A Multiple‐Channel Model of Task‐Dependent Ambiguity Resolution in Sentence Comprehension

Traxler, Pickering, and Clifton (1998) found that ambiguous sentences are read faster than their unambiguous counterparts. This so‐called ambiguity advantage has presented a major challenge to classical theories of human sentence comprehension (parsing) because its most prominent explanation, in the form of the unrestricted race model (URM), assumes that parsing is non‐deterministic. Recently, Swets, Desmet, Clifton, and Ferreira (2008) have challenged the URM. They argue that readers strategically underspecify the representation of ambiguous sentences to save time, unless disambiguation is required by task demands. When disambiguation is required, however, readers assign sentences full structure—and Swets et al. provide experimental evidence to this end. On the basis of their findings, they argue against the URM and in favor of a model of task‐dependent sentence comprehension. We show through simulations that the Swets et al. data do not constitute evidence for task‐dependent parsing because they can be explained by the URM. However, we provide decisive evidence from a German self‐paced reading study consistent with Swets et al.'s general claim about task‐dependent parsing. Specifically, we show that under certain conditions, ambiguous sentences can be read more slowly than their unambiguous counterparts, suggesting that the parser may create several parses, when required. Finally, we present the first quantitative model of task‐driven disambiguation that subsumes the URM, and we show that it can explain both Swets et al.'s results and our findings.     

Exponential-Family Random Graph Models for Multi-Layer Networks

Psychometrika - Multi-layer networks arise when more than one type of relation is observed on a common set of actors. Modeling such networks within the exponential-family random graph (ERG)...     

The history of an error

Lukács has had a colorful career as a Communist theoretician. One of the strangest events is the fact that he continued to recant in 1967, when there was no longer the external pressure to do so. This may be due to the fact that his differences with Marx on subject-object, praxis, etc., are not those of a humanist.     

Using mouse models to explore genotype-phenotype relationship in Down syndrome

Down Syndrome (DS) caused by trisomy 21 is characterized by a variety of phenotypes and involves multiple organs. Sequencing of human chromosome 21 (HSA21) and subsequently of its orthologues on mouse chromosome 16 have created an unprecedented opportunity to explore the complex relationship between various DS phenotypes and the extra copy of approximately 300 genes on HSA21. Advances in genetics together with the ability to generate genetically well-defined mouse models have been instrumental in understanding the relationships between genotype and phenotype in DS. Indeed, elucidation of these relationships will play an important role in understanding the pathophysiological basis of this disorder and helping to develop therapeutic interventions. A successful example of using such a strategy is our recent studies exploring the relationship between failed nerve growth factor (NGF) transport and amyloid precursor protein (App) overexpression. We found that increased dosage of the gene for App is linked to failed NGF signaling and cholinergic neurodegeneration in a mouse model of DS. Herein, we discuss several mouse models of DS and explore the emergence of exciting new insights into genotype-phenotype relationships, particularly those related to nervous system abnormalities. An important conclusion is that uncovering these relationships is enhanced by working from carefully defined phenotypes to the genes responsible.     

Four dimensions of self-defining memories (specificity, meaning, content, and affect) and their relationships to self-restraint, distress, and repressive defensiveness

This study examines four dimensions of self-defining memory (specificity, meaning, content, and affect) and their relationship to self-restraint, distress, and defensiveness. The development and validation of a protocol for measuring specificity, meaning, and affect in self-defining memories is discussed. Specificity is operationalized as the temporal and detailed specificity of the narrative. Meaning refers to the participant's stepping back from the narrative to derive higher personal meaning or a life lesson. Affect reflects subjective emotion upon recall. Agreement between two raters scoring 1040 memories was kappa=.83 for specificity and kappa=.72 for meaning. The protocol is compatible with Thorne and McLean's scoring system for content (the types of events in memories). The current study compared individual differences in the four dimensions of 10 self-defining memories collected from 103 undergraduates to scores of self-restraint, distress, and repressive defensiveness, as measured by the Weinberger Adjustment Inventory. Memory specificity was inversely related to repressive defensiveness, while greater memory meaning was linked to moderate and high levels of self-restraint. Memory content and affect predicted individuals' degree of subjective distress. Based on these findings, the authors discuss the place of self-defining memories in Conway and Pleydell-Pearce's Self-Memory System model of autobiographical memory and personality, more generally.     

On interchangeability of Nash equilibria in multi-player strategic games

The article studies properties of interchangeability of pure, mixed, strict, and strict mixed Nash equilibria. The main result is a sound and complete axiomatic system that describes properties of interchangeability in all four settings. It has been previously shown that the same axiomatic system also describes properties of independence in probability theory, nondeducibility in information flow, and non-interference in concurrency theory.     

Observing Preschoolers’ Social-Emotional Behavior: Structure,Foundations, and Prediction of Early School Success

Social-emotional behavior of 352 3- and 4-year-olds attending private childcare and Head Start programs was observed using the Minnesota Preschool Affect Checklist, Revised (MPAC-R). Goals of the investigation included (a) using MPAC-R data to extract a shortened version, MPAC-R/S, comparing structure, internal consistency, test–retest reliability, and stability of both versions; and, using the shortened measure, to examine (b) age, gender, and risk status differences in social-emotional behaviors; (c) contributions of emotion knowledge and executive function to social-emotional behaviors; and (d) contributions of social-emotional behaviors to early school adjustment and kindergarten academic success. Results show that reliability of MPAC-R/S was as good, or better, than the MPAC-R. MPAC-R/S structure, at both times of observation, included emotionally negative/aggressive, emotionally regulated/prosocial, and emotionally positive/productive behaviors; MPAC-R structure was similar but less replicable over time. Age, gender, and risk differences were found. Children's emotion knowledge contributed to later emotionally regulated/prosocial behavior. Finally, preschool emotionally negative/aggressive behaviors were associated with concurrent and kindergarten school success, and there was evidence of social-emotional behavior mediating relations between emotion knowledge or executive function, and school outcomes. The importance of portable, empirically supported observation measures of social-emotional behaviors is discussed along with possible applications, teacher utilization, and implementation barriers.