "gambling task" (GT), a subgroup of substance dependent individuals (SDI) opted for choices that yield high immediate gains in spite of higher future losses. This resembles the behavior of patients with ventromedial (VM) prefrontal cortex lesions. In this study, we addressed the possibility that hypersensitivity to reward may account for the "myopia" for the future in this subgroup of SDI. We used a variant version of the GT, in which the good decks yielded high immediate punishment but higher delayed reward. The bad decks yielded low immediate punishment and lower delayed reward. We measured the skin conductance response (SCR) of subjects after receiving reward (reward SCR) and during their pondering from which deck to choose (anticipatory SCR). A subgroup of SDI who was not impaired on the original GT performed normally on the variant GT. The subgroup of SDI who was impaired on the original GT showed two levels of performance on the variant GT. One subgroup (36% of the sample) performed poorly on the variant GT, and showed similar behavioral and physiological impairments to VM patients. The other subgroup of SDI (64% of the sample) performed normally on the variant task, but had abnormally large physiological responses to reward, i.e. large SCR after receiving reward (reward SCR) and large SCR in anticipation of outcomes that yield large reward. Thus, the combined cognitive and physiological approach of assessing decision-making characterizes three sub-populations of SDI. One sub-population is without impairments that can be detected by any measure of the GT paradigm. Another sub-population is similar to VM patients in that they are insensitive to the future, both positive and negative. A third sub-population is hypersensitive to reward, so that the presence or the prospect of receiving, reward dominates their behavior.

Reward-seeking behavior and addiction: cause or cog?

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Arias-Carrión, Oscar; Salama, Mohamed

2012-09-01

Although dopaminergic system represents the cornerstone in rewarding, other neurotransmitters can modulate both the reward system and the psychomotor effects of addictive drugs. Many hypotheses have been proposed for a better understanding of the reward system and its role in drug addiction. However, after many years of investigation, no single theory can completely explain the neural basis of drug addiction. Recent reports introduce novel neurotransmitters into the game e.g. dynorphins, orexins, histamine, gheralin and galanin. The interacting functions of these neurotransmitters have shown that the reward system and its role in drug dependence, is far more complicated than was thought before. Individual variations exist regarding response to drug exposure, vulnerability for addiction and the effects of different cues on reward systems. Consequently, genetic variations of neurotransmission are thought to influence reward processing that in turn may affect distinctive social behavior and susceptibility to addiction. However, the individual variations can not be based mainly on genetics; environmental factors seem to play a role too. Here we discuss the current knowledge about the orquestic regulation of different neurotransmitters on reward-seeking behavior and their potential effect on drug addiction.

Gender dimorphism of brain reward system volumes in alcoholism.

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Sawyer, Kayle S; Oscar-Berman, Marlene; Barthelemy, Olivier J; Papadimitriou, George M; Harris, Gordon J; Makris, Nikos

2017-05-30

The brain's reward network has been reported to be smaller in alcoholic men compared to nonalcoholic men, but little is known about the volumes of reward regions in alcoholic women. Morphometric analyses were performed on magnetic resonance brain scans of 60 long-term chronic alcoholics (ALC; 30 men) and 60 nonalcoholic controls (NC; 29 men). We derived volumes of total brain, and cortical and subcortical reward-related structures including the dorsolateral prefrontal (DLPFC), orbitofrontal, and cingulate cortices, and the temporal pole, insula, amygdala, hippocampus, nucleus accumbens septi (NAc), and ventral diencephalon (VDC). We examined the relationships of the volumetric findings to drinking history. Analyses revealed a significant gender interaction for the association between alcoholism and total reward network volumes, with ALC men having smaller reward volumes than NC men and ALC women having larger reward volumes than NC women. Analyses of a priori subregions revealed a similar pattern of reward volume differences with significant gender interactions for DLPFC and VDC. Overall, the volume of the cerebral ventricles in ALC participants was negatively associated with duration of abstinence, suggesting decline in atrophy with greater length of sobriety. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Extending overjustification: the effect of perceived reward-giver intention on response to rewards.

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Forehand, M R

2000-12-01

The perceived intention model incorporates a new moderator, beliefs about reward-giver intention, into the overjustification paradigm. In 2 simulated shopping studies featuring products paired with promotional rewards, consumers who believed the marketer was promotion focused (reward used to encourage purchase) reported lower purchase intentions and brand attitudes for promoted products after promotion, whereas consumers who believed the marketer was reward focused (promotion used to distribute the reward) showed no attitude change. Promotion-focus beliefs lowered attitudes by heightening the contingency between the promotion and purchase and thereby increasing the perceived causal role of the reward. This effect was contingent on initial behavior--postpromotion attitude change occurred for consumers who actively engaged in product decisions but not for consumers who passively observed the choice sets.

I endeavor to make it: effort increases valuation of subsequent monetary reward.

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Ma, Qingguo; Meng, Liang; Wang, Lei; Shen, Qiang

2014-03-15

Although it is commonly accepted that the amount of effort we put into accomplishing a task would exert an influence on subsequent reward processing and outcome evaluation, whether effort is incorporated as a cost or it would increase the valuation of concomitant reward is still under debate. In this study, EEGs were recorded while subjects performed calculation tasks that required different amount of effort, correct responses of which were followed by either no reward or fixed compensation. Results showed that high effort induced larger differentiated FRN responses to the reward and non-reward discrepancy across two experimental conditions. Furthermore, P300 manifested valence effect during reward feedback, with more positive amplitudes for reward than for non-reward only in the high effort condition. These results suggest that effort might increase subjective evaluation toward subsequent reward. Copyright © 2013 Elsevier B.V. All rights reserved.

Neural Processing of Calories in Brain Reward Areas Can be Modulated by Reward Sensitivity

NARCIS (Netherlands)

van Rijn, Inge; Griffioen-Roose, Sanne; de Graaf, Cees; Smeets, Paul A M

A food's reward value is dependent on its caloric content. Furthermore, a food's acute reward value also depends on hunger state. The drive to obtain rewards (reward sensitivity), however, differs between individuals. Here, we assessed the association between brain responses to calories in the mouth

Regional brain activation supporting cognitive control in the context of reward is associated with treated adolescents’ marijuana problem severity at follow-up: A preliminary study

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Tammy Chung

2015-12-01

Full Text Available This preliminary study examined the extent to which regional brain activation during a reward cue antisaccade (AS task was associated with 6-month treatment outcome in adolescent substance users. Antisaccade performance provides a sensitive measure of executive function and cognitive control, and generally improves with reward cues. We hypothesized that when preparing to execute an AS, greater activation in regions associated with cognitive and oculomotor control supporting AS, particularly during reward cue trials, would be associated with lower substance use severity at 6-month follow-up. Adolescents (n = 14, ages 14–18 recruited from community-based outpatient treatment completed an fMRI reward cue AS task (reward and neutral conditions, and provided follow-up data. Results indicated that AS errors decreased in reward, compared to neutral, trials. AS behavioral performance, however, was not associated with treatment outcome. As hypothesized, activation in regions of interest (ROIs associated with cognitive (e.g., ventrolateral prefrontal cortex and oculomotor control (e.g., supplementary eye field during reward trials were inversely correlated with marijuana problem severity at 6-months. ROI activation during neutral trials was not associated with outcomes. Results support the role of motivational (reward cue factors to enhance cognitive control processes, and suggest a potential brain-based correlate of youth treatment outcome.

The use of preferred social stimuli as rewards for rhesus macaques in behavioural neuroscience.

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Helen Gray

Full Text Available Macaques are often motivated to perform in neuroscientific experiments by implementing fluid restriction protocols. Daily access to water is controlled and the monkeys are rewarded with droplets of fluid for performing correct trials in the laboratory. Although these protocols are widely used and highly effective, it is important from a 3Rs perspective to investigate refinements that may help to lessen the severity of the fluid restriction applied. We assessed the use of social stimuli (images of conspecifics as rewards for four rhesus macaques performing simple cognitive tasks. We found that individual preferences for images of male faces, female perinea and control stimuli could be identified in each monkey. However, using preferred images did not translate into effective motivators on a trial-by-trial basis: animals preferred fluid rewards, even when fluid restriction was relaxed. There was no difference in the monkeys' performance of a task when using greyscale versus colour images. Based on our findings, we cannot recommend the use of social stimuli, in this form, as a refinement to current fluid restriction protocols. We discuss the potential alternatives and possibilities for future research.

Two facets of patience in young children: Waiting with and without an explicit reward.

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Barragan-Jason, Gladys; Atance, Cristina; Kopp, Leia; Hopfensitz, Astrid

2018-07-01

Patience, or the ability to tolerate delay, is typically studied using delay of gratification (DoG) tasks. However, among other factors (e.g., type of reward), the use of a reward to test patience is affected by an individual's motivation to obtain the reward (e.g., degree of preference for the small vs. large reward). In addition, DoG tasks do not assess the extent to which an individual can wait in the absence of an explicit reward-or what we term "patience as a virtue." Accordingly, the current study used a new measure of patience-the "pure waiting paradigm"-in which 3- to 5-year-old children waited 3 min with nothing to do and with no explicit reward. We then examined the relation between performance on this task (as assessed by children's spontaneous patient behaviors) and performance on two DoG tasks (candy and video rewards). Significant correlations were found between DoG performance and patient behaviors in the pure waiting paradigm, especially when controlling for motivation. These results and methodology show for the first time a direct link between patience as a virtue and DoG performance and also provide new insights about the study of patience in children. Copyright © 2018 Elsevier Inc. All rights reserved.

Comparing the neural basis of monetary reward and cognitive feedback during information-integration category learning.

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Daniel, Reka; Pollmann, Stefan

2010-01-06

The dopaminergic system is known to play a central role in reward-based learning (Schultz, 2006), yet it was also observed to be involved when only cognitive feedback is given (Aron et al., 2004). Within the domain of information-integration category learning, in which information from several stimulus dimensions has to be integrated predecisionally (Ashby and Maddox, 2005), the importance of contingent feedback is well established (Maddox et al., 2003). We examined the common neural correlates of reward anticipation and prediction error in this task. Sixteen subjects performed two parallel information-integration tasks within a single event-related functional magnetic resonance imaging session but received a monetary reward only for one of them. Similar functional areas including basal ganglia structures were activated in both task versions. In contrast, a single structure, the nucleus accumbens, showed higher activation during monetary reward anticipation compared with the anticipation of cognitive feedback in information-integration learning. Additionally, this activation was predicted by measures of intrinsic motivation in the cognitive feedback task and by measures of extrinsic motivation in the rewarded task. Our results indicate that, although all other structures implicated in category learning are not significantly affected by altering the type of reward, the nucleus accumbens responds to the positive incentive properties of an expected reward depending on the specific type of the reward.

Associations among smoking, anhedonia, and reward learning in depression.

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Liverant, Gabrielle I; Sloan, Denise M; Pizzagalli, Diego A; Harte, Christopher B; Kamholz, Barbara W; Rosebrock, Laina E; Cohen, Andrew L; Fava, Maurizio; Kaplan, Gary B

2014-09-01

Depression and cigarette smoking co-occur at high rates. However, the etiological mechanisms that contribute to this relationship remain unclear. Anhedonia and associated impairments in reward learning are key features of depression, which also have been linked to the onset and maintenance of cigarette smoking. However, few studies have investigated differences in anhedonia and reward learning among depressed smokers and depressed nonsmokers. The goal of this study was to examine putative differences in anhedonia and reward learning in depressed smokers (n=36) and depressed nonsmokers (n=44). To this end, participants completed self-report measures of anhedonia and behavioral activation (BAS reward responsiveness scores) and as well as a probabilistic reward task rooted in signal detection theory, which measures reward learning (Pizzagalli, Jahn, & O'Shea, 2005). When considering self-report measures, depressed smokers reported higher trait anhedonia and reduced BAS reward responsiveness scores compared to depressed nonsmokers. In contrast to self-report measures, nicotine-satiated depressed smokers demonstrated greater acquisition of reward-based learning compared to depressed nonsmokers as indexed by the probabilistic reward task. Findings may point to a potential mechanism underlying the frequent co-occurrence of smoking and depression. These results highlight the importance of continued investigation of the role of anhedonia and reward system functioning in the co-occurrence of depression and nicotine abuse. Results also may support the use of treatments targeting reward learning (e.g., behavioral activation) to enhance smoking cessation among individuals with depression. Copyright © 2014. Published by Elsevier Ltd.

Effects of pulvinar inactivation on spatial decision-making between equal and asymmetric reward options.

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Wilke, Melanie; Kagan, Igor; Andersen, Richard A

2013-08-01

The ability to selectively process visual inputs and to decide between multiple movement options in an adaptive manner is critical for survival. Such decisions are known to be influenced by factors such as reward expectation and visual saliency. The dorsal pulvinar connects to a multitude of cortical areas that are involved in visuospatial memory and integrate information about upcoming eye movements with expected reward values. However, it is unclear whether the dorsal pulvinar is critically involved in spatial memory and reward-based oculomotor decision behavior. To examine this, we reversibly inactivated the dorsal portion of the pulvinar while monkeys performed a delayed memory saccade task that included choices between equally or unequally rewarded options. Pulvinar inactivation resulted in a delay of saccade initiation toward memorized contralesional targets but did not affect spatial memory. Furthermore, pulvinar inactivation caused a pronounced choice bias toward the ipsilesional hemifield when the reward value in the two hemifields was equal. However, this choice bias could be alleviated by placing a high reward target into the contralesional hemifield. The bias was less affected by the manipulation of relative visual saliency between the two competing targets. These results suggest that the dorsal pulvinar is involved in determining the behavioral desirability of movement goals while being less critical for spatial memory and reward processing.

Ventral striatal activity links adversity and reward processing in children.

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Kamkar, Niki H; Lewis, Daniel J; van den Bos, Wouter; Morton, J Bruce

2017-08-01

Adversity impacts many aspects of psychological and physical development including reward-based learning and decision-making. Mechanisms relating adversity and reward processing in children, however, remain unclear. Here, we show that adversity is associated with potentiated learning from positive outcomes and impulsive decision-making, but unrelated to learning from negative outcomes. We then show via functional magnetic resonance imaging that the link between adversity and reward processing is partially mediated by differences in ventral striatal response to rewards. The findings suggest that early-life adversity is associated with alterations in the brain's sensitivity to rewards accounting, in part, for the link between adversity and altered reward processing in children. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

The Influence of Teacher Motivation in the Context of Performance-Based Compensation

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Glass, Jason E.

2011-01-01

The purpose of this study was to examine teacher motivation in the context of performance-based compensation systems. The researcher specifically sought to address four research questions: 1. To what extent are teachers motivated for behavioristic/economic reasons and extrinsic rewards? 2. To what extent are teachers motivated for altruistic/PSM…

Integration of homeostatic signaling and food reward processing in the human brain.

Science.gov (United States)

Simon, Joe J; Wetzel, Anne; Sinno, Maria Hamze; Skunde, Mandy; Bendszus, Martin; Preissl, Hubert; Enck, Paul; Herzog, Wolfgang; Friederich, Hans-Christoph

2017-08-03

Food intake is guided by homeostatic needs and by the reward value of food, yet the exact relation between the two remains unclear. The aim of this study was to investigate the influence of different metabolic states and hormonal satiety signaling on responses in neural reward networks. Twenty-three healthy participants underwent functional magnetic resonance imaging while performing a task distinguishing between the anticipation and the receipt of either food- or monetary-related reward. Every participant was scanned twice in a counterbalanced fashion, both during a fasted state (after 24 hours fasting) and satiety. A functional connectivity analysis was performed to investigate the influence of satiety signaling on activation in neural reward networks. Blood samples were collected to assess hormonal satiety signaling. Fasting was associated with sensitization of the striatal reward system to the anticipation of food reward irrespective of reward magnitude. Furthermore, during satiety, individual ghrelin levels were associated with increased neural processing during the expectation of food-related reward. Our findings show that physiological hunger stimulates food consumption by specifically increasing neural processing during the expectation (i.e., incentive salience) but not the receipt of food-related reward. In addition, these findings suggest that ghrelin signaling influences hedonic-driven food intake by increasing neural reactivity during the expectation of food-related reward. These results provide insights into the neurobiological underpinnings of motivational processing and hedonic evaluation of food reward. ClinicalTrials.gov NCT03081585. This work was supported by the German Competence Network on Obesity, which is funded by the German Federal Ministry of Education and Research (FKZ 01GI1122E).

Motivation and reward systems

NARCIS (Netherlands)

van Eerde, W.; Vodosek, M.; den Hartog, D.N.; McNett, J.M.

2014-01-01

Reward systems are identified as one of the human resource management (HRM) practices that may impact motivation. Reward systems may consist of several components, including financial and nonfinancial rewards, in fixed and variable amounts. Reinforcement, expectancy, and equity principles are

Major depressive disorder is characterized by greater reward network activation to monetary than pleasant image rewards.

Science.gov (United States)

Smoski, Moria J; Rittenberg, Alison; Dichter, Gabriel S

2011-12-30

Anhedonia, the loss of interest or pleasure in normally rewarding activities, is a hallmark feature of unipolar Major Depressive Disorder (MDD). A growing body of literature has identified frontostriatal dysfunction during reward anticipation and outcomes in MDD. However, no study to date has directly compared responses to different types of rewards such as pleasant images and monetary rewards in MDD. To investigate the neural responses to monetary and pleasant image rewards in MDD, a modified Monetary Incentive Delay task was used during functional magnetic resonance imaging to assess neural responses during anticipation and receipt of monetary and pleasant image rewards. Participants included nine adults with MDD and 13 affectively healthy controls. The MDD group showed lower activation than controls when anticipating monetary rewards in right orbitofrontal cortex and subcallosal cortex, and when anticipating pleasant image rewards in paracingulate and supplementary motor cortex. The MDD group had relatively greater activation in right putamen when anticipating monetary versus pleasant image rewards, relative to the control group. Results suggest reduced reward network activation in MDD when anticipating rewards, as well as relatively greater hypoactivation to pleasant image than monetary rewards. 2011 Elsevier Ireland Ltd. All rights reserved.

Cognitive regulation of saccadic velocity by reward prospect.

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Chen, Lewis L; Hung, Leroy Y; Quinet, Julie; Kosek, Kevin

2013-08-01

It is known that expectation of reward speeds up saccades. Past studies have also shown the presence of a saccadic velocity bias in the orbit, resulting from a biomechanical regulation over varying eccentricities. Nevertheless, whether and how reward expectation interacts with the biomechanical regulation of saccadic velocities over varying eccentricities remains unknown. We addressed this question by conducting a visually guided double-step saccade task. The role of reward expectation was tested in monkeys performing two consecutive horizontal saccades, one associated with reward prospect and the other not. To adequately assess saccadic velocity and avoid adaptation, we systematically varied initial eye positions, saccadic directions and amplitudes. Our results confirmed the existence of a velocity bias in the orbit, i.e., saccadic peak velocity decreased linearly as the initial eye position deviated in the direction of the saccade. The slope of this bias increased as saccadic amplitudes increased. Nevertheless, reward prospect facilitated velocity to a greater extent for saccades away from than for saccades toward the orbital centre, rendering an overall reduction in the velocity bias. The rate (slope) and magnitude (intercept) of reward modulation over this velocity bias were linearly correlated with amplitudes, similar to the amplitude-modulated velocity bias without reward prospect, which presumably resulted from a biomechanical regulation. Small-amplitude (≤ 5°) saccades received little modulation. These findings together suggest that reward expectation modulated saccadic velocity not as an additive signal but as a facilitating mechanism that interacted with the biomechanical regulation. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Reward association facilitates distractor suppression in human visual search.

Science.gov (United States)

Gong, Mengyuan; Yang, Feitong; Li, Sheng

2016-04-01

Although valuable objects are attractive in nature, people often encounter situations where they would prefer to avoid such distraction while focusing on the task goal. Contrary to the typical effect of attentional capture by a reward-associated item, we provide evidence for a facilitation effect derived from the active suppression of a high reward-associated stimulus when cuing its identity as distractor before the display of search arrays. Selection of the target is shown to be significantly faster when the distractors were in high reward-associated colour than those in low reward-associated or non-rewarded colours. This behavioural reward effect was associated with two neural signatures before the onset of the search display: the increased frontal theta oscillation and the strengthened top-down modulation from frontal to anterior temporal regions. The former suggests an enhanced working memory representation for the reward-associated stimulus and the increased need for cognitive control to override Pavlovian bias, whereas the latter indicates that the boost of inhibitory control is realized through a frontal top-down mechanism. These results suggest a mechanism in which the enhanced working memory representation of a reward-associated feature is integrated with task demands to modify attentional priority during active distractor suppression and benefit behavioural performance. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Multiple reward-cue contingencies favor expectancy over uncertainty in shaping the reward-cue attentional salience.

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De Tommaso, Matteo; Mastropasqua, Tommaso; Turatto, Massimo

2018-01-25

Reward-predicting cues attract attention because of their motivational value. A debated question regards the conditions under which the cue's attentional salience is governed more by reward expectancy rather than by reward uncertainty. To help shedding light on this relevant issue, here, we manipulated expectancy and uncertainty using three levels of reward-cue contingency, so that, for example, a high level of reward expectancy (p = .8) was compared with the highest level of reward uncertainty (p = .5). In Experiment 1, the best reward-cue during conditioning was preferentially attended in a subsequent visual search task. This result was replicated in Experiment 2, in which the cues were matched in terms of response history. In Experiment 3, we implemented a hybrid procedure consisting of two phases: an omission contingency procedure during conditioning, followed by a visual search task as in the previous experiments. Crucially, during both phases, the reward-cues were never task relevant. Results confirmed that, when multiple reward-cue contingencies are explored by a human observer, expectancy is the major factor controlling both the attentional and the oculomotor salience of the reward-cue.

The amygdala, reward and emotion.

Science.gov (United States)

Murray, Elisabeth A

2007-11-01

Recent research provides new insights into amygdala contributions to positive emotion and reward. Studies of neuronal activity in the monkey amygdala and of autonomic responses mediated by the monkey amygdala show that, contrary to a widely held view, the amygdala is just as important for processing positive reward and reinforcement as it is for negative. In addition, neuropsychological studies reveal that the amygdala is essential for only a fraction of what might be considered 'stimulus-reward processing', and that the neural substrates for emotion and reward are partially nonoverlapping. Finally, evidence suggests that two systems within the amygdala, operating in parallel, enable reward-predicting cues to influence behavior; one mediates a general, arousing effect of reward and the other links the sensory properties of reward to emotion.

Reward-prospect interacts with trial-by-trial preparation for potential distraction.

Science.gov (United States)

Marini, Francesco; van den Berg, Berry; Woldorff, Marty G

2015-02-01

When attending for impending visual stimuli, cognitive systems prepare to identify relevant information while ignoring irrelevant, potentially distracting input. Recent work (Marini et al., 2013) showed that a supramodal distracter-filtering mechanism is invoked in blocked designs involving expectation of possible distracter stimuli, although this entails a cost ( distraction-filtering cost ) on speeded performance when distracters are expected but not presented. Here we used an arrow-flanker task to study whether an analogous cost, potentially reflecting the recruitment of a specific distraction-filtering mechanism, occurs dynamically when potential distraction is cued trial-to-trial ( cued distracter-expectation cost ). In order to promote the maximal utilization of cue information by participants, in some experimental conditions the cue also signaled the possibility of earning a monetary reward for fast and accurate performance. This design also allowed us to investigate the interplay between anticipation for distracters and anticipation of reward, which is known to engender attentional preparation. Only in reward contexts did participants show a cued distracter-expectation cost, which was larger with higher reward prospect and when anticipation for both distracters and reward were manipulated trial-to-trial. Thus, these results indicate that reward prospect interacts with the distracter expectation during trial-by-trial preparatory processes for potential distraction. These findings highlight how reward guides cue-driven attentional preparation.

High temporal discounters overvalue immediate rewards rather than undervalue future rewards: an event-related brain potential study.

Science.gov (United States)

Cherniawsky, Avital S; Holroyd, Clay B

2013-03-01

Impulsivity is characterized in part by heightened sensitivity to immediate relative to future rewards. Although previous research has suggested that "high discounters" in intertemporal choice tasks tend to prefer immediate over future rewards because they devalue the latter, it remains possible that they instead overvalue immediate rewards. To investigate this question, we recorded the reward positivity, a component of the event-related brain potential (ERP) associated with reward processing, with participants engaged in a task in which they received both immediate and future rewards and nonrewards. The participants also completed a temporal discounting task without ERP recording. We found that immediate but not future rewards elicited the reward positivity. High discounters also produced larger reward positivities to immediate rewards than did low discounters, indicating that high discounters relatively overvalued immediate rewards. These findings suggest that high discounters may be more motivated than low discounters to work for monetary rewards, irrespective of the time of arrival of the incentives.

Addictive drugs and brain stimulation reward.

Science.gov (United States)

Wise, R A

1996-01-01

Direct electrical or chemical stimulation of specific brain regions can establish response habits similar to those established by natural rewards such as food or sexual contact. Cocaine, mu and delta opiates, nicotine, phencyclidine, and cannabis each have actions that summate with rewarding electrical stimulation of the medial forebrain bundle (MFB). The reward-potentiating effects of amphetamine and opiates are associated with central sites of action where these drugs also have their direct rewarding effects, suggesting common mechanisms for drug reward per se and for drug potentiation of brain stimulation reward. The central sites at which these and perhaps other drugs of abuse potentiate brain stimulation reward and are rewarding in their own right are consistent with the hypothesis that the laboratory reward of brain stimulation and the pharmacological rewards of addictive drugs are habit forming because they act in the brain circuits that subserve more natural and biologically significant rewards.

Effect of social influence on effort-allocation for monetary rewards.

Science.gov (United States)

Gilman, Jodi M; Treadway, Michael T; Curran, Max T; Calderon, Vanessa; Evins, A Eden

2015-01-01

Though decades of research have shown that people are highly influenced by peers, few studies have directly assessed how the value of social conformity is weighed against other types of costs and benefits. Using an effort-based decision-making paradigm with a novel social influence manipulation, we measured how social influence affected individuals' decisions to allocate effort for monetary rewards during trials with either high or low probability of receiving a reward. We found that information about the effort-allocation of peers modulated participant choices, specifically during conditions of low probability of obtaining a reward. This suggests that peer influence affects effort-based choices to obtain rewards especially under conditions of risk. This study provides evidence that people value social conformity in addition to other costs and benefits when allocating effort, and suggests that neuroeconomic studies that assess trade-offs between effort and reward should consider social environment as a factor that can influence decision-making.

Effect of social influence on effort-allocation for monetary rewards.

Directory of Open Access Journals (Sweden)

Jodi M Gilman

Full Text Available Though decades of research have shown that people are highly influenced by peers, few studies have directly assessed how the value of social conformity is weighed against other types of costs and benefits. Using an effort-based decision-making paradigm with a novel social influence manipulation, we measured how social influence affected individuals' decisions to allocate effort for monetary rewards during trials with either high or low probability of receiving a reward. We found that information about the effort-allocation of peers modulated participant choices, specifically during conditions of low probability of obtaining a reward. This suggests that peer influence affects effort-based choices to obtain rewards especially under conditions of risk. This study provides evidence that people value social conformity in addition to other costs and benefits when allocating effort, and suggests that neuroeconomic studies that assess trade-offs between effort and reward should consider social environment as a factor that can influence decision-making.

Food reward system: current perspectives and future research needs.

Science.gov (United States)

Alonso-Alonso, Miguel; Woods, Stephen C; Pelchat, Marcia; Grigson, Patricia Sue; Stice, Eric; Farooqi, Sadaf; Khoo, Chor San; Mattes, Richard D; Beauchamp, Gary K

2015-05-01

This article reviews current research and cross-disciplinary perspectives on the neuroscience of food reward in animals and humans, examines the scientific hypothesis of food addiction, discusses methodological and terminology challenges, and identifies knowledge gaps and future research needs. Topics addressed herein include the role of reward and hedonic aspects in the regulation of food intake, neuroanatomy and neurobiology of the reward system in animals and humans, responsivity of the brain reward system to palatable foods and drugs, translation of craving versus addiction, and cognitive control of food reward. The content is based on a workshop held in 2013 by the North American Branch of the International Life Sciences Institute. © The Author(s) 2015. Published by Oxford University Press on behalf of the International Life Sciences Institute.

A Fly's Eye View of Natural and Drug Reward.

Science.gov (United States)

Lowenstein, Eve G; Velazquez-Ulloa, Norma A

2018-01-01

Animals encounter multiple stimuli each day. Some of these stimuli are innately appetitive or aversive, while others are assigned valence based on experience. Drugs like ethanol can elicit aversion in the short term and attraction in the long term. The reward system encodes the predictive value for different stimuli, mediating anticipation for attractive or punishing stimuli and driving animal behavior to approach or avoid conditioned stimuli. The neurochemistry and neurocircuitry of the reward system is partly evolutionarily conserved. In both vertebrates and invertebrates, including Drosophila melanogaster , dopamine is at the center of a network of neurotransmitters and neuromodulators acting in concert to encode rewards. Behavioral assays in D. melanogaster have become increasingly sophisticated, allowing more direct comparison with mammalian research. Moreover, recent evidence has established the functional modularity of the reward neural circuits in Drosophila . This functional modularity resembles the organization of reward circuits in mammals. The powerful genetic and molecular tools for D. melanogaster allow characterization and manipulation at the single-cell level. These tools are being used to construct a detailed map of the neural circuits mediating specific rewarding stimuli and have allowed for the identification of multiple genes and molecular pathways that mediate the effects of reinforcing stimuli, including their rewarding effects. This report provides an overview of the research on natural and drug reward in D. melanogaster , including natural rewards such as sugar and other food nutrients, and drug rewards including ethanol, cocaine, amphetamine, methamphetamine, and nicotine. We focused mainly on the known genetic and neural mechanisms underlying appetitive reward for sugar and reward for ethanol. We also include genes, molecular pathways, and neural circuits that have been identified using assays that test the palatability of the rewarding

A Markov reward model checker

NARCIS (Netherlands)

Katoen, Joost P.; Maneesh Khattri, M.; Zapreev, I.S.; Zapreev, I.S.

2005-01-01

This short tool paper introduces MRMC, a model checker for discrete-time and continuous-time Markov reward models. It supports reward extensions of PCTL and CSL, and allows for the automated verification of properties concerning long-run and instantaneous rewards as well as cumulative rewards. In

Dissociable influences of reward motivation and positive emotion on cognitive control.

Science.gov (United States)

Chiew, Kimberly S; Braver, Todd S

2014-06-01

It is becoming increasingly appreciated that affective and/or motivational influences contribute strongly to goal-oriented cognition and behavior. An unresolved question is whether emotional manipulations (i.e., direct induction of affectively valenced subjective experience) and motivational manipulations (e.g., delivery of performance-contingent rewards and punishments) have similar or distinct effects on cognitive control. Prior work has suggested that reward motivation can reliably enhance a proactive mode of cognitive control, whereas other evidence is suggestive that positive emotion improves cognitive flexibility, but reduces proactive control. However, a limitation of the prior research is that reward motivation and positive emotion have largely been studied independently. Here, we directly compared the effects of positive emotion and reward motivation on cognitive control with a tightly matched, within-subjects design, using the AX-continuous performance task paradigm, which allows for relative measurement of proactive versus reactive cognitive control. High-resolution pupillometry was employed as a secondary measure of cognitive dynamics during task performance. Robust increases in behavioral and pupillometric indices of proactive control were observed with reward motivation. The effects of positive emotion were much weaker, but if anything, also reflected enhancement of proactive control, a pattern that diverges from some prior findings. These results indicate that reward motivation has robust influences on cognitive control, while also highlighting the complexity and heterogeneity of positive-emotion effects. The findings are discussed in terms of potential neurobiological mechanisms.

The multiple decrement life table: a unifying framework for cause-of-death analysis in ecology.

Science.gov (United States)

Carey, James R

1989-01-01

The multiple decrement life table is used widely in the human actuarial literature and provides statistical expressions for mortality in three different forms: i) the life table from all causes-of-death combined; ii) the life table disaggregated into selected cause-of-death categories; and iii) the life table with particular causes and combinations of causes eliminated. The purpose of this paper is to introduce the multiple decrement life table to the ecological literature by applying the methods to published death-by-cause information on Rhagoletis pomonella. Interrelations between the current approach and conventional tools used in basic and applied ecology are discussed including the conventional life table, Key Factor Analysis and Abbott's Correction used in toxicological bioassay.

The Influence of Reward Associations on Conflict Processing in the Stroop Task

Science.gov (United States)

Krebs, Ruth M.; Boehler, Carsten N.; Woldorff, Marty G.

2010-01-01

Performance in a behavioral task can be facilitated by associating stimulus properties with reward. In contrast, conflicting information is known to impede task performance. Here we investigated how reward associations influence the within-trial processing of conflicting information using a color-naming Stroop task in which a subset of ink colors…

Signals can trump rewards in attracting seed-dispersing ants.

Directory of Open Access Journals (Sweden)

Kyle M Turner

Full Text Available Both rewards and signals are important in mutualisms. In myrmecochory, or seed dispersal by ants, the benefits to plants are relatively well studied, but less is known about why ants pick up and move seeds. We examined seed dispersal by the ant Aphaenogaster rudis of four co-occurring species of plants, and tested whether morphology, chemical signaling, or the nutritional quality of fatty seed appendages called elaiosomes influenced dispersal rates. In removal trials, ants quickly collected diaspores (seeds plus elaiosomes of Asarum canadense, Trillium grandiflorum, and Sanguinaria canadensis, but largely neglected those of T. erectum. This discrepancy was not explained by differences in the bulk cost-benefit ratio, as assessed by the ratio of seed to elaiosome mass. We also provisioned colonies with diaspores from one of these four plant species or no diaspores as a control. Colonies performed best when fed S. canadensis diaspores, worst when fed T. grandiflorum, and intermediately when fed A. canadense, T. erectum, or no diaspores. Thus, the nutritional rewards in elaiosomes affected colony performance, but did not completely predict seed removal. Instead, high levels of oleic acid in T. grandiflorum elaiosomes may explain why ants disperse these diaspores even though they reduce ant colony performance. We show for the first time that different elaiosome-bearing plants provide rewards of different quality to ant colonies, but also that ants appear unable to accurately assess reward quality when encountering seeds. Instead, we suggest that signals can trump rewards as attractants of ants to seeds.

Low putamen activity associated with poor reward sensitivity in childhood chronic fatigue syndrome

Directory of Open Access Journals (Sweden)

Kei Mizuno, Ph.D.

2016-01-01

Full Text Available Motivational signals influence a wide variety of cognitive processes and components of behavioral performance. Cognitive dysfunction in patients with childhood chronic fatigue syndrome (CCFS may be closely associated with a low motivation to learn induced by impaired neural reward processing. However, the extent to which reward processing is impaired in CCFS patients is unclear. The aim of the present functional magnetic resonance imaging (fMRI study was to determine whether brain activity in regions related to reward sensitivity is impaired in CCFS patients. fMRI data were collected from 13 CCFS patients (mean age, 13.6 ± 1.0 years and 13 healthy children and adolescents (HCA (mean age, 13.7 ± 1.3 years performing a monetary reward task. Neural activity in high- and low-monetary-reward conditions was compared between CCFS and HCA groups. Severity of fatigue and the reward obtained from learning in daily life were evaluated by questionnaires. Activity of the putamen was lower in the CCFS group than in the HCA group in the low-reward condition, but not in the high-reward condition. Activity of the putamen in the low-reward condition in CCFS patients was negatively and positively correlated with severity of fatigue and the reward from learning in daily life, respectively. We previously revealed that motivation to learn was correlated with striatal activity, particularly the neural activity in the putamen. This suggests that in CCFS patients low putamen activity, associated with altered dopaminergic function, decreases reward sensitivity and lowers motivation to learn.

Deep brain stimulation of the subthalamic nucleus improves reward-based decision-learning in Parkinson's disease

NARCIS (Netherlands)

van Wouwe, N.C.; Ridderinkhof, K.R.; van den Wildenberg, W.P.M.; Band, G.P.H.; Abisogun, A.; Elias, W.J.; Frysinger, R.; Wylie, S.A.

2011-01-01

Recently, the subthalamic nucleus (STN) has been shown to be critically involved in decision-making, action selection, and motor control. Here we investigate the effect of deep brain stimulation (DBS) of the STN on reward-based decision-learning in patients diagnosed with Parkinson's disease (PD).

The dark side of monetary incentive: how does extrinsic reward crowd out intrinsic motivation.

Science.gov (United States)

Ma, Qingguo; Jin, Jia; Meng, Liang; Shen, Qiang

2014-02-12

It was widely believed that incentives could effectively enhance the motivation of both students and employees. However, psychologists reported that extrinsic reward actually could undermine individuals' intrinsic motivation to a given interesting task, which challenged viewpoints from traditional incentive theories. Numerous studies have been carried out to test and explain the undermining effect; however, the neural basis of this effect is still elusive. Here, we carried out an electrophysiological study with a simple but interesting stopwatch task to explore to what extent the performance-based monetary reward undermines individuals' intrinsic motivation toward the task. The electrophysiological data showed that the differentiated feedback-related negativity amplitude toward intrinsic success failure divergence was prominently reduced once the extrinsic reward was imposed beforehand. However, such a difference was not observed in the control group, in which no extrinsic reward was provided throughout the experiment. Furthermore, such a pattern was not observed for P300 amplitude. Therefore, the current results indicate that extrinsic reward demotivates the intrinsic response of individuals toward success-failure outcome, which was reflected in the corresponding reduced motivational-related differentiated feedback-related negativity, but not in amplitude of P300.

Estimation of Correlation Functions by the Random Decrement Technique

DEFF Research Database (Denmark)

Brincker, Rune; Krenk, Steen; Jensen, Jakob Laigaard

responses simulated by two SDOF ARMA models loaded by the same bandlimited white noise. The speed and the accuracy of the RDD technique is compared to the Fast Fourier Transform (FFT) technique. The RDD technique does not involve multiplications, but only additions. Therefore, the technique is very fast......The Random Decrement (RDD) Technique is a versatile technique for characterization of random signals in the time domain. In this paper a short review of the theoretical basis is given, and the technique is illustrated by estimating auto-correlation functions and cross-correlation functions on modal...

Estimation of Correlation Functions by the Random Decrement Technique

DEFF Research Database (Denmark)

Brincker, Rune; Krenk, Steen; Jensen, Jacob Laigaard

1991-01-01

responses simulated by two SDOF ARMA models loaded by the same band-limited white noise. The speed and the accuracy of the RDD technique is compared to the Fast Fourier Transform (FFT) technique. The RDD technique does not involve multiplications, but only additions. Therefore, the technique is very fast......The Random Decrement (RDD) Technique is a versatile technique for characterization of random signals in the time domain. In this paper a short review of the theoretical basis is given, and the technique is illustrated by estimating auto-correlation functions and cross-correlation functions on modal...

Estimation of Correlation Functions by the Random Decrement Technique

DEFF Research Database (Denmark)

Brincker, Rune; Krenk, Steen; Jensen, Jakob Laigaard

1992-01-01

responses simulated by two SDOF ARMA models loaded by the same bandlimited white noise. The speed and the accuracy of the RDD technique is compared to the Fast Fourier Transform (FFT) technique. The RDD technique does not involve multiplications, but only additions. Therefore, the technique is very fast......The Random Decrement (RDD) Technique is a versatile technique for characterization of random signals in the time domain. In this paper a short review of the theoretical basis is given, and the technique is illustrated by estimating auto-correlation functions and cross-correlation functions on modal...

Pain and suicidality: Insights from reward and addiction neuroscience

OpenAIRE

Elman, Igor; Borsook, David; Volkow, Nora D.

2013-01-01

Suicidality is exceedingly prevalent in pain patients. Although the pathophysiology of this link remains unclear, it may be potentially related to the partial congruence of physical and emotional pain systems. The latter system’s role in suicide is also conspicuous during setbacks and losses sustained in the context of social attachments. Here we propose a model based on the neural pathways mediating reward and anti-reward (i.e., allostatic adjustment to recurrent activation of the reward cir...

Intertwining personal and reward relevance: evidence from the drift-diffusion model.

Science.gov (United States)

Yankouskaya, A; Bührle, R; Lugt, E; Stolte, M; Sui, J

2018-01-24

In their seminal paper 'Is our self nothing but reward', Northoff and Hayes (Biol Psychiatry 69(11):1019-1025, Northoff, Hayes, Biological Psychiatry 69(11):1019-1025, 2011) proposed three models of the relationship between self and reward and opened a continuing debate about how these different fields can be linked. To date, none of the proposed models received strong empirical support. The present study tested common and distinct effects of personal relevance and reward values by de-componenting different stages of perceptual decision making using a drift-diffusion approach. We employed a recently developed associative matching paradigm where participants (N = 40) formed mental associations between five geometric shapes and five labels referring personal relevance in the personal task, or five shape-label pairings with different reward values in the reward task and then performed a matching task by indicating whether a displayed shape-label pairing was correct or incorrect. We found that common effects of personal relevance and monetary reward were manifested in the facilitation of behavioural performance for high personal relevance and high reward value as socially important signals. The differential effects between personal and monetary relevance reflected non-decisional time in a perceptual decision process, and task-specific prioritization of stimuli. Our findings support the parallel processing model (Northoff & Hayes, Biol Psychiatry 69(11):1019-1025, Northoff, Hayes, Biological Psychiatry 69(11):1019-1025, 2011) and suggest that self-specific processing occurs in parallel with high reward processing. Limitations and further directions are discussed.

Relating lab to life: Decrements in attention over time predict math productivity among children with ADHD.

Science.gov (United States)

Fosco, Whitney D; Hawk, Larry W

2017-02-01

A child's ability to sustain attention over time (AOT) is critical in attention-deficit/hyperactivity disorder (ADHD), yet no prior work has examined the extent to which a child's decrement in AOT on laboratory tasks relates to clinically-relevant behavior. The goal of this study is to provide initial evidence for the criterion validity of laboratory assessments of AOT. A total of 20 children with ADHD (7-12 years of age) who were enrolled in a summer treatment program completed two lab attention tasks (a continuous performance task and a self-paced choice discrimination task) and math seatwork. Analyses focused on relations between attention task parameters and math productivity. Individual differences in overall attention (OA) measures (averaged across time) accounted for 23% of the variance in math productivity, supporting the criterion validity of lab measures of attention. The criterion validity was enhanced by consideration of changes in AOT. Performance on all laboratory attention measures deteriorated as time-on-task increased, and individual differences in the decrement in AOT accounted for 40% of the variance in math productivity. The only variable to uniquely predict math productivity was from the self-paced choice discrimination task. This study suggests that attention tasks in the lab do predict a clinically-relevant target behavior in children with ADHD, supporting their use as a means to study attention processes in a controlled environment. Furthermore, this prediction is improved when attention is examined as a function of time-on-task and when the attentional demands are consistent between lab and life contexts.

U.S. Geological Survey Rewarding Environment Culture Study, 2002

Science.gov (United States)

Nash, Janis C.; Paradise-Tornow, Carol A.; Gray, Vicki K.; Griffin-Bemis, Sarah P.; Agnew, Pamela R.; Bouchet, Nicole M.

2010-01-01

became available The dividends of creating a rewarding work environment can be great. As the results of the USGS Rewarding Environment Culture Study of 2002 indicate, creating a rewarding work environment is an investment that can have an important impact on the outcomes that the USGS values?the vitality of our science, the satisfaction of our customers, and the morale, commitment, and performance of our employees.

Test anxiety in medical school is unrelated to academic performance but correlates with an effort/reward imbalance.

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Hahn, Henry; Kropp, Peter; Kirschstein, Timo; Rücker, Gernot; Müller-Hilke, Brigitte

2017-01-01

During their early years at medical school, students repeatedly criticize their workload, time constraints and test associated stress. At the same time, depressiveness and anxiety among first and second year medical students are on the rise. We therefore hypothesized that test anxiety may be related to depressiveness and considered cognitive and academic performances as confounders for the former and psychosocial distress for the latter. A whole class of 200 second year students was invited to participate in the study. Anxiety as a trait, depressiveness, crystallized intelligence, verbal fluency and psychosocial distress were assessed using validated tests and questionnaires. Acute state anxiety and sympathetic stress parameters were measured in real life situations immediately before an oral and a written exam and paired tests were used to compare the individual anxieties at the various time points. Previous academic performances were self-reported, the results of the impending exams were monitored. Finally, correlations were performed to test for interrelatedness between academic performances and the various personal, cognitive and psychosocial factors. Acute test anxiety did not correlate with depressiveness nor did it correlate with previous nor impending academic performances nor any of the expected confounders on academic performance. However both, depressiveness and test anxiety strongly correlated with the perceived imbalance between efforts spent and rewards received. Moreover, anxiety as a trait not only correlated with acute state anxiety before an exam but was also significantly correlated to the feeling of over-commitment. Depressiveness during the early years of medical school seems unrelated to test anxiety and academic performance. Instead, it strongly correlated with the psychosocial distress emanating from attending medical school and points at a perceived imbalance between efforts spent and rewards received.

Introduction: Addiction and Brain Reward and Anti-Reward Pathways

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Gardner, Eliot L.

2013-01-01

Addictive drugs have in common that they are voluntarily self-administered by laboratory animals (usually avidly) and that they enhance the functioning of the reward circuitry of the brain (producing the “high” that the drug-user seeks). The core reward circuitry consists of an “in series” circuit linking the ventral tegmental area, nucleus accumbens, and ventral pallidum - via the medial forebrain bundle. Although originally believed to encode simply the set-point of hedonic tone, these circuits are now believed to be functionally far more complex - also encoding attention, expectancy of reward, disconfirmation of reward expectancy, and incentive motivation. “Hedonic dysregulation” within these circuits may lead to addiction. The “second-stage” dopaminergic component in this reward circuitry is the crucial addictive-drug-sensitive component. All addictive drugs have in common that they enhance (directly or indirectly or even transsynaptically) dopaminergic reward synaptic function in the nucleus accumbens. Drug self-administration is regulated by nucleus accumbens dopamine levels, and is done to keep nucleus accumbens dopamine within a specific elevated range (to maintain a desired hedonic level). For some classes of addictive drugs (e.g., opiates), tolerance to the euphoric effects develops with chronic use. Post-use dysphoria then comes to dominate reward circuit hedonic tone, and addicts no longer use drugs to get “high,” but simply to get back to normal (“get straight”). The brain circuits mediating the pleasurable effects of addictive drugs are anatomically, neurophysiologically, and neurochemically different from those mediating physical dependence, and from those mediating craving and relapse. There are important genetic variations in vulnerability to drug addiction, yet environmental factors such as stress and social defeat also alter brain-reward mechanisms in such a manner as to impart vulnerability to addiction. In short, the �

Reward Learning, Neurocognition, Social Cognition, and Symptomatology in Psychosis.

Science.gov (United States)

Lewandowski, Kathryn E; Whitton, Alexis E; Pizzagalli, Diego A; Norris, Lesley A; Ongur, Dost; Hall, Mei-Hua

2016-01-01

Patients with psychosis spectrum disorders exhibit deficits in social and neurocognition, as well as hallmark abnormalities in motivation and reward processing. Aspects of reward processing may overlap behaviorally and neurobiologically with some elements of cognitive functioning, and abnormalities in these processes may share partially overlapping etiologies in patients. However, whether reward processing and cognition are associated across the psychoses and linked to state and trait clinical symptomatology is unclear. The present study examined associations between cognitive functioning, reward learning, and clinical symptomatology in a cross-diagnostic sample. Patients with schizophrenia (SZ; n = 37), bipolar I disorder with psychosis (BD; n = 42), and healthy controls (n = 29) were assessed for clinical symptoms (patients only), neurocognitive functioning using the MATRICS Battery (MCCB) and reward learning using the probabilistic reward task (PRT). Groups were compared on neurocognition and PRT response bias, and associations between PRT response bias and neurocognition or clinical symptoms were examined controlling for demographic variables and PRT task difficulty (discriminability). Patients with SZ performed worse than controls on most measures of neurocognition; patients with BD exhibited deficits in some domains between the level of patients with SZ and controls. The SZ - but not BD - group exhibited deficits in social cognition compared to controls. Patients and controls did not differ on PRT response bias, but did differ on PRT discriminability. Better response bias across the sample was associated with poorer social cognition, but not neurocognition; conversely, discriminability was associated with neurocognition but not social cognition. Symptoms of psychosis, particularly negative symptoms, were associated with poorer response bias across patient groups. Reward learning was associated with symptoms of psychosis - in particular negative

The Effect of Reward on Orienting and Reorienting in Exogenous Cueing

NARCIS (Netherlands)

Bucker, B.; Theeuwes, J.

2014-01-01

It is thought that reward-induced motivation influences perceptual, attentional, and cognitive control processes to facilitate behavioral performance. In this study, we investigated the effect of reward-induced motivation on exogenous attention orienting and inhibition of return (IOR). Attention was

Probiotic Streptococcus thermophilus FP4 and Bifidobacterium breve BR03 Supplementation Attenuates Performance and Range-of-Motion Decrements Following Muscle Damaging Exercise

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Ralf Jäger

2016-10-01

Full Text Available Probiotics have immunomodulatory effects. However, little is known about the potential benefit of probiotics on the inflammation subsequent to strenuous exercise. In a double-blind, randomized, placebo controlled, crossover design separated by a 21-day washout, 15 healthy resistance-trained men ingested an encapsulated probiotic Streptococcus (S. thermophilus FP4 and Bifidobacterium (B. breve BR03 at 5 bn live cells (AFU concentration each, or a placebo, daily for 3 weeks prior to muscle-damaging exercise (ClinicalTrials.gov NCT02520583. Isometric strength, muscle soreness, range of motion and girth, and blood interleukin-6 (IL-6 and creatine kinase (CK concentrations were measured from pre- to 72 h post-exercise. Statistical analysis was via mixed models and magnitude-based inference to the standardized difference. Probiotic supplementation resulted in an overall decrease in circulating IL-6, which was sustained to 48 h post-exercise. In addition, probiotic supplementation likely enhanced isometric average peak torque production at 24 to 72 h into the recovery period following exercise (probiotic–placebo point effect ±90% CI: 24 h, 11% ± 7%; 48 h, 12% ± 18%; 72 h, 8% ± 8%. Probiotics also likely moderately increased resting arm angle at 24 h (2.4% ± 2.0% and 48 h (1.9% ± 1.9% following exercise, but effects on soreness and flexed arm angle and CK were unclear. These data suggest that dietary supplementation with probiotic strains S. thermophilus FP4 and B. breve BR03 attenuates performance decrements and muscle tension in the days following muscle-damaging exercise.

Probiotic Streptococcus thermophilus FP4 and Bifidobacterium breve BR03 Supplementation Attenuates Performance and Range-of-Motion Decrements Following Muscle Damaging Exercise.

Science.gov (United States)

Jäger, Ralf; Purpura, Martin; Stone, Jason D; Turner, Stephanie M; Anzalone, Anthony J; Eimerbrink, Micah J; Pane, Marco; Amoruso, Angela; Rowlands, David S; Oliver, Jonathan M

2016-10-14

Probiotics have immunomodulatory effects. However, little is known about the potential benefit of probiotics on the inflammation subsequent to strenuous exercise. In a double-blind, randomized, placebo controlled, crossover design separated by a 21-day washout, 15 healthy resistance-trained men ingested an encapsulated probiotic Streptococcus ( S. ) thermophilus FP4 and Bifidobacterium ( B. ) breve BR03 at 5 bn live cells (AFU) concentration each, or a placebo, daily for 3 weeks prior to muscle-damaging exercise (ClinicalTrials.gov NCT02520583). Isometric strength, muscle soreness, range of motion and girth, and blood interleukin-6 (IL-6) and creatine kinase (CK) concentrations were measured from pre- to 72 h post-exercise. Statistical analysis was via mixed models and magnitude-based inference to the standardized difference. Probiotic supplementation resulted in an overall decrease in circulating IL-6, which was sustained to 48 h post-exercise. In addition, probiotic supplementation likely enhanced isometric average peak torque production at 24 to 72 h into the recovery period following exercise (probiotic-placebo point effect ±90% CI: 24 h, 11% ± 7%; 48 h, 12% ± 18%; 72 h, 8% ± 8%). Probiotics also likely moderately increased resting arm angle at 24 h (2.4% ± 2.0%) and 48 h (1.9% ± 1.9%) following exercise, but effects on soreness and flexed arm angle and CK were unclear. These data suggest that dietary supplementation with probiotic strains S. thermophilus FP4 and B. breve BR03 attenuates performance decrements and muscle tension in the days following muscle-damaging exercise.

Reward and punishment.

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Sigmund, K; Hauert, C; Nowak, M A

2001-09-11

Minigames capturing the essence of Public Goods experiments show that even in the absence of rationality assumptions, both punishment and reward will fail to bring about prosocial behavior. This result holds in particular for the well-known Ultimatum Game, which emerges as a special case. But reputation can induce fairness and cooperation in populations adapting through learning or imitation. Indeed, the inclusion of reputation effects in the corresponding dynamical models leads to the evolution of economically productive behavior, with agents contributing to the public good and either punishing those who do not or rewarding those who do. Reward and punishment correspond to two types of bifurcation with intriguing complementarity. The analysis suggests that reputation is essential for fostering social behavior among selfish agents, and that it is considerably more effective with punishment than with reward.

The Roles of Dopamine and Hypocretin in Reward: A Electroencephalographic Study.

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Mensen, Armand; Poryazova, Rositsa; Huegli, Gordana; Baumann, Christian R; Schwartz, Sophie; Khatami, Ramin

2015-01-01

The proper functioning of the mesolimbic reward system is largely dependent on the neurotransmitter dopamine. Recent evidence suggests that the hypocretin system has significant projections to this reward system. We examined the distinct effects of reduced dopamine or reduced hypocretin levels on reward activity in patients with Parkinson's disease, dopamine deficient, as well as patients with narcolepsy-cataplexy, hypocretin depleted, and healthy controls. Participants performed a simple game-like task while high-density electroencephalography was recorded. Topography and timing of event-related potentials for both reward cue, and reward feedback was examined across the entire dataset. While response to reward cue was similar in all groups, two distinct time points were found to distinguish patients and controls for reward feedback. Around 160 ms both patient groups had reduced ERP amplitude compared to controls. Later at 250 ms, both patient groups also showed a clear event-related potential (ERP), which was absent in controls. The initial differences show that both patient groups show a similar, blunted response to reward delivery. The second potential corresponds to the classic feedback-related negativity (FRN) potential which relies on dopamine activity and reflects reward prediction-error signaling. In particular the mismatch between predicted reward and reward subsequently received was significantly higher in PD compared to NC, independent of reward magnitude and valence. The intermediate FRN response in NC highlights the contribution of hypocretin in reward processing, yet also shows that this is not as detrimental to the reward system as in Parkinson's. Furthermore, the inability to generate accurate predictions in NC may explain why hypocretin deficiency mediates cataplexy triggered by both positive and negative emotions.

The Roles of Dopamine and Hypocretin in Reward: A Electroencephalographic Study.

Directory of Open Access Journals (Sweden)

Armand Mensen

Full Text Available The proper functioning of the mesolimbic reward system is largely dependent on the neurotransmitter dopamine. Recent evidence suggests that the hypocretin system has significant projections to this reward system. We examined the distinct effects of reduced dopamine or reduced hypocretin levels on reward activity in patients with Parkinson's disease, dopamine deficient, as well as patients with narcolepsy-cataplexy, hypocretin depleted, and healthy controls. Participants performed a simple game-like task while high-density electroencephalography was recorded. Topography and timing of event-related potentials for both reward cue, and reward feedback was examined across the entire dataset. While response to reward cue was similar in all groups, two distinct time points were found to distinguish patients and controls for reward feedback. Around 160 ms both patient groups had reduced ERP amplitude compared to controls. Later at 250 ms, both patient groups also showed a clear event-related potential (ERP, which was absent in controls. The initial differences show that both patient groups show a similar, blunted response to reward delivery. The second potential corresponds to the classic feedback-related negativity (FRN potential which relies on dopamine activity and reflects reward prediction-error signaling. In particular the mismatch between predicted reward and reward subsequently received was significantly higher in PD compared to NC, independent of reward magnitude and valence. The intermediate FRN response in NC highlights the contribution of hypocretin in reward processing, yet also shows that this is not as detrimental to the reward system as in Parkinson's. Furthermore, the inability to generate accurate predictions in NC may explain why hypocretin deficiency mediates cataplexy triggered by both positive and negative emotions.

Measurement-based reliability/performability models

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Hsueh, Mei-Chen

1987-01-01

Measurement-based models based on real error-data collected on a multiprocessor system are described. Model development from the raw error-data to the estimation of cumulative reward is also described. A workload/reliability model is developed based on low-level error and resource usage data collected on an IBM 3081 system during its normal operation in order to evaluate the resource usage/error/recovery process in a large mainframe system. Thus, both normal and erroneous behavior of the system are modeled. The results provide an understanding of the different types of errors and recovery processes. The measured data show that the holding times in key operational and error states are not simple exponentials and that a semi-Markov process is necessary to model the system behavior. A sensitivity analysis is performed to investigate the significance of using a semi-Markov process, as opposed to a Markov process, to model the measured system.

Quantifying the determinants of decremental response in critical ventricular tachycardia substrate.

Science.gov (United States)

Beheshti, Mohammadali; Nayyar, Sachin; Magtibay, Karl; Massé, Stéphane; Porta-Sanchez, Andreu; Haldar, Shouvik; Bhaskaran, Abhishek; Vigmond, Edward; Nanthakumar, Kumaraswamy

2018-05-28

Decremental response evoked with extrastimulation (DEEP) is a useful tool for determining diastolic return path of ventricular tachycardia (VT). Though a targeted VT ablation is feasible with this approach, determinants of DEEP response have not been studied OBJECTIVES: To elucidate the effects of clinically relevant factors, specifically, the proximity of the stimulation site to the arrhythmogenic scar, stimulation wave direction, number of channels open in the scar, size of the scar and number of extra stimuli on decrement and entropy of DEEP potentials. In a 3-dimensional bi-domain simulation of human ventricular tissue (TNNP cell model), an irregular subendocardial myopathic region was generated. An irregular channel of healthy tissue with five potential entry branches was shaped into the myopathic region. A bipolar electrogram was derived from two electrodes positioned in the centre of the myopathic region. Evoked delays between far-field and local Electrogram (EGM) following an extrastimulus (S1-S2, 500-350 ms) were measured as the stimulation site, channel branches, and inexcitable tissue size were altered. Stimulation adjacent to the inexcitable tissue from the side opposite to the point-of-entry produces longest DEEP delay. The DEEP delay shortens when the stimulation point is farther away from the scar, and it decreases maximally when stimulation is done from a site beside a conduction barrier. Entropy increases with S2 when stimulation site is from farther away. An unprotected channel structure with multiple side-branch openings had shorter DEEP delay compared to a protected channel structure with a paucity of additional side-branch openings and a point-of-entry on the side opposite to the pacing source. Addition of a second shorter extrastimulus did not universally lead to higher DEEP delay CONCLUSIONS: Location and direction of the wavefront in relation to scar entry and size of scar determine the degree of evoked response while the number of

Neuromodulatory adaptive combination of correlation-based learning in cerebellum and reward-based learning in basal ganglia for goal-directed behavior control.

Science.gov (United States)

Dasgupta, Sakyasingha; Wörgötter, Florentin; Manoonpong, Poramate

2014-01-01

Goal-directed decision making in biological systems is broadly based on associations between conditional and unconditional stimuli. This can be further classified as classical conditioning (correlation-based learning) and operant conditioning (reward-based learning). A number of computational and experimental studies have well established the role of the basal ganglia in reward-based learning, where as the cerebellum plays an important role in developing specific conditioned responses. Although viewed as distinct learning systems, recent animal experiments point toward their complementary role in behavioral learning, and also show the existence of substantial two-way communication between these two brain structures. Based on this notion of co-operative learning, in this paper we hypothesize that the basal ganglia and cerebellar learning systems work in parallel and interact with each other. We envision that such an interaction is influenced by reward modulated heterosynaptic plasticity (RMHP) rule at the thalamus, guiding the overall goal directed behavior. Using a recurrent neural network actor-critic model of the basal ganglia and a feed-forward correlation-based learning model of the cerebellum, we demonstrate that the RMHP rule can effectively balance the outcomes of the two learning systems. This is tested using simulated environments of increasing complexity with a four-wheeled robot in a foraging task in both static and dynamic configurations. Although modeled with a simplified level of biological abstraction, we clearly demonstrate that such a RMHP induced combinatorial learning mechanism, leads to stabler and faster learning of goal-directed behaviors, in comparison to the individual systems. Thus, in this paper we provide a computational model for adaptive combination of the basal ganglia and cerebellum learning systems by way of neuromodulated plasticity for goal-directed decision making in biological and bio-mimetic organisms.

Charging versus rewarding : A comparison of road-pricing and rewarding peak avoidance in the Netherlands

NARCIS (Netherlands)

Tillema, Taede; Ben-Elia, Eran; Ettema, Dick; van Delden, Janet

The aim of this paper is to compare two congestion management schemes road-pricing and peak avoidance rewarding and their impact on commuter behaviour, based on two studies that were conducted in the Netherlands. The road-pricing study is based on stated preference data, whereas the study involving

The cognitive effects and decrements following concussion

Directory of Open Access Journals (Sweden)

Tracey Covassin

2010-05-01

Full Text Available Tracey Covassin, Robert J ElbinMichigan State University, Department of Kinesiology, East Lansing, MI, USAAbstract: Sports-related concussion is an injury that continues to receive attention from both the popular media and sports medicine community. The many different symptom presentations and cognitive decrements that follow concussions, have made this injury difficult to detect and manage. Furthermore, concussed athletes should not always be entrusted to appropriately self-report their concussion symptoms; therefore the burden falls on the clinician and coach. Recent management recommendations call for using a multi-faceted approach to managing concussion, which consists of neurocognitive testing before (ie, baseline/preseason and after injury. In addition age, sex, and previous history of concussion have been found to influence the risk and recovery from this injury.Keywords: cognitive function, neurocognitive testing, concussion

The Effects of Reward, Punishment, and Knowledge of Results on Children's Discrimination Learning

Science.gov (United States)

Donohue, Barbara; Ratliff, Richard G.

1976-01-01

The differential effects of contingent reward (candy), punishment (loss of candy), and knowledge of results (KOR) were investigated in eighty 9- to 10-year-old males. Level of performance of groups receiving KOR was significantly higher than performance on groups rewarded or punished with candy. (MS)

Mutual Influence of Reward Anticipation and Emotion on Brain Activity during Memory Retrieval.

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Yan, Chunping; Liu, Fang; Li, Yunyun; Zhang, Qin; Cui, Lixia

2017-01-01

Previous studies on the joint effect of reward motivation and emotion on memory retrieval have obtained inconsistent results. Furthermore, whether and how any such joint effect might vary over time remains unclear too. Accordingly, using the event-related potential (ERP) measurement of high temporal resolution, our study investigates the cognitive and brain mechanisms of monetary reward and emotion affecting the retrieval processes of episodic memory. Twenty undergraduate and graduate students participated in the research, and our study's behavioral results indicated that reward (relative to no reward) and negative emotion (relative to positive and neutral emotion) significantly improved recognition performance. The ERP results showed that there were significant interactions between monetary reward and emotion on memory retrieval, and the reward effects of positive, neutral, and negative memory occurred at varied intervals in mean amplitude. The reward effect of positive memory appeared relatively early, at 260-330 ms after the stimulus onset in the frontal-frontocentral area, at 260-500 ms in the centroparietal-parietal area and at 500-700 ms in the frontocentral area. However, the reward effects of neutral and negative memory occurred relatively later, and that of negative memory appeared at 500-700 ms in the frontocentral and centroparietal area and that of neutral memory was at 500-700 ms in the frontocentral and centroparietal-parietal area. Meanwhile, significant FN400 old/new effects were observed in the negative and rewarded positive items, and the old/new effects of negative items appeared earlier at FN400 than positive items. Also, significant late positive component (LPC) old/new effects were found in the positive, negative, and rewarded neutral items. These results suggest that, monetary reward and negative emotion significantly improved recognition performance, and there was a mutual influence between reward and emotion on brain activity during memory

Mutual Influence of Reward Anticipation and Emotion on Brain Activity during Memory Retrieval

Directory of Open Access Journals (Sweden)

Chunping Yan

2017-10-01

Full Text Available Previous studies on the joint effect of reward motivation and emotion on memory retrieval have obtained inconsistent results. Furthermore, whether and how any such joint effect might vary over time remains unclear too. Accordingly, using the event-related potential (ERP measurement of high temporal resolution, our study investigates the cognitive and brain mechanisms of monetary reward and emotion affecting the retrieval processes of episodic memory. Twenty undergraduate and graduate students participated in the research, and our study’s behavioral results indicated that reward (relative to no reward and negative emotion (relative to positive and neutral emotion significantly improved recognition performance. The ERP results showed that there were significant interactions between monetary reward and emotion on memory retrieval, and the reward effects of positive, neutral, and negative memory occurred at varied intervals in mean amplitude. The reward effect of positive memory appeared relatively early, at 260–330 ms after the stimulus onset in the frontal-frontocentral area, at 260–500 ms in the centroparietal-parietal area and at 500–700 ms in the frontocentral area. However, the reward effects of neutral and negative memory occurred relatively later, and that of negative memory appeared at 500–700 ms in the frontocentral and centroparietal area and that of neutral memory was at 500–700 ms in the frontocentral and centroparietal-parietal area. Meanwhile, significant FN400 old/new effects were observed in the negative and rewarded positive items, and the old/new effects of negative items appeared earlier at FN400 than positive items. Also, significant late positive component (LPC old/new effects were found in the positive, negative, and rewarded neutral items. These results suggest that, monetary reward and negative emotion significantly improved recognition performance, and there was a mutual influence between reward and emotion on

Altered neural processing of reward and punishment in adolescents with Major Depressive Disorder.

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Landes, I; Bakos, S; Kohls, G; Bartling, J; Schulte-Körne, G; Greimel, E

2018-05-01

Altered reward and punishment function has been suggested as an important vulnerability factor for the development of Major Depressive Disorder (MDD). Prior ERP studies found evidence for neurophysiological dysfunctions in reinforcement processes in adults with MDD. To date, only few ERP studies have examined the neural underpinnings of reinforcement processing in adolescents diagnosed with MDD. The present event-related potential (ERP) study aimed to investigate neurophysiological mechanisms of anticipation and consumption of reward and punishment in adolescents with MDD in one comprehensive paradigm. During ERP recording, 25 adolescents with MDD and 29 healthy controls (12-17 years) completed a Monetary Incentive Delay Task comprising both a monetary reward and a monetary punishment condition. During anticipation, the cue-P3 signaling attentional allocation was recorded. During consumption, the feedback-P3 and Reward Positivity (RewP) were recorded to capture attentional allocation and outcome evaluation, respectively. Compared to controls, adolescents with MDD showed prolonged cue-P3 latencies to reward cues. Furthermore, unlike controls, adolescents with MDD displayed shorter feedback-P3 latencies in the reward versus punishment condition. RewPs did not differ between groups. It remains unanswered whether the observed alterations in adolescent MDD represent a state or trait. Delayed neural processing of reward cues corresponds to the clinical presentation of adolescent MDD with reduced motivational tendencies to obtain rewards. Relatively shorter feedback-P3 latencies in the reward versus punishment condition could indicate a high salience of performance-contingent reward. Frequent exposure of negatively biased adolescents with MDD to performance-contingent rewards might constitute a promising intervention approach. Copyright © 2018 Elsevier B.V. All rights reserved.

Different populations of subthalamic neurons encode cocaine vs. sucrose reward and predict future error.

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Lardeux, Sylvie; Paleressompoulle, Dany; Pernaud, Remy; Cador, Martine; Baunez, Christelle

2013-10-01

The search for treatment of cocaine addiction raises the challenge to find a way to diminish motivation for the drug without decreasing it for natural rewards. Subthalamic nucleus (STN) inactivation decreases motivation for cocaine while increasing motivation for food, suggesting that STN can dissociate different rewards. Here, we investigated how rat STN neurons respond to cues predicting cocaine or sucrose and to reward delivery while rats are performing a discriminative stimuli task. We show that different neuronal populations of STN neurons encode cocaine and sucrose. In addition, we show that STN activity at the cue onset predicts future error. When changing the reward predicted unexpectedly, STN neurons show capacities of adaptation, suggesting a role in reward-prediction error. Furthermore, some STN neurons show a response to executive error (i.e., "oops neurons") that is specific to the missed reward. These results position the STN as a nexus where natural rewards and drugs of abuse are coded differentially and can influence the performance. Therefore, STN can be viewed as a structure where action could be taken for the treatment of cocaine addiction.

Response of the REWARD detection system to the presence of a Radiological Dispersal Device

International Nuclear Information System (INIS)

Luís, R.; Fleta, C.; Balbuena, J.; Baptista, M.; Barros, S.; Disch, C.; Jumilla, C.; Lozano, M.; Marques, J.G.; Vaz, P.

2016-01-01

The objective of the REWARD project consisted in building a mobile system for real time, wide area radiation surveillance, using a CdZnTe detector for gamma radiation and a neutron detector based on novel silicon technologies. The sensing unit includes a GPS system and a wireless communication interface to send the data remotely to a monitoring base station, where it will be analyzed in real time and correlated with historical data from the tag location, in order to generate an alarm when an abnormal situation is detected. The main objective of this work consisted in making predictions regarding the behavior of the REWARD system in the presence of a Radiological Dispersion Device (RDD), one of the reference scenarios foreseen for REWARD, using experimental data and the Monte Carlo simulation program MCNP6. Experimental tests were performed at the Fire Brigades Facilities in Rome and at the Naples Fire Brigades. The response of the REWARD detection system to the presence of an RDD is predicted and discussed. - Highlights: • A prototype mobile system for real-time, wide-area radiation surveillance was built. • Experimental measurements and Monte Carlo simulations were used to test the system. • The system is suitable to detect and identify radiation sources in threat scenarios.

Neurogenetic Impairments of Brain Reward Circuitry Links to Reward Deficiency Syndrome (RDS): Potential Nutrigenomic Induced Dopaminergic Activation

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Blum, K; Oscar-Berman, M; Giordano, J; Downs, BW; Simpatico, T; Han, D; Femino, John

2012-01-01

Work from our laboratory in both in-patient and outpatient facilities utilizing the Comprehensive Analysis of Reported Drugs (CARD)™ found a significant lack of compliance to prescribed treatment medications and a lack of abstinence from drugs of abuse during active recovery. This unpublished, ongoing research provides an impetus to develop accurate genetic diagnosis and holistic approaches that will safely activate brain reward circuitry in the mesolimbic dopamine system. This editorial focuses on the neurogenetics of brain reward systems with particular reference to genes related to dopaminergic function. The terminology “Reward Deficiency Syndrome” (RDS), used to describe behaviors found to have an association with gene-based hypodopaminergic function, is a useful concept to help expand our understanding of Substance Use Disorder (SUD), process addictions, and other obsessive, compulsive and impulsive behaviors. This editorial covers the neurological basis of pleasure and the role of natural and unnatural reward in motivating and reinforcing behaviors. Additionally, it briefly describes the concept of natural dopamine D2 receptor agonist therapy coupled with genetic testing of a panel of reward genes, the Genetic Addiction Risk Score (GARS). It serves as a spring-board for this combination of novel approaches to the prevention and treatment of RDS that was developed from fundamental genomic research. We encourage further required studies. PMID:23264886

Dorsomedial striatum lesions affect adjustment to reward uncertainty, but not to reward devaluation or omission.

Science.gov (United States)

Torres, Carmen; Glueck, Amanda C; Conrad, Shannon E; Morón, Ignacio; Papini, Mauricio R

2016-09-22

The dorsomedial striatum (DMS) has been implicated in the acquisition of reward representations, a proposal leading to the hypothesis that it should play a role in situations involving reward loss. We report the results of an experiment in which the effects of DMS excitotoxic lesions were tested in consummatory successive negative contrast (reward devaluation), autoshaping training with partial vs. continuous reinforcement (reward uncertainty), and appetitive extinction (reward omission). Animals with DMS lesions exhibited reduced lever pressing responding, but enhanced goal entries, during partial reinforcement training in autoshaping. However, they showed normal negative contrast, acquisition under continuous reinforcement (CR), appetitive extinction, and response facilitation in early extinction trials. Open-field testing also indicated normal motor behavior. Thus, DMS lesions selectively affected the behavioral adjustment to a situation involving reward uncertainty, producing a behavioral reorganization according to which goal tracking (goal entries) became predominant at the expense of sign tracking (lever pressing). This pattern of results shows that the function of the DMS in situations involving reward loss is not general, but restricted to reward uncertainty. We suggest that a nonassociative, drive-related process induced by reward uncertainty requires normal output from DMS neurons. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Dopamine receptor blockade attenuates the general incentive motivational effects of noncontingently delivered rewards and reward-paired cues without affecting their ability to bias action selection.

Science.gov (United States)

Ostlund, Sean B; Maidment, Nigel T

2012-01-01

Environmental cues affect our behavior in a variety of ways. Despite playing an invaluable role in guiding our daily activities, such cues also appear to trigger the harmful, compulsive behaviors that characterize addiction and other disorders of behavioral control. In instrumental conditioning, rewards and reward-paired cues bias action selection and invigorate reward-seeking behaviors, and appear to do so through distinct neurobehavioral processes. Although reward-paired cues are known to invigorate performance through a dopamine-dependent incentive motivational process, it is not known if dopamine also mediates the influence of rewards and reward-paired cues over action selection. The current study contrasted the effects of systemic administration of the nonspecific dopamine receptor antagonist flupentixol on response invigoration and action bias in Pavlovian-instrumental transfer, a test of cue-elicited responding, and in instrumental reinstatement, a test of noncontingent reward-elicited responding. Hungry rats were trained on two different stimulus-outcome relationships (eg, tone-grain pellets and noise-sucrose solution) and two different action-outcome relationships (eg, left press-grain and right press-sucrose). At test, we found that flupentixol pretreatment blocked the response invigoration generated by the cues but spared their ability to bias action selection to favor the action whose outcome was signaled by the cue being presented. The response-biasing influence of noncontingent reward deliveries was also unaffected by flupentixol. Interestingly, although flupentixol had a modest effect on the immediate response invigoration produced by those rewards, it was particularly potent in countering the lingering enhancement of responding produced by multiple reward deliveries. These findings indicate that dopamine mediates the general incentive motivational effects of noncontingent rewards and reward-paired cues but does not support their ability to bias

Extinction Can Reduce the Impact of Reward Cues on Reward-Seeking Behavior.

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Lovibond, Peter F; Satkunarajah, Michelle; Colagiuri, Ben

2015-07-01

Reward-associated cues are thought to promote relapse after treatment of appetitive disorders such as drug-taking, binge eating, and gambling. This process has been modelled in the laboratory using a Pavlovian-instrumental transfer (PIT) design in which Pavlovian cues facilitate instrumental reward-directed action. Attempts to reduce facilitation by cue exposure (extinction) have produced mixed results. We tested the effect of extinction in a recently developed PIT procedure using a natural reward, chocolate, in human participants. Facilitation of instrumental responding was only observed in participants who were aware of the Pavlovian contingencies. Pavlovian extinction successfully reduced, but did not completely eliminate, expectancy of reward and facilitation of instrumental responding. The results indicate that exposure can reduce the ability of cues to promote reward-directed behavior in the laboratory. However, the residual potency of extinguished cues means that additional active strategies may be needed in clinical practice to train patients to resist the impact of these cues in their environment. Copyright © 2015. Published by Elsevier Ltd.

Effects of personality traits on collaborative performance in problem-based learning tutorials.

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Jang, Hye Won; Park, Seung Won

2016-12-01

To examine the relationship between students' collaborative performance in a problem-based learning (PBL) environment and their personality traits. Methods:This retrospective, cross-sectional study was conducted using student data of a PBL program between 2013 and 2014 at Sungkyunkwan University School of Medicine, Seoul, South Korea. Eighty students were included in the study. Student data from the Temperament and Character Inventory were used as a measure of their personality traits. Peer evaluation scores during PBL were used as a measure of students' collaborative performance. Results: Simple regression analyses indicated that participation was negatively related to harm avoidance and positively related to persistence, whereas preparedness for the group work was negatively related to reward dependence. On multiple regression analyses, low reward dependence remained a significant predictor of preparedness. Grade-point average (GPA)  was negatively associated with novelty seeking and cooperativeness and was positively associated with persistence.  Conclusion: Medical students who are less dependent on social reward are more likely to complete assigned independent work to prepare for the PBL tutorials. The findings of this study can help educators better understand and support medical students who are at risk of struggling in collaborative learning environments.

From conflict management to reward-based decision making: actors and critics in primate medial frontal cortex.

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Silvetti, Massimo; Alexander, William; Verguts, Tom; Brown, Joshua W

2014-10-01

The role of the medial prefrontal cortex (mPFC) and especially the anterior cingulate cortex has been the subject of intense debate for the last decade. A number of theories have been proposed to account for its function. Broadly speaking, some emphasize cognitive control, whereas others emphasize value processing; specific theories concern reward processing, conflict detection, error monitoring, and volatility detection, among others. Here we survey and evaluate them relative to experimental results from neurophysiological, anatomical, and cognitive studies. We argue for a new conceptualization of mPFC, arising from recent computational modeling work. Based on reinforcement learning theory, these new models propose that mPFC is an Actor-Critic system. This system is aimed to predict future events including rewards, to evaluate errors in those predictions, and finally, to implement optimal skeletal-motor and visceromotor commands to obtain reward. This framework provides a comprehensive account of mPFC function, accounting for and predicting empirical results across different levels of analysis, including monkey neurophysiology, human ERP, human neuroimaging, and human behavior. Copyright © 2013 Elsevier Ltd. All rights reserved.

Reward sensitivity is associated with brain activity during erotic stimulus processing.

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Costumero, Victor; Barrós-Loscertales, Alfonso; Bustamante, Juan Carlos; Ventura-Campos, Noelia; Fuentes, Paola; Rosell-Negre, Patricia; Ávila, César

2013-01-01

The behavioral approach system (BAS) from Gray's reinforcement sensitivity theory is a neurobehavioral system involved in the processing of rewarding stimuli that has been related to dopaminergic brain areas. Gray's theory hypothesizes that the functioning of reward brain areas is modulated by BAS-related traits. To test this hypothesis, we performed an fMRI study where participants viewed erotic and neutral pictures, and cues that predicted their appearance. Forty-five heterosexual men completed the Sensitivity to Reward scale (from the Sensitivity to Punishment and Sensitivity to Reward Questionnaire) to measure BAS-related traits. Results showed that Sensitivity to Reward scores correlated positively with brain activity during reactivity to erotic pictures in the left orbitofrontal cortex, left insula, and right ventral striatum. These results demonstrated a relationship between the BAS and reward sensitivity during the processing of erotic stimuli, filling the gap of previous reports that identified the dopaminergic system as a neural substrate for the BAS during the processing of other rewarding stimuli such as money and food.

Reward sensitivity is associated with brain activity during erotic stimulus processing.

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Victor Costumero

Full Text Available The behavioral approach system (BAS from Gray's reinforcement sensitivity theory is a neurobehavioral system involved in the processing of rewarding stimuli that has been related to dopaminergic brain areas. Gray's theory hypothesizes that the functioning of reward brain areas is modulated by BAS-related traits. To test this hypothesis, we performed an fMRI study where participants viewed erotic and neutral pictures, and cues that predicted their appearance. Forty-five heterosexual men completed the Sensitivity to Reward scale (from the Sensitivity to Punishment and Sensitivity to Reward Questionnaire to measure BAS-related traits. Results showed that Sensitivity to Reward scores correlated positively with brain activity during reactivity to erotic pictures in the left orbitofrontal cortex, left insula, and right ventral striatum. These results demonstrated a relationship between the BAS and reward sensitivity during the processing of erotic stimuli, filling the gap of previous reports that identified the dopaminergic system as a neural substrate for the BAS during the processing of other rewarding stimuli such as money and food.

Reward networks in the brain as captured by connectivity measures

Directory of Open Access Journals (Sweden)

Estela Camara

2009-12-01

Full Text Available An assortment of human behaviors is thought to be driven by rewards including reinforcement learning, novelty processing, learning, decision making, economic choice, incentive motivation, and addiction. In each case the ventral tegmental area / ventral striatum (Nucleus accumbens system (VTA-VS has been implicated as a key structure by functional imaging studies, mostly on the basis of standard, univariate analyses. Here we propose that standard fMRI analysis needs to be complemented by methods that take into account the differential connectivity of the VTA-VS system in the different behavioral contexts in order to describe reward based processes more appropriately. We first consider the wider network for reward processing as it emerged from animal experimentation. Subsequently, an example for a method to assess functional connectivity is given. Finally, we illustrate the usefulness of such analyses by examples regarding reward valuation, reward expectation and the role of reward in addiction.

Cortical Brain Activity Reflecting Attentional Biasing Toward Reward-Predicting Cues Covaries with Economic Decision-Making Performance.

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San Martín, René; Appelbaum, Lawrence G; Huettel, Scott A; Woldorff, Marty G

2016-01-01

Adaptive choice behavior depends critically on identifying and learning from outcome-predicting cues. We hypothesized that attention may be preferentially directed toward certain outcome-predicting cues. We studied this possibility by analyzing event-related potential (ERP) responses in humans during a probabilistic decision-making task. Participants viewed pairs of outcome-predicting visual cues and then chose to wager either a small (i.e., loss-minimizing) or large (i.e., gain-maximizing) amount of money. The cues were bilaterally presented, which allowed us to extract the relative neural responses to each cue by using a contralateral-versus-ipsilateral ERP contrast. We found an early lateralized ERP response, whose features matched the attention-shift-related N2pc component and whose amplitude scaled with the learned reward-predicting value of the cues as predicted by an attention-for-reward model. Consistently, we found a double dissociation involving the N2pc. Across participants, gain-maximization positively correlated with the N2pc amplitude to the most reliable gain-predicting cue, suggesting an attentional bias toward such cues. Conversely, loss-minimization was negatively correlated with the N2pc amplitude to the most reliable loss-predicting cue, suggesting an attentional avoidance toward such stimuli. These results indicate that learned stimulus-reward associations can influence rapid attention allocation, and that differences in this process are associated with individual differences in economic decision-making performance. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Reward eliminates retrieval-induced forgetting.

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Imai, Hisato; Kim, Dongho; Sasaki, Yuka; Watanabe, Takeo

2014-12-02

Although it is well known that reward enhances learning and memory, how extensively such enhancement occurs remains unclear. To address this question, we examined how reward influences retrieval-induced forgetting (RIF) in which the retrieval of a nonpracticed item under the same category as a practiced item is worse than the retrieval of a nonpracticed item outside the category. Subjects were asked to try to encode category-exemplar pairs (e.g., FISH-salmon). Then, they were presented with a category name and a two-letter word stem (e.g., FISH-sa) and were asked to complete an encoded word (retrieval practice). For a correct response, apple juice was given as a reward in the reward condition and a beeping sound was presented in the no-reward condition. Finally, subjects were asked to report whether each exemplar had been presented in the first phase. RIF was replicated in the no-reward condition. However, in the reward condition, RIF was eliminated. These results suggest that reward enhances processing of retrieval of unpracticed members by mechanisms such as spreading activation within the same category, irrespective of whether items were practiced or not.

The role of the striatum in effort-based decision-making in the absence of reward.

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Schouppe, Nathalie; Demanet, Jelle; Boehler, Carsten N; Ridderinkhof, K Richard; Notebaert, Wim

2014-02-05

Decision-making involves weighing costs against benefits, for instance, in terms of the effort it takes to obtain a reward of a given magnitude. This evaluation process has been linked to the dorsal anterior cingulate cortex (dACC) and the striatum, with activation in these brain structures reflecting the discounting effect of effort on reward. Here, we investigate how cognitive effort influences neural choice processes in the absence of an extrinsic reward. Using functional magnetic resonance imaging in humans, we used an effort-based decision-making task in which participants were required to choose between two options for a subsequent flanker task that differed in the amount of cognitive effort. Cognitive effort was manipulated by varying the proportion of incongruent trials associated with each choice option. Choice-locked activation in the striatum was higher when participants chose voluntarily for the more effortful alternative but displayed the opposite trend on forced-choice trials. The dACC revealed a similar, yet only trend-level significant, activation pattern. Our results imply that activation levels in the striatum reflect a cost-benefit analysis, in which a balance is made between effort discounting and the intrinsic motivation to choose a cognitively challenging task. Moreover, our findings indicate that it matters whether this challenge is voluntarily chosen or externally imposed. As such, the present findings contrast with classical findings on effort discounting that found reductions in striatum activation for higher effort by finding enhancements of the same neural circuits when a cognitively challenging task is voluntarily selected and does not entail the danger of losing reward.

Evidence for the negative impact of reward on self-regulated learning.

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Wehe, Hillary S; Rhodes, Matthew G; Seger, Carol A

2015-01-01

The undermining effect refers to the detrimental impact rewards can have on intrinsic motivation to engage in a behaviour. The current study tested the hypothesis that participants' self-regulated learning behaviours are susceptible to the undermining effect. Participants were assigned to learn a set of Swahili-English word pairs. Half of the participants were offered a reward for performance, and half were not offered a reward. After the initial study phase, participants were permitted to continue studying the words during a free period. The results were consistent with an undermining effect: Participants who were not offered a reward spent more time studying the words during the free period. The results suggest that rewards may negatively impact self-regulated learning behaviours and provide support for the encouragement of intrinsic motivation.

Ventral striatal activity links adversity and reward processing in children

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Kamkar, N.H.; Lewis, D.J.; van den Bos, W.; Morton, J.B.

2017-01-01

Adversity impacts many aspects of psychological and physical development including reward-based learning and decision-making. Mechanisms relating adversity and reward processing in children, however, remain unclear. Here, we show that adversity is associated with potentiated learning from positive

Temporal dynamics of reward anticipation in the human brain.

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Zhang, Yuanyuan; Li, Qi; Wang, Zhao; Liu, Xun; Zheng, Ya

2017-09-01

Reward anticipation is a complex process including cue evaluation, motor preparation, and feedback anticipation. The present study investigated whether these psychological processes were dissociable on neural dynamics in terms of incentive valence and approach motivation. We recorded EEG when participants were performing a monetary incentive delay task, and found a cue-P3 during the cue-evaluation stage, a contingent negative variation (CNV) during the motor-preparation stage, and a stimulus-preceding negativity (SPN) during the feedback-anticipation stage. Critically, both the cue-P3 and SPN exhibited an enhanced sensitivity to gain versus loss anticipation, which was not observed for the CNV. Moreover, both the cue-P3 and SPN, instead of the CNV, for gain anticipation selectively predicted the participants' approach motivation as measured in a following effort expenditure for rewards task, particularly when reward uncertainty was maximal. Together, these results indicate that reward anticipation consists of several sub-stages, each with distinct functional significance, thus providing implications for neuropsychiatric diseases characterized by dysfunction in anticipatory reward processing. Copyright © 2017 Elsevier B.V. All rights reserved.