Optimism as a Prior Belief about the Probability of Future Reward

Abstract

Optimists hold positive a priori beliefs about the future. In Bayesian statistical theory, a priori beliefs can be overcome by experience. However, optimistic beliefs can at times appear surprisingly resistant to evidence, suggesting that optimism might also influence how new information is selected and learned. Here, we use a novel Pavlovian conditioning task, embedded in a normative framework, to directly assess how trait optimism, as classically measured using self-report questionnaires, influences choices between visual targets, by learning about their association with reward progresses. We find that trait optimism relates to an a priori belief about the likelihood of rewards, but not losses, in our task. Critically, this positive belief behaves like a probabilistic prior, i.e. its influence reduces with increasing experience. Contrary to findings in the literature related to unrealistic optimism and self-beliefs, it does not appear to influence the iterative learning process directly.

Neuroticism Impairs the Use of Reward Values for Decision-Making inMajor Depression

“…The paradigm (Figure 1) was adapted from Stankevicius and colleagues [36] and performed during fMRI scanning. The experiment was implemented in MATLAB R R2007 (The MathWorks, Inc., Natick, MA) using the Psychophysics Toolbox [10,31,25].…”

“…Next, we fitted the winning model of Stankevicius and colleagues [36] (see Table 2), which tests the hypothesis that subjects behave as Bayesian observers during the task. This model assumed that at the decision time for a given fractal, participants estimate the number of times the fractal was followed by a reward (the likelihood) and combine this evidence with a prior belief about the probability of rewards associated with the fractals.…”

“…Although the observations are not modelled on a trial-by-trial basis, this model assumes that the likelihood is computed by (implicitly) counting, and perfectly remembering, the number of times each fractal is associated with reward. In the original experiment, Stankevicius and colleagues [36] found that the mean of the participants' prior belief distribution correlated positively with their optimism scores (LOT-R). A more recent analysis of the same data also revealed a negative correlation of the prior mean with neuroticism scores (see Supplement).…”

“…Currently, however, the supporting evidence is based almost entirely on subjective clinical interviews and rating scales with little objective behavioural evidence. Here we addressed this issue of subjectivity using a novel experimental paradigm and computational models of decision-making.We used a probabilistic reward-learning task, which has previously been reported to demonstrate individual behavioural differences that were associated with Life Orientation Test -Revised (LOT-R; measuring optimism) scores [36], as well as neuroticism scores (see Methods and Materials and Supplement) in healthy people. In the task, participants were asked to maximize their rewards by choosing between fractal stimuli, for which they could estimate the probability of reward from previous passive observations, and another target associated with an explicit reward probability value.…”

Adaptación de la Escala de Realismo de Liang y Dunn para emprendedores potenciales / Adaptation to Spanish of the Liang and Dunn’s realism scale for potential entrepreneurs

“…Recientemente se están dedicando numerosos esfuerzos y recursos a indagar sobre los mecanismos psicológicos, computacionales y neurológicos asociados con una percepción optimista de la realidad (e. g., Sharot, 2011;Sharot, Riccardi, Raio, y Phelps, 2007;Stankevicius, Huys, Kalra y Seriès, 2014) dadas las consecuencias positivas que reporta cierto grado de optimismo en las personas. En el ámbito de la creación y gestión de empresas el optimismo también es considerado como algo positivo pero, de manera parecida a como sucede fuera del área de los negocios (e. g., Sweeny et al, 2006;Sweeny y Shepperd, 2010), un exceso de optimismo o un optimismo no realista puede ser indeseable para una idea emprendedora incipiente (Liang y Dunn, 2010a;López y García, 2011).…”