Associations between miscellaneous symptoms and symptom dimensions in adults with obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a debilitating psychiatric condition with a heterogeneous array of obsessions and compulsions. Although factor analytic studies have identified symptom dimensions comprising the clinical presentation of OCD, many frequently reported miscellaneous symptoms are not considered in factor analytic studies because they do not fit conceptually within a particular symptom category, despite being functionally related. In the present study, we examined the associations between miscellaneous symptoms and OCD symptom dimensions in a sample of 111 adults with OCD. Overall, most miscellaneous symptoms were associated with one or more symptom dimensions in previously identified four- (14 of the 22 symptoms) and five-factor models (12 of the 22 symptoms). In both models, Contamination/Cleaning was the only dimension not related to any miscellaneous symptom. The present results provide information about which miscellaneous symptoms may be related to particular symptom dimensions, which will assist in clinical evaluations and help planning behavioral psychotherapy (e.g., hierarchy development).     

Spatial memories of virtual environments: How egocentric experience, intrinsic structure, and extrinsic structure interact

Previous research has uncovered three primary cues that influence spatial memory organization:egocentric experience, intrinsic structure (object defined), and extrinsic structure (environment defined). In the present experiments, we assessed the relative importance of these cues when all three were available during learning. Participants learned layouts from two perspectives in immersive virtual reality. In Experiment 1, axes defined by intrinsic and extrinsic structures were in conflict, and learning occurred from two perspectives, each aligned with either the intrinsic or the extrinsic structure. Spatial memories were organized around a reference direction selected from the first perspective, regardless of its alignment with intrinsic or extrinsic structures. In Experiment 2, axes defined by intrinsic and extrinsic structures were congruent, and spatial memories were organized around reference axes defined by those congruent structures, rather than by the initially experienced view. The findings are discussed in the context of spatial memory theory as it relates to real and virtual environments.     

The shape of human navigation: how environmental geometry is used in maintenance of spatial orientation

The role of environmental geometry in maintaining spatial orientation was measured in immersive virtual reality using a spatial updating task (requiring maintenance of orientation during locomotion) within rooms varying in rotational symmetry (the number of room orientations providing the same perspective). Spatial updating was equally good in trapezoidal, rectangular and square rooms (one-fold, two-fold and four-fold rotationally symmetric, respectively) but worse in a circular room (∞-fold rotationally symmetric). This contrasts with reorientation performance, which was incrementally impaired by increasing rotational symmetry. Spatial updating performance in a shape-changing room (containing visible corners and flat surfaces, but changing its shape over time) was no better than performance in a circular room, indicating that superior spatial updating performance in angular environments was due to remembered room shape, rather than improved self-motion perception in the presence of visible corners and flat surfaces.     

Response mode differences in perspective taking: Differences in representation or differences in retrieval?

Three experiments explored whether response mode differences in perspective taking result from different spatial representations or different retrieval processes. Participants learned object locations and then, while blindfolded, pointed to or verbally described object locations from perspectives aligned or misaligned with their facing direction and aligned or misaligned with the learning perspective. Pointing was facilitated from the perspective aligned with the body during testing. Similar facilitation occurred when verbally labeling, but only when conducted in the context of pointing (e.g., after pointing). Without this pointing context, or after third-person strategy instructions, the effect of body alignment was eliminated for verbal responses. Pointing was less responsive to context and strategy. Across all conditions, performance was facilitated for the learning perspective. Taken together, these experiments indicate that response mode differences are due to differences in the retrieval process, which varies with strategy, rather than differences in the organization of the underlying spatial memory.     

Body- and environmental-stabilized processing of spatial knowledge

In 5 experiments, the authors examined the perceptual and cognitive processes used to track the locations of objects during locomotion. Participants learned locations of 9 objects on the outer part of a turntable from a single viewpoint while standing in the middle of the turntable. They subsequently pointed to objects while facing the learning heading and a new heading, using imagined headings that corresponded to their current actual body heading and the other actual heading. Participants in 4 experiments were asked to imagine that the objects moved with them as they turned and were shown or only told that the objects would move with them; in Experiment 5, participants were shown that objects could move with them but were asked to ignore this as they turned. Results showed that participants tracked object locations as though the objects moved with them when shown but not when told about the consequences of their locomotion. Once activated, this processing mode could not be suppressed by instructions. Results indicated that people process object locations in a body- or an environment-stabilized manner during locomotion, depending on the perceptual consequences of locomotion.     

Where’s the difficulty in standardized reading tests: The passage or the question?

The purpose of this investigation was to examine the extent to which item and text characteristics predict item difficulty on the comprehension portion of the Gates-MacGinitie Reading Tests for the 7th–9th and 10th–12th grade levels. Detailed item-based analyses were performed on 192 comprehension questions on the basis of the cognitive processing model framework proposed by Embretson and colleagues (Embretson & Wetzel, 1987). Item difficulty was analyzed in terms of various passage features (e.g., word frequency and number of propositions) and individual-question characteristics (e.g., abstractness and degree of inferential processing), using hierarchical linear modeling. The results indicated that the difficulty of the items in the test for the 7th–9th grade level is primarily influenced by text features—in particular, vocabulary difficulty—whereas the difficulty of the items in the test for the 10th–12th grade level is less systematically influenced by text features.     

Agential obligation as non-agential personal obligation plus agency

I explore various ways of integrating the framework for predeterminism, agency, and ability in [P. McNamara, Nordic J. Philos. Logic 5 (2) (2000) 135] with a framework for obligations. However, the agential obligation operator explored here is defined in terms of a non-agential yet personal obligation operator and a non-deontic (and non-normal) agency operator. This is contrary to the main current trend, which assumes statements of personal obligation always take agential complements. Instead, I take the basic form to be an agent's being obligated to be such that p. I sketch some logics for agential obligation based on personal obligation and agency, first in a fairly familiar context that rules out conflicting personal obligations (and derivatively, conflicting agential obligations), and then in contexts that do allow for conflicts (of both sorts). Finally, a solution to van Fraassen's puzzle is sketched, and an important theorem is proved.     

Decision-making under uncertainty: biases and Bayesians

Animals (including humans) often face circumstances in which the best choice of action is not certain. Environmental cues may be ambiguous, and choices may be risky. This paper reviews the theoretical side of decision-making under uncertainty, particularly with regard to unknown risk (ambiguity). We use simple models to show that, irrespective of pay-offs, whether it is optimal to bias probability estimates depends upon how those estimates have been generated. In particular, if estimates have been calculated in a Bayesian framework with a sensible prior, it is best to use unbiased estimates. We review the extent of evidence for and against viewing animals (including humans) as Bayesian decision-makers. We pay particular attention to the Ellsberg Paradox, a classic result from experimental economics, in which human subjects appear to deviate from optimal decision-making by demonstrating an apparent aversion to ambiguity in a choice between two options with equal expected rewards. The paradox initially seems to be an example where decision-making estimates are biased relative to the Bayesian optimum. We discuss the extent to which the Bayesian paradigm might be applied to the evolution of decision-makers and how the Ellsberg Paradox may, with a deeper understanding, be resolved.     

The bit in the middle and why it’s important: a computational analysis of the linguistic features of body paragraphs

This study examines the relationship between the linguistic characteristics of body paragraphs of student essays and the total number of paragraphs in the essays. Results indicate a significant relationship between the total number of paragraphs and a variety of linguistic characteristics known to affect student essay scores. These linguistic characteristics (e.g., semantic overlap, syntactic complexity) contribute to two underlying factors (i.e., textual cohesion and difficulty) that are used as dependent variables in mixed-effect models. Results suggest that student essays with 5-8 paragraphs tend to be more linguistically consistent than student essays with 3, 4, and 9 paragraphs. Essays with totals of 5-8 paragraphs, considered by many educators to contain an optimal number of paragraphs, may include functionally and structurally similar paragraphs. These findings could aid writing researchers and educators in obtaining a clearer view of the relationship between the total number of paragraphs comprising an essay and the linguistic characteristics that affect essay evaluation. Consequently, writing interventions may become better equipped to pinpoint student difficulties and facilitate student writing skills by providing more detailed and informed feedback.     

空间情境模型的更新：认知方式的影响

采用前照应解决(anaphora resolution)与学习探测相结合的实验范式以及移动窗口技术探讨不同认知方式个体的空间情境模型更新能力的差异。实验1发现, 场依存性被试在高预见性条件下表现出空间距离效应, 低预见性条件下则没有; 而场独立性被试刚好相反。实验2通过在关键句中提示路径房间的一个物品深入探讨更新过程中不同认知方式个体更新模式的差异, 结果发现, 两类被试在低预见性记叙文中都表现出了明显的空间距离效应。这表明, 场独立性个体的空间情境模型更新能力高于场依存性个体的更新能力。