Expectancy bias and the persistence of posttraumatic stress

Anxious individuals tend to overestimate the probability that encounters with anxiogenic stimuli (CS) will be followed by aversive consequences (UCS). This study examined whether such (biased) UCS expectancies predict the persistence of PTSD symptoms. A total of 265 soldiers were recruited before a four-month deployment to Iraq in 2004. About 2-5 months after deployment, 171 (65%) soldiers completed self-report scales about adverse events in Iraq and PTSD symptoms, and a UCS expectancy task. In this task, participants were exposed to a series of deployment-related and deployment-unrelated (control) picture stimuli. For each trial, the participants indicated the subjective probability that a particular slide would be followed by an imminent loud noise. Around 15 months after deployment, 130 (76%) soldiers completed surveys about PTSD symptoms again. Only a small group of participants had high levels of PTSD symptoms. Regression analyses showed that the level of PTSD symptoms at 15 months was predicted by earlier PTSD symptoms, but also and independently by an enhanced UCS expectancy to deployment-related stimuli. The findings support the notion that UCS expectancy bias contributes to the persistence of PTSD symptoms.     

An assessment of response, direction and place learning by rats in a water T-maze

Behavioral data suggest that distinguishable orientations may be necessary for place learning even when distal cues define different start points in the room and a unique goal location. We examined whether changes in orientation are also important in place learning and navigation in a water T-maze. In Experiment 1, rats were trained to locate a hidden platform and given a no-platform probe trial after 16 and 64 trials with the maze moved to a new position. Direction and response strategies were more prevalent than a place strategy. In Experiment 2, acquisition of place, response and direction strategies was assessed in a water T-maze that was moved between two locations during training. Rats were impaired on the place task when the maze was translated (moved to the L or R) but were successful when the maze was rotated across trials. These data are consistent with findings from appetitive tasks.     

同一性地位理论及其扩展模型

Marcia的同一性地位理论及其模型开辟了同一性研究的实证道路。在此基础上产生了诸多扩展模型,主要有Berzonsky的同一性风格模型;Grotevant的同一性探索过程模型;Kerplman的同一性控制模型;Luyckx的四维度模型;Crocetti的三维度模型。该文对这些模型的基本内容、价值与局限进行了简评,并指出了同一性地位理论模型发展的特点及未来趋势。     

失败恐惧的影响因素及其对学业成绩的影响

该研究力图探讨教养及气质因素与失败恐惧的关系,以及失败恐惧对学业成绩的影响及其机制。对427名高一学生施测失败表现评估量表、父母教养方式评价量表、行为抑制/行为激活量表、防御性期望和反思量表、自我阻碍量表,并收集被试期末考试成绩。相关分析、回归分析、路径分析等表明,失败恐惧与教养、气质因素均有密切关系;其对学业成绩具有间接的消极影响。     

The development of category learning strategies: What makes the difference?

Category learning can be achieved by identifying common features among category members, distinctive features among non-members, or both. These processes are psychologically and computationally distinct, and may have implications for the acquisition of categories at different hierarchical levels. The present study examines an account of children’s difficulty in acquiring categories at the subordinate level grounded on these distinct comparison processes. Adults and children performed category learning tasks in which they were exposed either to pairs of objects from the same novel category or pairs of objects from different categories. The objects were designed so that for each category learning task, two features determined category membership whereas two other features were task irrelevant. In the learning stage participants compared pairs of objects noted to be either from the same category or from different categories. Object pairs were chosen so that the objective amount of information provided to the participants was identical in the two learning conditions. We found that when presented only with object pairs noted to be from the same category, young children (6 ? YO ? 9.5) learned the novel categories just as well as older children (10 ? YO ? 14) and adults. However, when presented only with object pairs known to be from different categories, unlike older children and adults, young children failed to learn the novel categories. We discuss cognitive and computational factors that may give rise to this comparison bias, as well as its expected outcomes.     

Short-term gains, long-term pains: How cues about state aid learning in dynamic environments

Successful investors seeking returns, animals foraging for food, and pilots controlling aircraft all must take into account how their current decisions will impact their future standing. One challenge facing decision makers is that options that appear attractive in the short-term may not turn out best in the long run. In this paper, we explore human learning in a dynamic decision making task which places short- and long-term rewards in conflict. Our goal in these studies was to evaluate how people’s mental representation of a task affects their ability to discover an optimal decision strategy. We find that perceptual cues that readily align with the underlying state of the task environment help people overcome the impulsive appeal of short-term rewards. Our experimental manipulations, predictions, and analyses are motivated by current work in reinforcement learning which details how learners value delayed outcomes in sequential tasks and the importance that “state” identification plays in effective learning.     

Speech errors reflect the phonotactic constraints in recently spoken syllables, but not in recently heard syllables

Adults rapidly learn phonotactic constraints from brief production or perception experience. Three experiments asked whether this learning is modality-specific, occurring separately in production and perception, or whether perception transfers to production. Participant pairs took turns repeating syllables in which particular consonants were restricted to particular syllable positions. Speakers’ errors reflected learning of the constraints present in the sequences they produced, regardless of whether their partner produced syllables with the same constraints, or opposing constraints. Although partial transfer could be induced (Experiment 3), simply hearing and encoding syllables produced by others did not affect speech production to the extent that error patterns were altered. Learning of new phonotactic constraints was predominantly restricted to the modality in which those constraints were experienced.     

From domain-generality to domain-sensitivity: 4-Month-olds learn an abstract repetition rule in music that 7-month-olds do not

Learning must be constrained for it to lead to productive generalizations. Although biology is undoubtedly an important source of constraints, prior experience may be another, leading learners to represent input in ways that are more conducive to some generalizations than others, and/or to up- and down-weight features when entertaining generalizations. In two experiments, 4-month-old and 7-month-old infants were familiarized with sequences of musical chords or tones adhering either to an AAB pattern or an ABA pattern. In both cases, the 4-month-olds learned the generalization, but the 7-month-olds did not. The success of the 4-month-olds appears to contradict an account that this type of pattern learning is the provenance of a language-specific rule-learning module. It is not yet clear what drives the age-related change, but plausible candidates include differential experience with language and music, as well as interactions between general cognitive development and stimulus complexity.     

Learning in reverse: Eight-month-old infants track backward transitional probabilities

Numerous recent studies suggest that human learners, including both infants and adults, readily track sequential statistics computed between adjacent elements. One such statistic, transitional probability, is typically calculated as the likelihood that one element predicts another. However, little is known about whether listeners are sensitive to the directionality of this computation. To address this issue, we tested 8-month-old infants in a word segmentation task, using fluent speech drawn from an unfamiliar natural language. Critically, test items were distinguished solely by their backward transitional probabilities. The results provide the first evidence that infants track backward statistics in fluent speech.     

Mutual influence of implicit and explicit attitudes

Research and theory distinguish two types of attitude: automatic evaluative reactions and deliberate evaluative judgments, referred to as implicit and explicit attitudes, respectively. Although these attitudes are distinct, they may influence each other. Four studies tested whether implicit and explicit attitudes are both influenced by propositional and associative learning. We also tested whether changes in one kind of attitude mediate changes in the other. Study 1 found that propositional learning about novel individuals directly influenced explicit attitudes and indirectly influenced implicit attitudes through changes in explicit attitudes. Studies 2 and 3 replicated this finding and extended it by simultaneously demonstrating that associative learning through Evaluative Conditioning directly influences implicit attitudes and indirectly influences explicit attitudes through changes in implicit attitudes. Study 4 replicated these effects for attitudes toward familiar, rather than novel, targets. These results suggest that implicit and explicit attitudes can share common antecedents and influence each other.