Search

Many animals, including humans, must make decisions when outcomes involve risk and/or ambiguity. To explore the evolutionary roots of decision making when outcomes are unknown, we modified the Balloon Analogue Risk Task (BART) for use with tufted capuchin monkeys (Sapajus [Cebus] apella), creating the Primate Analogue Risk Task (PART). Using both the BART and the PART, we first compared human performance across the two tasks using analogous parameters. Humans' performance on the two tasks was positively correlated. Next, we tested capuchin monkeys' performance on the PART to assess their decision-making strategies in the context of ambiguity. Secondarily, although it was not the main goal of the study, this allowed us to look at species differences between capuchins' and humans' performance. Finally, we investigated the influence of prior experience on human and capuchin decision-making behavior. Neither capuchins nor humans behaved differently following an unsuccessful trial compared to a successful trial. We found individual differences in capuchin monkeys' choice behavior, though as a whole they demonstrated a pattern of reward maximization over time. Finally, as a species, capuchins had lower PART risk scores than humans. This paradigm presents a useful way to assess behavior in a context with uncertain outcomes using a comparative approach. [ABSTRACT FROM AUTHOR]

In the Chinese writing system, there are no interword spaces to mark word boundaries. To understand how Chinese readers conquer this challenge, we constructed an integrated model of word processing and eye-movement control during Chinese reading (CRM). The model contains a word-processing module and an eye-movement control module. The word-processing module perceives new information within the perceptual span around a fixation. The model uses the interactive activation framework (McClelland & Rumelhart, 1981) to simulate word processing, but some new assumptions were made to address the word segmentation problem in Chinese reading. All the words supported by characters in the perceptual span are activated and they compete for a winner. When one word wins the competition, it is identified and it is simultaneously segmented from text. The eye-movement control module makes the decision regarding when and where to move the eyes using the activation information of word units and character units provided by the word-processing module. The model estimates how many characters can be processed during a fixation, and then makes a saccade to somewhere beyond this point. The model successfully simulated important findings on the relation between word processing and eye-movement control, how Chinese readers choose saccade targets, how Chinese readers segment words with ambiguous boundaries, and how Chinese readers process information with parafoveal vision during Chinese sentence reading. The current model thus provides insights on how Chinese readers address some important challenges, such as word segmentation and saccade-target selection. [ABSTRACT FROM AUTHOR]

The purpose of the present meta-analysis was to quantify the effects that stress has on decisions made under uncertainty. We hypothesized that stress increases reward seeking and risk taking through alterations of dopamine firing rates and reduces executive control by hindering optimal prefrontal cortex functioning. In certain decision situations, increased reward seeking and risk taking is dysfunctional, whereas in others, this is not the case. We also assumed that the type of stressor plays a role. In addition, moderating variables are analyzed, such as the hormonal stress response, the time between stress onset and decisions, and the participants' age and gender. We included studies in the meta-analysis that investigated decision making after a laboratory stress-induction versus a control condition (k = 32 datasets, N = 1829 participants). A random-effects model revealed that overall, stress conditions lead to decisions that can be described as more disadvantageous, more reward seeking, and more risk taking than nonstress conditions (d = .17). In those situations in which increased reward seeking and risk taking is disadvantageous, stress had significant effects (d = .26), whereas in other situations, no effects were observed (d = .01). Effects were observed under processive stressors (d = .19), but not under systemic ones (d = .09). Moderation analyses did not reveal any significant results. We concluded that stress deteriorates overall decision-making performance through the mechanisms proposed. The effects differ, depending on the decision situation and the type of stressor, but not on the characteristics of the individuals. [ABSTRACT FROM AUTHOR]

Based on the motivated information processing in groups model, we predicted that low personal need for structure (PNS) among team members helps team dynamic decision-making performance on highly ambiguous tasks, but hurts performance on tasks low in ambiguity. In a laboratory experiment involving 22 groups of army cadets performing a command-and-control task, we measured PNS and manipulated informational ambiguity. We found that team PNS was negatively related to team performance when tasks were high in ambiguity and positively related to performance when tasks were less ambiguous. This effect was mediated by information processing and behavioral coordination. [ABSTRACT FROM AUTHOR]

Theoretical accounts of risky choice framing effects assume that decision makers interpret framing options as extensionally equivalent, such that if 600 lives are at stake, saving 200 implies that 400 die. However, many scholars have argued that framing effects are caused, instead, by filling in pragmatically implied information. This linguistic ambiguity hypothesis is grounded in neo-Gricean pragmatics, information leakage, and schema theory. In 2 experiments, we conducted critical tests of the linguistic ambiguity hypothesis and its relation to framing. We controlled for this crucial implied information by disambiguating it using instructions and detailed examples, followed by multiple quizzes. After disambiguating missing information, we presented standard framing problems plus truncated versions, varying types of missing information. Truncations were also critical tests of prospect theory and fuzzy trace theory. Participants were not only college students, but also middle-age adults (who showed similar results). Contrary to the ambiguity hypothesis, participants who interpreted missing information as complementary to stated information nonetheless showed robust framing effects. Although adding words like "at least" can change interpretations of framing information, this form of linguistic ambiguity is not necessary to observe risky choice framing effects. [ABSTRACT FROM AUTHOR]

Advantageous decision making progressively develops into early adulthood, most specifically in complex and motivationally salient decision situations in which direct feedback on gains and losses is provided (Figner & Weber, 2011). However, the factors that underlie this developmental improvement in decision making are still not well understood. The current study therefore investigates 2 potential factors, long-term memory and working memory, by assigning a large developmental sample (7-29 years of age) to a condition with either high or low demands on long-term and working memory. The first condition featured an age-adapted version of the Iowa Gambling Task (IGT; Bechara, Damasio, Damasio, & Anderson, 1994; i.e., a noninformed situation), whereas the second condition provided an external store where explicit information on gains, losses, and probabilities per choice option was presented (i.e., an informed situation). Consistent with previous developmental IGT studies, children up to age 12 did not learn to prefer advantageous options in the noninformed condition. In contrast, all age groups learned to prefer the advantageous options in the informed conditions, although a slight developmental increase in advantageous decision making remained. These results indicate that lowering dependence on long-term and working memory improves children's advantageous decision making. The results additionally suggest that other factors, like inhibitory control processes, may play an additional role in the development of advantageous decision making. [ABSTRACT FROM AUTHOR]

An ambiguity disadvantage (slower responses for ambiguous words, e.g., bank, than for unambiguous words) has been reported in semantic tasks (L. R. Gottlob, S. D. Goldinger, G. O. Stone, & G. C. Van Orden, 1999; Y. Hino, S. J. Lupker, & P. M. Pexman, 2002; C. D. Piercey & S. Joordens, 2000) and has been attributed to the meaning activation process. The authors tested an alternative explanation: The ambiguity disadvantage arises from the decision-making process in semantic tasks. The authors examined effects of ambiguity on unrelated trials in a relatedness decision task, because these trials are free from response competition created by ambiguous words on related trials. Results showed no ambiguity effect on unrelated trials (Experiments 2, 3c, and 5c) and an ambiguity disadvantage on related trials (Experiments 3a, 3b, 5a, and 5b). [ABSTRACT FROM AUTHOR]