With age comes wisdom: decision making in younger and older adults

In two experiments, younger and older adults performed decision-making tasks in which reward values available were either independent of or dependent on the previous sequence of choices made. The choice-independent task involved learning and exploiting the options that gave the highest rewards on each trial. In this task, the stability of the expected reward for each option was not influenced by the previous choices participants made. The choice-dependent task involved learning how each choice influenced future rewards for two options and making the best decisions based on that knowledge. Younger adults performed better when rewards were independent of choice, whereas older adults performed better when rewards were dependent on choice. These findings suggest a fundamental difference in the way in which younger adults and older adults approach decision-making situations. We discuss the results in the context of prominent decision-making theories and offer possible explanations based on neurobiological and behavioral changes associated with aging.     

Heterogeneity of strategy use in the Iowa gambling task: A comparison of win-stay/lose-shift and reinforcement learning models

The Iowa gambling task (IGT) has been used in numerous studies, often to examine decision-making performance in different clinical populations. Reinforcement learning (RL) models such as the expectancy valence (EV) model have often been used to characterize choice behavior in this work, and accordingly, parameter differences from these models have been used to examine differences in decision-making processes between different populations. These RL models assume a strategy whereby participants incrementally update the expected rewards for each option and probabilistically select options with higher expected rewards. Here we show that a formal model that assumes a win-stay/lose-shift (WSLS) strategy—which is sensitive only to the outcome of the previous choice—provides the best fit to IGT data from about half of our sample of healthy young adults, and that a prospect valence learning (PVL) model that utilizes a decay reinforcement learning rule provides the best fit to the other half of the data. Further analyses suggested that the better fits of the WSLS model to many participants’ data were not due to an enhanced ability of the WSLS model to mimic the RL strategy assumed by the PVL and EV models. These results suggest that WSLS is a common strategy in the IGT and that both heuristic-based and RL-based models should be used to inform decision-making behavior in the IGT and similar choice tasks.     

Feedback and stimulus-offset timing effects in perceptual category learning

We examined how feedback delay and stimulus offset timing affected declarative, rule-based and procedural, information–integration category-learning. We predicted that small feedback delays of several hundred milliseconds would lead to the best information–integration learning based on a highly regarded neurobiological model of learning in the striatum. In Experiment 1 information–integration learning was best with feedback delays of 500 ms compared to delays of 0 and 1000 ms. This effect was only obtained if the stimulus offset following the response. Rule-based learning was unaffected by the length of feedback delay, but was better when the stimulus was present throughout feedback than when it offset following the response. In Experiment 2 we found that a large variance (SD = 150 ms) in feedback delay times around a mean delay of 500 ms attenuated information–integration learning, but a small variance (SD = 75 ms) did not. In Experiment 3 we found that the delay between stimulus offset and feedback is more critical to information–integration learning than the delay between the response and feedback. These results demonstrate the importance of feedback timing in category-learning situations where a declarative, verbalizable rule cannot easily be used as a heuristic to classify members into their correct category.     

Body dissatisfaction, bulimic symptoms, and clothing practices among college women

Clothing use may be a behavioral avoidance strategy for individuals with body dissatisfaction and eating pathology. The authors administered the Body Image Avoidance Questionnaire (J. C. Rosen, D. Srebnik, E. Saltzberg, & S. Wendt, 1991), the Bulimia Test-Revised (M. Thelen, J. Farmer, S. Wonderlich, & M. Smith, 1991), and the Body dissatisfaction subscale of the Eating Disorder Inventory (D. M. Garner, M. P. Olmstead, & J. Polivy, 1983) to undergraduate college women from two universities (N = 540). Results indicated that women who were more dissatisfied with their bodies (beta = .396) and had greater disordered eating behaviors (beta = .378) were more likely to engage in clothing-related appearance-management behaviors (p < .001), including wearing apparel to camouflage their bodies; avoiding revealing, brightly colored, or tightly fitting clothing; and avoiding shopping for clothing. These findings suggest that the presence of certain clothing-related appearance-management behaviors may be a warning sign that an individual is at risk for developing an eating disorder or may currently have an eating disorder.     

解读曼殊五部曲

苏曼殊是清末民初萃集革命与刨作于一身的“奇人异僧”。从革命的角度说,他意志坚定,积极投身于孙中山领导的资产阶级民主革命,为推翻清朝统治和袁世凯帝制尽心竭力;从创作的角度说,他多才多艺,以风格独特的诗歌、小说、散、翻译、绘画树帜坛,赢得生前和身后无数读的击节和赞赏;从身份的角度说,他是个亦僧亦俗、亦侠亦儒的革命和艺家。他曾获得的桂冠大体停留在不大反映本质的“诗僧”、“情僧”、“风流和尚”、“革命和尚”等一类称号上,然而随着这位传奇的历史人物的“真面目”越来越清晰呈现于世,而不再继续充当人们揣测的对象。     

无限慈悲的观音菩萨

菩萨是梵文音译“菩提萨”的简称,其菩提汉译为觉悟,萨汉译为众生,或有情(一切有感情之物),全译为觉有情、觉悟的众生之意。根据修行的层次,菩萨可分为胁侍菩萨和供养菩萨。胁侍菩萨是修行层次最高的菩萨,其修行觉悟仅次于佛或等同于佛。每尊佛都有两位或几位胁侍菩萨。在石窟壁画中经常画的“八大菩萨”,即是释迦牟尼佛左右的胁侍菩萨——文殊菩萨、普贤菩     

Ostracism Reduces Reliance on Poor Advice from Others during Decision Making

Decision making is rarely context‐free, and often, both social information and non‐social information are weighed into one's decisions. Incorporating information into a decision can be influenced by previous experiences. Ostracism has extensive effects, including taxing cognitive resources and increasing social monitoring. In decision making situations, individuals are often faced with both objective and social information and must choose which information to include or filter out. How will ostracism affect the reliance on objective and social information during decision making? Participants (N = 245) in Experiment 1 were randomly assigned to be included or ostracized in a standardized, group task. They then performed a dynamic decision making task that involved the presentation of either non‐social (i.e. biased reward feedback) or social (i.e., poor advice from a previous participant) misleading information. In Experiment 2, participants (N = 105) completed either the ostracism non‐social condition or social misleading information condition with explicit instructions stating that the advice given was from an individual who did not partake in the group task. Ostracized individuals relied more on non‐social misleading information and performed worse than included individuals. However, ostracized individuals discounted misleading social information and outperformed included individuals. Results of Experiment 2 replicated the findings of Experiment 1. Across two experiments, ostracized individuals were more critical of advice from others, both individuals who may have ostracized them and unrelated individuals. In other words, compared with included individuals, ostracized individuals underweighted advice from another individual but overweighed non‐social information during decision making. We conclude that when deceptive objective information is present, ostracism results in disadvantageous decision making. Copyright © 2015 John Wiley & Sons, Ltd.     

Dopamine,depressive symptoms,and decision-making: the relationship between spontaneous eye blink rate and depressive symptoms predicts Iowa Gambling Task performance

Depressive symptomatology has been associated with alterations in decision-making, although conclusions have been mixed, with depressed individuals showing impairments in some contexts but advantages in others. The dopaminergic system may link depressive symptoms with decision-making performance. We assessed the role of striatal dopamine D₂ receptor density, using spontaneous eye blink rates, in moderating the relationship between depressive symptoms and decision-making performance in a large undergraduate sample that had not been screened for mental illness (N?=?104). The regression results revealed that eye blink rate moderated the relationship between depressive symptoms and advantageous decisions on the Iowa Gambling Task, in which individuals with more depressive symptomatology and high blink rates (higher striatal dopamine D₂ receptor density) performed better on the task. Our computational modeling results demonstrated that depressive symptoms alone were associated with enhanced loss-aversive behavior, whereas individuals with high blink rates and elevated depressive symptoms tended to persevere in selecting options that led to net gains (avoiding options with net losses). These findings suggest that variation in striatal dopamine D₂ receptor availability in individuals with depressive symptoms may contribute to differences in decision-making behavior.