A Process Model of Causal Reasoning

How do we make causal judgments? Many studies have demonstrated that people are capable causal reasoners, achieving success on tasks from reasoning to categorization to interventions. However, less is known about the mental processes used to achieve such sophisticated judgments. We propose a new process model—the mutation sampler—that models causal judgments as based on a sample of possible states of the causal system generated using the Metropolis–Hastings sampling algorithm. Across a diverse array of tasks and conditions encompassing over 1,700 participants, we found that our model provided a consistently closer fit to participant judgments than standard causal graphical models. In particular, we found that the biases introduced by mutation sampling accounted for people's consistent, predictable errors that the normative model by definition could not. Moreover, using a novel experimental methodology, we found that those biases appeared in the samples that participants explicitly judged to be representative of a causal system. We conclude by advocating sampling methods as plausible process-level accounts of the computations specified by the causal graphical model framework and highlight opportunities for future research to identify not just what reasoners compute when drawing causal inferences, but also how they compute it.     

Antenatal caregiving representations and perinatal behavior in mothers with severe lifetime psychopathology

Psychopathology poses a risk for optimal parenting. The current study explored antenatal caregiving representations as markers for later risk of nonoptimal maternal behavior among mothers with severe mental illness. Sixty-five mothers diagnosed with psychosis, bipolar disorder, depression (psychopathology group), and nonclinical controls participated in a longitudinal study from pregnancy to 16 weeks after birth. Mental health diagnoses and caregiving representations were assessed during pregnancy. Maternal behavior was assessed during the 5-min recovery phase of the still-face paradigm at 16 weeks. Mothers with psychopathology reported significantly higher levels of “heightened” caregiving representations (i.e., separation anxiety from the child) than did controls. The only significant diagnostic group difference in perinatal maternal behavior was that mothers diagnosed with depression exhibited more overriding-intrusive behavior than did nonclinical control mothers. Regression modeling results showed that antenatal caregiving representations of “role reversal” predicted significantly lower levels of sensitivity and higher levels of overriding-intrusive behavior independent of the effect of psychopathology. The findings can be interpreted in the context of representational transformation to motherhood during pregnancy. The results provide preliminary evidence for the potential of a new questionnaire measure of caregiving representations as a screening instrument for antenatal representational risk.     

身体表征的分离:二分解释模型及其证据

身体表征是一种内部结构,它具有追踪身体状态并对其进行编码的功能。这种结构可以对身体进行错误的表征,并可以从身体中分离出来。来自海豹肢症与躯体失认症等方面的病例,证实部分身体畸形与脑损伤患者的身体表征存在分离;来自橡胶手错觉与全身错觉的实验证据,验证了健康个体身体表征分离的事实。基于上述证据,以身体图式和身体意象为二分维度的模型解释了身体表征的分离。未来的研究可以从神经心理学实验和虚拟现实技术着手,对身体表征的分离进行深入探究。     

跨期选择中的年龄差异及其机制

随着老龄化形势日益严峻, 老年人的跨期选择受到越来越多学者的关注。目前关于跨期选择的年老化研究尚存分歧:有研究发现老年人比年轻人更偏好未来获得更大收益; 也有研究发现老年人的选择偏好和年轻人一样, 甚至比年轻人更偏好近期收益。从时间表征和结果价值表征两个维度上的加工过程去分析其对老年人跨期选择的影响, 并进一步阐述认知、动机和情绪因素对两个维度加工过程的影响, 这对于理解当前老年人跨期选择领域研究的分歧有重要科学意义。     

视觉空间工作记忆组间差异的神经机制

为考察视觉空间工作记忆（working memory, WM）维持和操作的组间差异及其神经机制,本研究记录了高、低WM组完成延迟再认（维持）任务和心理旋转（操作）任务时的行为和事件相关电位数据。结果发现,在操作任务中,高WM组比低WM组的反应时显著更短;高WM组的中前额叶慢波显著更正、双侧后顶区慢波显著更负,并且两者的波幅显著负相关。在维持任务中,两组被试的反应时无显著差异;高WM组的中前额叶慢波显著更正。结果表明,高WM组的执行注意能力可能更强,能通过有效调节和分配加工资源来表征视觉信息。     

Processes of similarity judgment

Similarity underlies fundamental cognitive capabilities such as memory, categorization, decision making, problem solving, and reasoning. Although recent approaches to similarity appreciate the structure of mental representations, they differ in the processes posited to operate over these representations. We present an experiment that differentiates among extant structural accounts of similarity in their ability to account for patterns of similarity ratings. These data pose a challenge for transformation-based models and all but one mapping-based model, the Similarity as Interactive Activation and Mapping (SIAM) model of similarity.     

Perception as abduction: turning sensor data into meaningful representation

This article presents a formal theory of robot perception as a form of abduction. The theory pins down the process whereby low-level sensor data is transformed into a symbolic representation of the external world, drawing together aspects such as incompleteness, top-down information flow, active perception, attention, and sensor fusion in a unifying framework. In addition, a number of themes are identified that are common to both the engineer concerned with developing a rigorous theory of perception, such as the one on offer here, and the philosopher of mind who is exercised by questions relating to mental representation and intentionality.     

Expectations about numerical events in four lemur species (Eulemur fulvus, Eulemur mongoz, Lemur catta and Varecia rubra)

Although much is known about how some primates—in particular, monkeys and apes—represent and enumerate different numbers of objects, very little is known about the numerical abilities of prosimian primates. Here, we explore how four lemur species (Eulemur fulvus, E. mongoz, Lemur catta, and Varecia rubra) represent small numbers of objects. Specifically, we presented lemurs with three expectancy violation looking time experiments aimed at exploring their expectations about a simple 1+1 addition event. In these experiments, we presented subjects with displays in which two lemons were sequentially added behind an occluder and then measured subjects duration of looking to expected and unexpected outcomes. In experiment 1, subjects looked reliably longer at an unexpected outcome of only one object than at an expected outcome of two objects. Similarly, subjects in experiment 2 looked reliably longer at an unexpected outcome of three objects than at an expected outcome of two objects. In experiment 3, subjects looked reliably longer at an unexpected outcome of one object twice the size of the original than at an expected outcome of two objects of the original size. These results suggest that some prosimian primates understand the outcome of simple arithmetic operations. These results are discussed in light of similar findings in human infants and other adult primates.This revised version was published online in March 2005 with corrections to Fig. 6.     

Partial Knowledge of Word Meanings: Thematic and Taxonomic Representations

The type of information (taxonomic or thematic) available at different levels of knowledge was investigated. Following extensive norming to identify taxonomic and thematic associates of low-frequency nouns, participants determined if taxonomic or thematic associates were meaningfully related to target words at three levels of knowledge: target words they correctly defined (known), recognized as familiar (frontier), or mistakenly denied as part of the language (unknown). In another experiment, participants reported which type of relationship (taxonomic or thematic) was preferred. Results indicated that both types of information were available at all levels of knowledge. However, accuracy and preference were greater for taxonomic associates across word levels. A differential increase in available thematic information relative to taxonomic information was found. Implications for the acquisition and representation of word meanings are discussed.     

On the representation of Portuguese gender-inflected words in the mental lexicon

This study aims at verifying whether Portuguese gender-inflected nouns and adjectives are represented as full forms as suggested by Spanish data (Dominguez, Cuetos, & Segui, 1999). A series of lexical decision experiments is reported. Grammatical gender, frequency dominance, and grammatical category are manipulated and cumulative frequency is controlled. The results do not provide support for a full form representation of gender-inflected words. They suggest that grammatical category, or the nature of the inflectional process involved (lexical or syntactic), affects the way words are represented and accessed. Shorter recognition latencies were obtained for nouns drawn from Feminine dominant gender-inflected pairs than from Masculine dominant pairs whereas a tendency in the opposite direction was observed in adjectives. The effect of frequency dominance appears, nevertheless, to be restricted to feminine nouns. The data are compatible with the view that masculine nouns and adjectives are represented as gender-unmarked forms. These results are discussed in relation to current dual-access models of word recognition and to the notion of "interpretability" of lexico-syntactic features, as put forward in the Minimalist Program of Generative Linguistics.