Nucleus accumbens activation mediates the influence of reward cues on financial risk-taking

In functional magnetic resonance imaging (FMRI) research, nucleus accumbens (NAcc) activation spontaneously increases prior to financial risk taking. Since anticipation of diverse rewards can increase NAcc activation, even incidental reward cues may influence financial risk-taking. Using event-related FMRI, we predicted and found that anticipation of viewing rewarding stimuli (erotic pictures for 15 heterosexual males) increased financial risk taking, and that this effect was partially mediated by increases in NAcc activation. These results are consistent with the notion that incidental reward cues influence financial risk taking by altering anticipatory affect, and so identify a neuropsychological mechanism that may underlie effective emotional appeals in financial, marketing, and political domains.neuroeconomics, neurofinance, brain, financial risk taking, risk preferences, decision making, nucleus accumbens, striatum, reward cues, FMRI, brain imaging

Nucleus accumbens activation mediates the influence of reward cues on financial risk-taking

In functional magnetic resonance imaging (FMRI) research, nucleus accumbens (NAcc) activation spontaneously increases prior to financial risk taking. Since anticipation of diverse rewards can increase NAcc activation, even incidental reward cues may influence financial risk-taking. Using event-related FMRI, we predicted and found that anticipation of viewing rewarding stimuli (erotic pictures for 15 heterosexual males) increased financial risk taking, and that this effect was partially mediated by increases in NAcc activation. These results are consistent with the notion that incidental reward cues influence financial risk taking by altering anticipatory affect, and so identify a neuropsychological mechanism that may underlie effective emotional appeals in financial, marketing, and political domains

Nucleus accumbens activation mediates the influence of reward cues on financial risk-taking

In functional magnetic resonance imaging (FMRI) research, nucleus accumbens (NAcc) activation spontaneously increases prior to financial risk taking. Since anticipation of diverse rewards can increase NAcc activation, even incidental reward cues may influence financial risk-taking. Using event-related FMRI, we predicted and found that anticipation of viewing rewarding stimuli (erotic pictures for 15 heterosexual males) increased financial risk taking, and that this effect was partially mediated by increases in NAcc activation. These results are consistent with the notion that incidental reward cues influence financial risk taking by altering anticipatory affect, and so identify a neuropsychological mechanism that may underlie effective emotional appeals in financial, marketing, and political domains

The Affective Impact of Financial Skewness on Neural Activity and Choice

Few finance theories consider the influence of “skewness” (or large and asymmetric but unlikely outcomes) on financial choice. We investigated the impact of skewed gambles on subjects' neural activity, self-reported affective responses, and subsequent preferences using functional magnetic resonance imaging (FMRI). Neurally, skewed gambles elicited more anterior insula activation than symmetric gambles equated for expected value and variance, and positively skewed gambles also specifically elicited more nucleus accumbens (NAcc) activation than negatively skewed gambles. Affectively, positively skewed gambles elicited more positive arousal and negatively skewed gambles elicited more negative arousal than symmetric gambles equated for expected value and variance. Subjects also preferred positively skewed gambles more, but negatively skewed gambles less than symmetric gambles of equal expected value. Individual differences in both NAcc activity and positive arousal predicted preferences for positively skewed gambles. These findings support an anticipatory affect account in which statistical properties of gambles—including skewness—can influence neural activity, affective responses, and ultimately, choice

Under pressure: Response urgency modulates striatal and insula activity during decision-making under risk

When deciding whether to bet in situations that involve potential monetary loss or gain (mixed gambles), a subjective sense of pressure can influence the evaluation of the expected utility associated with each choice option. Here, we explored how gambling decisions, their psychophysiological and neural counterparts are modulated by an induced sense of urgency to respond. Urgency influenced decision times and evoked heart rate responses, interacting with the expected value of each gamble. Using functional MRI, we observed that this interaction was associated with changes in the activity of the striatum, a critical region for both reward and choice selection, and within the insula, a region implicated as the substrate of affective feelings arising from interoceptive signals which influence motivational behavior. Our findings bridge current psychophysiological and neurobiological models of value representation and action-programming, identifying the striatum and insular cortex as the key substrates of decision-making under risk and urgency

Ideal Spin Filters: Theoretical Study of Electron Transmission Through Ordered and Disordered Interfaces Between Ferromagnetic Metals and Semiconductors

It is predicted that certain atomically ordered interfaces between some ferromagnetic metals (F) and semiconductors (S) should act as ideal spin filters that transmit electrons only from the majority spin bands or only from the minority spin bands of the F to the S at the Fermi energy, even for F with both majority and minority bands at the Fermi level. Criteria for determining which combinations of F, S and interface should be ideal spin filters are formulated. The criteria depend only on the bulk band structures of the S and F and on the translational symmetries of the S, F and interface. Several examples of systems that meet these criteria to a high degree of precision are identified. Disordered interfaces between F and S are also studied and it is found that intermixing between the S and F can result in interfaces with spin anti-filtering properties, the transmitted electrons being much less spin polarized than those in the ferromagnetic metal at the Fermi energy. A patent application based on this work has been commenced by Simon Fraser University.Comment: RevTeX, 12 pages, 5 figure

Tenosynovial giant cell tumors as accidental findings after episodes of distortion of the ankle: two case reports

<p>Abstract</p> <p>Introduction</p> <p>Tenosynovial giant cell tumors are benign tumors of uncertain pathogenesis. They occur in the joints, tendons and synovial bursas. Due to a high recurrence rate of up to 50%, some authors call a giant cell tumor a semimalignant tumor. To date, less than 10 cases of tenosynovial giant cell tumor of the ankle have been published in the international medical literature.</p> <p>Case presentation</p> <p>In this case report, we present two patients with localized tumors that were detected accidentally after the occurrence of ankle sprains with persisting pain in the joint. The tumors were resected by open marginal surgery and regular follow-up examinations were carried out.</p> <p>Conclusions</p> <p>We present an unusual occurrence of a tumor along with a possible follow-up strategy, which has not been previously discussed in the international literature.</p

Efeito do tempo de repouso sobre produção e qualidade do leite de vacas mantidas em pastagem polifítica e sistema de Pastoreio Racional Voisin

Na pecuária leiteira, a produção de leite com maiores teores de compostos benéficos à saúde, tais como os ácidos graxos poliinsaturados e carotenoides, encontrados com abundância em produção à pasto, são um diferencial no mercado. Desse modo, este trabalho teve como objetivo avaliar o efeito de pastagens manejadas com três diferentes intervalos de corte, 14 dias (T14), 28 dias (T28) e 56 dias (T56) na composição do leite produzido. Os animais foram divididos em seis grupos e as pastagens manejadas nos respectivos intervalos. Para os compostos de interesse no leite, nos grupos T14 e T28 foram encontrados maiores teores de luteína (P<0,05) e do ácido graxo C20:5 (P<0,005) comparados ao T56. Para os demais parâmetros avaliados (demais ácidos graxos, carotenoides e vitaminas A e E), não se encontrou diferenças entre os tratamentos. Diante disso, o menor intervalo de corte resultou em um leite mais saudável.In dairy farming, the production of dairy products with greater concentrations of benefitial health compounds can add value to the product, such as carotenoids and polyunsaturated fatty acids. The aim of this study is to evaluate the effect of pasture management with three different cutting intervals (14, 28 and 56 days) on selected milk compounds. Animals were divided in 6 groups in a double latin-square design. Compounds of interest in milk were higher in T14 and T28 than T56 for lutein (P = 0.02) and C20:5 (P<0.005). Conjugated linoleic acid (CLA), vaccenic acid, omega 3 and 6, the ratio (omega6 / omega3), tocopherol, retinol and beta-carotene did not differ between treatments. There was no difference between T14 and T28, but T56 was different from both treatments for the diet consumed, bite rate and some milk components. Overall, the results show that the shorter cutting interval resulted in healthier milk.Eje: A1 Sistemas de producción de base agroecológica (Trabajos científicos)Facultad de Ciencias Agrarias y Forestale

The Job Search Intensity Supply Curve: How Labor Market Conditions Affect Job Search Effort

During the Great Recession of 2007, unemployment reached nearly 10 percent and the ratio of unemployment to open positions (as measured by the Help Wanted OnLine Index) more than tripled. The weak labor market prompted an unprecedented extension in the length of time in which a claimant can collect unemployment insurance (UI) to 99 weeks, at an expense to date of $226.4 billion. While many claim that extending UI during a recession will reduce search intensity, the effect of weak labor market conditions on search remains a mystery. As a result, policymakers are in the dark as to whether UI extensions reduce already low search effort during recessions or perhaps decrease excessive search, which causes congestion in the labor market. At the same time, modelers of the labor market have little empirical justification for their assumptions on how search intensity changes over the business cycle. This paper develops a search model where the impact of macro labor market conditions on a worker’s search effort depends on whether these two factors are substitutes or complements in the job search process. Parameter estimates of the structural model using a sample of unemployment spells from the National Longitudinal Survey of Youth 1997 indicate that macro labor market conditions and individual search effort are complements and move together over the business cycle. The estimation also reveals that more risk-averse and less wealthy individuals exhibit less search effort