Learning, risk attitude and hot stoves in restless bandit problems

This research examines decisions from experience in restless bandit problems. Two experiments revealed four main effects. (1) Risk neutrality: the typical participant did not learn to become risk averse, a contradiction of the hot stove effect. (2) Sensitivity to the transition probabilities that govern the Markov process. (3) Positive recency: the probability of a risky choice being repeated was higher after a win than after a loss. (4) Inertia: the probability of a risky choice being repeated following a loss was higher than the probability of a risky choice after a safe choice. These results can be described with a simple contingent sampler model, which assumes that choices are made based on small samples of experiences contingent on the current state.     

Inference and update

We look at two fundamental logical processes, often intertwined in planning and problem solving: inference and update. Inference is an internal process with which we uncover what is implicit in the information we already have. Update, on the other hand, is produced by external communication, usually in the form of announcements and in general in the form of observations, giving us information that might not have been available (even implicitly) before. Both processes have received attention from the logic community, usually separately. In this work, we develop a logical language that allows us to describe them together. We present syntax, semantics and a complete axiom system; we discuss similarities and differences with other approaches and mention how the work can be extended.     

Extending probabilistic dynamic epistemic logic

This paper aims to extend in two directions the probabilistic dynamic epistemic logic provided in Kooi’s paper (J Logic Lang Inform 12(4):381–408, 2003) and to relate these extensions to ones made in van Benthem et al. (Proceedings of LOFT’06. Liverpool, 2006). Kooi’s probabilistic dynamic epistemic logic adds to probabilistic epistemic logic sentences that express consequences of public announcements. The paper (van Benthem et al., Proceedings of LOFT’06. Liverpool, 2006) extends (Kooi, J Logic Lang Inform 12(4):381–408, 2003) to using action models, but in both papers, the probabilities are discrete, and are defined on trivial σ-algebras over finite sample spaces. The first extension offered in this paper is to add a previous-time operator to a probabilistic dynamic epistemic logic similar to Kooi’s in (J Logic Lang Inform 12(4):381–408, 2003). The other is to involve non-trivial σ-algebras and continuous probabilities in probabilistic dynamic epistemic logic.     

Hostility‐ and gender‐related differences in oscillatory responses to emotional facial expressions

Hostility is associated with biases in the perception of emotional facial expressions, such that ambiguous or neutral expressions tend to be perceived as threatening or angry. In this study, the effects of hostility and gender on the perception of angry, neutral, and happy faces and on the oscillatory dynamics of cortical responses elicited by these presentations were investigated using time–frequency decomposition by means of wavelet transforms. Feelings of hostility predisposed subjects to perceive happy and neutral faces as less friendly. This effect was more pronounced in women. In hostile subjects, presentation of emotional facial expressions also evoked stronger posterior synchronization in the theta and diminished desynchronization in the alpha band. This may signify a prevalence of emotional responding over cognitive processing. These effects were also more pronounced in females. Hostile females, but not hostile males, additionally showed a widespread synchronization in the alpha band. This synchronization is tentatively explained as a manifestation of inhibitory control which is present in aggressive females, but not in aggressive males. Aggr. Behav. 35:502–513, 2009. © 2009 Wiley‐Liss, Inc.     

Presidential speechmaking style: Emotional response to micro-expressions of facial affect

Research considering the effect of Presidential speech making style shows individuals are likely to attend to and be emotionally affected by the facial expressions of leaders, especially those that are inappropriate for the context. In this study we tested how rapid and subtle expressions of facial affect (i.e., expressions of less than one-second, often termed micro-expressions) in speeches by a political leader impacts participants’ emotional state. We do this by removing seven brief expressions (less than one-second) from a nearly twelve minute televised speech by President George H. W. Bush concerning the 1990 commitment of US military in response to Iraq’s invasion of Kuwait. FACS coding identified all these expressions as containing a component of smiling (lip corner puller: AU12), in some cases with the addition of other facial movements (sometimes associated with anger and/or disgust). Experiments carried out on 206 university undergraduates showed emotional state was altered as a result of these micro-expressions when the control (unaltered speech) and experimental group (micro-expressions removed from speech) were compared. Specifically, participants who viewed the micro-expressions felt less threatened and less angry. Thus, facial expression (even very brief micro-expressions) can have a significant impact on the receiver of a political speech.

选择、自我表达与选择扩散效应

自我表达会影响西方人的态度, 产生选择扩散效应。国外相关的跨文化研究发现东方人不存在该效应。通过4个实验研究中国文化下自我表达对选择态度的影响, 发现选择方式(主动、被动)和自我表达形式(直接、间接)对选择态度产生影响。无论是自己的主动选择还是强加的被动选择, 直接的自我表达会增加对所获对象的喜爱程度, 表现为对获得性的肯定。研究者认为, 两种选择方式下不同的心理加工过程导致了这种获得性：直接表达使个人态度暴露在外, 进行主动选择时要对他人的给予做出肯定回应; 而进行被动选择时, 人们要减缓因利益受损可能导致的失调, 同时中国文化下的面子策略也使人们增加对所获对象的喜爱程度。不过, 间接的自我表达对选择态度的影响不明显。研究者认为, 多个影响因素的相互消长使选择态度得以维持。     

不同注意条件下动态面孔表情识别的ERP研究

利用ERP技术对16名被试在不同注意负荷下对动态表情识别的脑时程特点进行了考察,结果发现：N170成分不受注意负荷和表情效价影响;低注意负荷条件下动态表情加工早期负性表情诱发的EPN成分（early posterior negativity）显著大于中性、正性表情,后期高级分析阶段正、负性表情均诱发明显的LPP成分（late positive potentials）,且负性较正性表情诱发更大的LPP成分;而在高注意负荷条件下并未发现表情识别诱发明显的EPN或LPP成分。这些结果说明,动态表情识别明显受到注意资源调节,只有在注意资源不断增加时表情加工才会出现注意偏向效应,尤以负性表情的加工优势最为凸显且持久,正性表情相对微弱和短暂。     

精神分裂症病人对成人面部表情的辨别

本文对比研究了精神分裂症病人和正常人对成人面部表情辨别的水平,发现精神分裂症病人存在着表情辨别障碍。病程长、以阴性症状为主的病人易出现这种障碍。表情辨别障碍是一种情绪障碍,属阴性症状。     

Judgment in a dynamic task: Microburst forecasting

The major goals of this research are to (a) study professionals engaging in dynamic, representative task conditions, (b) apply lens model theory to these conditions, (c) learn how judgments are changed in response to changing conditions, and (d) utilize a hierarchical judgment model to investigate the judgment process from perception of data to final judgment. The results indicate that (a) agreement regarding inferred cue values is modest, not because of differences in perception of proximal, directly observed cue values but because of differences in inferences drawn from them, (b) agreement in probability judgments is higher when inferred cue values are specified, (c) little change in judgments occurred over time, and (d) confidence increased over time. The results regarding agreement and accuracy over time were ambiguous.     

Changes in imitative behavior during early infancy

Changes in imitative behavior and attentiveness were observed in 40 infants when they were 2 to 6 months of age. The facial expressions happy, sad, and surprised were modeled in a trials-to-criterion procedure, and the infants' looking time and mouth movements were recorded by an observer who was unaware of the face being modeled. In addition, the observer recorded her guess as to the expression being modeled by the corresponding expression on the infant's face and rated the infant's expressivity. The results suggested that looking time, correspondence between the mouth expression of the infant and the mouth expression modeled, accuracy of the observer's guess, and expressivity ratings decreased from 2 to 3 and 4 to 6 months. Although matching of mouth movements with the modeled mouth movements and accuracy of guesses were greater than chance over the 2 to 6 month-period, the decreases in these measures suggest that imitative behavior declined across early infancy. The decrease in looking time suggests that imitative behavior and attentiveness may be related and highlights the limitation of this paradigm for assessing the development of imitation during early infancy.