Quantifier comprehension in corticobasal degeneration

In this study, we investigated patients with focal neurodegenerative diseases to examine a formal linguistic distinction between classes of generalized quantifiers, like "some X" and "less than half of X." Our model of quantifier comprehension proposes that number knowledge is required to understand both first-order and higher-order quantifiers. The present results demonstrate that corticobasal degeneration (CBD) patients, who have number knowledge impairments but little evidence for a deficit understanding other aspects of language, are impaired in their comprehension of quantifiers relative to healthy seniors, Alzheimer's disease (AD) and frontotemporal dementia (FTD) patients [F(3,77)=4.98; p<.005]. Moreover, our model attempts to honor a distinction in complexity between classes of quantifiers such that working memory is required to comprehend higher-order quantifiers. Our results support this distinction by demonstrating that FTD and AD patients, who have working memory limitations, have greater difficulty understanding higher-order quantifiers relative to first-order quantifiers [F(1,77)=124.29; p<.001]. An important implication of these findings is that the meaning of generalized quantifiers appears to involve two dissociable components, number knowledge and working memory, which are supported by distinct brain regions.     

Large-scale neural network for sentence processing

Our model of sentence comprehension includes at least grammatical processes important for structure-building, and executive resources such as working memory that support these grammatical processes. We hypothesized that a core network of brain regions supports grammatical processes, and that additional brain regions are activated depending on the working memory demands associated with processing a particular grammatical feature. We used functional magnetic resonance imaging (fMRI) to test this hypothesis by comparing cortical activation patterns during coherence judgments of sentences with three different syntactic features. We found activation of the ventral portion of left inferior frontal cortex during judgments of violations of each grammatical feature. Increased recruitment of the dorsal portion of left inferior frontal cortex was seen during judgments of violations of specific grammatical features that appear to involve a more prominent working memory component. Left posterolateral temporal cortex and anterior cingulate were also implicated in judging some of the grammatical features. Our observations are consistent with a large-scale neural network for sentence processing that includes a core set of regions for detecting and repairing several different kinds of grammatical features, and additional regions that appear to participate depending on the working memory demands associated with processing a particular grammatical feature.     

Connectivity among semantic associates: an fMRI study of semantic priming

Semantic priming refers to a reduction in the reaction time to identify or make a judgment about a stimulus that has been immediately preceded by a semantically related word or picture and is thought to result from a partial overlap in the semantic associates of the two words. A semantic priming lexical decision task using spoken words was presented in event-related fMRI and behavioral paradigms. Word pairs varied in terms of semantic relatedness and the connectivity between associates. Thirteen right-handed subjects underwent fMRI imaging and 10 additional subjects were tested in a behavioral version of the semantic priming task. It was hypothesized priming would be greatest, reaction time fastest, and cortical activation reduced the most for related word pairs of high connectivity, followed by related word pairs of low connectivity, and then by unrelated word pairs. Behavioral and fMRI results confirmed these predictions. fMRI activity located primarily in bilateral posterior superior and middle temporal regions showed modulation by connectivity and relatedness. The results suggest that these regions are involved in semantic processing.     

Bifactor models and rotations: exploring the extent to which multidimensional data yield univocal scale scores

The application of psychological measures often results in item response data that arguably are consistent with both unidimensional (a single common factor) and multidimensional latent structures (typically caused by parcels of items that tap similar content domains). As such, structural ambiguity leads to seemingly endless "confirmatory" factor analytic studies in which the research question is whether scale scores can be interpreted as reflecting variation on a single trait. An alternative to the more commonly observed unidimensional, correlated traits, or second-order representations of a measure's latent structure is a bifactor model. Bifactor structures, however, are not well understood in the personality assessment community and thus rarely are applied. To address this, herein we (a) describe issues that arise in conceptualizing and modeling multidimensionality, (b) describe exploratory (including Schmid-Leiman [Schmid & Leiman, 1957] and target bifactor rotations) and confirmatory bifactor modeling, (c) differentiate between bifactor and second-order models, and (d) suggest contexts where bifactor analysis is particularly valuable (e.g., for evaluating the plausibility of subscales, determining the extent to which scores reflect a single variable even when the data are multidimensional, and evaluating the feasibility of applying a unidimensional item response theory (IRT) measurement model). We emphasize that the determination of dimensionality is a related but distinct question from either determining the extent to which scores reflect a single individual difference variable or determining the effect of multidimensionality on IRT item parameter estimates. Indeed, we suggest that in many contexts, multidimensional data can yield interpretable scale scores and be appropriately fitted to unidimensional IRT models.     

Alternative Factor Models and Heritability of the Short Leyton Obsessional Inventory—Children’s Version

An alternative models framework was used to test three confirmatory factor analytic models for the Short Leyton Obsessional Inventory-Children’s Version (Short LOI-CV) in a general population sample of 517 young adolescent twins (11–16 years). A one-factor model as implicit in current classification systems of Obsessive–Compulsive Disorder (OCD), a two-factor obsessions and compulsions model, and a multidimensional model corresponding to the three proposed subscales of the Short LOI-CV (labelled Obsessions/Incompleteness, Numbers/Luck and Cleanliness) were considered. The three-factor model was the only model to provide an adequate explanation of the data. Twin analyses suggested significant quantitative sex differences in heritability for both the Obsessions/Incompleteness and Numbers/Luck dimensions with these being significantly heritable in males only (heritability of 60% and 65% respectively). The correlation between the additive genetic effects for these two dimensions in males was 0.95 suggesting they largely share the same genetic risk factors.     

Using Point-Of-View Video Modeling and Forward Chaining to Teach a Functional Self-Help Skill to a Child with Autism

This study examined the effectiveness of point-of-view video modeling in a forward-chaining procedure to teach a 4-year-old boy with autism to serve himself an afternoon snack. Task analysis was undertaken, and the task was divided into 3 phases with 1 video produced for each phase. A changing criterion design was used to evaluate the effects of the intervention on the participant’s ability to independently prepare and serve himself Weetbix. The results indicated that the combination of point-of-view modeling and forward chaining was effective in teaching the child to serve himself a snack without any prompting. The results also indicated that although the skill was maintained at follow-up, generalization to snacks other than Weetbix and to a different setting was limited. Parents reported satisfaction both with the procedures undertaken and with the outcomes of the intervention.     

Phonological recoding,rapid automatized naming,and orthographic knowledge

Phonological recoding, orthographic knowledge, and rapid automatized naming (RAN) are three major contributors to word identification. However, the interrelations between these components remain somewhat unclear. The current analyses focus on how phonological recoding and alphanumeric versus non-alphanumeric RAN contribute to different components of orthographic knowledge (word specific vs. general). Results indicate that alphanumeric and non-alphanumeric RAN contribute to orthographic knowledge components differently. Alphanumeric RAN relates more to word-specific orthographic knowledge, whereas non-alphanumeric RAN relates more to general orthographic knowledge. Furthermore, phonological recoding is more closely related to word-specific orthographic knowledge than to general orthographic knowledge.     

The Relation Between Early Adolescents’ Trust Beliefs in Peers and Reactions to Peer Provocation: Attributions of Intention and Retaliation

The authors examined the relation between early adolescents’ trust beliefs in peers and both their attributions for, and retaliatory aggression to, peer provocation. One hundred and eight-five early adolescents (102 male) from the United Kingdom (M age = 12 years, 2 months, SD = 3 months) completed the Children's Generalized Trust Beliefs in peer subscale (K. J. Rotenberg, C. Fox, et al., 2005) and reported the intentions of, and their retaliatory aggression to, hypothetical peer provocation. A curvilinear relation was found between trust beliefs in peers and retaliatory aggression but not for attributions of intention. Early adolescents with low and those with very high trust beliefs in peers reported greater retaliatory aggression than did early adolescents with the middle range of trust beliefs. The findings supported the conclusion that early adolescents who are high trusting, as well as those are very low trusting, are at risk for psychosocial maladjustment. Support was not obtained for a hostility attribution bias interpretation of those patterns.     

Reflex Responses of Human Lip Muscles to Mechanical Stimulation During Speech

The role played by reflex pathways in the production of movement has been a significant issue for motor control theorists interested in a wide variety of motor behaviors. From studies of locomotion and chewing, it appears that gains in reflex pathways can be altered so that activity in these pathways does not produce destabilizing responses during movement. In speech production, recent experimental evidence has been interpreted to suggest that autogenetic lip reflexes (perioral reflexes) are suppressed during sustained phonation or speech production. The present study was conducted to assess the effects of phonation, direction of movement, and ongoing speech production on reflex responses of lip muscles. The present results suggest, in contrast to earlier work, that this reflex pathway is not suppressed during phonation or speech. However, the response may appear to be suppressed or absent because the amplitude of the observed response depends upon the activation levels of the various muscles of the lower lip and, therefore, indirectly on the nature of the gesture the subject is instructed to produce.     

Kinematic and Electromyographic Changes That Occur as a Function of Learning a Time-constrained Aiming Task

The present study attempted to examine the changes associated with learning two time-constrained aiming movements at the neuromuscular and behavioral levels of analysis. Electromyographic data and movement kinematics were used to assess changes due to practice. Eight right-handed females were required to perform a 45° horizontal forearm extension in either 200 ms or 500 ms for 100 trials on each of four consecutive days. Both groups demonstrated an improvement in performance and a decrease in within-subject variability in the endpoint response measures, movement trajectory, and myoelectric pattern. With practice, there was a decrease in the amount of cocontraction between the agonist and antagonist muscles during movement execution, which indicated an elimination of unwanted neural activity. For the 200 ms task, the acceleration profile became symmetrical and a triphasic myoelectric pattern became evident. The deceleratory phase of the 500 ms task was longer than the acceleratory phase, and a biphasic pattern became apparent. The results suggest that two different control strategies were developed in the execution of the two movements examined. In addition, the relative invariance of the spatial-temporal dependent measures, as compared to the variability of the EMG, led us to the conclusion that the movement planning hierarchy was concerned with the spatial-temporal domain, whereas the amplitude and timing of muscular activity were planned at a lower level and thus played a subordinate role in movement production.