Famous faces but not remembered spaces influence vertical line bisections.

Whereas the ventral visual processing stream mediates facial and object recognition, the dorsal stream mediates recognition of spatial relationships. In addition, ventral lesions have been reported to induce visual inattention to the upper visual field and dorsal lesions inattention to the lower field. The purpose of this study is to test the hypothesis that activation of the ventral stream will induce an upward attentional bias and activation of the dorsal stream, a downward bias, as assessed by vertical line bisection tests. Twelve healthy right-handed individuals performed vertical line bisections. During these trials, either pictures of famous faces or dots in different spatial locations were presented above and below the line. The participants were asked to recognize and remember the faces or locations of dots while they performed the bisections. In control trials, they were no faces or dots. An upward bias was observed in all conditions. This upward bias was significantly increased in the face recognition and recall condition, but not altered in the dot location condition. Although the face task appeared to activate the ventral stream and increase the upward vertical bias, the failure of the dot localization task to alter the bias may be related task selection. Dorsolateral lesions cause optic ataxia, a disorder of the egocentric "where" system, and the dot location task in this study was allocentric. Thus, further research will be needed to learn whether an egocentric spatial localization task, with a memory component, will alter the vertical attentional bias.

Effects of semantic elaboration and typicality on picture naming in Alzheimer disease.

PURPOSE: Individuals with probable Alzheimer disease (pAD) are frequently impaired at picture naming. This study examined whether a semantic elaboration task would facilitate naming in pAD, and whether training either semantically typical or atypical stimulus items facilitated generalized improvement in picture naming and category generation tasks. METHODS: Twelve adults with mild-moderate pAD participated in the study. Participants performed an experimental semantic elaboration training task using a subset of typical items from one category and atypical items from another category. The third category, acted as a control (i.e., no items were trained). The study assessed change in category generation and a picture naming within the three target categories. RESULTS: Individuals showed significantly improved category generation and naming, but changes were not limited to trained categories. Naming of trained atypical items improved significantly. Participants showed significantly improved naming of untrained typical items from categories trained with typical items. CONCLUSIONS: Semantic elaboration of typical items within a semantic category can lead to generalized improvement in other typical items in the category in mild-moderate pAD. This is consistent with theories postulating that typical category items share overlapping distributed representations. Further exploration of the effects of semantic elaboration on word-finding in pAD is warranted, especially the possibility of within-category generalization.

The Syntax of Defection and Cooperation: The Effects of the Implicit Sentences Nice Act Versus Act Nice on Behavior Change.

The syntactic organization of incidentally presented word pairs may affect behavior by providing actors with implicit propositions about how to behave. In Experiment 1, participants who had already played turns of a mixed-motive game were less cooperative after an explicit propositional suggestion that they had been nice in prior turns but were more cooperative after the suggestion that they should be nice in upcoming turns. In three subsequent experiments, implicit priming with the phrase nice act produced greater levels of defection, implying that actors responded to the implicit suggestion that they had been sufficiently nice already. In contrast, act nice produced greater levels of cooperation, implying that actors responded to the implicit suggestion that they should try to be nicer in upcoming turns. These effects occurred outside of awareness and disappeared when the interval between the words was long and when behavior was measured after a delay.

Understanding of anesthesia machine function is enhanced with a transparent reality simulation.

INTRODUCTION: Photorealistic simulations may provide efficient transfer of certain skills to the real system, but by being opaque may fail to encourage deeper learning of the structure and function of the system. Schematic simulations that are more abstract, with less visual fidelity but make system structure and function transparent, may enhance deeper learning and optimize retention and transfer of learning. We compared learning effectiveness of these 2 modes of externalizing the output of a common simulation engine (the Virtual Anesthesia Machine, VAM) that models machine function and dynamics and responds in real time to user interventions such as changes in gas flow or ventilation. METHODS: Undergraduate students (n = 39) and medical students (n = 35) were given a single, 1-hour guided learning session with either a Transparent or an Opaque version of the VAM simulation. The following day, the learners' knowledge of machine components, function, and dynamics was tested. RESULTS: The Transparent-VAM groups scored higher than the Opaque-VAM groups on a set of multiple-choice questions concerning conceptual knowledge about anesthesia machines (P = 0.009), provided better and more complete explanations of component function (P = 0.003), and were more accurate in remembering and inferring cause-and-effect dynamics of the machine and relations among components (P = 0.003). Although the medical students outperformed undergraduates on all measures, a similar pattern of benefits for the Transparent VAM was observed for these 2 groups. CONCLUSIONS: Schematic simulations that transparently allow learners to visualize, and explore, underlying system dynamics and relations among components may provide a more effective mental model for certain systems. This may lead to a deeper understanding of how the system works, and therefore, we believe, how to detect and respond to potentially adverse situations.

Event-related potential studies of language and emotion: words, phrases, and task effects.

This chapter reviews research that focuses on the effects of emotionality of single words, and of simple phrases, on event-related brain potentials when these are presented visually in various tasks. In these studies, presentation of emotionally evocative language material has consistently elicited a late (c. 300-600 ms post-onset) positive-going, largely frontal-central shift in the event-related potentials (ERPs), relative to neutral materials. Overall, affectively pleasant and unpleasant words or phrases are quite similar in their neuroelectric profiles and rarely differ substantively. This emotionality effect is enhanced in both amplitude and latency when emotional content is task relevant, but is also reliably observed when the task involves other semantically engaging tasks. On the other hand, it can be attenuated or eliminated when the task does not involve semantic evaluation (e.g., lexical decisions to words or orthographic judgments to the spelling patterns) or when comprehension of phrases requires integration of the connotative meaning of several words (e.g., compare dead puppy and dead tyrant). Taken together, these studies suggest that the emotionality of written language has a rapid and robust impact on ERPs, which can be modulated by specific task demands as well as the linguistic context in which the affective stimulus occurs.

Processing words with emotional connotation: an FMRI study of time course and laterality in rostral frontal and retrosplenial cortices.

Responses of rostral frontal and retrosplenial cortices to the emotional significance of words were measured using functional magnetic resonance imaging (fMRI). Twenty-six strongly right-handed participants engaged in a language task that alternated between silent word generation to categories with positive, negative, or neutral emotional connotation and a baseline task of silent repetition of emotionally neutral words. Activation uniquely associated with word generation to categories with positive or negative versus neutral emotional connotation occurred bilaterally in rostral frontal and retrosplenial cortices. Furthermore, the time courses of activity in these areas differed, indicating that they subserve different functions in processing the emotional connotation of words. Namely, the retrosplenial cortex appears to be involved in evaluating the emotional salience of information from external sources, whereas the rostral frontal cortex also plays a role in internal generation of words with emotional connotation. In both areas, activity associated with positive or negative emotional connotation was more extensive in the left hemisphere than the right, regardless of valence, presumably due to the language demands of word generation. The present findings localize specific areas in the brain that are involved in processing emotional meaning of words within the brain's distributed semantic system. In addition, time course analysis reveals diverging mechanisms in anterior and posterior cortical areas during processing of words with emotional significance.

Semantic monitoring of words with emotional connotation during fMRI: contribution of anterior left frontal cortex.

Previous studies showed that cortex in the anterior portions of the left frontal and temporal lobes participates in generating words with emotional connotations and processing pictures with emotional content. If these cortices process the semantic attribute of emotional connotation, they should be active whenever processing emotional connotation, without respect to modality of input or mode of output. Thus, we hypothesized that they would activate during monitoring of words with emotional connotations. Sixteen normal subjects performed semantic monitoring of words with emotional connotations, animal names, and implement names during fMRI. Cortex in the anterior left frontal lobe demonstrated significant activity for monitoring words with emotional connotations compared to monitoring tone sequences, animal names, or implement names. Together, the current and previous results implicate cortex in the anterior left frontal lobe in semantic processing of emotional connotation, consistent with connections of this cortex to paralimbic association areas. Current findings also indicate that neural substrates for processing emotional connotation are independent of substrates for processing the categories of living and nonliving things.